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Sun W, Wang M, Shi Z, Wang P, Wang J, Du B, Wang S, Sun Z, Liu Z, Wei L, Yang D, He X, Wang J. VP2 mediates the release of the feline calicivirus RNA genome by puncturing the endosome membrane of infected cells. J Virol 2024; 98:e0035024. [PMID: 38591900 DOI: 10.1128/jvi.00350-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Accepted: 03/19/2024] [Indexed: 04/10/2024] Open
Abstract
Feline calicivirus (FCV) is one of the few members of the Caliciviridae family that grows well in cell lines and, therefore, serves as a surrogate to study the biology of other viruses in the family. Conley et al. (14) demonstrated that upon the receptor engagement to the capsid, FCV VP2 forms a portal-like assembly, which might provide a channel for RNA release. However, the process of calicivirus RNA release is not yet fully understood. Our findings suggest that the separation of the FCV capsid from its genome RNA (gRNA) occurs rapidly in the early endosomes of infected cells. Using a liposome model decorated with the FCV cell receptor fJAM-A, we demonstrate that FCV releases its gRNA into the liposomes by penetrating membranes under low pH conditions. Furthermore, we found that VP2, which is rich in hydrophobic residues at its N-terminus, functions as the pore-forming protein. When we substituted the VP2 N-terminal hydrophobic residues, the gRNA release efficacy of the FCV mutants decreased. In conclusion, our results suggest that in the acidic environment of early endosomes, FCV VP2 functions as the pore-forming protein to mediate gRNA release into the cytoplasm of infected cells. This provides insight into the mechanism of calicivirus genome release.IMPORTANCEResearch on the biology and pathogenicity of certain caliciviruses, such as Norovirus and Sapovirus, is hindered by the lack of easy-to-use cell culture system. Feline calicivirus (FCV), which grows effectively in cell lines, is used as a substitute. At present, there is limited understanding of the genome release mechanism in caliciviruses. Our findings suggest that FCV uses VP2 to pierce the endosome membrane for genome release and provide new insights into the calicivirus gRNA release mechanism.
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Affiliation(s)
- Weiyao Sun
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Ming Wang
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Zhibin Shi
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Pengfei Wang
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Jinhui Wang
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Bingchen Du
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Shida Wang
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Zhenzhao Sun
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Zaisi Liu
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Lili Wei
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Decheng Yang
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Xijun He
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Jingfei Wang
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
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Hoffman HK, Aguilar RS, Clark AR, Groves NS, Pezeshkian N, Bruns MM, van Engelenburg SB. Endocytosed HIV-1 Envelope Glycoprotein Traffics to Rab14 + Late Endosomes and Lysosomes to Regulate Surface Levels in T-Cell Lines. J Virol 2022; 96:e0076722. [PMID: 35770989 PMCID: PMC9327703 DOI: 10.1128/jvi.00767-22] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Accepted: 06/06/2022] [Indexed: 11/20/2022] Open
Abstract
Production of infectious HIV-1 particles requires incorporation of the viral envelope glycoprotein (Env) at the plasma membrane (PM) of infected CD4+ T cells. Env trafficking to the PM exposes viral epitopes that can be exploited by the host immune system; however, HIV-1 can evade this response by endocytosis of excess Env from the PM. The fate of Env after internalization remains unclear, with evidence suggesting several different vesicular trafficking steps may be involved, including recycling pathways. To date, there have been very few studies documenting the trafficking pathways of native Env in infected T cells. Furthermore, it remains unclear whether there are T-cell-specific endosomal pathways regulating the fate of endocytic Env. Here, we use a pulse-labeling approach with a monovalent anti-Env Fab probe to characterize the trafficking of internalized Env within infected CD4+ T-cell lines, together with CRISPR/Cas9-mediated endogenous protein tagging, to assess the role of host cell Rab GTPases in Env trafficking. We show that endocytosed Env traffics to Rab14+ compartments that possess hallmarks of late endosomes and lysosomes. We also demonstrate that Env can recycle back to the PM, although we find that recycling does not occur at high rates when compared to the model recycling protein transferrin. These results help to resolve open questions about the fate and relevance of endocytosed Env in HIV-infected cells and suggest a novel role for Rab14 in a cell-type-specific late-endosomal/lysosomal trafficking pathway in T cells. IMPORTANCE HIV-1 envelope glycoprotein (Env) evades immune neutralization through many mechanisms. One immune evasion strategy may result from the internalization of excess surface-exposed Env to prevent antibody-dependent cellular cytotoxicity or neutralization. Characterization of the fate of endocytosed Env is critical to understand which vesicular pathways could be targeted to promote display of Env epitopes to the immune system. In this study, we characterize the endocytic fate of native Env, expressed from infected human T-cell lines. We demonstrate that Env is rapidly trafficked to a late-endosome/lysosome-like compartment and can be recycled to the cell surface for incorporation into virus assembly sites. This study implicates a novel intracellular compartment, marked by host-cell Rab14 GTPases, for the sequestration of Env. Therapeutic approaches aimed at mobilizing this intracellular pool of Env could lead to stronger immune control of HIV-1 infection via antibody-dependent cell-mediated cytotoxicity.
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Affiliation(s)
- Huxley K. Hoffman
- Molecular and Cellular Biophysics Program, Department of Biological Sciences, University of Denver, Denver, Colorado, USA
| | - Rebekah S. Aguilar
- Molecular and Cellular Biophysics Program, Department of Biological Sciences, University of Denver, Denver, Colorado, USA
| | - Austin R. Clark
- Molecular and Cellular Biophysics Program, Department of Biological Sciences, University of Denver, Denver, Colorado, USA
| | - Nicholas S. Groves
- Molecular and Cellular Biophysics Program, Department of Biological Sciences, University of Denver, Denver, Colorado, USA
| | - Nairi Pezeshkian
- Molecular and Cellular Biophysics Program, Department of Biological Sciences, University of Denver, Denver, Colorado, USA
| | - Merissa M. Bruns
- Molecular and Cellular Biophysics Program, Department of Biological Sciences, University of Denver, Denver, Colorado, USA
| | - Schuyler B. van Engelenburg
- Molecular and Cellular Biophysics Program, Department of Biological Sciences, University of Denver, Denver, Colorado, USA
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Windhaber S, Xin Q, Uckeley ZM, Koch J, Obr M, Garnier C, Luengo-Guyonnot C, Duboeuf M, Schur FKM, Lozach PY. The Orthobunyavirus Germiston Enters Host Cells from Late Endosomes. J Virol 2022; 96:e0214621. [PMID: 35019710 PMCID: PMC8906410 DOI: 10.1128/jvi.02146-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 01/03/2022] [Indexed: 01/01/2023] Open
Abstract
With more than 80 members worldwide, the Orthobunyavirus genus in the Peribunyaviridae family is a large genus of enveloped RNA viruses, many of which are emerging pathogens in humans and livestock. How orthobunyaviruses (OBVs) penetrate and infect mammalian host cells remains poorly characterized. Here, we investigated the entry mechanisms of the OBV Germiston (GERV). Viral particles were visualized by cryo-electron microscopy and appeared roughly spherical with an average diameter of 98 nm. Labeling of the virus with fluorescent dyes did not adversely affect its infectivity and allowed the monitoring of single particles in fixed and live cells. Using this approach, we found that endocytic internalization of bound viruses was asynchronous and occurred within 30 to 40 min. The virus entered Rab5a-positive (Rab5a+) early endosomes and, subsequently, late endosomal vacuoles containing Rab7a but not LAMP-1. Infectious entry did not require proteolytic cleavage, and endosomal acidification was sufficient and necessary for viral fusion. Acid-activated penetration began 15 to 25 min after initiation of virus internalization and relied on maturation of early endosomes to late endosomes. The optimal pH for viral membrane fusion was slightly below 6.0, and penetration was hampered when the potassium influx was abolished. Overall, our study provides real-time visualization of GERV entry into host cells and demonstrates the importance of late endosomal maturation in facilitating OBV penetration. IMPORTANCE Orthobunyaviruses (OBVs), which include La Crosse, Oropouche, and Schmallenberg viruses, represent a growing threat to humans and domestic animals worldwide. Ideally, preventing OBV spread requires approaches that target early stages of infection, i.e., virus entry. However, little is known about the molecular and cellular mechanisms by which OBVs enter and infect host cells. Here, we developed accurate, sensitive tools and assays to investigate the penetration process of GERV. Our data emphasize the central role of late endosomal maturation in GERV entry, providing a comprehensive overview of the early stages of an OBV infection. Our study also brings a complete toolbox of innovative methods to study each step of the OBV entry program in fixed and living cells, from virus binding and endocytosis to fusion and penetration. The information gained herein lays the foundation for the development of antiviral strategies aiming to block OBV entry.
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Affiliation(s)
- Stefan Windhaber
- CellNetworks-Cluster of Excellence Heidelberg, Germany
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Qilin Xin
- University of Lyon, INRAE, EPHE, IVPC, Lyon, France
| | - Zina M. Uckeley
- CellNetworks-Cluster of Excellence Heidelberg, Germany
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Jana Koch
- CellNetworks-Cluster of Excellence Heidelberg, Germany
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Martin Obr
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | | | | | | | | | - Pierre-Yves Lozach
- CellNetworks-Cluster of Excellence Heidelberg, Germany
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany
- University of Lyon, INRAE, EPHE, IVPC, Lyon, France
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Cuesta-Geijo MÁ, García-Dorival I, del Puerto A, Urquiza J, Galindo I, Barrado-Gil L, Lasala F, Cayuela A, Sorzano COS, Gil C, Delgado R, Alonso C. New insights into the role of endosomal proteins for African swine fever virus infection. PLoS Pathog 2022; 18:e1009784. [PMID: 35081156 PMCID: PMC8820605 DOI: 10.1371/journal.ppat.1009784] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 02/07/2022] [Accepted: 01/11/2022] [Indexed: 01/01/2023] Open
Abstract
African swine fever virus (ASFV) infectious cycle starts with the viral adsorption and entry into the host cell. Then, the virus is internalized via clathrin/dynamin mediated endocytosis and macropinocytosis. Similar to other viruses, ASF virion is then internalized and incorporated into the endocytic pathway. While the endosomal maturation entails luminal acidification, the decrease in pH acts on the multilayer structure of the virion dissolving the outer capsid. Upon decapsidation, the inner viral membrane is exposed to interact with the limiting membrane of the late endosome for fusion. Viral fusion is then necessary for the egress of incoming virions from endosomes into the cytoplasm, however this remains an intriguing and yet essential process for infection, specifically for the egress of viral nucleic acid into the cytoplasm for replication. ASFV proteins E248R and E199L, located at the exposed inner viral membrane, might be implicated in the fusion step. An interaction between these viral proteins and cellular endosomal proteins such as the Niemann-Pick C type 1 (NPC1) and lysosomal membrane proteins (Lamp-1 and -2) was shown. Furthermore, the silencing of these proteins impaired ASFV infection. It was also observed that NPC1 knock-out cells using CRISPR jeopardized ASFV infection and that the progression and endosomal exit of viral cores was arrested within endosomes at viral entry. These results suggest that the interactions of ASFV proteins with some endosomal proteins might be important for the membrane fusion step. In addition to this, reductions on ASFV infectivity and replication in NPC1 KO cells were accompanied by fewer and smaller viral factories. Our findings pave the way to understanding the role of proteins of the endosomal membrane in ASFV infection. African swine fever virus (ASFV) causes a deadly disease of pigs and wild boars that was endemic in Africa but has spread in recent years to Europe, Asia and Oceania with a high socioeconomic impact. ASFV enters the cell by endocytosis and has adapted to the endosomal conditions to acquire infectivity. Fusion of the internal viral membrane with the endosomal membrane is required for the exit of viral DNA into the cytoplasm to start replication. We have found that ASF virion internal membrane proteins E248R and E199L interact with the endosomal proteins Niemann Pick C1 (NPC1) and lysosomal membrane proteins (Lamp)-1 and -2. And, appear to be required for endosomal trafficking of ASF virions endosomal traffic and exit to the cytoplasm in the cell entry process. These molecules act regulating cholesterol flux from the endosome to the endoplasmic reticulum, and appear to be important for the viral infection cycle. In silenced and knockout cells, ASFV infection was affected at early and later stages. In null cells, virion entry and progression through the endosomal pathway at entry was arrested and several viral cores were retained at late endosomes without entering the fusion phase for cytoplasmic exit. These results provide new insights into the role of endosomal proteins for ASFV infection.
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Affiliation(s)
- Miguel Ángel Cuesta-Geijo
- Departmento de Biotecnología, INIA-CSIC, Centro Nacional Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Madrid, Spain
| | - Isabel García-Dorival
- Departmento de Biotecnología, INIA-CSIC, Centro Nacional Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Madrid, Spain
| | - Ana del Puerto
- Departmento de Biotecnología, INIA-CSIC, Centro Nacional Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Madrid, Spain
| | - Jesús Urquiza
- Departmento de Biotecnología, INIA-CSIC, Centro Nacional Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Madrid, Spain
| | - Inmaculada Galindo
- Departmento de Biotecnología, INIA-CSIC, Centro Nacional Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Madrid, Spain
| | - Lucía Barrado-Gil
- Departmento de Biotecnología, INIA-CSIC, Centro Nacional Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Madrid, Spain
| | - Fátima Lasala
- Instituto de Investigación Hospital 12 de Octubre Imas12, Madrid, Spain
| | - Ana Cayuela
- Centro Nacional de Biotecnología CSIC, Madrid, Spain
| | | | - Carmen Gil
- Centro de Investigaciones Biológicas Margarita Salas CSIC, Madrid, Spain
| | - Rafael Delgado
- Instituto de Investigación Hospital 12 de Octubre Imas12, Madrid, Spain
- Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain
| | - Covadonga Alonso
- Departmento de Biotecnología, INIA-CSIC, Centro Nacional Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Madrid, Spain
- * E-mail:
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Wang Z, Zhou Y, Bao L, Li D, Lv J, Wang D, Li S, Tong WM, Liu J, Qin C, Huang B. Escaping alveolar macrophage endosomal retention explains massive expansion of SARS-CoV-2 delta variant. Signal Transduct Target Ther 2021; 6:431. [PMID: 34921130 PMCID: PMC8679569 DOI: 10.1038/s41392-021-00845-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Revised: 11/18/2021] [Accepted: 11/28/2021] [Indexed: 12/02/2022] Open
Affiliation(s)
- Zhenfeng Wang
- Department of Immunology & National Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences (CAMS) & Peking Union Medical College, 100005, Beijing, China
| | - Yabo Zhou
- Department of Immunology & National Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences (CAMS) & Peking Union Medical College, 100005, Beijing, China
| | - Linlin Bao
- NHC Key Laboratory of Human Disease Comparative Medicine, Beijing Key Laboratory for Animal Models of Emerging and Remerging Infectious Diseases, Institute of Laboratory Animal Science, CAMS and Comparative Medicine Center, Peking Union Medical College, Beijing, China
| | - Dan Li
- NHC Key Laboratory of Human Disease Comparative Medicine, Beijing Key Laboratory for Animal Models of Emerging and Remerging Infectious Diseases, Institute of Laboratory Animal Science, CAMS and Comparative Medicine Center, Peking Union Medical College, Beijing, China
| | - Jiadi Lv
- Department of Immunology & National Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences (CAMS) & Peking Union Medical College, 100005, Beijing, China
| | - Dianheng Wang
- Department of Immunology & National Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences (CAMS) & Peking Union Medical College, 100005, Beijing, China
| | - Shunshun Li
- Department of Immunology & National Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences (CAMS) & Peking Union Medical College, 100005, Beijing, China
| | - Wei-Min Tong
- Department of Pathology, Institute of Basic Medical Sciences, CAMS and Peking Union Medical College, Beijing, China
| | - Jiangning Liu
- NHC Key Laboratory of Human Disease Comparative Medicine, Beijing Key Laboratory for Animal Models of Emerging and Remerging Infectious Diseases, Institute of Laboratory Animal Science, CAMS and Comparative Medicine Center, Peking Union Medical College, Beijing, China
| | - Chuan Qin
- NHC Key Laboratory of Human Disease Comparative Medicine, Beijing Key Laboratory for Animal Models of Emerging and Remerging Infectious Diseases, Institute of Laboratory Animal Science, CAMS and Comparative Medicine Center, Peking Union Medical College, Beijing, China.
| | - Bo Huang
- Department of Immunology & National Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences (CAMS) & Peking Union Medical College, 100005, Beijing, China.
- Department of Biochemistry & Molecular Biology, Tongji Medical College, Huazhong University of Science & Technology, 430030, Wuhan, China.
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Kumar S, Javed R, Mudd M, Pallikkuth S, Lidke KA, Jain A, Tangavelou K, Gudmundsson SR, Ye C, Rusten TE, Anonsen JH, Lystad AH, Claude-Taupin A, Simonsen A, Salemi M, Phinney B, Li J, Guo LW, Bradfute SB, Timmins GS, Eskelinen EL, Deretic V. Mammalian hybrid pre-autophagosomal structure HyPAS generates autophagosomes. Cell 2021; 184:5950-5969.e22. [PMID: 34741801 PMCID: PMC8616855 DOI: 10.1016/j.cell.2021.10.017] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 05/12/2021] [Accepted: 10/15/2021] [Indexed: 12/14/2022]
Abstract
The biogenesis of mammalian autophagosomes remains to be fully defined. Here, we used cellular and in vitro membrane fusion analyses to show that autophagosomes are formed from a hitherto unappreciated hybrid membrane compartment. The autophagic precursors emerge through fusion of FIP200 vesicles, derived from the cis-Golgi, with endosomally derived ATG16L1 membranes to generate a hybrid pre-autophagosomal structure, HyPAS. A previously unrecognized apparatus defined here controls HyPAS biogenesis and mammalian autophagosomal precursor membranes. HyPAS can be modulated by pharmacological agents whereas its formation is inhibited upon severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection or by expression of SARS-CoV-2 nsp6. These findings reveal the origin of mammalian autophagosomal membranes, which emerge via convergence of secretory and endosomal pathways, and show that this process is targeted by microbial factors such as coronaviral membrane-modulating proteins.
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Affiliation(s)
- Suresh Kumar
- Autophagy Inflammation and Metabolism Center, University of New Mexico Health Sciences Center, Albuquerque, NM, USA; Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Ruheena Javed
- Autophagy Inflammation and Metabolism Center, University of New Mexico Health Sciences Center, Albuquerque, NM, USA; Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Michal Mudd
- Autophagy Inflammation and Metabolism Center, University of New Mexico Health Sciences Center, Albuquerque, NM, USA; Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Sandeep Pallikkuth
- Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM, USA
| | - Keith A Lidke
- Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM, USA
| | - Ashish Jain
- Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Karthikeyan Tangavelou
- Autophagy Inflammation and Metabolism Center, University of New Mexico Health Sciences Center, Albuquerque, NM, USA; Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | | | - Chunyan Ye
- Center for Global Health, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | | | | | | | - Aurore Claude-Taupin
- Autophagy Inflammation and Metabolism Center, University of New Mexico Health Sciences Center, Albuquerque, NM, USA; Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Anne Simonsen
- Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Michelle Salemi
- Proteomics Core, University of California Davis, Davis, CA, USA
| | - Brett Phinney
- Proteomics Core, University of California Davis, Davis, CA, USA
| | - Jing Li
- Department of Surgery, University of Virginia, Charlottesville, VA, USA
| | - Lian-Wang Guo
- Department of Surgery, University of Virginia, Charlottesville, VA, USA
| | - Steven B Bradfute
- Center for Global Health, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Graham S Timmins
- Autophagy Inflammation and Metabolism Center, University of New Mexico Health Sciences Center, Albuquerque, NM, USA; School of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | | | - Vojo Deretic
- Autophagy Inflammation and Metabolism Center, University of New Mexico Health Sciences Center, Albuquerque, NM, USA; Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA.
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Xia X, Wu W, Cui Y, Roy P, Zhou ZH. Bluetongue virus capsid protein VP5 perforates membranes at low endosomal pH during viral entry. Nat Microbiol 2021; 6:1424-1432. [PMID: 34702979 PMCID: PMC9015746 DOI: 10.1038/s41564-021-00988-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 09/22/2021] [Indexed: 01/25/2023]
Abstract
Bluetongue virus (BTV) is a non-enveloped virus and causes substantial morbidity and mortality in ruminants such as sheep. Fashioning a receptor-binding protein (VP2) and a membrane penetration protein (VP5) on the surface, BTV releases its genome-containing core (VP3 and VP7) into the host cell cytosol after perforation of the endosomal membrane. Unlike enveloped ones, the entry mechanisms of non-enveloped viruses into host cells remain poorly understood. Here we applied single-particle cryo-electron microscopy, cryo-electron tomography and structure-guided functional assays to characterize intermediate states of BTV cell entry in endosomes. Four structures of BTV at the resolution range of 3.4-3.9 Å show the different stages of structural rearrangement of capsid proteins on exposure to low pH, including conformational changes of VP5, stepwise detachment of VP2 and a small shift of VP7. In detail, sensing of the low-pH condition by the VP5 anchor domain triggers three major VP5 actions: projecting the hidden dagger domain, converting a surface loop to a protonated β-hairpin that anchors VP5 to the core and stepwise refolding of the unfurling domains into a six-helix stalk. Cryo-electron tomography structures of BTV interacting with liposomes show a length decrease of the VP5 stalk from 19.5 to 15.5 nm after its insertion into the membrane. Our structures, functional assays and structure-guided mutagenesis experiments combined indicate that this stalk, along with dagger domain and the WHXL motif, creates a single pore through the endosomal membrane that enables the viral core to enter the cytosol. Our study unveils the detailed mechanisms of BTV membrane penetration and showcases general methods to study cell entry of other non-enveloped viruses.
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Affiliation(s)
- Xian Xia
- Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeles, Los Angeles, CA, USA
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA, USA
| | - Weining Wu
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, UK
| | - Yanxiang Cui
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA, USA
| | - Polly Roy
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, UK
| | - Z Hong Zhou
- Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeles, Los Angeles, CA, USA.
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA, USA.
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Russell T, Samolej J, Hollinshead M, Smith GL, Kite J, Elliott G. Novel Role for ESCRT-III Component CHMP4C in the Integrity of the Endocytic Network Utilized for Herpes Simplex Virus Envelopment. mBio 2021; 12:e02183-20. [PMID: 33975940 PMCID: PMC8262985 DOI: 10.1128/mbio.02183-20] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 03/31/2021] [Indexed: 12/29/2022] Open
Abstract
Enveloped viruses exploit cellular trafficking pathways for their morphogenesis, providing potential scope for the development of new antiviral therapies. We have previously shown that herpes simplex virus 1 (HSV1) utilizes recycling endocytic membranes as the source of its envelope, in a process involving four Rab GTPases. To identify novel factors involved in HSV1 envelopment, we have screened a small interfering RNA (siRNA) library targeting over 80 human trafficking proteins, including coat proteins, adaptor proteins, fusion factors, fission factors, and Rab effectors. The depletion of 11 factors reduced virus yields by 20- to 100-fold, including three early secretory pathway proteins, four late secretory pathway proteins, and four endocytic pathway proteins, three of which are membrane fission factors. Five of the 11 targets were chosen for further analysis in virus infection, where it was found that the absence of only 1, the fission factor CHMP4C, but not the CHMP4A or CHMP4B paralogues, reduced virus production at the final stage of morphogenesis. Ultrastructural and confocal microscopy of CHMP4C-depleted, HSV1-infected cells showed an accumulation of endocytic membranes; extensive tubulation of recycling, transferrin receptor-positive endosomes indicative of aberrant fission; and a failure in virus envelopment. No effect on the late endocytic pathway was detected, while exogenous CHMP4C was shown to localize to recycling endosomes. Taken together, these data reveal a novel role for the CHMP4C fission factor in the integrity of the recycling endosomal network, which has been unveiled through the dependence of HSV1 on these membranes for the acquisition of their envelopes.IMPORTANCE Cellular transport pathways play a fundamental role in secretion and membrane biogenesis. Enveloped viruses exploit these pathways to direct their membrane proteins to sites of envelopment and, as such, are powerful tools for unraveling subtle activities of trafficking factors, potentially pinpointing therapeutic targets. Using the sensitive biological readout of virus production, over 80 trafficking factors involved in diverse and poorly defined cellular processes have been screened for involvement in the complex process of HSV1 envelopment. Out of 11 potential targets, CHMP4C, a key component in the cell cycle abscission checkpoint, stood out as being required for the process of virus wrapping in endocytic tubules, where it localized. In the absence of CHMP4C, recycling endocytic membranes failed to undergo scission in infected cells, causing transient tubulation and accumulation of membranes and unwrapped virus. These data reveal a new role for this important cellular factor in the biogenesis of recycling endocytic membranes.
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Affiliation(s)
- Tiffany Russell
- Department of Microbial Sciences, University of Surrey, Guildford, United Kingdom
| | - Jerzy Samolej
- Department of Microbial Sciences, University of Surrey, Guildford, United Kingdom
| | | | - Geoffrey L Smith
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Joanne Kite
- Department of Microbial Sciences, University of Surrey, Guildford, United Kingdom
| | - Gillian Elliott
- Department of Microbial Sciences, University of Surrey, Guildford, United Kingdom
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9
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Mayberry CL, Bond AC, Wilczek MP, Mehmood K, Maginnis MS. Sending mixed signals: polyomavirus entry and trafficking. Curr Opin Virol 2021; 47:95-105. [PMID: 33690104 DOI: 10.1016/j.coviro.2021.02.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 02/14/2021] [Accepted: 02/15/2021] [Indexed: 12/31/2022]
Abstract
Polyomaviruses are mostly non-pathogenic, yet some can cause human disease especially under conditions of immunosuppression, including JC, BK, and Merkel cell polyomaviruses. Direct interactions between viruses and the host early during infection dictate the outcome of disease, many of which remain enigmatic. However, significant work in recent years has contributed to our understanding of how this virus family establishes an infection, largely due to advances made for animal polyomaviruses murine and SV40. Here we summarize the major findings that have contributed to our understanding of polyomavirus entry, trafficking, disassembly, signaling, and immune evasion during the infectious process and highlight major unknowns in these processes that are open areas of study.
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Affiliation(s)
- Colleen L Mayberry
- Department of Molecular and Biomedical Sciences, The University of Maine, Orono, ME, USA
| | - Avery Cs Bond
- Department of Molecular and Biomedical Sciences, The University of Maine, Orono, ME, USA
| | - Michael P Wilczek
- Department of Molecular and Biomedical Sciences, The University of Maine, Orono, ME, USA
| | - Kashif Mehmood
- Department of Molecular and Biomedical Sciences, The University of Maine, Orono, ME, USA
| | - Melissa S Maginnis
- Department of Molecular and Biomedical Sciences, The University of Maine, Orono, ME, USA; Graduate School in Biomedical Sciences and Engineering, The University of Maine, Orono, ME, USA.
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10
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Nabavi SF, Habtemariam S, Berindan-Neagoe I, Cismaru CA, Schaafsma D, Ghavami S, Banach M, Aghaabdollahian S, Nabavi SM. Rationale for Effective Prophylaxis Against COVID-19 Through Simultaneous Blockade of Both Endosomal and Non-Endosomal SARS-CoV-2 Entry into Host Cell. Clin Transl Sci 2021; 14:431-433. [PMID: 33406317 PMCID: PMC7993271 DOI: 10.1111/cts.12949] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 11/08/2020] [Indexed: 11/30/2022] Open
Affiliation(s)
- Seyed Fazel Nabavi
- Applied Biotechnology Research CenterBaqiyatallah University of Medical SciencesTehranIran
| | - Solomon Habtemariam
- Pharmacognosy Research Laboratories and Herbal Analysis Services UKUniversity of GreenwichKentUK
| | - Ioana Berindan-Neagoe
- Department of Functional Genomics and Experimental PathologyThe Oncology Institute “Prof.Dr. Ion Chiricuta”Cluj-NapocaRomania
| | - Cosmin Andrei Cismaru
- Department of Functional Genomics and Experimental PathologyThe Oncology Institute “Prof.Dr. Ion Chiricuta”Cluj-NapocaRomania
| | | | - Saeid Ghavami
- Department of Human Anatomy and Cell SciencesRady Faculty of Health SciencesMax Rady College of MedicineUniversity of ManitobaWinnipegManitobaCanada
| | - Maciej Banach
- Department of HypertensionLodz, Medical UniversityLodzPoland
- Polish Mother's Memorial Hospital Research Institute (PMMHRI)LodzPoland
| | - Safieh Aghaabdollahian
- Department of NanobiotechnologyNew Technologies Research GroupPasteur Institute of IranTehranIran
| | - Seyed Mohammad Nabavi
- Applied Biotechnology Research CenterBaqiyatallah University of Medical SciencesTehranIran
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11
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Liu LK, Liu MJ, Li DL, Liu HP. Recent insights into anti-WSSV immunity in crayfish. Dev Comp Immunol 2021; 116:103947. [PMID: 33253753 DOI: 10.1016/j.dci.2020.103947] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 11/24/2020] [Accepted: 11/24/2020] [Indexed: 06/12/2023]
Abstract
White spot syndrome virus (WSSV) is currently the most severely viral pathogen for farmed crustaceans such as shrimp and crayfish, which has been causing huge economic losses for crustaceans farming worldwide every year. Unfortunately, study on the molecular mechanisms of WSSV has been restricted by the lack of crustacean cell lines for WSSV propagation as well as the incompletely annotated genomes for host species, resulting in limited elucidation for WSSV pathogenesis at present. In addition to the findings of anti-WSSV response in shrimp, some of novel cellular events involved in WSSV infection have been recently revealed in crayfish, including endocytosis and intracellular transport of WSSV, innate immune pathways in response to WSSV infection, and regulation of viral gene expression by host genes. Despite these advances, many fundamental gaps in WSSV pathogenesis are still remaining, for example, how WSSV genome enters into nucleus and how the progeny virions are fully assembled in the host cell nucleus. In this review, recent findings in WSSV infection mechanism and the antiviral immunity against WSSV in crayfish are summarized and discussed, which may provide us a better understanding of the WSSV pathogenesis as well as new ideas for the target design of antiviral drugs against WSSV in crustaceans farming.
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Affiliation(s)
- Ling-Ke Liu
- State-Province Joint Engineering Laboratory of Marine Bioproducts and Technology; State Key Laboratory of Marine Environmental Science; College of Ocean and Earth Sciences, Xiamen University; Xiamen 361102, Fujian, China
| | - Man-Jun Liu
- State-Province Joint Engineering Laboratory of Marine Bioproducts and Technology; State Key Laboratory of Marine Environmental Science; College of Ocean and Earth Sciences, Xiamen University; Xiamen 361102, Fujian, China
| | - Dong-Li Li
- State-Province Joint Engineering Laboratory of Marine Bioproducts and Technology; State Key Laboratory of Marine Environmental Science; College of Ocean and Earth Sciences, Xiamen University; Xiamen 361102, Fujian, China
| | - Hai-Peng Liu
- State-Province Joint Engineering Laboratory of Marine Bioproducts and Technology; State Key Laboratory of Marine Environmental Science; College of Ocean and Earth Sciences, Xiamen University; Xiamen 361102, Fujian, China; Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology (Qingdao), China.
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12
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Zhao Z, Qin P, Huang YW. Lysosomal ion channels involved in cellular entry and uncoating of enveloped viruses: Implications for therapeutic strategies against SARS-CoV-2. Cell Calcium 2021; 94:102360. [PMID: 33516131 PMCID: PMC7825922 DOI: 10.1016/j.ceca.2021.102360] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 01/13/2021] [Accepted: 01/15/2021] [Indexed: 12/21/2022]
Abstract
Ion channels are necessary for correct lysosomal function including degradation of cargoes originating from endocytosis. Almost all enveloped viruses, including coronaviruses (CoVs), enter host cells via endocytosis, and do not escape endosomal compartments into the cytoplasm (via fusion with the endolysosomal membrane) unless the virus-encoded envelope proteins are cleaved by lysosomal proteases. With the ongoing outbreak of severe acute respiratory syndrome (SARS)-CoV-2, endolysosomal two-pore channels represent an exciting and emerging target for antiviral therapies. This review focuses on the latest knowledge of the effects of lysosomal ion channels on the cellular entry and uncoating of enveloped viruses, which may aid in development of novel therapies against emerging infectious diseases such as SARS-CoV-2.
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Affiliation(s)
- Zhuangzhuang Zhao
- Key Laboratory of Animal Virology of Ministry of Agriculture, Institute of Preventive Veterinary Medicine, Department of Veterinary Medicine, Zhejiang University, Hangzhou 310058, China
| | - Pan Qin
- Key Laboratory of Animal Virology of Ministry of Agriculture, Institute of Preventive Veterinary Medicine, Department of Veterinary Medicine, Zhejiang University, Hangzhou 310058, China
| | - Yao-Wei Huang
- Key Laboratory of Animal Virology of Ministry of Agriculture, Institute of Preventive Veterinary Medicine, Department of Veterinary Medicine, Zhejiang University, Hangzhou 310058, China.
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13
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Huang YL, Huang MT, Sung PS, Chou TY, Yang RB, Yang AS, Yu CM, Hsu YW, Chang WC, Hsieh SL. Endosomal TLR3 co-receptor CLEC18A enhances host immune response to viral infection. Commun Biol 2021; 4:229. [PMID: 33603190 PMCID: PMC7893028 DOI: 10.1038/s42003-021-01745-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 01/07/2021] [Indexed: 12/15/2022] Open
Abstract
Human C-type lectin member 18A (CLEC18A) is ubiquitously expressed in human, and highest expression levels are found in human myeloid cells and liver. In contrast, mouse CLEC18A (mCLEC18A) is only expressed in brain, kidney and heart. However, the biological functions of CLEC18A are still unclear. We have shown that a single amino acid change (S339 →R339) in CTLD domain has profound effect in their binding to polysaccharides and house dust mite allergens. In this study, we further demonstrate that CLEC18A and its mutant CLEC18A(S339R) associate with TLR3 in endosome and bind poly (I:C) specifically. Compared to TLR3 alone, binding affinity to poly (I:C) is further increased in TLR3-CLEC18A and TLR3-CLEC18A(S339R) complexes. Moreover, CLEC18A and CLEC18A(S339R) enhance the production of type I and type III interferons (IFNs), but not proinflammatory cytokines, in response to poly (I:C) or H5N1 influenza A virus (IAV) infection. Compared to wild type (WT) mice, ROSA-CLEC18A and ROSA-CLEC18A(S339R) mice generate higher amounts of interferons and are more resistant to H5N1 IAV infection. Thus, CLEC18A is a TLR3 co-receptor, and may contribute to the differential immune responses to poly (I:C) and IAV infection between human and mouse.
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Affiliation(s)
- Ya-Lang Huang
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | | | - Pei-Shan Sung
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Teh-Ying Chou
- Department of Pathology, Taipei Veterans General Hospital, Taipei, Taiwan
- Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Ruey-Bing Yang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - An-Suei Yang
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Chung-Ming Yu
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Yu-Wen Hsu
- Department of Clinical Pharmacy, School of Pharmacy, Taipei Medical University, Taipei, Taiwan
| | - Wei-Chiao Chang
- Department of Clinical Pharmacy, School of Pharmacy, Taipei Medical University, Taipei, Taiwan
| | - Shie-Liang Hsieh
- Genomics Research Center, Academia Sinica, Taipei, Taiwan.
- Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan.
- Department of Medical Research and Education, Taipei Veterans General Hospital, Taipei, Taiwan.
- Institute for Cancer Biology and Drug Discovery, Taipei Medical University, Taipei, Taiwan.
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14
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Xu J, Berastegui-Cabrera J, Carretero-Ledesma M, Chen H, Xue Y, Wold EA, Pachón J, Zhou J, Sánchez-Céspedes J. Discovery of a Small Molecule Inhibitor of Human Adenovirus Capable of Preventing Escape from the Endosome. Int J Mol Sci 2021; 22:ijms22041617. [PMID: 33562748 PMCID: PMC7915867 DOI: 10.3390/ijms22041617] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Revised: 01/26/2021] [Accepted: 02/02/2021] [Indexed: 12/16/2022] Open
Abstract
Human adenoviruses (HAdVs) display a wide range of tissue tropism and can cause an array of symptoms from mild respiratory illnesses to disseminated and life-threatening infections in immunocompromised individuals. However, no antiviral drug has been approved specifically for the treatment of HAdV infections. Herein, we report our continued efforts to optimize salicylamide derivatives and discover compound 16 (JMX0493) as a potent inhibitor of HAdV infection. Compound 16 displays submicromolar IC50 values, a higher selectivity index (SI > 100) and 2.5-fold virus yield reduction compared to our hit compound niclosamide. Moreover, unlike niclosamide, our mechanistic studies suggest that the antiviral activity of compound 16 against HAdV is achieved through the inhibition of viral particle escape from the endosome, which bars subsequent uncoating and the presentation of lytic protein VI.
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Affiliation(s)
- Jimin Xu
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch (UTMB), Galveston, TX 77555, USA; (J.X.); (H.C.); (Y.X.); (E.A.W.)
| | - Judith Berastegui-Cabrera
- Unit of Infectious Diseases, Microbiology and Preventive Medicine, Institute of Biomedicine of Seville (IBiS), University Hospital Virgen del Rocío, CSIC, University of Seville, E41013 Seville, Spain; (J.B.-C.); (M.C.-L.); (J.P.)
| | - Marta Carretero-Ledesma
- Unit of Infectious Diseases, Microbiology and Preventive Medicine, Institute of Biomedicine of Seville (IBiS), University Hospital Virgen del Rocío, CSIC, University of Seville, E41013 Seville, Spain; (J.B.-C.); (M.C.-L.); (J.P.)
| | - Haiying Chen
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch (UTMB), Galveston, TX 77555, USA; (J.X.); (H.C.); (Y.X.); (E.A.W.)
| | - Yu Xue
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch (UTMB), Galveston, TX 77555, USA; (J.X.); (H.C.); (Y.X.); (E.A.W.)
| | - Eric A. Wold
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch (UTMB), Galveston, TX 77555, USA; (J.X.); (H.C.); (Y.X.); (E.A.W.)
| | - Jerónimo Pachón
- Unit of Infectious Diseases, Microbiology and Preventive Medicine, Institute of Biomedicine of Seville (IBiS), University Hospital Virgen del Rocío, CSIC, University of Seville, E41013 Seville, Spain; (J.B.-C.); (M.C.-L.); (J.P.)
- Department of Medicine, University of Seville, E-41009 Seville, Spain
| | - Jia Zhou
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch (UTMB), Galveston, TX 77555, USA; (J.X.); (H.C.); (Y.X.); (E.A.W.)
- Correspondence: (J.Z.); (J.S.-C.); Tel.: +(1)-409-772-9748 (J.Z.); +(34)-955-923-100 (J.S.-C.)
| | - Javier Sánchez-Céspedes
- Unit of Infectious Diseases, Microbiology and Preventive Medicine, Institute of Biomedicine of Seville (IBiS), University Hospital Virgen del Rocío, CSIC, University of Seville, E41013 Seville, Spain; (J.B.-C.); (M.C.-L.); (J.P.)
- Correspondence: (J.Z.); (J.S.-C.); Tel.: +(1)-409-772-9748 (J.Z.); +(34)-955-923-100 (J.S.-C.)
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15
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Xu M, Perdomo MF, Mattola S, Pyöriä L, Toppinen M, Qiu J, Vihinen-Ranta M, Hedman K, Nokso-Koivisto J, Aaltonen LM, Söderlund-Venermo M. Persistence of Human Bocavirus 1 in Tonsillar Germinal Centers and Antibody-Dependent Enhancement of Infection. mBio 2021; 12:e03132-20. [PMID: 33531399 PMCID: PMC7858059 DOI: 10.1128/mbio.03132-20] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 12/08/2020] [Indexed: 12/11/2022] Open
Abstract
Human bocavirus 1 (HBoV1), a nonenveloped single-stranded DNA parvovirus, causes mild to life-threatening respiratory tract infections, acute otitis media, and encephalitis in young children. HBoV1 often persists in nasopharyngeal secretions for months, hampering diagnosis. It has also been shown to persist in pediatric palatine and adenoid tonsils, which suggests that lymphoid organs are reservoirs for virus spread; however, the tissue site and host cells remain unknown. Our aim was to determine, in healthy nonviremic children with preexisting HBoV1 immunity, the adenotonsillar persistence site(s), host cell types, and virus activity. We discovered that HBoV1 DNA persists in lymphoid germinal centers (GCs), but not in the corresponding tonsillar epithelium, and that the cell types harboring the virus are mainly naive, activated, and memory B cells and monocytes. Both viral DNA strands and both sides of the genome were detected, as well as infrequent mRNA. Moreover, we showed, in B-cell and monocyte cultures and ex vivo tonsillar B cells, that the cellular uptake of HBoV1 occurs via the Fc receptor (FcγRII) through antibody-dependent enhancement (ADE). This resulted in viral mRNA transcription, known to occur exclusively from double-stranded DNA in the nucleus, however, with no detectable productive replication. Confocal imaging with fluorescent virus-like particles moreover disclosed endocytosis. To which extent the active HBoV1 GC persistence has a role in chronic inflammation or B-cell maturation disturbances, and whether the virus can be reactivated, will be interesting topics for forthcoming studies.IMPORTANCE Human bocavirus 1 (HBoV1), a common pediatric respiratory pathogen, can persist in airway secretions for months hampering diagnosis. It also persists in tonsils, providing potential reservoirs for airway shedding, with the exact location, host cell types, and virus activity unknown. Our study provides new insights into tonsillar HBoV1 persistence. We observed HBoV1 persistence exclusively in germinal centers where immune maturation occurs, and the main host cells were B cells and monocytes. In cultured cell lines and primary tonsillar B cells, we showed the virus uptake to be significantly enhanced by HBoV1-specific antibodies, mediated by the cellular IgG receptor, leading to viral mRNA synthesis, but without detectable productive replication. Possible implications of such active viral persistence could be tonsillar inflammation, disturbances in immune maturation, reactivation, or cell death with release of virus DNA, explaining the long-lasting HBoV1 airway shedding.
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Affiliation(s)
- Man Xu
- Department of Virology, University of Helsinki, Helsinki, Finland
| | | | - Salla Mattola
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland
- Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland
| | - Lari Pyöriä
- Department of Virology, University of Helsinki, Helsinki, Finland
| | - Mari Toppinen
- Department of Virology, University of Helsinki, Helsinki, Finland
| | - Jianming Qiu
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Maija Vihinen-Ranta
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland
- Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland
| | - Klaus Hedman
- Department of Virology, University of Helsinki, Helsinki, Finland
- Helsinki University Hospital, Helsinki, Finland
| | - Johanna Nokso-Koivisto
- Department of Otorhinolaryngology-Head and Neck Surgery, Helsinki University Hospital, Helsinki, Finland
- University of Helsinki, Helsinki, Finland
| | - Leena-Maija Aaltonen
- Department of Otorhinolaryngology-Head and Neck Surgery, Helsinki University Hospital, Helsinki, Finland
- University of Helsinki, Helsinki, Finland
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16
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Stewart CM, Phan A, Bo Y, LeBlond ND, Smith TKT, Laroche G, Giguère PM, Fullerton MD, Pelchat M, Kobasa D, Côté M. Ebola virus triggers receptor tyrosine kinase-dependent signaling to promote the delivery of viral particles to entry-conducive intracellular compartments. PLoS Pathog 2021; 17:e1009275. [PMID: 33513206 PMCID: PMC7875390 DOI: 10.1371/journal.ppat.1009275] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 02/10/2021] [Accepted: 01/04/2021] [Indexed: 11/23/2022] Open
Abstract
Filoviruses, such as the Ebola virus (EBOV) and Marburg virus (MARV), are causative agents of sporadic outbreaks of hemorrhagic fevers in humans. To infect cells, filoviruses are internalized via macropinocytosis and traffic through the endosomal pathway where host cathepsin-dependent cleavage of the viral glycoproteins occurs. Subsequently, the cleaved viral glycoprotein interacts with the late endosome/lysosome resident host protein, Niemann-Pick C1 (NPC1). This interaction is hypothesized to trigger viral and host membrane fusion, which results in the delivery of the viral genome into the cytoplasm and subsequent initiation of replication. Some studies suggest that EBOV viral particles activate signaling cascades and host-trafficking factors to promote their localization with host factors that are essential for entry. However, the mechanism through which these activating signals are initiated remains unknown. By screening a kinase inhibitor library, we found that receptor tyrosine kinase inhibitors potently block EBOV and MARV GP-dependent viral entry. Inhibitors of epidermal growth factor receptor (EGFR), tyrosine protein kinase Met (c-Met), and the insulin receptor (InsR)/insulin like growth factor 1 receptor (IGF1R) blocked filoviral GP-mediated entry and prevented growth of replicative EBOV in Vero cells. Furthermore, inhibitors of c-Met and InsR/IGF1R also blocked viral entry in macrophages, the primary targets of EBOV infection. Interestingly, while the c-Met and InsR/IGF1R inhibitors interfered with EBOV trafficking to NPC1, virus delivery to the receptor was not impaired in the presence of the EGFR inhibitor. Instead, we observed that the NPC1 positive compartments were phenotypically altered and rendered incompetent to permit viral entry. Despite their different mechanisms of action, all three RTK inhibitors tested inhibited virus-induced Akt activation, providing a possible explanation for how EBOV may activate signaling pathways during entry. In sum, these studies strongly suggest that receptor tyrosine kinases initiate signaling cascades essential for efficient post-internalization entry steps. Ebola virus (EBOV) and Marburg virus (MARV) are zoonotic pathogens that can cause severe hemorrhagic fevers in humans and non-human primates. They are members of the growing Filoviridae family that also includes three other species of Ebolaviruses known to be highly pathogenic in humans. While vaccines for EBOV are being deployed and showed high efficacy, pan-filoviral treatment is still lacking. To infect cells, EBOV requires the endosomal/lysosomal resident protein Niemann-Pick C1 (NPC1). Accordingly, viral particles require extensive trafficking within endosomal pathways for entry and delivery of the viral genome into the host cell cytoplasm. Here, we used chemical biology to reveal that EBOV triggers receptor tyrosine kinase (RTK)-dependent signaling to traffic to intracellular vesicles that contain the receptor and are conducive to entry. The characterization of host trafficking factors and signaling pathways that are potentially triggered by the virus are important as these could be targeted for antiviral therapies. In our study, we identified several RTK inhibitors, some of which are FDA-approved drugs, that potently block EBOV infection. Since all filoviruses known to date, even Měnglà virus that was recently discovered in bats in China, use NPC1 as their entry receptor, these inhibitors have the potential to be effective pan-filovirus antivirals.
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Affiliation(s)
- Corina M. Stewart
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Canada
- Centre for Infection, Immunity, and Inflammation, University of Ottawa, Ottawa, Canada
| | - Alexandra Phan
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Canada
- Centre for Infection, Immunity, and Inflammation, University of Ottawa, Ottawa, Canada
| | - Yuxia Bo
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Canada
- Centre for Infection, Immunity, and Inflammation, University of Ottawa, Ottawa, Canada
| | - Nicholas D. LeBlond
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada
- Centre for Infection, Immunity, and Inflammation, University of Ottawa, Ottawa, Canada
| | - Tyler K. T. Smith
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada
- Centre for Infection, Immunity, and Inflammation, University of Ottawa, Ottawa, Canada
| | - Geneviève Laroche
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada
| | - Patrick M. Giguère
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada
| | - Morgan D. Fullerton
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada
- Centre for Infection, Immunity, and Inflammation, University of Ottawa, Ottawa, Canada
- Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, Canada
| | - Martin Pelchat
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada
| | - Darwyn Kobasa
- Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Canada
- Department of Medical Microbiology, University of Manitoba, Winnipeg, Canada
| | - Marceline Côté
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Canada
- Centre for Infection, Immunity, and Inflammation, University of Ottawa, Ottawa, Canada
- Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, Canada
- * E-mail:
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17
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Haldar S, Okamoto K, Dunning RA, Kasson PM. Precise Triggering and Chemical Control of Single-Virus Fusion within Endosomes. J Virol 2020; 95:e01982-20. [PMID: 33115879 PMCID: PMC7737740 DOI: 10.1128/jvi.01982-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 10/07/2020] [Indexed: 11/20/2022] Open
Abstract
Many enveloped viruses infect cells within endocytic compartments. The pH drop that accompanies endosomal maturation, often in conjunction with proteolysis, triggers viral proteins to insert into the endosomal membrane and drive fusion. Fusion dynamics have been studied by tracking viruses within living cells, which limits the precision with which fusion can be synchronized and controlled, and reconstituting viral fusion to synthetic membranes, which introduces nonphysiological membrane curvature and composition. To overcome these limitations, we report chemically controllable triggering of single-virus fusion within endosomes. We isolated influenza (A/Aichi/68; H3N2) virus:endosome conjugates from cells, immobilized them in a microfluidic flow cell, and rapidly and controllably triggered fusion. Observed lipid-mixing kinetics were surprisingly similar to those of influenza virus fusion with model membranes of opposite curvature: 80% of single-virus events had indistinguishable kinetics. This result suggests that endosomal membrane curvature is not a key permissive feature for viral entry, at least lipid mixing. The assay preserved endosomal membrane asymmetry and protein composition, providing a platform to test how cellular restriction factors and altered endosomal trafficking affect viral membrane fusion.IMPORTANCE Many enveloped viruses infect cells via fusion to endosomes, but controlling this process within living cells has been challenging. We studied the fusion of influenza virus virions to endosomes in a chemically controllable manner. Extracting virus:endosome conjugates from cells and exogenously triggering fusion permits precise study of virus:endosome fusion kinetics. Surprisingly, endosomal curvature does not grossly alter fusion kinetics, although membrane deformability does. This supports a model for influenza virus entry where cells restrict or permit membrane fusion by changing deformability, for instance, using interferon-induced proteins.
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Affiliation(s)
- Sourav Haldar
- Science for Life Laboratory, Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Kenta Okamoto
- Science for Life Laboratory, Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Rebecca A Dunning
- Department of Molecular Physiology, University of Virginia, Charlottesville, Virginia, USA
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
| | - Peter M Kasson
- Science for Life Laboratory, Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
- Department of Molecular Physiology, University of Virginia, Charlottesville, Virginia, USA
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
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18
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Uhlorn BL, Jackson R, Li S, Bratton SM, Van Doorslaer K, Campos SK. Vesicular trafficking permits evasion of cGAS/STING surveillance during initial human papillomavirus infection. PLoS Pathog 2020; 16:e1009028. [PMID: 33253291 PMCID: PMC7728285 DOI: 10.1371/journal.ppat.1009028] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 12/10/2020] [Accepted: 10/02/2020] [Indexed: 12/26/2022] Open
Abstract
Oncogenic human papillomaviruses (HPVs) replicate in differentiating epithelium, causing 5% of cancers worldwide. Like most other DNA viruses, HPV infection initiates after trafficking viral genome (vDNA) to host cell nuclei. Cells possess innate surveillance pathways to detect microbial components or physiological stresses often associated with microbial infections. One of these pathways, cGAS/STING, induces IRF3-dependent antiviral interferon (IFN) responses upon detection of cytosolic DNA. Virion-associated vDNA can activate cGAS/STING during initial viral entry and uncoating/trafficking, and thus cGAS/STING is an obstacle to many DNA viruses. HPV has a unique vesicular trafficking pathway compared to many other DNA viruses. As the capsid uncoats within acidic endosomal compartments, minor capsid protein L2 protrudes across vesicular membranes to facilitate transport of vDNA to the Golgi. L2/vDNA resides within the Golgi lumen until G2/M, whereupon vesicular L2/vDNA traffics along spindle microtubules, tethering to chromosomes to access daughter cell nuclei. L2/vDNA-containing vesicles likely remain intact until G1, following nuclear envelope reformation. We hypothesize that this unique vesicular trafficking protects HPV from cGAS/STING surveillance. Here, we investigate cGAS/STING responses to HPV infection. DNA transfection resulted in acute cGAS/STING activation and downstream IFN responses. In contrast, HPV infection elicited minimal cGAS/STING and IFN responses. To determine the role of vesicular trafficking in cGAS/STING evasion, we forced premature viral penetration of vesicular membranes with membrane-perturbing cationic lipids. Such treatment renders a non-infectious trafficking-defective mutant HPV infectious, yet susceptible to cGAS/STING detection. Overall, HPV evades cGAS/STING by its unique subcellular trafficking, a property that may contribute to establishment of infection.
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Affiliation(s)
- Brittany L. Uhlorn
- Cancer Biology Graduate Interdisciplinary Program, The University of Arizona, Tucson, Arizona, United States of America
| | - Robert Jackson
- School of Animal & Comparative Biomedical Sciences, The University of Arizona, Tucson, Arizona, United States of America
| | - Shuaizhi Li
- Department of Immunobiology, The University of Arizona, Tucson, Arizona, United States of America
| | - Shauna M. Bratton
- Department of Physiology, The University of Arizona, Tucson, Arizona, United States of America
| | - Koenraad Van Doorslaer
- Cancer Biology Graduate Interdisciplinary Program, The University of Arizona, Tucson, Arizona, United States of America
- School of Animal & Comparative Biomedical Sciences, The University of Arizona, Tucson, Arizona, United States of America
- Department of Immunobiology, The University of Arizona, Tucson, Arizona, United States of America
- BIO5 Institute, The University of Arizona, Tucson, Arizona, United States of America
- Genetics Graduate Interdisciplinary Program, The University of Arizona, Tucson, Arizona, United States of America
| | - Samuel K. Campos
- Cancer Biology Graduate Interdisciplinary Program, The University of Arizona, Tucson, Arizona, United States of America
- Department of Immunobiology, The University of Arizona, Tucson, Arizona, United States of America
- BIO5 Institute, The University of Arizona, Tucson, Arizona, United States of America
- Department of Molecular & Cellular Biology, The University of Arizona, Tucson, Arizona, United States of America
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19
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Genoyer E, Kulej K, Hung CT, Thibault PA, Azarm K, Takimoto T, Garcia BA, Lee B, Lakdawala S, Weitzman MD, López CB. The Viral Polymerase Complex Mediates the Interaction of Viral Ribonucleoprotein Complexes with Recycling Endosomes during Sendai Virus Assembly. mBio 2020; 11:e02028-20. [PMID: 32843550 PMCID: PMC7448285 DOI: 10.1128/mbio.02028-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 07/23/2020] [Indexed: 11/20/2022] Open
Abstract
Paramyxoviruses are negative-sense single-stranded RNA viruses that comprise many important human and animal pathogens, including human parainfluenza viruses. These viruses bud from the plasma membrane of infected cells after the viral ribonucleoprotein complex (vRNP) is transported from the cytoplasm to the cell membrane via Rab11a-marked recycling endosomes. The viral proteins that are critical for mediating this important initial step in viral assembly are unknown. Here, we used the model paramyxovirus, murine parainfluenza virus 1, or Sendai virus (SeV), to investigate the roles of viral proteins in Rab11a-driven virion assembly. We previously reported that infection with SeV containing high levels of copy-back defective viral genomes (DVGs) (DVG-high SeV) generates heterogenous populations of cells. Cells enriched in full-length (FL) virus produce viral particles containing standard or defective viral genomes, while cells enriched in DVGs do not, despite high levels of defective viral genome replication. Here, we took advantage of this heterogenous cell phenotype to identify proteins that mediate interaction of vRNPs with Rab11a. We examined the roles of matrix protein and nucleoprotein and determined that their presence is not sufficient to drive interaction of vRNPs with recycling endosomes. Using a combination of mass spectrometry and comparative analyses of protein abundance and localization in DVG-high and FL-virus-high (FL-high) cells, we identified viral polymerase complex component protein L and, specifically, its cofactor C as interactors with Rab11a. We found that accumulation of L and C proteins within the cell is the defining feature that differentiates cells that proceed to viral egress from cells containing viruses that remain in replication phases.IMPORTANCE Paramyxoviruses are members of a family of viruses that include a number of pathogens imposing significant burdens on human health. In particular, human parainfluenza viruses are an important cause of pneumonia and bronchiolitis in children for which there are no vaccines or directly acting antivirals. These cytoplasmic replicating viruses bud from the plasma membrane and co-opt cellular endosomal recycling pathways to traffic viral ribonucleoprotein complexes from the cytoplasm to the membrane of infected cells. The viral proteins required for viral engagement with the recycling endosome pathway are still not known. Here, we used the model paramyxovirus Sendai virus, or murine parainfluenza virus 1, to investigate the role of viral proteins in this initial step of viral assembly. We found that the viral polymerase components large protein L and accessory protein C are necessary for engagement with recycling endosomes. These findings are important in identifying viral proteins as potential targets for development of antivirals.
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Affiliation(s)
- Emmanuelle Genoyer
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Katarzyna Kulej
- Division of Protective Immunity and Division of Cancer Pathobiology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Chuan Tien Hung
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Patricia A Thibault
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Kristopher Azarm
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Toru Takimoto
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, New York, USA
| | - Benjamin A Garcia
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Benhur Lee
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Seema Lakdawala
- Department of Microbiology & Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Matthew D Weitzman
- Division of Protective Immunity and Division of Cancer Pathobiology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Carolina B López
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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20
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Wang XW, Vasta GR, Wang JX. The functional relevance of shrimp C-type lectins in host-pathogen interactions. Dev Comp Immunol 2020; 109:103708. [PMID: 32305304 DOI: 10.1016/j.dci.2020.103708] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 04/10/2020] [Accepted: 04/10/2020] [Indexed: 06/11/2023]
Abstract
C-type lectins (CTLs) are key recognition proteins in shrimp immunity. A few years ago we reviewed sequence information, ligand specificity, expression profiles and specific functions of the shrimp CTLs. Since then, multiple integrated studies that implemented biochemical approaches using both the native and recombinant proteins, functional genetic approaches using RNA interference, and mechanistic studies by analyzing protein-protein interactions were carried out. Results from these rigorous studies revealed the functions and mechanisms of action of selected members of the shrimp CTL family. This review focuses on this new knowledge, that includes unique structural aspects, functions, and mechanisms in host-pathogen interactions, the functional relevance of regions other than the C-type lectin domain, and the regulation of transcription of shrimp CTLs. Thus, this review aims to provide a detailed update of recent studies that have contributed to our better understanding of the shrimp immune events that involve CTL functions.
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Affiliation(s)
- Xian-Wei Wang
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, State Key Laboratory of Microbial Technology, Shandong University, Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.
| | - Gerardo R Vasta
- Department of Microbiology and Immunology, School of Medicine, University of Maryland Baltimore, Institute of Marine and Environmental Technology, Baltimore, MD, USA
| | - Jin-Xing Wang
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, State Key Laboratory of Microbial Technology, Shandong University, Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.
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21
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Kounatidis I, Stanifer ML, Phillips MA, Paul-Gilloteaux P, Heiligenstein X, Wang H, Okolo CA, Fish TM, Spink MC, Stuart DI, Davis I, Boulant S, Grimes JM, Dobbie IM, Harkiolaki M. 3D Correlative Cryo-Structured Illumination Fluorescence and Soft X-ray Microscopy Elucidates Reovirus Intracellular Release Pathway. Cell 2020; 182:515-530.e17. [PMID: 32610083 PMCID: PMC7391008 DOI: 10.1016/j.cell.2020.05.051] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 04/14/2020] [Accepted: 05/28/2020] [Indexed: 01/15/2023]
Abstract
Imaging of biological matter across resolution scales entails the challenge of preserving the direct and unambiguous correlation of subject features from the macroscopic to the microscopic level. Here, we present a correlative imaging platform developed specifically for imaging cells in 3D under cryogenic conditions by using X-rays and visible light. Rapid cryo-preservation of biological specimens is the current gold standard in sample preparation for ultrastructural analysis in X-ray imaging. However, cryogenic fluorescence localization methods are, in their majority, diffraction-limited and fail to deliver matching resolution. We addressed this technological gap by developing an integrated, user-friendly platform for 3D correlative imaging of cells in vitreous ice by using super-resolution structured illumination microscopy in conjunction with soft X-ray tomography. The power of this approach is demonstrated by studying the process of reovirus release from intracellular vesicles during the early stages of infection and identifying intracellular virus-induced structures.
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Affiliation(s)
- Ilias Kounatidis
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK
| | - Megan L Stanifer
- Department of Infectious Diseases, Molecular Virology, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Michael A Phillips
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK; Micron Advanced Imaging Consortium, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK; Division of Structural Biology, The Henry Wellcome Building for Genomic Medicine, Roosevelt Drive, Oxford, OX3 7BN, UK
| | - Perrine Paul-Gilloteaux
- Université de Nantes, CNRS, INSERM, l'institut du thorax, Nantes, France; Nantes Université, CHU Nantes, Inserm, CNRS, SFR Santé, Inserm UMS 016, CNRS UMS3556, Nantes, France
| | | | - Hongchang Wang
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK
| | - Chidinma A Okolo
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK
| | - Thomas M Fish
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK
| | - Matthew C Spink
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK
| | - David I Stuart
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK; Division of Structural Biology, The Henry Wellcome Building for Genomic Medicine, Roosevelt Drive, Oxford, OX3 7BN, UK
| | - Ilan Davis
- Micron Advanced Imaging Consortium, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Steeve Boulant
- Department of Infectious Diseases, Virology, Heidelberg University Hospital, 69120 Heidelberg, Germany; Research Group "Cellular polarity and viral infection," German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Jonathan M Grimes
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK; Division of Structural Biology, The Henry Wellcome Building for Genomic Medicine, Roosevelt Drive, Oxford, OX3 7BN, UK
| | - Ian M Dobbie
- Micron Advanced Imaging Consortium, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Maria Harkiolaki
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK.
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22
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Izumida M, Hayashi H, Tanaka A, Kubo Y. Cathepsin B Protease Facilitates Chikungunya Virus Envelope Protein-Mediated Infection via Endocytosis or Macropinocytosis. Viruses 2020; 12:v12070722. [PMID: 32635194 PMCID: PMC7412492 DOI: 10.3390/v12070722] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 06/29/2020] [Accepted: 07/02/2020] [Indexed: 02/07/2023] Open
Abstract
Chikungunya virus (CHIKV) is an enveloped virus that enters host cells and transits within the endosomes before starting its replication cycle, the precise mechanism of which is yet to be elucidated. Endocytosis and endosome acidification inhibitors inhibit infection by CHIKV, murine leukemia virus (MLV), or SARS-coronavirus, indicating that these viral entries into host cells occur through endosomes and require endosome acidification. Although endosomal cathepsin B protease is necessary for MLV, Ebola virus, and SARS-CoV infections, its role in CHIKV infection is unknown. Our results revealed that endocytosis inhibitors attenuated CHIKV-pseudotyped MLV vector infection in 293T cells but not in TE671 cells. In contrast, macropinocytosis inhibitors attenuated CHIKV-pseudotyped MLV vector infection in TE671 cells but not in 293T cells, suggesting that CHIKV host cell entry occurs via endocytosis or macropinocytosis, depending on the cell lines used. Cathepsin B inhibitor and knockdown by an shRNA suppressed CHIKV-pseudotyped MLV vector infection both in 293T and TE671 cells. These results show that cathepsin B facilitates CHIKV infection regardless of the entry pathway.
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Affiliation(s)
- Mai Izumida
- Department of Clinical Medicine, Institute of Tropical Medicine, Nagasaki University, Nagasaki 852-8523, Japan
- Correspondence: (M.I.); (Y.K.)
| | - Hideki Hayashi
- Medical University Research Administrator, Nagasaki University School of Medicine, Nagasaki 852-8523, Japan;
| | - Atsushi Tanaka
- Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan;
| | - Yoshinao Kubo
- Department of Clinical Medicine, Institute of Tropical Medicine, Nagasaki University, Nagasaki 852-8523, Japan
- Program for Nurturing Global Leaders in Tropical and Emerging Communicable Diseases, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8523, Japan
- Correspondence: (M.I.); (Y.K.)
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23
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Albakri MM, Veliz FA, Fiering SN, Steinmetz NF, Sieg SF. Endosomal toll-like receptors play a key role in activation of primary human monocytes by cowpea mosaic virus. Immunology 2020; 159:183-192. [PMID: 31630392 PMCID: PMC6954739 DOI: 10.1111/imm.13135] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 09/20/2019] [Accepted: 10/14/2019] [Indexed: 12/30/2022] Open
Abstract
The plant virus, cowpea mosaic virus (CPMV), has demonstrated a remarkable capacity to induce anti-tumour immune responses following direct administration into solid tumours. The molecular pathways that account for these effects and the capacity of CPMV to activate human cells are not well defined. Here, we examine the ability of CPMV particles to activate human monocytes, dendritic cells (DCs) and macrophages. Monocytes in peripheral blood mononuclear cell cultures and purified CD14+ monocytes were readily activated by CPMV in vitro, leading to induction of HLA-DR, CD86, PD-L1, IL-15R and CXCL10 expression. Monocytes released chemokines, CXCL10, MIP-1α and MIP-1β into cell culture supernatants after incubation with CPMV. DC subsets (pDC and mDC) and monocyte-derived macrophages also demonstrated evidence of activation after incubation with CPMV. Inhibitors of spleen tyrosine kinase (SYK), endocytosis or endocytic acidification impaired the capacity of CPMV to activate monocytes. Furthermore, CPMV activation of monocytes was partially blocked by a TLR7/8 antagonist. These data demonstrate that CPMV activates human monocytes in a manner dependent on SYK signalling, endosomal acidification and with an important contribution from TLR7/8 recognition.
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Affiliation(s)
- Marwah M. Albakri
- Department of PathologySchool of MedicineCase Western Reserve UniversityClevelandOHUSA
- Department of Medical Laboratory TechnologyCollege of Applied Medical SciencesTaibah UniversityMedinaSaudi Arabia
| | - Frank A. Veliz
- Department of Biomedical EngineeringSchool of MedicineCase Western Reserve UniversityClevelandOHUSA
| | - Steven N. Fiering
- Department of Microbiology and ImmunologyGeisel School of Medicine at DartmouthNorris Cotton Cancer CenterLebanonNHUSA
| | - Nicole F. Steinmetz
- Department of NanoEngineeringUniversity of California San DiegoLa JollaCAUSA
- Department of RadiologyUniversity of California San DiegoLa JollaCAUSA
- Department of BioengineeringUniversity of California San DiegoLa JollaCAUSA
- Moores Cancer CenterUniversity of California San DiegoLa JollaCAUSA
| | - Scott F. Sieg
- Division of Infectious Diseases and HIV MedicineSchool of MedicineCase Western Reserve UniversityClevelandOHUSA
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24
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Wang F, Pan H, Yao X, He H, Liu L, Luo Y, Zhou H, Zheng M, Zhang R, Ma Y, Cai L. Bioorthogonal Metabolic Labeling Utilizing Protein Biosynthesis for Dynamic Visualization of Nonenveloped Enterovirus 71 Infection. ACS Appl Mater Interfaces 2020; 12:3363-3370. [PMID: 31845579 DOI: 10.1021/acsami.9b17412] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Bioorthogonal metabolic labeling through the endogenous cellular metabolic pathways (e.g., phospholipid and sugar) is a promising approach for effectively labeling live viruses. However, it remains a big challenge to label nonenveloped viruses due to lack of host-derived envelopes. Herein, a novel bioorthogonal labeling strategy is developed utilizing protein synthesis pathway to label and trace nonenveloped viruses. The results show that l-azidohomoalanine (Aha), an azido derivative of methionine, is more effective than azido sugars to introduce azido motifs into viral capsid proteins by substituting methionine residues during viral protein biosynthesis and assembly. The azide-modified EV71 (N3-EV71) particles are then effectively labeled with dibenzocyclooctyl (DBCO)-functionalized fluorescence probes through an in situ bioorthogonal reaction with well-preserved viral infectivity. Dual-labeled imaging clearly clarifies that EV71 virions primarily bind to scavenger receptors and are internalized through clathrin-mediated endocytosis. The viral particles are then transported into early and late endosomes where viral RNA is released in a low-pH dependent manner at about 70 min postinfection. These results first reveal viral trafficking and uncoating mechanisms, which may shed light on the pathogenesis of EV71 infection and contribute to antiviral drug discovery.
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Affiliation(s)
- Fangfang Wang
- Guangdong Key Laboratory of Nanomedicine, CAS-HK Joint Lab of Biomaterials, CAS Key Lab for Health Informatics, Shenzhen Engineering Laboratory of Nanomedicine and Nanoformulations , Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences , Shenzhen 518055 , P. R. China
- University of Chinese Academy of Sciences , Beijing 100049 , P.R. China
| | - Hong Pan
- Guangdong Key Laboratory of Nanomedicine, CAS-HK Joint Lab of Biomaterials, CAS Key Lab for Health Informatics, Shenzhen Engineering Laboratory of Nanomedicine and Nanoformulations , Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences , Shenzhen 518055 , P. R. China
- University of Chinese Academy of Sciences , Beijing 100049 , P.R. China
| | - Xiangjie Yao
- Shenzhen Centre for Disease Control and Prevention , Shenzhen 518100 , P. R. China
| | - Huamei He
- Guangdong Key Laboratory of Nanomedicine, CAS-HK Joint Lab of Biomaterials, CAS Key Lab for Health Informatics, Shenzhen Engineering Laboratory of Nanomedicine and Nanoformulations , Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences , Shenzhen 518055 , P. R. China
| | - Lanlan Liu
- Guangdong Key Laboratory of Nanomedicine, CAS-HK Joint Lab of Biomaterials, CAS Key Lab for Health Informatics, Shenzhen Engineering Laboratory of Nanomedicine and Nanoformulations , Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences , Shenzhen 518055 , P. R. China
- University of Chinese Academy of Sciences , Beijing 100049 , P.R. China
| | - Yingmei Luo
- Guangdong Key Laboratory of Nanomedicine, CAS-HK Joint Lab of Biomaterials, CAS Key Lab for Health Informatics, Shenzhen Engineering Laboratory of Nanomedicine and Nanoformulations , Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences , Shenzhen 518055 , P. R. China
| | - Haimei Zhou
- Guangdong Key Laboratory of Nanomedicine, CAS-HK Joint Lab of Biomaterials, CAS Key Lab for Health Informatics, Shenzhen Engineering Laboratory of Nanomedicine and Nanoformulations , Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences , Shenzhen 518055 , P. R. China
| | - Mingbin Zheng
- Guangdong Key Laboratory of Nanomedicine, CAS-HK Joint Lab of Biomaterials, CAS Key Lab for Health Informatics, Shenzhen Engineering Laboratory of Nanomedicine and Nanoformulations , Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences , Shenzhen 518055 , P. R. China
| | - Renli Zhang
- Shenzhen Centre for Disease Control and Prevention , Shenzhen 518100 , P. R. China
| | - Yifan Ma
- Guangdong Key Laboratory of Nanomedicine, CAS-HK Joint Lab of Biomaterials, CAS Key Lab for Health Informatics, Shenzhen Engineering Laboratory of Nanomedicine and Nanoformulations , Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences , Shenzhen 518055 , P. R. China
- HRYZ Biotech Co. , Shenzhen 518057 , P. R. China
| | - Lintao Cai
- Guangdong Key Laboratory of Nanomedicine, CAS-HK Joint Lab of Biomaterials, CAS Key Lab for Health Informatics, Shenzhen Engineering Laboratory of Nanomedicine and Nanoformulations , Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences , Shenzhen 518055 , P. R. China
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25
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Abstract
Microtubules, part of the cytoskeleton, are indispensable for intracellular movement, cell division, and maintaining cell shape and polarity. In addition, microtubules play an important role in viral infection. In this review, we summarize the role of the microtubules' network during polyomavirus infection. Polyomaviruses usurp microtubules and their motors to travel via early and late acidic endosomes to the endoplasmic reticulum. As shown for SV40, kinesin-1 and microtubules are engaged in the release of partially disassembled virus from the endoplasmic reticulum to the cytosol, and dynein apparently assists in the further disassembly of virions prior to their translocation to the cell nucleus-the place of their replication. Polyomavirus gene products affect the regulation of microtubule dynamics. Early T antigens destabilize microtubules and cause aberrant mitosis. The role of these activities in tumorigenesis has been documented. However, its importance for productive infection remains elusive. On the other hand, in the late phase of infection, the major capsid protein, VP1, of the mouse polyomavirus, counteracts T-antigen-induced destabilization. It physically binds microtubules and stabilizes them. The interaction results in the G2/M block of the cell cycle and prolonged S phase, which is apparently required for successful completion of the viral replication cycle.
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Affiliation(s)
| | | | - Jitka Forstová
- Department of Genetics and Microbiology, Faculty of Science, Charles University, BIOCEV, 25250 Vestec, Czech Republic; (L.H.); (K.B.)
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Benfield CT, MacKenzie F, Ritzefeld M, Mazzon M, Weston S, Tate EW, Teo BH, Smith SE, Kellam P, Holmes EC, Marsh M. Bat IFITM3 restriction depends on S-palmitoylation and a polymorphic site within the CD225 domain. Life Sci Alliance 2020; 3:e201900542. [PMID: 31826928 PMCID: PMC6907390 DOI: 10.26508/lsa.201900542] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 11/27/2019] [Accepted: 11/28/2019] [Indexed: 12/14/2022] Open
Abstract
Host interferon-induced transmembrane proteins (IFITMs) are broad-spectrum antiviral restriction factors. Of these, IFITM3 potently inhibits viruses that enter cells through acidic endosomes, many of which are zoonotic and emerging viruses with bats (order Chiroptera) as their natural hosts. We previously demonstrated that microbat IFITM3 is antiviral. Here, we show that bat IFITMs are characterized by strong adaptive evolution and identify a highly variable and functionally important site-codon 70-within the conserved CD225 domain of IFITMs. Mutation of this residue in microbat IFITM3 impairs restriction of representatives of four different virus families that enter cells via endosomes. This mutant shows altered subcellular localization and reduced S-palmitoylation, a phenotype copied by mutation of conserved cysteine residues in microbat IFITM3. Furthermore, we show that microbat IFITM3 is S-palmitoylated on cysteine residues C71, C72, and C105, mutation of each cysteine individually impairs virus restriction, and a triple C71A-C72A-C105A mutant loses all restriction activity, concomitant with subcellular re-localization of microbat IFITM3 to Golgi-associated sites. Thus, we propose that S-palmitoylation is critical for Chiropteran IFITM3 function and identify a key molecular determinant of IFITM3 S-palmitoylation.
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Affiliation(s)
- Camilla To Benfield
- Department of Pathobiology and Population Sciences, Royal Veterinary College, University of London, London, UK
| | - Farrell MacKenzie
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK
| | | | - Michela Mazzon
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Stuart Weston
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Edward W Tate
- Department of Chemistry, Imperial College London, London, UK
| | - Boon Han Teo
- Department of Pathobiology and Population Sciences, Royal Veterinary College, University of London, London, UK
| | - Sarah E Smith
- Kymab Ltd, The Bennet Building (B930), Babraham Research Campus, Cambridge, UK
| | - Paul Kellam
- Department of Infectious Disease, Imperial College Faculty of Medicine, Wright Fleming Institute, St Mary's Campus, London, UK
- Kymab Ltd, The Bennet Building (B930), Babraham Research Campus, Cambridge, UK
| | - Edward C Holmes
- Marie Bashir Institute for Infectious Diseases and Biosecurity, Charles Perkins Centre, School of Life and Environmental Sciences and Sydney Medical School, The University of Sydney, Sydney, New South Wales, Australia
| | - Mark Marsh
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK
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27
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Zhang F, Guo H, Chen Q, Ruan Z, Fang Q. Endosomes and Microtubles are Required for Productive Infection in Aquareovirus. Virol Sin 2019; 35:200-211. [PMID: 31858455 DOI: 10.1007/s12250-019-00178-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 09/18/2019] [Indexed: 12/20/2022] Open
Abstract
Grass carp reovirus (GCRV), the genus Aquareovirus in family Reoviridae, is viewed as the most pathogenic aquareovirus. To understand the molecular mechanism of how aquareovirus initiates productive infection, the roles of endosome and microtubule in cell entry of GCRV are investigated by using quantum dots (QDs)-tracking in combination with biochemical approaches. We found that GCRV infection and viral protein synthesis were significantly inhibited by pretreating host cells with endosome acidification inhibitors NH4Cl, chloroquine and bafilomycin A1 (Bafi). Confocal images indicated that GCRV particles could colocalize with Rab5, Rab7 and lysosomes in host cells. Further ultrastructural examination validated that viral particle was found in late endosomes. Moreover, disruption of microtubules with nocodazole clearly blocked GCRV entry, while no inhibitory effects were observed with cytochalasin D treated cells in viral infection, hinting that intracellular transportation of endocytic uptake in GCRV infected cells is via microtubules but not actin filament. Notably, viral particles were observed to transport along microtubules by using QD-labeled GCRV. Altogether, our results suggest that GCRV can use endosomes and microtubules to initiate productive infection.
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Affiliation(s)
- Fuxian Zhang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
- Wuhan Center for Animal Diseases Prevention and Control, Wuhan, 430071, China
| | - Hong Guo
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Qingxiu Chen
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Zheng Ruan
- Wuhan Center for Animal Diseases Prevention and Control, Wuhan, 430071, China
| | - Qin Fang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China.
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Chen YJ, Liu X, Tsai B. SV40 Hijacks Cellular Transport, Membrane Penetration, and Disassembly Machineries to Promote Infection. Viruses 2019; 11:v11100917. [PMID: 31590347 PMCID: PMC6832212 DOI: 10.3390/v11100917] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 09/23/2019] [Accepted: 09/23/2019] [Indexed: 12/22/2022] Open
Abstract
During entry, a virus must be transported through the endomembrane system of the host cell, penetrate a cellular membrane, and undergo capsid disassembly, to reach the cytosol and often the nucleus in order to cause infection. To do so requires the virus to coordinately exploit the action of cellular membrane transport, penetration, and disassembly machineries. How this is accomplished remains enigmatic for many viruses, especially for viruses belonging to the nonenveloped virus family. In this review, we present the current model describing infectious entry of the nonenveloped polyomavirus (PyV) SV40. Insights from SV40 entry are likely to provide strategies to combat PyV-induced diseases, and to illuminate cellular trafficking, membrane transport, and disassembly mechanisms.
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Affiliation(s)
- Yu-Jie Chen
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, BSRB 3043, Ann Arbor, MI 48109, USA.
| | - Xiaofang Liu
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, BSRB 3043, Ann Arbor, MI 48109, USA.
| | - Billy Tsai
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, BSRB 3043, Ann Arbor, MI 48109, USA.
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29
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Liu T, Li J, Liu Y, Qu Y, Li A, Li C, Zhang Q, Wu W, Li J, Liu Y, Li D, Wang S, Liang M. SNX11 Identified as an Essential Host Factor for SFTS Virus Infection by CRISPR Knockout Screening. Virol Sin 2019; 34:508-520. [PMID: 31215001 PMCID: PMC6814687 DOI: 10.1007/s12250-019-00141-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 05/17/2019] [Indexed: 01/23/2023] Open
Abstract
Severe fever with thrombocytopenia syndrome virus (SFTSV) is a highly pathogenic tick-borne bunyavirus that causes lethal infectious disease and severe fever with thrombocytopenia syndrome (SFTS) in humans. The molecular mechanisms and host cellular factors required for SFTSV infection remain uncharacterized. Using a genome-wide CRISPR-based screening strategy, we identified a host cellular protein, sorting nexin 11 (SNX11) which is involved in the intracellular endosomal trafficking pathway, as an essential cell factor for SFTSV infection. An SNX11-KO HeLa cell line was established, and SFTSV replication was significantly reduced. The glycoproteins of SFTSV were detected and remained in later endosomal compartments but were not detectable in the endoplasmic reticulum (ER) or Golgi apparatus. pH values in the endosomal compartments of the SNX11-KO cells increased compared with the pH of normal HeLa cells, and lysosomal-associated membrane protein 1 (LAMP1) expression was significantly elevated in the SNX11-KO cells. Overall, these results indicated that penetration of SFTSV from the endolysosomes into the cytoplasm of host cells was blocked in the cells lacking SNX11. Our study for the first time provides insight into the important role of the SNX11 as an essential host factor in the intracellular trafficking and penetrating process of SFTSV infection via potential regulation of viral protein sorting, membrane fusion, and other endocytic machinery.
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Affiliation(s)
- Tiezhu Liu
- Key Laboratory of Medical Virology and Viral Diseases, Ministry of Health of People's Republic of China, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China
| | - Jiajia Li
- Department of Microbiology, Anhui Medical University, Hefei, 230032, China
- The First Affiliated Hospital of Anhui Medical University, Hefei, 230022, China
| | - Yang Liu
- Key Laboratory of Medical Virology and Viral Diseases, Ministry of Health of People's Republic of China, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China
| | - Yuanyuan Qu
- Key Laboratory of Medical Virology and Viral Diseases, Ministry of Health of People's Republic of China, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China
| | - Aqian Li
- Key Laboratory of Medical Virology and Viral Diseases, Ministry of Health of People's Republic of China, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China
| | - Chuan Li
- Key Laboratory of Medical Virology and Viral Diseases, Ministry of Health of People's Republic of China, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China
| | - Quanfu Zhang
- Key Laboratory of Medical Virology and Viral Diseases, Ministry of Health of People's Republic of China, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China
| | - Wei Wu
- Key Laboratory of Medical Virology and Viral Diseases, Ministry of Health of People's Republic of China, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China
| | - Jiandong Li
- Key Laboratory of Medical Virology and Viral Diseases, Ministry of Health of People's Republic of China, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China
| | - Yan Liu
- Department of Microbiology, Anhui Medical University, Hefei, 230032, China
| | - Dexin Li
- Key Laboratory of Medical Virology and Viral Diseases, Ministry of Health of People's Republic of China, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China
| | - Shiwen Wang
- Key Laboratory of Medical Virology and Viral Diseases, Ministry of Health of People's Republic of China, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China.
- CDC-WIV Joint Research Center for Emerging Diseases and Biosafety, Wuhan, 430071, China.
| | - Mifang Liang
- Key Laboratory of Medical Virology and Viral Diseases, Ministry of Health of People's Republic of China, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China.
- CDC-WIV Joint Research Center for Emerging Diseases and Biosafety, Wuhan, 430071, China.
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30
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Suwan K, Yata T, Waramit S, Przystal JM, Stoneham CA, Bentayebi K, Asavarut P, Chongchai A, Pothachareon P, Lee KY, Topanurak S, Smith TL, Gelovani JG, Sidman RL, Pasqualini R, Arap W, Hajitou A. Next-generation of targeted AAVP vectors for systemic transgene delivery against cancer. Proc Natl Acad Sci U S A 2019; 116:18571-18577. [PMID: 31375630 PMCID: PMC6744886 DOI: 10.1073/pnas.1906653116] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Bacteriophage (phage) have attractive advantages as delivery systems compared with mammalian viruses, but have been considered poor vectors because they lack evolved strategies to confront and overcome mammalian cell barriers to infective agents. We reasoned that improved efficacy of delivery might be achieved through structural modification of the viral capsid to avoid pre- and postinternalization barriers to mammalian cell transduction. We generated multifunctional hybrid adeno-associated virus/phage (AAVP) particles to enable simultaneous display of targeting ligands on the phage's minor pIII proteins and also degradation-resistance motifs on the very numerous pVIII coat proteins. This genetic strategy of directed evolution bestows a next-generation of AAVP particles that feature resistance to fibrinogen adsorption or neutralizing antibodies and ability to escape endolysosomal degradation. This results in superior gene transfer efficacy in vitro and also in preclinical mouse models of rodent and human solid tumors. Thus, the unique functions of our next-generation AAVP particles enable improved targeted gene delivery to tumor cells.
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Affiliation(s)
- Keittisak Suwan
- Phage Therapy Group, Department of Brain Sciences, Imperial College London, W12 0NN London, United Kingdom
| | - Teerapong Yata
- Phage Therapy Group, Department of Brain Sciences, Imperial College London, W12 0NN London, United Kingdom
| | - Sajee Waramit
- Phage Therapy Group, Department of Brain Sciences, Imperial College London, W12 0NN London, United Kingdom
| | - Justyna M Przystal
- Phage Therapy Group, Department of Brain Sciences, Imperial College London, W12 0NN London, United Kingdom
| | - Charlotte A Stoneham
- Phage Therapy Group, Department of Brain Sciences, Imperial College London, W12 0NN London, United Kingdom
| | - Kaoutar Bentayebi
- Phage Therapy Group, Department of Brain Sciences, Imperial College London, W12 0NN London, United Kingdom
| | - Paladd Asavarut
- Phage Therapy Group, Department of Brain Sciences, Imperial College London, W12 0NN London, United Kingdom
| | - Aitthiphon Chongchai
- Thailand Excellence Center for Tissue Engineering and Stem Cells, Department of Biochemistry, Faculty of Medicine, Chiang Mai University, 50200 Chiang Mai, Thailand
| | - Peraphan Pothachareon
- Thailand Excellence Center for Tissue Engineering and Stem Cells, Department of Biochemistry, Faculty of Medicine, Chiang Mai University, 50200 Chiang Mai, Thailand
| | - Koon-Yang Lee
- Department of Aeronautics, Imperial College London, SW7 2AZ London, United Kingdom
| | - Supachai Topanurak
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, 10400 Bangkok, Thailand
| | - Tracey L Smith
- Rutgers Cancer Institute of New Jersey, Newark, NJ 07103
- Division of Cancer Biology, Department of Radiation Oncology, Rutgers New Jersey Medical School, Newark, NJ 07103
| | - Juri G Gelovani
- Karmanos Cancer Institute, School of Medicine, Wayne State University, Detroit, MI 48201
- Department of Biomedical Engineering, College of Engineering, Wayne State University, Detroit, MI 48201
| | - Richard L Sidman
- Department of Neurology, Harvard Medical School, Boston, MA 02115;
| | - Renata Pasqualini
- Rutgers Cancer Institute of New Jersey, Newark, NJ 07103;
- Division of Cancer Biology, Department of Radiation Oncology, Rutgers New Jersey Medical School, Newark, NJ 07103
| | - Wadih Arap
- Rutgers Cancer Institute of New Jersey, Newark, NJ 07103;
- Division of Hematology/Oncology, Department of Medicine, Rutgers New Jersey Medical School, Newark, NJ 07103
| | - Amin Hajitou
- Phage Therapy Group, Department of Brain Sciences, Imperial College London, W12 0NN London, United Kingdom;
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31
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Abstract
Viruses must navigate the complex endomembranous network of the host cell to cause infection. In the case of a non-enveloped virus that lacks a surrounding lipid bilayer, endocytic uptake from the plasma membrane is not sufficient to cause infection. Instead, the virus must travel within organelle membranes to reach a specific cellular destination that supports exposure or arrival of the virus to the cytosol. This is achieved by viral penetration across a host endomembrane, ultimately enabling entry of the virus into the nucleus to initiate infection. In this review, we discuss the entry mechanisms of three distinct non-enveloped DNA viruses-adenovirus (AdV), human papillomavirus (HPV), and polyomavirus (PyV)-highlighting how each exploit different intracellular transport machineries and membrane penetration apparatus associated with the endosome, Golgi, and endoplasmic reticulum (ER) membrane systems to infect a host cell. These processes not only illuminate a highly-coordinated interplay between non-enveloped viruses and their host, but may provide new strategies to combat non-enveloped virus-induced diseases.
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Affiliation(s)
- Chelsey C Spriggs
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Mara C Harwood
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, United States; Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Billy Tsai
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, United States; Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, MI, United States.
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32
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Zhang J, Chen J, Shi D, Shi H, Zhang X, Liu J, Cao L, Zhu X, Liu Y, Wang X, Ji Z, Feng L. Porcine deltacoronavirus enters cells via two pathways: A protease-mediated one at the cell surface and another facilitated by cathepsins in the endosome. J Biol Chem 2019; 294:9830-9843. [PMID: 31068417 PMCID: PMC6597833 DOI: 10.1074/jbc.ra119.007779] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 05/02/2019] [Indexed: 11/06/2022] Open
Abstract
Porcine deltacoronavirus (PDCoV) is a pathogen belonging to the genus Deltacoronavirus that in 2014 caused outbreaks of piglet diarrhea in the United States. To identify suitable therapeutic targets, a more comprehensive understanding of the viral entry pathway is required, particularly of the role of proteases. Here, we identified the proteases that activate the viral spike (S) glycoprotein to initiate cell entry and also pinpointed the host-cellular pathways that PDCoV uses for entry. Our results revealed that cathepsin L (CTSL) and cathepsin B (CTSB) in lysosomes and extracellular trypsin in cell cultures independently activate the S protein for membrane fusion. Pretreating the cells with the lysosomal acidification inhibitor bafilomycin-A1 (Baf-A1) completely inhibited PDCoV entry, and siRNA-mediated ablation of CTSL or CTSB expression significantly reduced viral infection, indicating that PDCoV uses an endosomal pathway for entry. Of note, trypsin treatment of cell cultures also activated PDCoV entry, even when the endosomal pathway was inhibited. This observation indicated that trypsin-induced S protein cleavage and activation in cell cultures enables viral entry directly from the cell surface. Our results provide critical insights into the PDCoV infection mechanism, uncovering two distinct viral entry pathways: one through cathepsin L and cathepsin B in the endosome and another via a protease at the cell surface. Because PDCoV infection sites represent a proteases-rich environment, these findings suggest that endosome inhibitor treatment alone is insufficient to block PDCoV entry into intestinal epithelial cells in vivo Therefore, approaches that inhibit viral entry from the cell membrane should also be considered.
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Affiliation(s)
- Jialin Zhang
- From the State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Jianfei Chen
- From the State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Da Shi
- From the State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Hongyan Shi
- From the State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Xin Zhang
- From the State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Jianbo Liu
- From the State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Liyan Cao
- From the State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Xiangdong Zhu
- From the State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Ye Liu
- From the State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Xiaobo Wang
- From the State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Zhaoyang Ji
- From the State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Li Feng
- From the State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
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Plegge T, Spiegel M, Krüger N, Nehlmeier I, Winkler M, González Hernández M, Pöhlmann S. Inhibitors of signal peptide peptidase and subtilisin/kexin-isozyme 1 inhibit Ebola virus glycoprotein-driven cell entry by interfering with activity and cellular localization of endosomal cathepsins. PLoS One 2019; 14:e0214968. [PMID: 30973897 PMCID: PMC6459477 DOI: 10.1371/journal.pone.0214968] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 03/24/2019] [Indexed: 11/30/2022] Open
Abstract
Emerging viruses such as severe fever and thrombocytopenia syndrome virus (SFTSV) and Ebola virus (EBOV) are responsible for significant morbidity and mortality. Host cell proteases that process the glycoproteins of these viruses are potential targets for antiviral intervention. The aspartyl protease signal peptide peptidase (SPP) has recently been shown to be required for processing of the glycoprotein precursor, Gn/Gc, of Bunyamwera virus and for viral infectivity. Here, we investigated whether SPP is also required for infectivity of particles bearing SFTSV-Gn/Gc. Entry driven by the EBOV glycoprotein (GP) and the Lassa virus glycoprotein (LASV-GPC) depends on the cysteine proteases cathepsin B and L (CatB/CatL) and the serine protease subtilisin/kexin-isozyme 1 (SKI-1), respectively, and was examined in parallel for control purposes. We found that inhibition of SPP and SKI-1 did not interfere with SFTSV Gn + Gc-driven entry but, unexpectedly, blocked entry mediated by EBOV-GP. The inhibition occurred at the stage of proteolytic activation and the SPP inhibitor was found to block CatL/CatB activity. In contrast, the SKI-1 inhibitor did not interfere with CatB/CatL activity but disrupted CatB localization in endo/lysosomes, the site of EBOV-GP processing. These results underline the potential of protease inhibitors for antiviral therapy but also show that previously characterized compounds might exert broader specificity than initially appreciated and might block viral entry via diverse mechanisms.
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Affiliation(s)
- Teresa Plegge
- Infection Biology Unit, German Primate Center–Leibniz Institute for Primate Research, Göttingen, Germany
- Faculty of Biology and Psychology, University Göttingen, Göttingen, Germany
| | - Martin Spiegel
- Infection Biology Unit, German Primate Center–Leibniz Institute for Primate Research, Göttingen, Germany
- Institute of Microbiology and Virology, Brandenburg Medical School Theodor Fontane, Senftenberg, Germany
| | - Nadine Krüger
- Institute of Virology, University of Veterinary Medicine Hannover, Hannover, Germany
- Research Center for Emerging Infections and Zoonoses, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Inga Nehlmeier
- Infection Biology Unit, German Primate Center–Leibniz Institute for Primate Research, Göttingen, Germany
| | - Michael Winkler
- Infection Biology Unit, German Primate Center–Leibniz Institute for Primate Research, Göttingen, Germany
| | - Mariana González Hernández
- Infection Biology Unit, German Primate Center–Leibniz Institute for Primate Research, Göttingen, Germany
- Faculty of Biology and Psychology, University Göttingen, Göttingen, Germany
| | - Stefan Pöhlmann
- Infection Biology Unit, German Primate Center–Leibniz Institute for Primate Research, Göttingen, Germany
- Faculty of Biology and Psychology, University Göttingen, Göttingen, Germany
- * E-mail:
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Denning D, Bennett S, Mullen T, Moyer C, Vorselen D, Wuite GJL, Nemerow G, Roos WH. Maturation of adenovirus primes the protein nano-shell for successful endosomal escape. Nanoscale 2019; 11:4015-4024. [PMID: 30768112 DOI: 10.1039/c8nr10182e] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The ability of adenoviruses to infect a broad range of species has spurred a growing interest in nanomedicine to use adenovirus as a cargo delivery vehicle. While successful maturation of adenovirus and controlled disassembly are critical for efficient infection, the underlying mechanisms regulating these processes are not well understood. Here, we present Atomic Force Microscopy nanoindentation and fatigue studies of adenovirus capsids at different maturation stages to scrutinize their dynamic uncoating properties. Surprisingly, we find that the early intermediate immature (lacking DNA) capsid is mechanically indistinguishable in both break force and spring constant from the mature (containing DNA) capsid. However, mature and immature capsids do display distinct disassembly pathways, as revealed by our mechanically-induced fatigue analysis. The mature capsid first loses the pentons, followed by either long-term capsid stability or abrupt and complete disassembly. However, the immature capsid has a stable penton region and undergoes a stochastic disassembly mechanism, thought to be due to the absence of genomic pressure. Strikingly, the addition of the genome alone is not sufficient to achieve penton destabilization as indicated by the penton stability of the maturation-intermediate mutant, G33A. Full penton destabilization was achieved only when the genome was present in addition to the successful maturation-linked proteolytic cleavage of preprotein VI. Therefore these findings strongly indicate that maturation of adenovirus in concert with genomic pressure induces penton destabilization and thus, primes the capsid for controlled disassembly. This latter aspect is critical for efficient infection and successful cargo delivery.
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Affiliation(s)
- D Denning
- Moleculaire Biofysica, Zernike Instituut, Rijksuniversiteit Groningen, The Netherlands and Natuur- en Sterrenkunde and LaserLaB, Vrije Universiteit Amsterdam, The Netherlands.
| | - S Bennett
- Department of Immunology and Microbiology, the Scripps Research Institute, La Jolla, CA 92037, USA.
| | - T Mullen
- Department of Immunology and Microbiology, the Scripps Research Institute, La Jolla, CA 92037, USA.
| | - C Moyer
- Department of Immunology and Microbiology, the Scripps Research Institute, La Jolla, CA 92037, USA.
| | - D Vorselen
- Natuur- en Sterrenkunde and LaserLaB, Vrije Universiteit Amsterdam, The Netherlands.
| | - G J L Wuite
- Natuur- en Sterrenkunde and LaserLaB, Vrije Universiteit Amsterdam, The Netherlands.
| | - G Nemerow
- Department of Immunology and Microbiology, the Scripps Research Institute, La Jolla, CA 92037, USA.
| | - W H Roos
- Moleculaire Biofysica, Zernike Instituut, Rijksuniversiteit Groningen, The Netherlands
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35
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Li C, Zheng H, Wang Y, Dong W, Liu Y, Zhang L, Zhang Y. Antiviral Role of IFITM Proteins in Classical Swine Fever Virus Infection. Viruses 2019; 11:v11020126. [PMID: 30704088 PMCID: PMC6409519 DOI: 10.3390/v11020126] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 01/22/2019] [Accepted: 01/29/2019] [Indexed: 12/24/2022] Open
Abstract
The proteins IFITM1, IFITM2, and IFITM3 are host effectors against a broad range of RNA viruses whose roles in classical swine fever virus (CSFV) infection had not yet been reported. We investigated the effect of these proteins on CSFV replication in mammalian cells. The proteins were overexpressed and silenced using lentiviruses. Confocal microscopy was used to determine the distribution of these proteins in the cells, and immunofluorescence colocalization analysis was used to evaluate the relationship between IFITMs and the CSFV endosomal pathway, including early endosomes, late endosomes, and lysosomes. IFITM1, IFITM2, or IFITM3 overexpression significantly inhibited CSFV replication, whereas protein knockdown enhanced CSFV replication. In porcine alveolar macrophages (PAMs), IFITM1 was mainly located at the cell surface, whereas IFITM2 and IFITM3 were mainly located in the cytoplasm. Following CSFV infection, the distribution of IFITM1 changed. IFITM1, IFITM2, and IFITM3 colocalization with Lamp1, IFITM2 with Rab5 and Rab7, and IFITM3 with Rab7 were observed in CSFV-infected cells. Collectively, these results provide insights into the possible mechanisms associated with the anti-CSFV action of the IFITM family.
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Affiliation(s)
- Cheng Li
- College of Veterinary Medicine, Northwest A&F University, Yangling 712100, China.
| | - Hongqing Zheng
- College of Veterinary Medicine, Northwest A&F University, Yangling 712100, China.
| | | | - Wang Dong
- College of Veterinary Medicine, Henan University of Animal Husbandry and Economy, Zhengzhou 450046, China.
| | - Yaru Liu
- College of Veterinary Medicine, Northwest A&F University, Yangling 712100, China.
| | - Liang Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling 712100, China.
| | - Yanming Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling 712100, China.
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Suddala KC, Lee CC, Meraner P, Marin M, Markosyan RM, Desai TM, Cohen FS, Brass AL, Melikyan GB. Interferon-induced transmembrane protein 3 blocks fusion of sensitive but not resistant viruses by partitioning into virus-carrying endosomes. PLoS Pathog 2019; 15:e1007532. [PMID: 30640957 PMCID: PMC6347298 DOI: 10.1371/journal.ppat.1007532] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 01/25/2019] [Accepted: 12/14/2018] [Indexed: 11/19/2022] Open
Abstract
Late endosome-resident interferon-induced transmembrane protein 3 (IFITM3) inhibits fusion of diverse viruses, including Influenza A virus (IAV), by a poorly understood mechanism. Despite the broad antiviral activity of IFITM3, viruses like Lassa virus (LASV), are fully resistant to its inhibitory effects. It is currently unclear whether resistance arises from a highly efficient fusion machinery that is capable of overcoming IFITM3 restriction or the ability to enter from cellular sites devoid of this factor. Here, we constructed and validated a functional IFITM3 tagged with EGFP or other fluorescent proteins. This breakthrough allowed live cell imaging of virus co-trafficking and fusion with endosomal compartments in cells expressing fluorescent IFITM3. Three-color single virus and endosome tracking revealed that sensitive (IAV), but not resistant (LASV), viruses become trapped within IFITM3-positive endosomes where they underwent hemifusion but failed to release their content into the cytoplasm. IAV fusion with IFITM3-containing compartments could be rescued by amphotericin B treatment, which has been previously shown to antagonize the antiviral activity of this protein. By comparison, virtually all LASV particles trafficked and fused with endosomes lacking detectable levels of fluorescent IFITM3, implying that this virus escapes restriction by utilizing endocytic pathways that are distinct from the IAV entry pathways. The importance of virus uptake and transport pathways is further reinforced by the observation that LASV glycoprotein-mediated cell-cell fusion is inhibited by IFITM3 and other members of the IFITM family expressed in target cells. Together, our results strongly support a model according to which IFITM3 accumulation at the sites of virus fusion is a prerequisite for its antiviral activity and that this protein traps viral fusion at a hemifusion stage by preventing the formation of fusion pores. We conclude that the ability to utilize alternative endocytic pathways for entry confers IFITM3-resistance to otherwise sensitive viruses.
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Affiliation(s)
- Krishna C Suddala
- Department of Pediatrics, Emory University, Atlanta, GA, United States of America
| | - Christine C Lee
- Department of Pediatrics, Emory University, Atlanta, GA, United States of America
| | - Paul Meraner
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, United States of America
| | - Mariana Marin
- Department of Pediatrics, Emory University, Atlanta, GA, United States of America
| | - Ruben M Markosyan
- Rush University Medical Center, Department of Physiology and Biophysics, Chicago, IL, United States of America
| | - Tanay M Desai
- Department of Pediatrics, Emory University, Atlanta, GA, United States of America
| | - Fredric S Cohen
- Rush University Medical Center, Department of Physiology and Biophysics, Chicago, IL, United States of America
| | - Abraham L Brass
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, United States of America
- Gastroenterology Division, Department of Medicine, University of Massachusetts Medical School, Worcester, MA, United States of America
| | - Gregory B Melikyan
- Department of Pediatrics, Emory University, Atlanta, GA, United States of America
- Children's Healthcare of Atlanta, Atlanta, GA, United States of America
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Wang H, Yuan X, Sun Y, Mao X, Meng C, Tan L, Song C, Qiu X, Ding C, Liao Y. Infectious bronchitis virus entry mainly depends on clathrin mediated endocytosis and requires classical endosomal/lysosomal system. Virology 2018; 528:118-136. [PMID: 30597347 PMCID: PMC7111473 DOI: 10.1016/j.virol.2018.12.012] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 12/17/2018] [Accepted: 12/18/2018] [Indexed: 12/27/2022]
Abstract
Although several reports suggest that the entry of infectious bronchitis virus (IBV) depends on lipid rafts and low pH, the endocytic route and intracellular trafficking are unclear. In this study, we aimed to shed greater light on early steps in IBV infection. By using chemical inhibitors, RNA interference, and dominant negative mutants, we observed that lipid rafts and low pH was indeed required for virus entry; IBV mainly utilized the clathrin mediated endocytosis (CME) for entry; GTPase dynamin 1 was involved in virus containing vesicle scission; and the penetration of IBV into cells led to active cytoskeleton rearrangement. By using R18 labeled virus, we found that virus particles moved along with the classical endosome/lysosome track. Functional inactivation of Rab5 and Rab7 significantly inhibited IBV infection. Finally, by using dual R18/DiOC labeled IBV, we observed that membrane fusion was induced after 1 h.p.i. in late endosome/lysosome. Intact lipid rafts is involved in IBV entry. Low pH in intracyplasmic vesicles is required for IBV entry. IBV penetrates cells via clathrin mediated endocytosis. IBV moves along with the classical endosome/lysosome track, finally fuses with late endosome/lysosome.
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Affiliation(s)
- Huan Wang
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, PR China
| | - Xiao Yuan
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, PR China
| | - Yingjie Sun
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, PR China
| | - Xiang Mao
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, PR China
| | - Chunchun Meng
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, PR China
| | - Lei Tan
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, PR China
| | - Cuiping Song
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, PR China
| | - Xusheng Qiu
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, PR China
| | - Chan Ding
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, PR China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, PR China.
| | - Ying Liao
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, PR China.
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Wirawan M, Fibriansah G, Marzinek JK, Lim XX, Ng TS, Sim AYL, Zhang Q, Kostyuchenko VA, Shi J, Smith SA, Verma CS, Anand G, Crowe JE, Bond PJ, Lok SM. Mechanism of Enhanced Immature Dengue Virus Attachment to Endosomal Membrane Induced by prM Antibody. Structure 2018; 27:253-267.e8. [PMID: 30471923 DOI: 10.1016/j.str.2018.10.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 08/28/2018] [Accepted: 10/15/2018] [Indexed: 11/19/2022]
Abstract
Dengue virus (DENV) particles are released from cells in different maturation states. Fully immature DENV (immDENV) is generally non-infectious, but can become infectious when complexed with anti-precursor membrane (prM) protein antibodies. It is unknown how anti-prM antibody-coated particles can undergo membrane fusion since the prM caps the envelope (E) protein fusion loop. Here, we determined cryoelectron microscopy (cryo-EM) maps of the immDENV:anti-prM complex at different pH values, mimicking the extracellular (pH 8.0) or endosomal (pH 5.0) environments. At pH 5.0, there are two structural classes with fewer antibodies bound than at pH 8.0. These classes may represent different maturation states. Molecular simulations, together with the measured high-affinity pr:antibody interaction (versus the weak pr:E interaction) and also the low pH cryo-EM structures, suggest how antibody:pr complex can dislodge from the E protein at low pH. This exposes the E protein fusion loop enhancing virus interaction with endosomes.
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Affiliation(s)
- Melissa Wirawan
- Program in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore 169857, Singapore; Centre for BioImaging Sciences, National University of Singapore, Singapore 117557, Singapore
| | - Guntur Fibriansah
- Program in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore 169857, Singapore; Centre for BioImaging Sciences, National University of Singapore, Singapore 117557, Singapore
| | - Jan K Marzinek
- Bioinformatics Institute, A(∗)STAR (Agency for Science, Technology and Research), Singapore 138671, Singapore; Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore
| | - Xin Xiang Lim
- Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore
| | - Thiam-Seng Ng
- Program in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore 169857, Singapore; Centre for BioImaging Sciences, National University of Singapore, Singapore 117557, Singapore
| | - Adelene Y L Sim
- Bioinformatics Institute, A(∗)STAR (Agency for Science, Technology and Research), Singapore 138671, Singapore
| | - Qian Zhang
- Program in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore 169857, Singapore; Centre for BioImaging Sciences, National University of Singapore, Singapore 117557, Singapore
| | - Victor A Kostyuchenko
- Program in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore 169857, Singapore; Centre for BioImaging Sciences, National University of Singapore, Singapore 117557, Singapore
| | - Jian Shi
- Centre for BioImaging Sciences, National University of Singapore, Singapore 117557, Singapore; Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore
| | - Scott A Smith
- Department of Medicine, Division of Infectious Diseases, Vanderbilt University, Nashville, TN 37232, USA; The Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Chandra S Verma
- Bioinformatics Institute, A(∗)STAR (Agency for Science, Technology and Research), Singapore 138671, Singapore; Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore; School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Ganesh Anand
- Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore
| | - James E Crowe
- The Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Departments of Pediatrics and Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
| | - Peter J Bond
- Bioinformatics Institute, A(∗)STAR (Agency for Science, Technology and Research), Singapore 138671, Singapore; Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore.
| | - Shee-Mei Lok
- Program in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore 169857, Singapore; Centre for BioImaging Sciences, National University of Singapore, Singapore 117557, Singapore.
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Liu J, Jardetzky TS, Chin AL, Johnson DC, Vanarsdall AL. The Human Cytomegalovirus Trimer and Pentamer Promote Sequential Steps in Entry into Epithelial and Endothelial Cells at Cell Surfaces and Endosomes. J Virol 2018; 92:e01336-18. [PMID: 30111564 PMCID: PMC6189492 DOI: 10.1128/jvi.01336-18] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 08/08/2018] [Indexed: 12/23/2022] Open
Abstract
Human cytomegalovirus (HCMV) infects a wide variety of human cell types by different entry pathways that involve distinct envelope glycoprotein complexes that include gH/gL, a trimer complex consisting of gHgL/gO, and a pentamer complex consisting of gH/gL/UL128/UL130/UL131. We characterized the effects of soluble forms of these proteins on HCMV entry. Soluble trimer and pentamer blocked entry of HCMV into epithelial and endothelial cells, whereas soluble gH/gL did not. Trimer inhibited HCMV entry into fibroblast cells, but pentamer and gH/gL did not. Both trimer and pentamer bound to the surfaces of fibroblasts and epithelial cells, whereas gH/gL did not bind to either cell type. Cell surface binding of trimer and pentamer did not involve heparin sulfate moieties. The ability of soluble trimer to block entry of HCMV into epithelial cells did not involve platelet-derived growth factor PDGFRα, which has been reported as a trimer receptor for fibroblasts. Soluble trimer reduced the amount of virus particles that could be adsorbed onto the surface of epithelial cells, whereas soluble pentamer had no effect on virus adsorption. However, soluble pentamer reduced the ability of virus particles to exit from early endosomes into the cytoplasm and then travel to the nucleus. These studies support a model in which both the trimer and pentamer are required for HCMV entry into epithelial and endothelial cells, with trimer interacting with cell surface receptors other than PDGFR and pentamer acting later in the entry pathway to promote egress from endosomes.IMPORTANCE HCMV infects nearly 80% of the world's population and causes significant morbidity and mortality. The current antiviral agents used to treat HCMV infections are prone to resistance and can be toxic to patients, and there is no current vaccine against HCMV available. The data in this report will lead to a better understanding of how essential HCMV envelope glycoproteins function during infection of biologically important cell types and will have significant implications for understanding HCMV pathogenesis for developing new therapeutics.
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Affiliation(s)
- Jing Liu
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California, USA
| | - Ted S Jardetzky
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California, USA
| | - Andrea L Chin
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, Oregon, USA
| | - David C Johnson
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, Oregon, USA
| | - Adam L Vanarsdall
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, Oregon, USA
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40
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Prokšová PG, Lipov J, Zelenka J, Hunter E, Langerová H, Rumlová M, Ruml T. Mason-Pfizer Monkey Virus Envelope Glycoprotein Cycling and Its Vesicular Co-Transport with Immature Particles. Viruses 2018; 10:E575. [PMID: 30347798 PMCID: PMC6212865 DOI: 10.3390/v10100575] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Revised: 10/10/2018] [Accepted: 10/18/2018] [Indexed: 12/25/2022] Open
Abstract
The envelope glycoprotein (Env) plays a crucial role in the retroviral life cycle by mediating primary interactions with the host cell. As described previously and expanded on in this paper, Env mediates the trafficking of immature Mason-Pfizer monkey virus (M-PMV) particles to the plasma membrane (PM). Using a panel of labeled RabGTPases as endosomal markers, we identified Env mostly in Rab7a- and Rab9a-positive endosomes. Based on an analysis of the transport of recombinant fluorescently labeled M-PMV Gag and Env proteins, we propose a putative mechanism of the intracellular trafficking of M-PMV Env and immature particles. According to this model, a portion of Env is targeted from the trans-Golgi network (TGN) to Rab7a-positive endosomes. It is then transported to Rab9a-positive endosomes and back to the TGN. It is at the Rab9a vesicles where the immature particles may anchor to the membranes of the Env-containing vesicles, preventing Env recycling to the TGN. These Gag-associated vesicles are then transported to the plasma membrane.
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Affiliation(s)
- Petra Grznárová Prokšová
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, 166 28 Prague, Czech Republic.
- Imaging methods core facility at BIOCEV, Faculty of Science, Charles University, 252 50 Prague, Czech Republic.
| | - Jan Lipov
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, 166 28 Prague, Czech Republic.
| | - Jaroslav Zelenka
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, 166 28 Prague, Czech Republic.
| | - Eric Hunter
- Emory Vaccine Center at the Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, USA.
| | - Hana Langerová
- Department of Biotechnology, University of Chemistry and Technology, 166 28 Prague, Czech Republic.
| | - Michaela Rumlová
- Department of Biotechnology, University of Chemistry and Technology, 166 28 Prague, Czech Republic.
| | - Tomáš Ruml
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, 166 28 Prague, Czech Republic.
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Abstract
Bovine herpesvirus 1 (BoHV-1) is an alphaherpesvirus that poses a significant challenge to health and welfare in the cattle industry. We investigated the cellular entry route utilized by BoHV-1. We report that BoHV-1 enters Madin Darby bovine kidney (MDBK) cells, bovine turbinate cells, and African green monkey kidney (Vero) cells via a low-pH-mediated endocytosis pathway. Treatment of MDBK cells with hypertonic medium, which inhibits receptor-mediated endocytosis, prevented infection as measured by a beta-galactosidase reporter assay. Treatment of cells with noncytotoxic concentrations of the lysosomotropic agents ammonium chloride and monensin, which block the acidification of endosomes, inhibited BoHV-1 entry in a concentration-dependent fashion. The kinetics of endocytic uptake of BoHV-1 from the cell surface was rapid (50% uptake by ∼5 min). Time-of-addition experiments indicated that the lysosomotropic agents acted at early times postinfection, consistent with entry. Inactivation of virions by pretreatment with mildly acidic pH is a hallmark characteristic of viruses that utilize a low-pH-activated entry pathway. When BoHV-1 particles were exposed to pH 5.0 in the absence of target membrane, infectivity was markedly reduced. Lastly, treatment of cells with the proteasome inhibitor MG132 inhibited BoHV-1 entry in a concentration-dependent manner. Together, these results support a model of BoHV-1 infection in which low endosomal pH is a critical host trigger for fusion of the viral envelope with an endocytic membrane and necessary for successful infection of the target cell.IMPORTANCE BoHV-1 is a ubiquitous pathogen affecting cattle populations worldwide. Infection can result in complicated, polymicrobial infections due to the immunosuppressive properties of the virus. While there are vaccines on the market, they only limit disease severity and spread but do not prevent infection. The financial and animal welfare ramifications of this virus are significant, and in order to develop more effective prevention and treatment regimens, a more complete understanding of the initial steps in viral infection is necessary. This research establishes the initial entry pathway of BoHV-1, which provides a foundation for future development of effective treatments and preventative vaccines. Additionally, it allows comparisons to the entry pathways of other alphaherpesviruses, such as HSV-1.
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Affiliation(s)
- Gabrielle Pastenkos
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
| | - Becky Lee
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
| | - Suzanne M Pritchard
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
| | - Anthony V Nicola
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
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Gonzalez-Quintial R, Nguyen A, Kono DH, Oldstone MBA, Theofilopoulos AN, Baccala R. Lupus acceleration by a MAVS-activating RNA virus requires endosomal TLR signaling and host genetic predisposition. PLoS One 2018; 13:e0203118. [PMID: 30199535 PMCID: PMC6130858 DOI: 10.1371/journal.pone.0203118] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 08/09/2018] [Indexed: 12/19/2022] Open
Abstract
Viruses have long been implicated in the pathogenesis of autoimmunity, yet their contribution remains circumstantial partly due to the lack of well-documented information on infections prior to autoimmune disease onset. Here, we used the lymphocytic choriomeningitis virus (LCMV) as a model to mechanistically dissect the impact of viral infection on lupus-like autoimmunity. Virus persistence strongly enhanced disease in mice with otherwise weak genetic predisposition but not in highly predisposed or non-autoimmune mice, indicating a synergistic interplay between genetic susceptibility and virus infection. Moreover, endosomal Toll-like receptors (TLRs) and plasmacytoid dendritic cells (pDCs) were both strictly required for disease acceleration, even though LCMV also induces strong TLR-independent type I interferon (IFN-I) production via RNA helicases and MAVS in conventional DCs. These results suggest that LCMV enhances systemic autoimmunity primarily by providing stimulatory nucleic acids for endosomal TLR engagement, whereas overstimulation of the MAVS-dependent cytosolic pathway in the absence of endosomal TLR signaling is insufficient for disease induction.
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Affiliation(s)
- Rosana Gonzalez-Quintial
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Anthony Nguyen
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Dwight H. Kono
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Michael B. A. Oldstone
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Argyrios N. Theofilopoulos
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Roberto Baccala
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, California, United States of America
- * E-mail:
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Akimov SA, Polynkin MA, Jiménez-Munguía I, Pavlov KV, Batishchev OV. Phosphatidylcholine Membrane Fusion Is pH-Dependent. Int J Mol Sci 2018; 19:ijms19051358. [PMID: 29751591 PMCID: PMC5983597 DOI: 10.3390/ijms19051358] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Revised: 04/26/2018] [Accepted: 04/30/2018] [Indexed: 12/12/2022] Open
Abstract
Membrane fusion mediates multiple vital processes in cell life. Specialized proteins mediate the fusion process, and a substantial part of their energy is used for topological rearrangement of the membrane lipid matrix. Therefore, the elastic parameters of lipid bilayers are of crucial importance for fusion processes and for determination of the energy barriers that have to be crossed for the process to take place. In the case of fusion of enveloped viruses (e.g., influenza) with endosomal membrane, the interacting membranes are in an acidic environment, which can affect the membrane’s mechanical properties. This factor is often neglected in the analysis of virus-induced membrane fusion. In the present work, we demonstrate that even for membranes composed of zwitterionic lipids, changes of the environmental pH in the physiologically relevant range of 4.0 to 7.5 can affect the rate of the membrane fusion notably. Using a continual model, we demonstrated that the key factor defining the height of the energy barrier is the spontaneous curvature of the lipid monolayer. Changes of this parameter are likely to be caused by rearrangements of the polar part of lipid molecules in response to changes of the pH of the aqueous solution bathing the membrane.
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Affiliation(s)
- Sergey A Akimov
- Laboratory of Bioelectrochemistry, A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31/4 Leninskiy Prospekt, 119071 Moscow, Russia.
- Department of Theoretical Physics and Quantum Technologies, National University of Science and Technology "MISiS", 4 Leninskiy Prospekt, 119049 Moscow, Russia.
| | - Michael A Polynkin
- Laboratory of Bioelectrochemistry, A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31/4 Leninskiy Prospekt, 119071 Moscow, Russia.
| | - Irene Jiménez-Munguía
- Department of Engineering of Technological Equipment, National University of Science and Technology "MISiS", 4 Leninskiy Prospekt, 119049 Moscow, Russia.
| | - Konstantin V Pavlov
- Laboratory of Electrophysiology, Federal Clinical Center of Physical-Chemical Medicine of FMBA, 1a Malaya Pirogovskaya Street, 119435 Moscow, Russia.
| | - Oleg V Batishchev
- Laboratory of Bioelectrochemistry, A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31/4 Leninskiy Prospekt, 119071 Moscow, Russia.
- Department of Physics of Living Systems, Moscow Institute of Physics and Technology (State University), 9 Institutskiy Lane, 141700 Dolgoprudniy Moscow Region, Russia.
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Hulseberg CE, Fénéant L, Szymańska KM, White JM. Lamp1 Increases the Efficiency of Lassa Virus Infection by Promoting Fusion in Less Acidic Endosomal Compartments. mBio 2018; 9:e01818-17. [PMID: 29295909 PMCID: PMC5750398 DOI: 10.1128/mbio.01818-17] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Accepted: 11/21/2017] [Indexed: 01/20/2023] Open
Abstract
Lassa virus (LASV) is an arenavirus whose entry into host cells is mediated by a glycoprotein complex (GPC) comprised of a receptor binding subunit, GP1, a fusogenic transmembrane subunit, GP2, and a stable signal peptide. After receptor-mediated internalization, arenaviruses converge in the endocytic pathway, where they are thought to undergo low-pH-triggered, GPC-mediated fusion with a late endosome membrane. A unique feature of LASV entry is a pH-dependent switch from a primary cell surface receptor (α-dystroglycan) to an endosomal receptor, lysosomal-associated membrane protein (Lamp1). Despite evidence that the interaction between LASV GP1 and Lamp1 is critical, the function of Lamp1 in promoting LASV infection remains poorly characterized. Here we used wild-type (WT) and Lamp1 knockout (KO) cells to show that Lamp1 increases the efficiency of, but is not absolutely required for, LASV entry and infection. We then used cell-cell and pseudovirus-cell surface fusion assays to demonstrate that LASV GPC-mediated fusion occurs at a significantly higher pH when Lamp1 is present compared to when Lamp1 is missing. Correspondingly, we found that LASV entry occurs through less acidic endosomes in WT (Lamp1-positive) versus Lamp1 KO cells. We propose that, by elevating the pH threshold for fusion, Lamp1 allows LASV particles to exit the endocytic pathway before they encounter an increasingly acidic and harsh proteolytic environment, which could inactivate a significant percentage of incoming viruses. In this manner Lamp1 increases the overall efficiency of LASV entry and infection.IMPORTANCE Lassa virus is the most clinically important member of the Arenaviridae, a family that includes six additional biosafety level 4 (BSL4) hemorrhagic fever viruses. The lack of specific antiviral therapies for Lassa fever drives an urgent need to identify druggable targets, and interventions that block infection at the entry stage are particularly attractive. Lassa virus is only the second virus known to employ an intracellular receptor, the first being Ebola virus. Here we show that interaction with its intracellular receptor, Lamp1, enhances and upwardly shifts the pH dependence of fusion and consistently permits Lassa virus entry into cells through less acidic endosomes. We propose that in this manner, Lamp1 increases the overall efficiency of Lassa virus infection.
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Affiliation(s)
| | - Lucie Fénéant
- Department of Cell Biology, University of Virginia, Charlottesville, Virginia, USA
| | | | - Judith M White
- Department of Microbiology, University of Virginia, Charlottesville, Virginia, USA
- Department of Cell Biology, University of Virginia, Charlottesville, Virginia, USA
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Serfass JM, Takahashi Y, Zhou Z, Kawasawa YI, Liu Y, Tsotakos N, Young MM, Tang Z, Yang L, Atkinson JM, Chroneos ZC, Wang HG. Endophilin B2 facilitates endosome maturation in response to growth factor stimulation, autophagy induction, and influenza A virus infection. J Biol Chem 2017; 292:10097-10111. [PMID: 28455444 PMCID: PMC5473216 DOI: 10.1074/jbc.m117.792747] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 04/27/2017] [Indexed: 12/19/2022] Open
Abstract
Endocytosis, and the subsequent trafficking of endosomes, requires dynamic physical alterations in membrane shape that are mediated in part by endophilin proteins. The endophilin B family of proteins contains an N-terminal Bin/amphiphysin/Rvs (N-BAR) domain that induces membrane curvature to regulate intracellular membrane dynamics. Whereas endophilin B1 (SH3GLB1/Bif-1) is known to be involved in a number of cellular processes, including apoptosis, autophagy, and endocytosis, the cellular function of endophilin B2 (SH3GLB2) is not well understood. In this study, we used genetic approaches that revealed that endophilin B2 is not required for embryonic development in vivo but that endophilin B2 deficiency impairs endosomal trafficking in vitro, as evidenced by suppressed endosome acidification, EGFR degradation, autophagic flux, and influenza A viral RNA nuclear entry and replication. Mechanistically, although the loss of endophilin B2 did not affect endocytic internalization and lysosomal function, endophilin B2 appeared to regulate the trafficking of endocytic vesicles and autophagosomes to late endosomes or lysosomes. Moreover, we also found that despite having an intracellular localization and tissue distribution similar to endophilin B1, endophilin B2 is dispensable for mitochondrial apoptosis. Taken together, our findings suggest that endophilin B2 positively regulates the endocytic pathway in response to growth factor signaling, autophagy induction, and viral entry.
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Affiliation(s)
| | | | - Zhixiang Zhou
- the Department of Pediatrics
- the College of Life Science and Bioengineering, Beijing University of Technology, Beijing 100124, China
| | - Yuka Imamura Kawasawa
- From the Department of Pharmacology
- the Institute for Personalized Medicine, Department of Biochemistry and Molecular Biology, and
| | - Ying Liu
- From the Department of Pharmacology
| | | | | | | | | | | | - Zissis C Chroneos
- the Department of Pediatrics
- the Department of Microbiology & Immunology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033 and
| | - Hong-Gang Wang
- From the Department of Pharmacology,
- the Department of Pediatrics
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Baharom F, Thomas OS, Lepzien R, Mellman I, Chalouni C, Smed-Sörensen A. Visualization of early influenza A virus trafficking in human dendritic cells using STED microscopy. PLoS One 2017; 12:e0177920. [PMID: 28591131 PMCID: PMC5462357 DOI: 10.1371/journal.pone.0177920] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 05/05/2017] [Indexed: 12/01/2022] Open
Abstract
Influenza A viruses (IAV) primarily target respiratory epithelial cells, but can also replicate in immune cells, including human dendritic cells (DCs). Super-resolution microscopy provides a novel method of visualizing viral trafficking by overcoming the resolution limit imposed by conventional light microscopy, without the laborious sample preparation of electron microscopy. Using three-color Stimulated Emission Depletion (STED) microscopy, we visualized input IAV nucleoprotein (NP), early and late endosomal compartments (EEA1 and LAMP1 respectively), and HLA-DR (DC membrane/cytosol) by immunofluorescence in human DCs. Surface bound IAV were internalized within 5 min of infection. The association of virus particles with early endosomes peaked at 5 min when 50% of NP+ signals were also EEA1+. Peak association with late endosomes occurred at 15 min when 60% of NP+ signals were LAMP1+. At 30 min of infection, the majority of NP signals were in the nucleus. Our findings illustrate that early IAV trafficking in human DCs proceeds via the classical endocytic pathway.
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Affiliation(s)
- Faezzah Baharom
- Immunology and Allergy Unit, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
| | - Oliver S. Thomas
- Immunology and Allergy Unit, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
| | - Rico Lepzien
- Immunology and Allergy Unit, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
| | - Ira Mellman
- Genentech, Inc., 1 DNA Way, South San Francisco, CA, United States of America
| | - Cécile Chalouni
- Genentech, Inc., 1 DNA Way, South San Francisco, CA, United States of America
| | - Anna Smed-Sörensen
- Immunology and Allergy Unit, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
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Bergant M, Peternel Š, Pim D, Broniarczyk J, Banks L. Characterizing the spatio-temporal role of sorting nexin 17 in human papillomavirus trafficking. J Gen Virol 2017; 98:715-725. [PMID: 28475030 DOI: 10.1099/jgv.0.000734] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The human papillomavirus (HPV) L2 capsid protein plays an essential role during the early stages of viral infection. Previous studies have shown that the interaction between HPV L2 and endosomal sorting nexin 17 (SNX17) is conserved across multiple PV types where it plays an essential role in infectious entry, suggesting an evolutionarily conserved pathway of PV trafficking. Here we show that the peak time of interaction between HPV-16 L2 and SNX17 is rather early, at 2 h post-infection. Interestingly, the L2-SNX17 interaction appears to be important for facilitating capsid disassembly and L1 dissociation, suggesting that L2 recruitment of SNX17 occurs prior to capsid disassembly. Furthermore, we also found evidence of L2-SNX17 association at the later stages of infectious entry, suggesting that the SNX17-mediated sorting machinery is either involved at different stages of HPV trafficking or that L2-SNX17 interaction is a long-lasting event in HPV trafficking.
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Affiliation(s)
- Martina Bergant
- Centre for Biomedical Sciences and Engineering, University of Nova Gorica, Nova Gorica, Slovenia
- Laboratory for Environmental and Life Sciences, University of Nova Gorica, Nova Gorica, Slovenia
| | - Špela Peternel
- Centre for Biomedical Sciences and Engineering, University of Nova Gorica, Nova Gorica, Slovenia
| | - David Pim
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Justyna Broniarczyk
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
- Department of Molecular Virology, Adam Mickiewicz University, Poznan, Poland
| | - Lawrence Banks
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
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Ahmad W, Li Y, Guo Y, Wang X, Duan M, Guan Z, Liu Z, Zhang M. Rabies virus co-localizes with early (Rab5) and late (Rab7) endosomal proteins in neuronal and SH-SY5Y cells. Virol Sin 2017. [PMID: 28634871 DOI: 10.1007/s12250-017-3968-959:665-677,2010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023] Open
Abstract
Rabies virus (RABV) is a highly neurotropic virus that follows clathrin-mediated endocytosis and pH-dependent pathway for trafficking and invasion into endothelial cells. Early (Rab5, EEA1) and late (Rab7, LAMP1) endosomal proteins play critical roles in endosomal sorting, maturity and targeting various molecular cargoes, but their precise functions in the early stage of RABV neuronal infection remain elusive. In this study, the relationship between enigmatic entry of RABV with these endosomal proteins into neuronal and SH-SY5Y cells was investigated. Immunofluorescence, TCID50 titers, electron microscopy and western blotting were carried out to determine the molecular interaction of the nucleoprotein (N) of RABV with early or late endosomal proteins in these cell lines. The expression of N was also determined by down-regulating Rab5 and Rab7 in both cell lines through RNA interference. The results were indicative that N proficiently colocalized with Rab5/EEA1 and Rab7/LAMP1 in both cell lines at 24 and 48 h post-infection, while N titers significantly decreased in early infection of RABV. Down-regulation of Rab5 and Rab7 did not inhibit N expression, but it prevented productive infection via blocking the normal trafficking of RABV in a low pH environment. Ultrathin sections of cells studied by electron microscope also verified the close association of RABV with Rab5 and Rab7 in neurons. From the data it was concluded that primary entry of RABV strongly correlates with the kinetics of Rab-proteins present on early and late vesicles, which provides helpful clues to explain the early events of RABV in nerve cells.
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Affiliation(s)
- Waqas Ahmad
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, 130062, China
- Section of Epidemiology and Public Health, College of Veterinary and Animal Sciences, Jhang, 35200, Pakistan
| | - Yingying Li
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, 130062, China
| | - Yidi Guo
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, 130062, China
| | - Xinyu Wang
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, 130062, China
| | - Ming Duan
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, 130062, China
| | - Zhenhong Guan
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, 130062, China
| | - Zengshan Liu
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, 130062, China
| | - Maolin Zhang
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, 130062, China.
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Calton CM, Bronnimann MP, Manson AR, Li S, Chapman JA, Suarez-Berumen M, Williamson TR, Molugu SK, Bernal RA, Campos SK. Translocation of the papillomavirus L2/vDNA complex across the limiting membrane requires the onset of mitosis. PLoS Pathog 2017; 13:e1006200. [PMID: 28463988 PMCID: PMC5412990 DOI: 10.1371/journal.ppat.1006200] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 01/25/2017] [Indexed: 11/20/2022] Open
Abstract
The human papillomavirus type 16 (HPV16) L2 protein acts as a chaperone to ensure that the viral genome (vDNA) traffics from endosomes to the trans-Golgi network (TGN) and eventually the nucleus, where HPV replication occurs. En route to the nucleus, the L2/vDNA complex must translocate across limiting intracellular membranes. The details of this critical process remain poorly characterized. We have developed a system based on subcellular compartmentalization of the enzyme BirA and its cognate substrate to detect membrane translocation of L2-BirA from incoming virions. We find that L2 translocation requires transport to the TGN and is strictly dependent on entry into mitosis, coinciding with mitotic entry in synchronized cells. Cell cycle arrest causes retention of L2/vDNA at the TGN; only release and progression past G2/M enables translocation across the limiting membrane and subsequent infection. Microscopy of EdU-labeled vDNA reveals a rapid and dramatic shift in vDNA localization during early mitosis. At late G2/early prophase vDNA egresses from the TGN to a pericentriolar location, accumulating there through prometaphase where it begins to associate with condensed chromosomes. By metaphase and throughout anaphase the vDNA is seen bound to the mitotic chromosomes, ensuring distribution into both daughter nuclei. Mutations in a newly defined chromatin binding region of L2 potently blocked translocation, suggesting that translocation is dependent on chromatin binding during prometaphase. This represents the first time a virus has been shown to functionally couple the penetration of limiting membranes to cellular mitosis, explaining in part the tropism of HPV for mitotic basal keratinocytes.
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Affiliation(s)
- Christine M. Calton
- BIO5 Institute, University of Arizona, Tucson, Arizona, United States of America
| | - Matthew P. Bronnimann
- Department of Immunobiology, University of Arizona, Tucson, Arizona, United States of America
| | - Ariana R. Manson
- Department of Molecular & Cellular Biology, University of Arizona, Tucson, Arizona, United States of America
| | - Shuaizhi Li
- Department of Cellular & Molecular Medicine, University of Arizona, Tucson, Arizona, United States of America
| | - Janice A. Chapman
- BIO5 Institute, University of Arizona, Tucson, Arizona, United States of America
| | - Marcela Suarez-Berumen
- Department of Molecular & Cellular Biology, University of Arizona, Tucson, Arizona, United States of America
| | - Tatum R. Williamson
- Department of Molecular & Cellular Biology, University of Arizona, Tucson, Arizona, United States of America
| | - Sudheer K. Molugu
- Department of Chemistry, University of Texas at El Paso, El Paso, Texas, United States of America
| | - Ricardo A. Bernal
- Department of Chemistry, University of Texas at El Paso, El Paso, Texas, United States of America
| | - Samuel K. Campos
- BIO5 Institute, University of Arizona, Tucson, Arizona, United States of America
- Department of Immunobiology, University of Arizona, Tucson, Arizona, United States of America
- Department of Molecular & Cellular Biology, University of Arizona, Tucson, Arizona, United States of America
- Cancer Biology Graduate Interdisciplinary Program, University of Arizona, Tucson, Arizona, United States of America
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50
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Abstract
The Bunyavirales Order encompasses nine families of enveloped viruses containing a single-stranded negative-sense RNA genome divided into three segments. The small (S) and large (L) segments encode proteins participating in genome replication in the infected cell cytoplasm. The middle (M) segment encodes the viral glycoproteins Gn and Gc, which are derived from a precursor polyprotein by host cell proteases. Entry studies are available only for a few viruses in the Order, and in each case they were shown to enter cells via receptor-mediated endocytosis. The acidic endosomal pH triggers the fusion of the viral envelope with the membrane of an endosome. Structural studies on two members of this Order, the phleboviruses and the hantaviruses, have shown that the membrane fusion protein Gc displays a class II fusion protein fold and is homologous to its counterparts in flaviviruses and alphaviruses, which are positive-sense, single-stranded RNA viruses. We analyze here recent data on the structure and function of the structure of the phlebovirus Gc and hantavirus Gn and Gc glycoproteins, and extrapolate common features identified in the amino acid sequences to understand also the structure and function of their counterparts in other families of the Bunyavirales Order. Our analysis also identified clear structural homology between the hantavirus Gn and alphavirus E2 glycoproteins, which make a heterodimer with the corresponding fusion proteins Gc and E1, respectively, revealing that not only the fusion protein has been conserved across viral families.
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Affiliation(s)
- Pablo Guardado-Calvo
- Institut Pasteur, Unité de Virologie Structurale, Paris Cedex 15, France; CNRS UMR 3569 Virologie, Paris Cedex 15, France
| | - Félix A Rey
- Institut Pasteur, Unité de Virologie Structurale, Paris Cedex 15, France; CNRS UMR 3569 Virologie, Paris Cedex 15, France.
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