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Zhao J, Yu X, Shentu X, Li D. The application and development of electron microscopy for three-dimensional reconstruction in life science: a review. Cell Tissue Res 2024; 396:1-18. [PMID: 38416172 DOI: 10.1007/s00441-024-03878-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 02/13/2024] [Indexed: 02/29/2024]
Abstract
Imaging technologies have played a pivotal role in advancing biological research by enabling visualization of biological structures and processes. While traditional electron microscopy (EM) produces two-dimensional images, emerging techniques now allow high-resolution three-dimensional (3D) characterization of specimens in situ, meeting growing needs in molecular and cellular biology. Combining transmission electron microscopy (TEM) with serial sectioning inaugurated 3D imaging, attracting biologists seeking to explore cell ultrastructure and driving advancement of 3D EM reconstruction. By comprehensively and precisely rendering internal structure and distribution, 3D TEM reconstruction provides unparalleled ultrastructural insights into cells and molecules, holding tremendous value for elucidating structure-function relationships and broadly propelling structural biology. Here, we first introduce the principle of 3D reconstruction of cells and tissues by classical approaches in TEM and then discuss modern technologies utilizing TEM and on new SEM-based as well as cryo-electron microscope (cryo-EM) techniques. 3D reconstruction techniques from serial sections, electron tomography (ET), and the recent single-particle analysis (SPA) are examined; the focused ion beam scanning electron microscopy (FIB-SEM), the serial block-face scanning electron microscopy (SBF-SEM), and automatic tape-collecting lathe ultramicrotome (ATUM-SEM) for 3D reconstruction of large volumes are discussed. Finally, we review the challenges and development prospects of these technologies in life science. It aims to provide an informative reference for biological researchers.
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Affiliation(s)
- Jingjing Zhao
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection and Quarantine, College of Life Science, China , Jiliang University, Hangzhou, 310018, China
| | - Xiaoping Yu
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection and Quarantine, College of Life Science, China , Jiliang University, Hangzhou, 310018, China
| | - Xuping Shentu
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection and Quarantine, College of Life Science, China , Jiliang University, Hangzhou, 310018, China
| | - Danting Li
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection and Quarantine, College of Life Science, China , Jiliang University, Hangzhou, 310018, China.
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2
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Cabrera-Rodríguez R, Pérez-Yanes S, Lorenzo-Sánchez I, Trujillo-González R, Estévez-Herrera J, García-Luis J, Valenzuela-Fernández A. HIV Infection: Shaping the Complex, Dynamic, and Interconnected Network of the Cytoskeleton. Int J Mol Sci 2023; 24:13104. [PMID: 37685911 PMCID: PMC10487602 DOI: 10.3390/ijms241713104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 08/21/2023] [Accepted: 08/22/2023] [Indexed: 09/10/2023] Open
Abstract
HIV-1 has evolved a plethora of strategies to overcome the cytoskeletal barrier (i.e., actin and intermediate filaments (AFs and IFs) and microtubules (MTs)) to achieve the viral cycle. HIV-1 modifies cytoskeletal organization and dynamics by acting on associated adaptors and molecular motors to productively fuse, enter, and infect cells and then traffic to the cell surface, where virions assemble and are released to spread infection. The HIV-1 envelope (Env) initiates the cycle by binding to and signaling through its main cell surface receptors (CD4/CCR5/CXCR4) to shape the cytoskeleton for fusion pore formation, which permits viral core entry. Then, the HIV-1 capsid is transported to the nucleus associated with cytoskeleton tracks under the control of specific adaptors/molecular motors, as well as HIV-1 accessory proteins. Furthermore, HIV-1 drives the late stages of the viral cycle by regulating cytoskeleton dynamics to assure viral Pr55Gag expression and transport to the cell surface, where it assembles and buds to mature infectious virions. In this review, we therefore analyze how HIV-1 generates a cell-permissive state to infection by regulating the cytoskeleton and associated factors. Likewise, we discuss the relevance of this knowledge to understand HIV-1 infection and pathogenesis in patients and to develop therapeutic strategies to battle HIV-1.
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Affiliation(s)
- Romina Cabrera-Rodríguez
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Silvia Pérez-Yanes
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Iria Lorenzo-Sánchez
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Rodrigo Trujillo-González
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
- Analysis Department, Faculty of Mathematics, Universidad de La Laguna (ULL), 38200 La Laguna, Spain
| | - Judith Estévez-Herrera
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Jonay García-Luis
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Agustín Valenzuela-Fernández
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
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3
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Sanders S, Jensen Y, Reimer R, Bosse JB. From the beginnings to multidimensional light and electron microscopy of virus morphogenesis. Adv Virus Res 2023; 116:45-88. [PMID: 37524482 DOI: 10.1016/bs.aivir.2023.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/02/2023]
Abstract
Individual functional viral morphogenesis events are often dynamic, short, and infrequent and might be obscured by other pathways and dead-end products. Volumetric live cell imaging has become an essential tool for studying viral morphogenesis events. It allows following entire dynamic processes while providing functional evidence that the imaged process is involved in viral production. Moreover, it allows to capture many individual events and allows quantitative analysis. Finally, the correlation of volumetric live-cell data with volumetric electron microscopy (EM) can provide crucial insights into the ultrastructure and mechanisms of viral morphogenesis events. Here, we provide an overview and discussion of suitable imaging methods for volumetric correlative imaging of viral morphogenesis and frame them in a historical summary of their development.
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Affiliation(s)
- Saskia Sanders
- Department of Virology, Hannover Medical School, Hannover, Germany; Leibniz Institute of Virology (LIV), Hamburg, Germany; Centre for Structural Systems Biology, Hamburg, Germany; Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
| | - Yannick Jensen
- Department of Virology, Hannover Medical School, Hannover, Germany; Leibniz Institute of Virology (LIV), Hamburg, Germany; Centre for Structural Systems Biology, Hamburg, Germany; Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
| | | | - Jens B Bosse
- Department of Virology, Hannover Medical School, Hannover, Germany; Leibniz Institute of Virology (LIV), Hamburg, Germany; Centre for Structural Systems Biology, Hamburg, Germany; Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany.
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4
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Boucher T, Liang S, Brown AM. Advancing basic and translational research to deepen understanding of the molecular immune-mediated mechanisms regulating long-term persistence of HIV-1 in microglia in the adult human brain. J Leukoc Biol 2022; 112:1223-1231. [PMID: 35612272 PMCID: PMC9613482 DOI: 10.1002/jlb.1mr0422-620r] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 04/22/2022] [Indexed: 12/30/2022] Open
Abstract
Knowledge about the diversity microglia (MG) type and function in the rodent and human brain has advanced significantly in the last few years. Nevertheless, we have known for 40 years that MG, monocytes, and macrophages in the brain play crucial roles in the pathogenesis of the HIV-1 in all tissues. HIV enters and spreads in the brain early, long before the initiation of antiviral therapy. As a result, many people with HIV continue to experience neurologic and neuropsychiatric comorbid conditions collectively known as HIV-associated neurocognitive disorder (HAND). HIV pathogenic sequelae in the CNS pose a challenge for cure strategies. Detailed understanding at a mechanistic level of how low-level and latent HIV-1 infection in MG negatively impacts neuroglial function has remained somewhat elusive. Direct rigorous in vivo experimental validation that the virus can integrate into MG and assume a latent but reactivatable state has remained constrained. However, there is much excitement that human in vitro models for MG can now help close the gap. This review will provide a brief background to place the role of MG in the ongoing neurologic complications of HIV infection of the CNS, then focus on the use and refinement of human postmitotic monocyte-derived MG-like cells and how they are being applied to advance research on HIV persistence and proinflammatory signaling in the CNS. Critically, an understanding of myeloid plasticity and heterogeneity and rigorous attention to all aspects of cell handling is essential for reproducibility. Summary Sentence: This review focuses on human postmitotic monocyte-derived microglia-like cells as tools to advance research on HIV persistence and neuroinflammatory signaling.
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Affiliation(s)
- Thomas Boucher
- Department of NeurologyJohns Hopkins University School of MedicineBaltimoreMarylandUSA
| | - Shijun Liang
- Department of NeurologyJohns Hopkins University School of MedicineBaltimoreMarylandUSA
| | - Amanda M. Brown
- Department of NeurologyJohns Hopkins University School of MedicineBaltimoreMarylandUSA
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5
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Wang SF, Hung YH, Tsao CH, Chiang CY, Teoh PG, Chiang ML, Lin WH, Hsu DK, Jan HM, Lin HC, Lin CH, Liu FT, Chen HY. Galectin-3 facilitates cell-to-cell HIV-1 transmission by altering the composition of membrane lipid rafts in CD4 T cells. Glycobiology 2022; 32:760-777. [PMID: 35789267 DOI: 10.1093/glycob/cwac040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 05/28/2022] [Accepted: 06/13/2022] [Indexed: 11/13/2022] Open
Abstract
Galectin-3 (GAL3) is a β-galactoside-binding lectin expressed in CD4 T cells infected with human immunodeficiency virus-1 (HIV-1). GAL3 promotes HIV-1 budding by associating with ALIX and Gag p6. GAL3 has been shown to localize in membrane lipid rafts in dendritic cells and positively regulate cell migration. HIV-1 spreads between T cells by forming supramolecular structures (virological synapses [VSs]), whose integrity depends on lipid rafts. Here, we addressed the potential role of GAL3 in cell-to-cell transmission of HIV-1 in CD4 T cells. GAL3 expressed in donor cells was more important for facilitating HIV-1 cell-to-cell transfer than GAL3 expressed in target cells. GAL3 was found to be co-transferred with Gag from HIV-1-positive donor to HIV-1-negative target T cells. HIV-1 infection induced translocation of GAL3 together with Gag to the cell-cell interfaces and colocalize with GM1, where GAL3 facilitated VS formation. GAL3 regulated the coordinated transfer of Gag and flotillin-1 into plasma membrane fractions. Finally, depletion of GAL3 reduced the cholesterol levels in membrane lipid rafts in CD4 T cells. These findings provide evidence that endogenous GAL3 stimulates lipid raft components and facilitates intercellular HIV-1 transfer among CD4 T cells, offering another pathway by which GAL3 regulates HIV-1 infection. These findings may inform the treatment of HIV-1 infection based on targeting GAL3 to modulate lipid rafts.
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Affiliation(s)
- Sheng-Fan Wang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan.,Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yu-Hsien Hung
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Ching-Han Tsao
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan.,Ph.D. Program in Translational Medicine, Kaohsiung Medical University and Academia Sinica, Taiwan
| | - Cho-Ying Chiang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Pak-Guan Teoh
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Meng-Lin Chiang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Wei-Han Lin
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Daniel K Hsu
- Department of Dermatology, University of California Davis, California, USA
| | - Hau-Ming Jan
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Hsiu-Chu Lin
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Chun-Hung Lin
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Fu-Tong Liu
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan.,Department of Dermatology, University of California Davis, California, USA
| | - Huan-Yuan Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan.,Department of Dermatology, University of California Davis, California, USA
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6
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Chang K, Majmudar H, Tandon R, Volin MV, Tiwari V. Induction of Filopodia During Cytomegalovirus Entry Into Human Iris Stromal Cells. Front Microbiol 2022; 13:834927. [PMID: 35450284 PMCID: PMC9018114 DOI: 10.3389/fmicb.2022.834927] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 02/07/2022] [Indexed: 12/25/2022] Open
Abstract
Many viruses exploit thin projections of filopodia for cell entry and cell-to-cell spread. Using primary cultures of human iris stromal (HIS) cells derived from human eye donors, we report a significant increase in filopodia formation during human cytomegalovirus (HCMV) infection. Using confocal microscopy, we observed a large number of virions being frequently associated along the filopodia prior to cell infection. Depolymerization of actin filaments resulted in a significant inhibition of HCMV entry into HIS cell. Our results further revealed that the transient expression of HCMV envelope glycoprotein B (gB) triggers the induction of the filopodial system. Since gB is known to bind the diverse chains of heparan sulfate (HS), a comparative study was performed to evaluate the gB-mediated filopodial induction in cells expressing either wild-type HS and/or 3-O sulfated HS (3-OS HS). We found that cells co-expressing HCMV gB together with the 3-O sulfotranseferase-3 (3-OST-3) enzyme had a much higher and robust filopodia induction compared to cells co-expressing gB with wild-type HS. The above results were further verified by pre-treating HIS cells with anti-3-OS HS (G2) peptide and/or heparinase-I before challenging with HCMV infection, which resulted in a significant loss in the filopodial counts as well as decreased viral infectivity. Taken together, our findings highlight that HCMV entry into HIS cells actively modulates the actin cytoskeleton via coordinated actions possibly between gB and the 3-OS HS receptor to influence viral infectivity.
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Affiliation(s)
- Kenneth Chang
- Department of Microbiology and Immunology, College of Graduate Studies, Chicago College of Osteopathic Medicine, and Chicago College of Pharmacy, Midwestern University, Downers Grove, IL, United States
| | - Hardik Majmudar
- Department of Microbiology and Immunology, College of Graduate Studies, Chicago College of Osteopathic Medicine, and Chicago College of Pharmacy, Midwestern University, Downers Grove, IL, United States
| | - Ritesh Tandon
- Department of Microbiology and Immunology, University of Mississippi Medical Center, Jackson, MS, United States
| | - Michael V Volin
- Department of Microbiology and Immunology, College of Graduate Studies, Chicago College of Osteopathic Medicine, and Chicago College of Pharmacy, Midwestern University, Downers Grove, IL, United States
| | - Vaibhav Tiwari
- Department of Microbiology and Immunology, College of Graduate Studies, Chicago College of Osteopathic Medicine, and Chicago College of Pharmacy, Midwestern University, Downers Grove, IL, United States
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7
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Dynamics of HIV-1 Gag Processing as Revealed by Fluorescence Lifetime Imaging Microscopy and Single Virus Tracking. Viruses 2022; 14:v14020340. [PMID: 35215933 PMCID: PMC8874525 DOI: 10.3390/v14020340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 02/04/2022] [Accepted: 02/06/2022] [Indexed: 12/04/2022] Open
Abstract
The viral polyprotein Gag plays a central role for HIV-1 assembly, release and maturation. Proteolytic processing of Gag by the viral protease is essential for the structural rearrangements that mark the transition from immature to mature, infectious viruses. The timing and kinetics of Gag processing are not fully understood. Here, fluorescence lifetime imaging microscopy and single virus tracking are used to follow Gag processing in nascent HIV-1 particles in situ. Using a Gag polyprotein labelled internally with eCFP, we show that proteolytic release of the fluorophore from Gag is accompanied by an increase in its fluorescence lifetime. By tracking nascent virus particles in situ and analyzing the intensity and fluorescence lifetime of individual traces, we detect proteolytic cleavage of eCFP from Gag in a subset (6.5%) of viral particles. This suggests that for the majority of VLPs, Gag processing occurs with a delay after particle assembly.
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Fan M, Luo Y, Zhang B, Wang J, Chen T, Liu B, Sun Y, Nan Y, Hiscox JA, Zhao Q, Zhou EM. Cell Division Control Protein 42 Interacts With Hepatitis E Virus Capsid Protein and Participates in Hepatitis E Virus Infection. Front Microbiol 2021; 12:775083. [PMID: 34790187 PMCID: PMC8591454 DOI: 10.3389/fmicb.2021.775083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 10/13/2021] [Indexed: 11/30/2022] Open
Abstract
Hepatitis E Virus (HEV) causes viral hepatitis in humans worldwide, while a subset of HEV species, avian HEV, causes hepatitis-splenomegaly syndrome in chickens. To date, there are few reports on the host proteins interacting with HEV and being involved in viral infection. Previous pull-down assay combining mass spectrometry indicated that cell division control protein 42 (CDC42), a member belonging to the Rho GTPase family, was pulled down by avian HEV capsid protein. We confirmed the direct interaction between CDC42 and avian and mammalian HEV capsid proteins. The interaction can increase the amount of active guanosine triphosphate binding CDC42 state (GTP-CDC42). Subsequently, we determined that the expression and activity of CDC42 were positively correlated with HEV infection in the host cells. Using the different inhibitors of CDC42 downstream signaling pathways, we found that CDC42-MRCK (a CDC42-binding kinase)-non-myosin IIA (NMIIA) pathway is involved in naked avian and mammalian HEV infection, CDC42-associated p21-activated kinase 1 (PAK1)-NMIIA/Cofilin pathway is involved in quasi-enveloped mammalian HEV infection and CDC42-neural Wiskott-Aldrich syndrome protein-actin-polymerizing protein Arp2/3 pathway (CDC42-(N-)WASP-Arp2/3) pathway participates in naked and quasi-enveloped mammalian HEV infection. Collectively, these results demonstrated for the first time that HEV capsid protein can directly bind to CDC42, and non- and quasi-enveloped HEV use different CDC42 downstream signaling pathways to participate in viral infection. The study provided some new insights to understand the life cycle of HEV in host cells and a new target of drug design for combating HEV infection.
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Affiliation(s)
- Mengnan Fan
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Xianyang, China
| | - Yuhang Luo
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Xianyang, China
| | - Beibei Zhang
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Xianyang, China
| | - Jiaxi Wang
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Xianyang, China
| | - Tianxiang Chen
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Xianyang, China
| | - Baoyuan Liu
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Xianyang, China
| | - Yani Sun
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Xianyang, China
| | - Yuchen Nan
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Xianyang, China
| | - Julian A Hiscox
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Qin Zhao
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Xianyang, China
| | - En-Min Zhou
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Xianyang, China
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Pagliari L, Tarquini G, Loschi A, Buoso S, Kapun G, Ermacora P, Musetti R. Gimme shelter: three-dimensional architecture of the endoplasmic reticulum, the replication site of grapevine Pinot gris virus. FUNCTIONAL PLANT BIOLOGY : FPB 2021; 48:1074-1085. [PMID: 34462050 DOI: 10.1071/fp21084] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 07/05/2021] [Indexed: 06/13/2023]
Abstract
Grapevine leaf mottling and deformation is a novel grapevine disease that has been associated with grapevine Pinot gris virus (GPGV). The virus was observed exclusively inside membrane-bound structures in the bundle sheath cells of the infected grapevines. As reported widely in the literature, many positive-sense single-stranded RNA viruses modify host-cell membranes to form a variety of deformed organelles, which shelter viral genome replication from host antiviral compounds. Morphologically, the GPGV-associated membranous structures resemble the deformed endoplasmic reticulum described in other virus-host interactions. In this study we investigated the GPGV-induced membranous structures observed in the bundle sheath cells of infected plants. The upregulation of different ER stress-related genes was evidenced by RT-qPCR assays, further confirming the involvement of the ER in grapevine/GPGV interaction. Specific labelling of the membranous structures with an antibody against luminal-binding protein identified them as ER. Double-stranded RNA molecules, which are considered intermediates of viral replication, were localised exclusively in the ER-derived structures and indicated that GPGV exploited this organelle to replicate itself in a shelter niche. Novel analyses using focussed ion-beam scanning electron microscopy (FIB-SEM) were performed in grapevine leaf tissues to detail the three-dimensional organisation of the ER-derived structures and their remodelling due to virus replication.
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Affiliation(s)
- Laura Pagliari
- Department of Agriculture, Food, Environmental and Animal Sciences, University of Udine,via delle Scienze, 206, 33100 - Udine, Italy
| | - Giulia Tarquini
- Department of Agriculture, Food, Environmental and Animal Sciences, University of Udine,via delle Scienze, 206, 33100 - Udine, Italy
| | - Alberto Loschi
- Department of Agriculture, Food, Environmental and Animal Sciences, University of Udine,via delle Scienze, 206, 33100 - Udine, Italy
| | - Sara Buoso
- Department of Agriculture, Food, Environmental and Animal Sciences, University of Udine,via delle Scienze, 206, 33100 - Udine, Italy
| | - Gregor Kapun
- National Institute of Chemistry, Hajdrihova 19, SI-1001, Ljubljana, Slovenia; and Centre of Excellence on Nanoscience and Nanotechnology - Nanocenter, Jamova 39, SI1000 Ljubljana, Slovenia
| | - Paolo Ermacora
- Department of Agriculture, Food, Environmental and Animal Sciences, University of Udine,via delle Scienze, 206, 33100 - Udine, Italy
| | - Rita Musetti
- Department of Agriculture, Food, Environmental and Animal Sciences, University of Udine,via delle Scienze, 206, 33100 - Udine, Italy; and Corresponding author.
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10
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Sil S, Periyasamy P, Thangaraj A, Niu F, Chemparathy DT, Buch S. Advances in the Experimental Models of HIV-Associated Neurological Disorders. Curr HIV/AIDS Rep 2021; 18:459-474. [PMID: 34427869 DOI: 10.1007/s11904-021-00570-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/09/2021] [Indexed: 12/13/2022]
Abstract
PURPOSE OF REVIEW Involvement of the central nervous system (CNS) in HIV-1 infection is commonly associated with neurological disorders and cognitive impairment, commonly referred to as HIV-associated neurocognitive disorders (HAND). Severe and progressive neurocognitive impairment is rarely observed in the post-cART era; however, asymptomatic and mild neurocognitive disorders still exist, despite viral suppression. Additionally, comorbid conditions can also contribute to the pathogenesis of HAND. RECENT FINDINGS In this review, we summarize the characterization of HAND, factors contributing, and the functional impairments in both preclinical and clinical models. Specifically, we also discuss recent advances in the animal models of HAND and in in vitro cultures and the potential role of drugs of abuse in this model system of HAND. Potential peripheral biomarkers associated with HAND are also discussed. Overall, this review identifies some of the recent advances in the field of HAND in cell culture studies, animal models, clinical findings, and the limitations of each model system, which can play a key role in developing novel therapeutics in the field.
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Affiliation(s)
- Susmita Sil
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198-5880, USA.
| | - Palsamy Periyasamy
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198-5880, USA.
| | - Annadurai Thangaraj
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198-5880, USA
| | - Fang Niu
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198-5880, USA
| | - Divya T Chemparathy
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198-5880, USA
| | - Shilpa Buch
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198-5880, USA
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11
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Baena V, Conrad R, Friday P, Fitzgerald E, Kim T, Bernbaum J, Berensmann H, Harned A, Nagashima K, Narayan K. FIB-SEM as a Volume Electron Microscopy Approach to Study Cellular Architectures in SARS-CoV-2 and Other Viral Infections: A Practical Primer for a Virologist. Viruses 2021; 13:v13040611. [PMID: 33918371 PMCID: PMC8066521 DOI: 10.3390/v13040611] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 03/18/2021] [Accepted: 03/19/2021] [Indexed: 01/06/2023] Open
Abstract
The visualization of cellular ultrastructure over a wide range of volumes is becoming possible by increasingly powerful techniques grouped under the rubric “volume electron microscopy” or volume EM (vEM). Focused ion beam scanning electron microscopy (FIB-SEM) occupies a “Goldilocks zone” in vEM: iterative and automated cycles of milling and imaging allow the interrogation of microns-thick specimens in 3-D at resolutions of tens of nanometers or less. This bestows on FIB-SEM the unique ability to aid the accurate and precise study of architectures of virus-cell interactions. Here we give the virologist or cell biologist a primer on FIB-SEM imaging in the context of vEM and discuss practical aspects of a room temperature FIB-SEM experiment. In an in vitro study of SARS-CoV-2 infection, we show that accurate quantitation of viral densities and surface curvatures enabled by FIB-SEM imaging reveals SARS-CoV-2 viruses preferentially located at areas of plasma membrane that have positive mean curvatures.
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Affiliation(s)
- Valentina Baena
- Center for Molecular Microscopy, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; (V.B.); (R.C.); (P.F.); (E.F.); (T.K.); (H.B.); (A.H.); (K.N.)
- Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21701, USA
| | - Ryan Conrad
- Center for Molecular Microscopy, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; (V.B.); (R.C.); (P.F.); (E.F.); (T.K.); (H.B.); (A.H.); (K.N.)
- Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21701, USA
| | - Patrick Friday
- Center for Molecular Microscopy, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; (V.B.); (R.C.); (P.F.); (E.F.); (T.K.); (H.B.); (A.H.); (K.N.)
- Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21701, USA
| | - Ella Fitzgerald
- Center for Molecular Microscopy, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; (V.B.); (R.C.); (P.F.); (E.F.); (T.K.); (H.B.); (A.H.); (K.N.)
- Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21701, USA
| | - Taeeun Kim
- Center for Molecular Microscopy, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; (V.B.); (R.C.); (P.F.); (E.F.); (T.K.); (H.B.); (A.H.); (K.N.)
- Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21701, USA
| | - John Bernbaum
- National Institute of Allergy and Infectious Diseases, Division of Clinical Research, Integrated Research Facility at Fort Detrick (IRF-Frederick), Frederick, MD 21702, USA;
| | - Heather Berensmann
- Center for Molecular Microscopy, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; (V.B.); (R.C.); (P.F.); (E.F.); (T.K.); (H.B.); (A.H.); (K.N.)
- Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21701, USA
| | - Adam Harned
- Center for Molecular Microscopy, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; (V.B.); (R.C.); (P.F.); (E.F.); (T.K.); (H.B.); (A.H.); (K.N.)
- Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21701, USA
| | - Kunio Nagashima
- Center for Molecular Microscopy, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; (V.B.); (R.C.); (P.F.); (E.F.); (T.K.); (H.B.); (A.H.); (K.N.)
- Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21701, USA
| | - Kedar Narayan
- Center for Molecular Microscopy, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; (V.B.); (R.C.); (P.F.); (E.F.); (T.K.); (H.B.); (A.H.); (K.N.)
- Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21701, USA
- Correspondence:
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Sánchez Pina MA, Gómez-Aix C, Méndez-López E, Gosalvez Bernal B, Aranda MA. Imaging Techniques to Study Plant Virus Replication and Vertical Transmission. Viruses 2021; 13:358. [PMID: 33668729 PMCID: PMC7996213 DOI: 10.3390/v13030358] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 02/17/2021] [Accepted: 02/18/2021] [Indexed: 12/19/2022] Open
Abstract
Plant viruses are obligate parasites that need to usurp plant cell metabolism in order to infect their hosts. Imaging techniques have been used for quite a long time to study plant virus-host interactions, making it possible to have major advances in the knowledge of plant virus infection cycles. The imaging techniques used to study plant-virus interactions have included light microscopy, confocal laser scanning microscopy, and scanning and transmission electron microscopies. Here, we review the use of these techniques in plant virology, illustrating recent advances in the area with examples from plant virus replication and virus plant-to-plant vertical transmission processes.
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Affiliation(s)
- María Amelia Sánchez Pina
- Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC), Departamento de Biología del Estrés y Patología Vegetal, Grupo de Patología Vegetal, 30100 Murcia, Spain; (E.M.-L.); (B.G.B.)
| | - Cristina Gómez-Aix
- Abiopep S.L., R&D Department, Parque Científico de Murcia, Ctra. de Madrid, Km 388, Complejo de Espinardo, Edf. R, 2º, 30100 Murcia, Spain;
| | - Eduardo Méndez-López
- Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC), Departamento de Biología del Estrés y Patología Vegetal, Grupo de Patología Vegetal, 30100 Murcia, Spain; (E.M.-L.); (B.G.B.)
| | - Blanca Gosalvez Bernal
- Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC), Departamento de Biología del Estrés y Patología Vegetal, Grupo de Patología Vegetal, 30100 Murcia, Spain; (E.M.-L.); (B.G.B.)
| | - Miguel A. Aranda
- Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC), Departamento de Biología del Estrés y Patología Vegetal, Grupo de Patología Vegetal, 30100 Murcia, Spain; (E.M.-L.); (B.G.B.)
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Multiscale Electron Microscopy for the Study of Viral Replication Organelles. Viruses 2021; 13:v13020197. [PMID: 33525547 PMCID: PMC7912242 DOI: 10.3390/v13020197] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 01/22/2021] [Accepted: 01/25/2021] [Indexed: 11/17/2022] Open
Abstract
During infection with positive-strand RNA viruses, viral RNA synthesis associates with modified intracellular membranes that form unique and captivating structures in the cytoplasm of the infected cell. These viral replication organelles (ROs) play a key role in the replicative cycle of important human pathogens like coronaviruses, enteroviruses, or flaviviruses. From their discovery to date, progress in our understanding of viral ROs has closely followed new developments in electron microscopy (EM). This review gives a chronological account of this progress and an introduction to the different EM techniques that enabled it. With an ample repertoire of imaging modalities, EM is nowadays a versatile technique that provides structural and functional information at a wide range of scales. Together with well-established approaches like electron tomography or labeling methods, we examine more recent developments, such as volume scanning electron microscopy (SEM) and in situ cryotomography, which are only beginning to be applied to the study of viral ROs. We also highlight the first cryotomography analyses of viral ROs, which have led to the discovery of macromolecular complexes that may serve as RO channels that control the export of newly-made viral RNA. These studies are key first steps towards elucidating the macromolecular complexity of viral ROs.
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Abstract
The innate immune system is comprised of both cellular and humoral players that recognise and eradicate invading pathogens. Therefore, the interplay between retroviruses and innate immunity has emerged as an important component of viral pathogenesis. HIV-1 infection in humans that results in hematologic abnormalities and immune suppression is well represented by changes in the CD4/CD8 T cell ratio and consequent cell death causing CD4 lymphopenia. The innate immune responses by mucosal barriers such as complement, DCs, macrophages, and NK cells as well as cytokine/chemokine profiles attain great importance in acute HIV-1 infection, and thus, prevent mucosal capture and transmission of HIV-1. Conversely, HIV-1 has evolved to overcome innate immune responses through RNA-mediated rapid mutations, pathogen-associated molecular patterns (PAMPs) modification, down-regulation of NK cell activity and complement receptors, resulting in increased secretion of inflammatory factors. Consequently, epithelial tissues lining up female reproductive tract express innate immune sensors including anti-microbial peptides responsible for forming primary barriers and have displayed an effective potent anti-HIV activity during phase I/II clinical trials.
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Tice C, McDevitt J, Langford D. Astrocytes, HIV and the Glymphatic System: A Disease of Disrupted Waste Management? Front Cell Infect Microbiol 2020; 10:523379. [PMID: 33134185 PMCID: PMC7550659 DOI: 10.3389/fcimb.2020.523379] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Accepted: 08/19/2020] [Indexed: 12/17/2022] Open
Abstract
The discovery of the glial-lymphatic or glymphatic fluid clearance pathway in the rodent brain led researchers to search for a parallel system in humans and to question the implications of this pathway in neurodegenerative diseases. Magnetic resonance imaging studies revealed that several features of the glymphatic system may be present in humans. In both rodents and humans, this pathway promotes the exchange of interstitial fluid (ISF) and cerebrospinal fluid (CSF) through the arterial perivascular spaces into the brain parenchyma. This process is facilitated in part by aquaporin-4 (AQP4) water channels located primarily on astrocytic end feet that abut cerebral endothelial cells of the blood brain barrier. Decreased expression or mislocalization of AQP4 from astrocytic end feet results in decreased interstitial flow, thereby, promoting accumulation of extracellular waste products like hyperphosphorylated Tau (pTau). Accumulation of pTau is a neuropathological hallmark in Alzheimer's disease (AD) and is accompanied by mislocalization of APQ4 from astrocyte end feet to the cell body. HIV infection shares many neuropathological characteristics with AD. Similar to AD, HIV infection of the CNS contributes to abnormal aging with altered AQP4 localization, accumulation of pTau and chronic neuroinflammation. Up to 30% of people with HIV (PWH) suffer from HIV-associated neurocognitive disorders (HAND), and changes in AQP4 may be clinically important as a contributor to cognitive disturbances. In this review, we provide an overview and discussion of the potential contributions of NeuroHIV to glymphatic system functions by focusing on astrocytes and AQP4. Although HAND encompasses a wide range of neurocognitive impairments and levels of neuroinflammation vary among and within PWH, the potential contribution of disruption in AQP4 may be clinically important in some cases. In this review we discuss implications for possible AQP4 disruption on NeuroHIV disease trajectory and how HIV may influence AQP4 function.
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Affiliation(s)
- Caitlin Tice
- Department of Neuroscience, Lewis Katz School of Medicine, Philadelphia, PA, United States
| | - Jane McDevitt
- Department of Kinesiology, College of Public Health at Temple University, Philadelphia, PA, United States
| | - Dianne Langford
- Department of Neuroscience, Lewis Katz School of Medicine, Philadelphia, PA, United States
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16
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Abstract
A critical step in the life cycle of a virus is spread to a new target cell, which generally involves the release of new viral particles from the infected cell which can then initiate infection in the next target cell. While cell-free viral particles released into the extracellular environment are necessary for long distance spread, there are disadvantages to this mechanism. These include the presence of immune system components, the low success rate of infection by single particles, and the relative fragility of viral particles in the environment. Several mechanisms of direct cell-to-cell spread have been reported for animal viruses which would avoid the issues associated with cell-free particles. A number of viruses can utilize several different mechanisms of direct cell-to-cell spread, but our understanding of the differential usage by these pathogens is modest. Although the mechanisms of cell-to-cell spread differ among viruses, there is a common exploitation of key pathways and components of the cellular cytoskeleton. Remarkably, some of the viral mechanisms of cell-to-cell spread are surprisingly similar to those used by bacteria. Here we summarize the current knowledge of the conventional and non-conventional mechanisms of viral spread, the common methods used to detect viral spread, and the impact that these mechanisms can have on viral pathogenesis.
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Affiliation(s)
- Nicolas Cifuentes-Munoz
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, San Miguel, Santiago, Chile
| | - Farah El Najjar
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Rebecca Ellis Dutch
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, KY, United States.
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17
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Opioid and neuroHIV Comorbidity - Current and Future Perspectives. J Neuroimmune Pharmacol 2020; 15:584-627. [PMID: 32876803 PMCID: PMC7463108 DOI: 10.1007/s11481-020-09941-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 07/02/2020] [Indexed: 12/14/2022]
Abstract
With the current national opioid crisis, it is critical to examine the mechanisms underlying pathophysiologic interactions between human immunodeficiency virus (HIV) and opioids in the central nervous system (CNS). Recent advances in experimental models, methodology, and our understanding of disease processes at the molecular and cellular levels reveal opioid-HIV interactions with increasing clarity. However, despite the substantial new insight, the unique impact of opioids on the severity, progression, and prognosis of neuroHIV and HIV-associated neurocognitive disorders (HAND) are not fully understood. In this review, we explore, in detail, what is currently known about mechanisms underlying opioid interactions with HIV, with emphasis on individual HIV-1-expressed gene products at the molecular, cellular and systems levels. Furthermore, we review preclinical and clinical studies with a focus on key considerations when addressing questions of whether opioid-HIV interactive pathogenesis results in unique structural or functional deficits not seen with either disease alone. These considerations include, understanding the combined consequences of HIV-1 genetic variants, host variants, and μ-opioid receptor (MOR) and HIV chemokine co-receptor interactions on the comorbidity. Lastly, we present topics that need to be considered in the future to better understand the unique contributions of opioids to the pathophysiology of neuroHIV. Blood-brain barrier and the neurovascular unit. With HIV and opiate co-exposure (represented below the dotted line), there is breakdown of tight junction proteins and increased leakage of paracellular compounds into the brain. Despite this, opiate exposure selectively increases the expression of some efflux transporters, thereby restricting brain penetration of specific drugs. ![]()
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18
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Dorador J, Rodríguez-Tovar FJ. CroSSED sequence, a new tool for 3D processing in geosciences using the free software 3DSlicer. Sci Data 2020; 7:270. [PMID: 32796857 PMCID: PMC7429493 DOI: 10.1038/s41597-020-00614-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 07/30/2020] [Indexed: 12/28/2022] Open
Abstract
The scientific application of 3D imaging has evolved significantly over recent years. These techniques make it possible to study internal features by non-destructive analysis. Despite its potential, the development of 3D imaging in the Geosciences is behind other fields due to the high cost of commercial software and the scarce free alternatives. Most free software was designed for the Health Sciences, and the pre-settled workflows are not suited to geoscientific materials. Thus, an outstanding challenge in the Geosciences is to define workflows using free alternatives for Computed Tomography (CT) data processing, promoting data sharing, reproducibility, and the development of specific extensions. We present CroSSED, a processing sequence for 3D reconstructions of CT data, using 3DSlicer, a popular application in medical imaging. Its usefulness is exemplified in the study of burrows that have low-density contrast with respect to the host sediment. For geoscientists who have access to CT data and wish to reconstruct 3D structures, this method offers a wide range of possibilities and contributes to open-science and applied CT studies.
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Affiliation(s)
- Javier Dorador
- Department of Earth Sciences, Royal Holloway University of London, Egham, UK.
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19
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Abstract
PURPOSE OF REVIEW Perinatal HIV-1 infection is associated with an increased risk for neurologic impairments. With limited access to clinical specimens, animal models could advance our understanding of pediatric central nervous system (CNS) disease and viral persistence. Here, we summarize current findings on HIV-1 CNS infection from nonhuman primate (NHP) models and discuss their implications for improving pediatric clinical outcomes. RECENT FINDINGS SIV/SHIV can be found in the CNS of infant macaques within 48 h of challenge. Recent studies show an impermeable BBB during SIV infection, suggesting neuroinvasion in post-partum infection is likely not wholly attributed to barrier dysfunction. Histopathological findings reveal dramatic reductions in hippocampal neuronal populations and myelination in infected infant macaques, providing a link for cognitive impairments seen in pediatric cases. Evidence from humans and NHPs support the CNS as a functional latent reservoir, harbored in myeloid cells that may require unique eradication strategies. Studies in NHP models are uncovering early events, causes, and therapeutic targets of CNS disease as well as highlighting the importance of age-specific studies that capture the distinct features of pediatric HIV-1 infection.
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Affiliation(s)
| | - Katherine Bricker
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Ann Chahroudi
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA.
- Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA.
- Emory+Children's Center for Childhood Infections and Vaccines, Atlanta, GA, USA.
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Ladinsky MS, Gnanapragasam PN, Yang Z, West AP, Kay MS, Bjorkman PJ. Electron tomography visualization of HIV-1 fusion with target cells using fusion inhibitors to trap the pre-hairpin intermediate. eLife 2020; 9:58411. [PMID: 32697193 PMCID: PMC7394545 DOI: 10.7554/elife.58411] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 07/21/2020] [Indexed: 12/17/2022] Open
Abstract
Fusion of HIV-1 with the membrane of its target cell, an obligate first step in virus infectivity, is mediated by binding of the viral envelope (Env) spike protein to its receptors, CD4 and CCR5/CXCR4, on the cell surface. The process of viral fusion appears to be fast compared with viral egress and has not been visualized by EM. To capture fusion events, the process must be curtailed by trapping Env-receptor binding at an intermediate stage. We have used fusion inhibitors to trap HIV-1 virions attached to target cells by Envs in an extended pre-hairpin intermediate state. Electron tomography revealed HIV-1 virions bound to TZM-bl cells by 2–4 narrow spokes, with slightly more spokes present when evaluated with mutant virions that lacked the Env cytoplasmic tail. These results represent the first direct visualization of the hypothesized pre-hairpin intermediate of HIV-1 Env and improve our understanding of Env-mediated HIV-1 fusion and infection of host cells.
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Affiliation(s)
- Mark S Ladinsky
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | - Priyanthi Np Gnanapragasam
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | - Zhi Yang
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | - Anthony P West
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | - Michael S Kay
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, United States
| | - Pamela J Bjorkman
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
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21
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Faria Waziry PA, Raja A, Salmon C, Aldana N, Damodar S, Fukushima AR, Mayi BS. Impact of pyriproxyfen on virus behavior: implications for pesticide-induced virulence and mechanism of transmission. Virol J 2020; 17:93. [PMID: 32631404 PMCID: PMC7339562 DOI: 10.1186/s12985-020-01378-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 06/30/2020] [Indexed: 02/06/2023] Open
Abstract
Background More than 3 years since the last Zika virus (ZIKV) outbreak in Brazil, researchers are still deciphering the molecular mechanisms of neurovirulence and vertical transmission, as well as the best way to control spread of ZIKV, a flavivirus. The use of pesticides was the main strategy of mosquito control during the last ZIKV outbreak. Methods We used vesicular stomatitis virus (VSV) tagged with green fluorescent protein (GFP) as our prototypical virus to study the impact of insecticide pyriproxyfen (PPF). VZV-GFP infected and uninfected Jurkat, HeLa and trophoblast cells were treated with PPF and compared to untreated cells (control). Cell viability was determined by the MTT assay. Cell morphology, presence of extracellular vesicles (EVs), virus infection/GFP expression as well as active mitochondrial levels/localization were examined by confocal microscopy. Results PPF, which was used to control mosquito populations in Brazil prior to the ZIKV outbreak, enhances VSV replication and has cell membrane-altering properties in the presence of virus. PPF causes enhanced viral replication and formation of large EVs, loaded with virus as well as mitochondria. Treatment of trophoblasts or HeLa cells with increasing concentrations of PPF does not alter cell viability, however, it proportionately increases Jurkat cell viability. Increasing concentrations of PPF followed by VSV infection does not interfere with HeLa cell viability. Both Jurkats and trophoblasts show proportionately increased cell death with increased concentrations of PPF in the presence of virus. Conclusions We hypothesize that PPF disrupts the lipid microenvironment of mammalian cells, thereby interfering with pathways of viral replication. PPF lowers viability of trophoblasts and Jurkats in the presence of VSV, implying that the combination renders immune system impairment in infected individuals as well as enhanced vulnerability of fetuses towards viral vertical transmission. We hypothesize that similar viruses such as ZIKV may be vertically transmitted via EV-to-cell contact when exposed to PPF, thereby bypassing immune detection. The impact of pesticides on viral replication must be fully investigated before large scale use in future outbreaks of mosquito borne viruses.
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Affiliation(s)
- Paula A Faria Waziry
- Dr. Kiran C. Patel College of Osteopathic Medicine, Nova Southeastern University, 3400 Gulf to Bay Blvd, Clearwater, FL, 33759, USA
| | - Aarti Raja
- Department of Biological Sciences, Halmos College of Arts and Sciences, Nova Southeastern University, Fort Lauderdale, FL, 33314, USA
| | - Chloe Salmon
- Plymouth University, 3 Endsleigh Place, Drake Circus, Plymouth, England, PL4 8AA
| | - Nathalia Aldana
- Dr. Kiran C. Patel College of Osteopathic Medicine, Nova Southeastern University, 3200 S. University Dr, Fort Lauderdale, FL, 33328, USA
| | - Sruthi Damodar
- Dr. Kiran C. Patel College of Osteopathic Medicine, Nova Southeastern University, 3200 S. University Dr, Fort Lauderdale, FL, 33328, USA
| | - Andre Rinaldi Fukushima
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of Sao Paulo, São Paulo, Brazil
| | - Bindu S Mayi
- Dr. Kiran C. Patel College of Osteopathic Medicine, Nova Southeastern University, 3400 Gulf to Bay Blvd, Clearwater, FL, 33759, USA.
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Lutgen V, Narasipura SD, Barbian HJ, Richards M, Wallace J, Razmpour R, Buzhdygan T, Ramirez SH, Prevedel L, Eugenin EA, Al-Harthi L. HIV infects astrocytes in vivo and egresses from the brain to the periphery. PLoS Pathog 2020; 16:e1008381. [PMID: 32525948 PMCID: PMC7289344 DOI: 10.1371/journal.ppat.1008381] [Citation(s) in RCA: 91] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 02/04/2020] [Indexed: 12/25/2022] Open
Abstract
HIV invades the brain during acute infection. Yet, it is unknown whether long-lived infected brain cells release productive virus that can egress from the brain to re-seed peripheral organs. This understanding has significant implication for the brain as a reservoir for HIV and most importantly HIV interplay between the brain and peripheral organs. Given the sheer number of astrocytes in the human brain and their controversial role in HIV infection, we evaluated their infection in vivo and whether HIV infected astrocytes can support HIV egress to peripheral organs. We developed two novel models of chimeric human astrocyte/human peripheral blood mononuclear cells: NOD/scid-IL-2Rgc null (NSG) mice (huAstro/HuPBMCs) whereby we transplanted HIV (non-pseudotyped or VSVg-pseudotyped) infected or uninfected primary human fetal astrocytes (NHAs) or an astrocytoma cell line (U138MG) into the brain of neonate or adult NSG mice and reconstituted the animals with human peripheral blood mononuclear cells (PBMCs). We also transplanted uninfected astrocytes into the brain of NSG mice and reconstituted with infected PBMCs to mimic a biological infection course. As expected, the xenotransplanted astrocytes did not escape/migrate out of the brain and the blood brain barrier (BBB) was intact in this model. We demonstrate that astrocytes support HIV infection in vivo and egress to peripheral organs, at least in part, through trafficking of infected CD4+ T cells out of the brain. Astrocyte-derived HIV egress persists, albeit at low levels, under combination antiretroviral therapy (cART). Egressed HIV evolved with a pattern and rate typical of acute peripheral infection. Lastly, analysis of human cortical or hippocampal brain regions of donors under cART revealed that astrocytes harbor between 0.4–5.2% integrated HIV gag DNA and 2–7% are HIV gag mRNA positive. These studies establish a paradigm shift in the dynamic interaction between the brain and peripheral organs which can inform eradication of HIV reservoirs. HIV latency and residual low-level HIV replication is a major obstacle towards an HIV cure. HIV infects the brain in acute disease yet it is unknown whether long lived-infected brain cells release productive virus that can egress from the brain to re-seed peripheral organs and whether astrocytes are productively infected in vivo. We demonstrate astrocyte-initiated HIV spread from the brain to the spleen and lymph nodes, likely through T cell trafficking out of CNS and into peripheral organs. Additionally, brain sections from patients on cART show HIV integration in astrocytes. Collectively, given that astrocytes constitute ~60% of brain cells and even with a conservative rate of infection at >3%, astrocytes can be a significant reservoir for HIV. As such, cure initiatives must consider the contribution of the CNS to ongoing HIV replication within and outside of the brain.
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Affiliation(s)
- Victoria Lutgen
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, Illinois, United States of America
| | - Srinivas D. Narasipura
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, Illinois, United States of America
| | - Hannah J. Barbian
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, Illinois, United States of America
| | - Maureen Richards
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, Illinois, United States of America
| | - Jennillee Wallace
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, Illinois, United States of America
| | - Roshanak Razmpour
- Department of Pathology and Laboratory Medicine, The Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, United States of America
| | - Tetyana Buzhdygan
- Department of Pathology and Laboratory Medicine, The Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, United States of America
| | - Servio H. Ramirez
- Department of Pathology and Laboratory Medicine, The Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, United States of America
| | - Lisa Prevedel
- Department of Neuroscience, Cell Biology and Anatomy, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Eliseo A. Eugenin
- Department of Neuroscience, Cell Biology and Anatomy, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Lena Al-Harthi
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, Illinois, United States of America
- * E-mail:
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Llorente García I, Marsh M. A biophysical perspective on receptor-mediated virus entry with a focus on HIV. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2020; 1862:183158. [PMID: 31863725 PMCID: PMC7156917 DOI: 10.1016/j.bbamem.2019.183158] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 12/12/2019] [Accepted: 12/13/2019] [Indexed: 12/14/2022]
Abstract
As part of their entry and infection strategy, viruses interact with specific receptor molecules expressed on the surface of target cells. The efficiency and kinetics of the virus-receptor interactions required for a virus to productively infect a cell is determined by the biophysical properties of the receptors, which are in turn influenced by the receptors' plasma membrane (PM) environments. Currently, little is known about the biophysical properties of these receptor molecules or their engagement during virus binding and entry. Here we review virus-receptor interactions focusing on the human immunodeficiency virus type 1 (HIV), the etiological agent of acquired immunodeficiency syndrome (AIDS), as a model system. HIV is one of the best characterised enveloped viruses, with the identity, roles and structure of the key molecules required for infection well established. We review current knowledge of receptor-mediated HIV entry, addressing the properties of the HIV cell-surface receptors, the techniques used to measure these properties, and the macromolecular interactions and events required for virus entry. We discuss some of the key biophysical principles underlying receptor-mediated virus entry and attempt to interpret the available data in the context of biophysical mechanisms. We also highlight crucial outstanding questions and consider how new tools might be applied to advance understanding of the biophysical properties of viral receptors and the dynamic events leading to virus entry.
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Affiliation(s)
| | - Mark Marsh
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK
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Li GH, Maric D, Major EO, Nath A. Productive HIV infection in astrocytes can be established via a nonclassical mechanism. AIDS 2020; 34:963-978. [PMID: 32379159 PMCID: PMC7429268 DOI: 10.1097/qad.0000000000002512] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Astrocytes are proposed to be a critical reservoir of HIV in the brain. However, HIV infection of astrocytes is inefficient in vitro except for cell-to-cell transmission from HIV-infected cells. Here, we explore mechanisms by which cell-free HIV bypasses entry and postentry barriers leading to a productive infection. METHODS HIV infection of astrocytes was investigated by a variety of techniques including transfection of CD4-expressing plasmid, treatment with lysosomotropic agents or using a transwell culture system loaded with HIV-infected lymphocytes. Infection was monitored by HIV-1 p24 in culture supernatants and integrated proviral DNA was quantified by Alu-PCR. RESULTS Persistent HIV infection could be established in astrocytes by transfection of proviral DNA, transduction with VSV-G-pseudotyped viruses, transient expression of CD4 followed by HIV infection, or simultaneous treatment with lysosomotropic chloroquine or Tat-HA2 peptide with HIV infection. In absence of these treatments, HIV entered via endocytosis as seen by electronmicroscopy and underwent lysosomal degradation without proviral integration, indicating endocytosis is a dead end for HIV in astrocytes. Nevertheless, productive infection was observed when astrocytes were in close proximity but physically separated from HIV-infected lymphocytes in the transwell cultures. This occurred with X4 or dual tropic R5X4 viruses and was blocked by an antibody or antagonist to CXCR4. CONCLUSION A CD4-independent, CXCR4-dependent mechanism of viral entry is proposed, by which immature HIV particles from infected lymphocytes might directly bind to CXCR4 on astrocytes and trigger virus--cell fusion during or after the process of viral maturation. This mechanism may contribute to the formation of brain HIV reservoirs.
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Affiliation(s)
- Guan-Han Li
- Section of Infections of the Nervous System, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
| | - Dragan Maric
- Flow and Imaging Cytometry Core Facility, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
| | - Eugene O. Major
- Laboratory of Molecular Medicine and Neuroscience, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
| | - Avindra Nath
- Section of Infections of the Nervous System, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
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Host membrane lipids are trafficked to membranes of intravacuolar bacterium Ehrlichia chaffeensis. Proc Natl Acad Sci U S A 2020; 117:8032-8043. [PMID: 32193339 PMCID: PMC7149431 DOI: 10.1073/pnas.1921619117] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Ehrlichia chaffeensis, a cholesterol-rich and cholesterol-dependent obligate intracellular bacterium, partially lacks genes for glycerophospholipid biosynthesis. We found here that E. chaffeensis is dependent on host glycerolipid biosynthesis, as an inhibitor of host long-chain acyl CoA synthetases, key enzymes for glycerolipid biosynthesis, significantly reduced bacterial proliferation. E. chaffeensis cannot synthesize phosphatidylcholine or cholesterol but encodes enzymes for phosphatidylethanolamine (PE) biosynthesis; however, exogenous NBD-phosphatidylcholine, Bodipy-PE, and TopFluor-cholesterol were rapidly trafficked to ehrlichiae in infected cells. DiI (3,3'-dioctadecylindocarbocyanine)-prelabeled host-cell membranes were unidirectionally trafficked to Ehrlichia inclusion and bacterial membranes, but DiI-prelabeled Ehrlichia membranes were not trafficked to host-cell membranes. The trafficking of host-cell membranes to Ehrlichia inclusions was dependent on both host endocytic and autophagic pathways, and bacterial protein synthesis, as the respective inhibitors blocked both infection and trafficking of DiI-labeled host membranes to Ehrlichia In addition, DiI-labeled host-cell membranes were trafficked to autophagosomes induced by the E. chaffeensis type IV secretion system effector Etf-1, which traffic to and fuse with Ehrlichia inclusions. Cryosections of infected cells revealed numerous membranous vesicles inside inclusions, as well as multivesicular bodies docked on the inclusion surface, both of which were immunogold-labeled by a GFP-tagged 2×FYVE protein that binds to phosphatidylinositol 3-phosphate. Focused ion-beam scanning electron microscopy of infected cells validated numerous membranous structures inside bacteria-containing inclusions. Our results support the notion that Ehrlichia inclusions are amphisomes formed through fusion of early endosomes, multivesicular bodies, and early autophagosomes induced by Etf-1, and they provide host-cell glycerophospholipids and cholesterol that are necessary for bacterial proliferation.
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26
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Lê-Bury G, Deschamps C, Kizilyaprak C, Blanchard W, Daraspe J, Dumas A, Gordon MA, Hinton JCD, Humbel BM, Niedergang F. Increased intracellular survival of Salmonella Typhimurium ST313 in HIV-1-infected primary human macrophages is not associated with Salmonella hijacking the HIV compartment. Biol Cell 2020; 112:92-101. [PMID: 31922615 DOI: 10.1111/boc.201900055] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 11/28/2019] [Indexed: 12/28/2022]
Abstract
BACKGROUND Non-typhoidal Salmonella (NTS) causes a severe invasive syndrome (iNTS disease) described in HIV-positive adults. The impact of HIV-1 on Salmonella pathogenesis and the molecular basis for the differences between these bacteria and classical diarrhoeal S. Typhimurium remains unclear. RESULTS Here, we show that iNTS-associated S. Typhimurium Sequence Type 313 (ST313) bacteria show greater intracellular survival in primary human macrophages, compared with a 'classical' diarrhoeal S. Typhimurium ST19 isolate. The increased intracellular survival phenotype of ST313 is more pronounced in HIV-infected macrophages. We explored the possibility that the bacteria take advantage of the HIV-associated viral-containing compartments created in human macrophages that have low pH. Confocal fluorescence microscopy and focussed ion beam-scanning electron microscopy tomography showed that Salmonella did not co-localise extensively with HIV-positive compartments. CONCLUSION The capacity of ST313 bacteria to survive better than ST19 bacteria within primary human macrophages is enhanced in cells pre-infected with HIV-1. Our results indicate that the ST313 bacteria do not directly benefit from the niche created by the virus in HIV-1-infected macrophages, and that they might take advantage from a more globally modified host cell. SIGNIFICANCE A better understanding of the interplay between HIV-1 and Salmonella is important not only for these bacteria but also for other opportunistic pathogens.
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Affiliation(s)
- G Lê-Bury
- Institut Cochin, Université de Paris, INSERM, U1016, CNRS, UMR 8104, Paris, F-75014, France
| | - C Deschamps
- Institut Cochin, Université de Paris, INSERM, U1016, CNRS, UMR 8104, Paris, F-75014, France
| | - C Kizilyaprak
- Faculté de Biologie et de Médecine, Electron Microscopy Facility, Université de Lausanne, Lausanne, Switzerland
| | - W Blanchard
- Faculté de Biologie et de Médecine, Electron Microscopy Facility, Université de Lausanne, Lausanne, Switzerland
| | - J Daraspe
- Faculté de Biologie et de Médecine, Electron Microscopy Facility, Université de Lausanne, Lausanne, Switzerland
| | - A Dumas
- Institut Cochin, Université de Paris, INSERM, U1016, CNRS, UMR 8104, Paris, F-75014, France
| | - M A Gordon
- Institute of Infection and Global Health, University of Liverpool, Liverpool, UK.,Malawi-Liverpool-Welcome Trust B=Clinical Research Programme, Malawi
| | - J C D Hinton
- Institute of Integrative Biology, University of Liverpool, Liverpool, UK
| | - B M Humbel
- Faculté de Biologie et de Médecine, Electron Microscopy Facility, Université de Lausanne, Lausanne, Switzerland.,IMG, Okinawa Institute of Science and Technology, Onna-son, Okinawa, Japan
| | - F Niedergang
- Institut Cochin, Université de Paris, INSERM, U1016, CNRS, UMR 8104, Paris, F-75014, France
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Weiner A, Enninga J. The Pathogen–Host Interface in Three Dimensions: Correlative FIB/SEM Applications. Trends Microbiol 2019; 27:426-439. [DOI: 10.1016/j.tim.2018.11.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 11/27/2018] [Accepted: 11/30/2018] [Indexed: 12/17/2022]
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Swanstrom AE, Del Prete GQ, Deleage C, Elser SE, Lackner AA, Hoxie JA. The SIV Envelope Glycoprotein, Viral Tropism, and Pathogenesis: Novel Insights from Nonhuman Primate Models of AIDS. Curr HIV Res 2019; 16:29-40. [PMID: 29173176 DOI: 10.2174/1570162x15666171124123116] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 10/12/2017] [Accepted: 10/13/2017] [Indexed: 12/14/2022]
Abstract
BACKGROUND Cellular tropism of human immunodeficiency virus (HIV-1) is closely linked to interactions between the viral envelope glycoprotein (Env) with CD4 and chemokine receptor family members, CCR5 and CXCR4. This interaction plays a key role in determining anatomic sites that are infected in vivo and the cascade of early and late events that result in chronic immune activation, immunosuppression and ultimately, AIDS. CD4+ T cells are critical to adaptive immune responses, and their early and rapid infection in gut lamina propria and secondary lymphoid tissues in susceptible hosts likely contributes to viral persistence and progression to disease. CD4+ macrophages are also infected, although their role in HIV-1 pathogenesis is more controversial. METHODS Pathogenic infection by simian immunodeficiency viruses (SIV) in Asian macaques as models of HIV-1 infection has enabled the impact of cellular tropism on pathogenesis to be directly probed. This review will highlight examples in which experimental interventions during SIV infection or the introduction of viral mutations have altered cellular tropism and, subsequently, pathogenesis. RESULTS Alterations to the interaction of Env and its cellular receptors has been shown to result in changes to CD4 dependence, coreceptor specificity, and viral tropism for gut CD4+ T cells and macrophages. CONCLUSION Collectively, these findings have yielded novel insights into the critical role of the viral Env and tropism as a driver of pathogenesis and host control and have helped to identify new areas for targeted interventions in therapy and prevention of HIV-1 infection.
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Affiliation(s)
- Adrienne E Swanstrom
- AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research Inc., Frederick, MD, United States
| | - Gregory Q Del Prete
- AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research Inc., Frederick, MD, United States
| | - Claire Deleage
- AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research Inc., Frederick, MD, United States
| | - Samra E Elser
- Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | - Andrew A Lackner
- Tulane National Primate Research Center, Covington, LA, United States
| | - James A Hoxie
- Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
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Al-Harti L, Joseph J, Nath A. Astrocytes as an HIV CNS reservoir: highlights and reflections of an NIMH-sponsored symposium. J Neurovirol 2018; 24:665-669. [PMID: 30397827 DOI: 10.1007/s13365-018-0691-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Accepted: 10/24/2018] [Indexed: 12/30/2022]
Abstract
This a summary of a National Institute of Mental Health (NIMH) sponsored symposium that was focused on the role of astrocytes as a reservoir of the human immunodeficiency virus in the brain. The talks were grouped into four themes. The first theme reviewed the evidence for HIV infection of astrocytes and discussed the challenges in the use of traditional methods of immunostaining and in situ hybridization for detection of infected astrocytes. The second theme focused on mechanisms of HIV entry into astrocytes and discussed CD4 independent mechanisms, such as receptor-mediated endocytosis and transmission of HIV by cell-to-cell contact with infected lymphocytes. The third theme focused on epigenetic regulation of HIV latency in astrocytes and other factors, such as cytokines and transcriptional factors regulating HIV replication in astrocytes. The fourth theme focused on therapeutic approaches, such as gene editing to block persistently infected astrocytes. A discussion that followed was focused on major unanswered questions in the field and future directions for research.
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Affiliation(s)
- Lena Al-Harti
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, 1735 West Harrison Street, Room 614 Cohn, Chicago, IL, 60612, USA.
| | - Jeymohan Joseph
- Section of Infections of the Nervous System, National Institutes of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Avindra Nath
- HIV Neuropathogenesis, Genetics and Therapeutics Branch, Division of AIDS Research, National Institute of Mental Health, Bldg 10, Room 7C-103, Bethesda, MD, 20892, USA.
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Cougot N, Douillard T, Dalmas F, Pradelle N, Gauthier R, Sanon C, Grosgogeat B, Colon P, Chevalier J. Towards quantitative analysis of enamel erosion by focused ion beam tomography. Dent Mater 2018; 34:e289-e300. [DOI: 10.1016/j.dental.2018.08.304] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 07/30/2018] [Accepted: 08/27/2018] [Indexed: 10/28/2022]
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Bayliss RJ, Piguet V. Masters of manipulation: Viral modulation of the immunological synapse. Cell Microbiol 2018; 20:e12944. [PMID: 30123959 PMCID: PMC6492149 DOI: 10.1111/cmi.12944] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 08/01/2018] [Accepted: 08/14/2018] [Indexed: 02/06/2023]
Abstract
In order to thrive, viruses have evolved to manipulate host cell machinery for their own benefit. One major obstacle faced by pathogens is the immunological synapse. To enable efficient replication and latency in immune cells, viruses have developed a range of strategies to manipulate cellular processes involved in immunological synapse formation to evade immune detection and control T-cell activation. In vitro, viruses such as human immunodeficiency virus 1 and human T-lymphotropic virus type 1 utilise structures known as virological synapses to aid transmission of viral particles from cell to cell in a process termed trans-infection. The formation of the virological synapse provides a gateway for virus to be transferred between cells avoiding the extracellular space, preventing antibody neutralisation or recognition by complement. This review looks at how viruses are able to subvert intracellular signalling to modulate immune function to their advantage and explores the role synapse formation has in viral persistence and cell-to-cell transmission.
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Affiliation(s)
- Rebecca J. Bayliss
- Division of Infection and Immunity, School of MedicineCardiff UniversityCardiffUK
| | - Vincent Piguet
- Division of Infection and Immunity, School of MedicineCardiff UniversityCardiffUK
- Division of Dermatology, Department of MedicineUniversity of TorontoTorontoOntarioCanada
- Division of DermatologyWomen's College HospitalTorontoOntarioCanada
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32
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Li Y, Wu Q, Huang L, Yuan C, Wang J, Yang Q. An alternative pathway of enteric PEDV dissemination from nasal cavity to intestinal mucosa in swine. Nat Commun 2018; 9:3811. [PMID: 30232333 PMCID: PMC6145876 DOI: 10.1038/s41467-018-06056-w] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 08/08/2018] [Indexed: 02/06/2023] Open
Abstract
Porcine epidemic diarrhea virus (PEDV) has catastrophic impacts on the global pig industry. Although the fecal–oral route is generally accepted, an increased number of reports indicate that airborne transmission may contribute to PEDV outbreak. Here, we show that PEDV could cause typical diarrhea in piglets through a nasal spray. Firstly, PEDV can develop a transient nasal epithelium infection. Subsequently, PEDV-carrying dendritic cells (DCs) allow the virus to be transferred to CD3+ T cells via the virological synapse. Finally, virus-loaded CD3+ T cells reach the intestine through the blood circulation, leading to intestinal infection via cell-to-cell contact. Our study provides evidence for airborne transmission of a gastrointestinal infected coronavirus and illustrates the mechanism of its transport from the entry site to the pathogenic site. Outbreaks of porcine epidemic diarrhea virus (PEDV) have seriously affected pig farms around the world. Here, Li et al. show that PEDV can cause disease in piglets when inoculated by nasal spray, and provide insights into the cellular mechanisms underlying PEDV dissemination within the host.
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Affiliation(s)
- Yuchen Li
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Weigang 1, Nanjing, 210095, Jiangsu, PR China
| | - Qingxin Wu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Weigang 1, Nanjing, 210095, Jiangsu, PR China
| | - Lulu Huang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Weigang 1, Nanjing, 210095, Jiangsu, PR China
| | - Chen Yuan
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Weigang 1, Nanjing, 210095, Jiangsu, PR China
| | - Jialu Wang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Weigang 1, Nanjing, 210095, Jiangsu, PR China
| | - Qian Yang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Weigang 1, Nanjing, 210095, Jiangsu, PR China.
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Colasuonno F, Borghi R, Niceforo A, Muzzi M, Bertini E, Di Giulio A, Moreno S, Compagnucci C. Senescence-associated ultrastructural features of long-term cultures of induced pluripotent stem cells (iPSCs). Aging (Albany NY) 2018; 9:2209-2222. [PMID: 29064821 PMCID: PMC5680563 DOI: 10.18632/aging.101309] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Accepted: 10/15/2017] [Indexed: 12/12/2022]
Abstract
Induced pluripotent stem cells (iPSCs) hold great promise for developing personalized regenerative medicine, however characterization of their biological features is still incomplete. Moreover, changes occurring in long-term cultured iPSCs have been reported, suggesting these as a model of cellular aging. For this reason, we addressed the ultrastructural characterization of iPSCs, with a focus on possible time-dependent changes, involving specific cell compartments. To this aim, we comparatively analysed cultures at different timepoints, by an innovative electron microscopic technology (FIB/SEM). We observed progressive loss of cell-to-cell contacts, associated with increased occurrence of exosomes. Mitochondria gradually increased, while acquiring an elongated shape, with well-developed cristae. Such mitochondrial maturation was accompanied by their turnover, as assessed by the presence of autophagomes (undetectable in young iPSCs), some containing recognizable mitochondria. This finding was especially frequent in middle-aged iPSCs, while being occasional in aged cells, suggesting early autophagic activation followed by a decreased efficiency of the process with culturing time. Accordingly, confocal microscopy showed age-dependent alterations to the expression and distribution of autophagic markers. Interestingly, responsivity to rapamycin, highest in young iPSCs, was almost lost in aged cells. Overall, our results strongly support long-term cultured iPSCs as a model for studying relevant aspects of cellular senescence, involving intercellular communication, energy metabolism, and autophagy.
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Affiliation(s)
- Fiorella Colasuonno
- Department of Science, LIME, University "Roma Tre", Rome 00146, Italy.,Department of Neuroscience, Unit of Neuromuscular and Neurodegenerative Diseases, Laboratory of Molecular Medicine, Bambino Gesu' Children's Research Hospital, IRCCS, Rome 00146, Italy
| | - Rossella Borghi
- Department of Science, LIME, University "Roma Tre", Rome 00146, Italy.,Department of Neuroscience, Unit of Neuromuscular and Neurodegenerative Diseases, Laboratory of Molecular Medicine, Bambino Gesu' Children's Research Hospital, IRCCS, Rome 00146, Italy
| | - Alessia Niceforo
- Department of Science, LIME, University "Roma Tre", Rome 00146, Italy.,Department of Neuroscience, Unit of Neuromuscular and Neurodegenerative Diseases, Laboratory of Molecular Medicine, Bambino Gesu' Children's Research Hospital, IRCCS, Rome 00146, Italy
| | - Maurizio Muzzi
- Department of Science, LIME, University "Roma Tre", Rome 00146, Italy
| | - Enrico Bertini
- Department of Neuroscience, Unit of Neuromuscular and Neurodegenerative Diseases, Laboratory of Molecular Medicine, Bambino Gesu' Children's Research Hospital, IRCCS, Rome 00146, Italy
| | - Andrea Di Giulio
- Department of Science, LIME, University "Roma Tre", Rome 00146, Italy
| | - Sandra Moreno
- Department of Science, LIME, University "Roma Tre", Rome 00146, Italy
| | - Claudia Compagnucci
- Department of Neuroscience, Unit of Neuromuscular and Neurodegenerative Diseases, Laboratory of Molecular Medicine, Bambino Gesu' Children's Research Hospital, IRCCS, Rome 00146, Italy
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Narasimhulu VGS, Bellamy-McIntyre AK, Laumaea AE, Lay CS, Harrison DN, King HAD, Drummer HE, Poumbourios P. Distinct functions for the membrane-proximal ectodomain region (MPER) of HIV-1 gp41 in cell-free and cell-cell viral transmission and cell-cell fusion. J Biol Chem 2018; 293:6099-6120. [PMID: 29496992 DOI: 10.1074/jbc.ra117.000537] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 02/21/2018] [Indexed: 11/06/2022] Open
Abstract
HIV-1 is spread by cell-free virions and by cell-cell viral transfer. We asked whether the structure and function of a broad neutralizing antibody (bNAb) epitope, the membrane-proximal ectodomain region (MPER) of the viral gp41 transmembrane glycoprotein, differ in cell-free and cell-cell-transmitted viruses and whether this difference could be related to Ab neutralization sensitivity. Whereas cell-free viruses bearing W666A and I675A substitutions in the MPER lacked infectivity, cell-associated mutant viruses were able to initiate robust spreading infection. Infectivity was restored to cell-free viruses by additional substitutions in the cytoplasmic tail (CT) of gp41 known to disrupt interactions with the viral matrix protein. We observed contrasting effects on cell-free virus infectivity when W666A was introduced to two transmitted/founder isolates, but both mutants could still mediate cell-cell spread. Domain swapping indicated that the disparate W666A phenotypes of the cell-free transmitted/founder viruses are controlled by sequences in variable regions 1, 2, and 4 of gp120. The sequential passaging of an MPER mutant (W672A) in peripheral blood mononuclear cells enabled selection of viral revertants with loss-of-glycan suppressor mutations in variable region 1, suggesting a functional interaction between variable region 1 and the MPER. An MPER-directed bNAb neutralized cell-free virus but not cell-cell viral spread. Our results suggest that the MPER of cell-cell-transmitted virions has a malleable structure that tolerates mutagenic disruption but is not accessible to bNAbs. In cell-free virions, interactions mediated by the CT impose an alternative MPER structure that is less tolerant of mutagenic alteration and is efficiently targeted by bNAbs.
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Affiliation(s)
- Vani G S Narasimhulu
- From the Virus Entry and Vaccines Laboratory, Burnet Institute, Melbourne, Victoria 3004.,the Department of Microbiology and Immunology at the Peter Doherty Institute, University of Melbourne, Parkville, Victoria 3010, and
| | - Anna K Bellamy-McIntyre
- From the Virus Entry and Vaccines Laboratory, Burnet Institute, Melbourne, Victoria 3004.,the Departments of Microbiology and
| | - Annamarie E Laumaea
- From the Virus Entry and Vaccines Laboratory, Burnet Institute, Melbourne, Victoria 3004.,the Department of Microbiology and Immunology at the Peter Doherty Institute, University of Melbourne, Parkville, Victoria 3010, and
| | - Chan-Sien Lay
- Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - David N Harrison
- From the Virus Entry and Vaccines Laboratory, Burnet Institute, Melbourne, Victoria 3004
| | - Hannah A D King
- From the Virus Entry and Vaccines Laboratory, Burnet Institute, Melbourne, Victoria 3004.,the Department of Microbiology and Immunology at the Peter Doherty Institute, University of Melbourne, Parkville, Victoria 3010, and
| | - Heidi E Drummer
- From the Virus Entry and Vaccines Laboratory, Burnet Institute, Melbourne, Victoria 3004.,the Department of Microbiology and Immunology at the Peter Doherty Institute, University of Melbourne, Parkville, Victoria 3010, and.,the Departments of Microbiology and
| | - Pantelis Poumbourios
- From the Virus Entry and Vaccines Laboratory, Burnet Institute, Melbourne, Victoria 3004, .,the Departments of Microbiology and.,Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
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Chen JL, Nong GM. [Advances in application of Jurkat cell model in research on infectious diseases]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2018; 20:236-242. [PMID: 29530126 PMCID: PMC7389782 DOI: 10.7499/j.issn.1008-8830.2018.03.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 12/09/2017] [Accepted: 02/05/2018] [Indexed: 10/13/2023]
Abstract
Infectious diseases can be caused by multiple pathogens, which can produce specific immune response in human body. The immune response produced by T cells is cellular immunity, which plays an important role in the anti-infection process of human body, and can participate in immunological protection and cause immunopathology. The outcome of various infectious diseases is closely related to cellular immune function, especially the function of T cells. Jurkat cells belong to the human acute T lymphocyte leukemia cell line. Jurkat cell model can simulate the function T lymphocytes, so it is widely used in the in vitro studies of T cell signal transduction, cytokines, and receptor expression, and can provide reference and guidance for the treatment of various infectious diseases and the research on their pathogenesis. The Jurkat cell model has been widely used in the in vitro studies of viral diseases and atypical pathogens, but parasitic infection studies using the Jurkat cell model are still rare. This article reviews advances in the application of Jurkat cell model in the research on infectious diseases.
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Affiliation(s)
- Jing-Lun Chen
- Department of Pediatrics, First Affiliated Hospital of Guangxi Medical University, Nanning 530021, China.
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Abstract
While HIV-1 infection of target cells with cell-free viral particles has been largely documented, intercellular transmission through direct cell-to-cell contact may be a predominant mode of propagation in host. To spread, HIV-1 infects cells of the immune system and takes advantage of their specific particularities and functions. Subversion of intercellular communication allows to improve HIV-1 replication through a multiplicity of intercellular structures and membrane protrusions, like tunneling nanotubes, filopodia, or lamellipodia-like structures involved in the formation of the virological synapse. Other features of immune cells, like the immunological synapse or the phagocytosis of infected cells are hijacked by HIV-1 and used as gateways to infect target cells. Finally, HIV-1 reuses its fusogenic capacity to provoke fusion between infected donor cells and target cells, and to form infected syncytia with high capacity of viral production and improved capacities of motility or survival. All these modes of cell-to-cell transfer are now considered as viral mechanisms to escape immune system and antiretroviral therapies, and could be involved in the establishment of persistent virus reservoirs in different host tissues.
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Affiliation(s)
- Lucie Bracq
- Inserm U1016, Institut Cochin, Paris, France.,CNRS, UMR8104, Paris, France.,Université Paris-Descartes, Sorbonne Paris-Cité, Paris, France.,International Associated Laboratory (LIA VirHost), Institut Pasteur Shanghai-Chinese Academy of Sciences, Shanghai, China.,International Associated Laboratory (LIA VirHost), CNRS, Université Paris-Descartes, Institut Pasteur, Paris, France
| | - Maorong Xie
- Inserm U1016, Institut Cochin, Paris, France.,CNRS, UMR8104, Paris, France.,Université Paris-Descartes, Sorbonne Paris-Cité, Paris, France.,International Associated Laboratory (LIA VirHost), CNRS, Université Paris-Descartes, Institut Pasteur, Paris, France
| | - Serge Benichou
- Inserm U1016, Institut Cochin, Paris, France.,CNRS, UMR8104, Paris, France.,Université Paris-Descartes, Sorbonne Paris-Cité, Paris, France.,International Associated Laboratory (LIA VirHost), Institut Pasteur Shanghai-Chinese Academy of Sciences, Shanghai, China.,International Associated Laboratory (LIA VirHost), CNRS, Université Paris-Descartes, Institut Pasteur, Paris, France
| | - Jérôme Bouchet
- Inserm U1016, Institut Cochin, Paris, France.,CNRS, UMR8104, Paris, France.,Université Paris-Descartes, Sorbonne Paris-Cité, Paris, France.,International Associated Laboratory (LIA VirHost), CNRS, Université Paris-Descartes, Institut Pasteur, Paris, France
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Ospina Stella A, Turville S. All-Round Manipulation of the Actin Cytoskeleton by HIV. Viruses 2018; 10:v10020063. [PMID: 29401736 PMCID: PMC5850370 DOI: 10.3390/v10020063] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 01/24/2018] [Accepted: 01/29/2018] [Indexed: 12/21/2022] Open
Abstract
While significant progress has been made in terms of human immunodeficiency virus (HIV) therapy, treatment does not represent a cure and remains inaccessible to many people living with HIV. Continued mechanistic research into the viral life cycle and its intersection with many aspects of cellular biology are not only fundamental in the continued fight against HIV, but also provide many key observations of the workings of our immune system. Decades of HIV research have testified to the integral role of the actin cytoskeleton in both establishing and spreading the infection. Here, we review how the virus uses different strategies to manipulate cellular actin networks and increase the efficiency of various stages of its life cycle. While some HIV proteins seem able to bind to actin filaments directly, subversion of the cytoskeleton occurs indirectly by exploiting the power of actin regulatory proteins, which are corrupted at multiple levels. Furthermore, this manipulation is not restricted to a discrete class of proteins, but rather extends throughout all layers of the cytoskeleton. We discuss prominent examples of actin regulators that are exploited, neutralized or hijacked by the virus, and address how their coordinated deregulation can lead to changes in cellular behavior that promote viral spreading.
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Affiliation(s)
- Alberto Ospina Stella
- The Kirby Institute, University of New South Wales (UNSW), Sydney NSW 2052, Australia.
| | - Stuart Turville
- The Kirby Institute, University of New South Wales (UNSW), Sydney NSW 2052, Australia.
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38
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Jin X, Cao X, Wang X, Jiang J, Wan J, Laliberté JF, Zhang Y. Three-Dimensional Architecture and Biogenesis of Membrane Structures Associated with Plant Virus Replication. FRONTIERS IN PLANT SCIENCE 2018; 9:57. [PMID: 29441085 PMCID: PMC5797596 DOI: 10.3389/fpls.2018.00057] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 01/11/2018] [Indexed: 05/20/2023]
Abstract
Positive-sense (+) RNA viruses represent the most abundant group of viruses and are dependent on the host cell machinery to replicate. One remarkable feature that occurs after (+) RNA virus entry into cells is the remodeling of host endomembranes, leading to the formation of viral replication factories. Recently, rapid progress in three-dimensional (3D) imaging technologies, such as electron tomography (ET) and focused ion beam-scanning electron microscopy (FIB-SEM), has enabled researchers to visualize the novel membrane structures induced by viruses at high resolution. These 3D imaging technologies provide new mechanistic insights into the viral infection cycle. In this review, we summarize the latest reports on the cellular remodeling that occurs during plant virus infection; in particular, we focus on studies that provide 3D architectural information on viral replication factories. We also outline the mechanisms underlying the formation of these membranous structures and discuss possible future research directions.
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Affiliation(s)
- Xuejiao Jin
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Xiuling Cao
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Xueting Wang
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Jun Jiang
- Institut National de la Recherche Scientifique—Institut Armand-Frappier, Laval, QC, Canada
| | - Juan Wan
- Institut National de la Recherche Scientifique—Institut Armand-Frappier, Laval, QC, Canada
| | - Jean-François Laliberté
- Institut National de la Recherche Scientifique—Institut Armand-Frappier, Laval, QC, Canada
- *Correspondence: Jean-François Laliberté
| | - Yongliang Zhang
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, China
- Yongliang Zhang
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Russell RA, Chojnacki J, Jones DM, Johnson E, Do T, Eggeling C, Padilla-Parra S, Sattentau QJ. Astrocytes Resist HIV-1 Fusion but Engulf Infected Macrophage Material. Cell Rep 2017; 18:1473-1483. [PMID: 28178524 PMCID: PMC5316642 DOI: 10.1016/j.celrep.2017.01.027] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 11/13/2016] [Accepted: 01/12/2017] [Indexed: 11/03/2022] Open
Abstract
HIV-1 disseminates to diverse tissues and establishes long-lived viral reservoirs. These reservoirs include the CNS, in which macrophage-lineage cells, and as suggested by many studies, astrocytes, may be infected. Here, we have investigated astrocyte infection by HIV-1. We confirm that astrocytes trap and internalize HIV-1 particles for subsequent release but find no evidence that these particles infect the cell. Astrocyte infection was not observed by cell-free or cell-to-cell routes using diverse approaches, including luciferase and GFP reporter viruses, fixed and live-cell fusion assays, multispectral flow cytometry, and super-resolution imaging. By contrast, we observed intimate interactions between HIV-1-infected macrophages and astrocytes leading to signals that might be mistaken for astrocyte infection using less stringent approaches. These results have implications for HIV-1 infection of the CNS, viral reservoir formation, and antiretroviral therapy.
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Affiliation(s)
- Rebecca A Russell
- The Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Jakub Chojnacki
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - Daniel M Jones
- Division of Structural Biology, University of Oxford, The Henry Wellcome Building for Genomic Medicine, Headington, Oxford OX3 7BN, UK; Wellcome Trust Centre for Human Genetics, Cellular Imaging Core, University of Oxford, Oxford OX3 7BN, UK
| | - Errin Johnson
- The Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Thao Do
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Christian Eggeling
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - Sergi Padilla-Parra
- Division of Structural Biology, University of Oxford, The Henry Wellcome Building for Genomic Medicine, Headington, Oxford OX3 7BN, UK; Wellcome Trust Centre for Human Genetics, Cellular Imaging Core, University of Oxford, Oxford OX3 7BN, UK
| | - Quentin J Sattentau
- The Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK.
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The sleeping beauty kissed awake: new methods in electron microscopy to study cellular membranes. Biochem J 2017; 474:1041-1053. [DOI: 10.1042/bcj20160990] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 01/03/2017] [Accepted: 01/23/2017] [Indexed: 01/12/2023]
Abstract
Electron microscopy (EM) for biological samples, developed in the 1940–1950s, changed our conception about the architecture of eukaryotic cells. It was followed by a period where EM applied to cell biology had seemingly fallen asleep, even though new methods with important implications for modern EM were developed. Among these was the discovery that samples can be preserved by chemical fixation and most importantly by rapid freezing without the formation of crystalline ice, giving birth to the world of cryo-EM. The past 15–20 years are hallmarked by a tremendous interest in EM, driven by important technological advances. Cryo-EM, in particular, is now capable of revealing structures of proteins at a near-atomic resolution owing to improved sample preparation methods, microscopes and cameras. In this review, we focus on the challenges associated with the imaging of membranes by EM and give examples from the field of host–pathogen interactions, in particular of virus-infected cells. Despite the advantages of imaging membranes under native conditions in cryo-EM, conventional EM will remain an important complementary method, in particular if large volumes need to be imaged.
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Prasad A, Kulkarni R, Jiang S, Groopman JE. Cocaine Enhances DC to T-cell HIV-1 Transmission by Activating DC-SIGN/LARG/LSP1 Complex and Facilitating Infectious Synapse Formation. Sci Rep 2017; 7:40648. [PMID: 28094782 PMCID: PMC5240552 DOI: 10.1038/srep40648] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 12/09/2016] [Indexed: 02/06/2023] Open
Abstract
DC-SIGN is a dendritic cell surface structure which participates in binding and transmission of HIV-1. Here, for the first time we demonstrate that cocaine induces over expression of DC-SIGN and significantly enhances virus transfer from DCs to T-cells by increasing the binding and internalization of HIV-1 in DCs. We found that cocaine activates a DC-SIGN mediated 'signalosome' complex by enhancing its association with LARG and LSP1. Further, LARG was observed to participate in DC-SIGN mediated internalization of HIV-1 in DCs. Intracellular trafficking studies of HIV-1 in cocaine treated DCs revealed increased co-localization of HIV-1 with endosomal or multi vesicular body (MVB) markers such as CD81 and VPS4 and decreased co-localization with the phagolysomal marker LAMP1; this signified altered intracellular trafficking and decreased degradation of HIV-1 in cocaine treated DCs. Furthermore, we found that cocaine induced activation of LARG which in turn activated Rho A and the focal adhesion molecules FAK, Pyk2 and paxillin. This signaling cascade enhanced the formation of an infectious synapse between DCs and T-cells. Our study provides insight into the molecular mechanisms of cocaine's contribution to key components in HIV pathogenesis and highlights novel targets for interrupting the virus life cycle in substance using hosts.
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Affiliation(s)
- Anil Prasad
- Division of Experimental Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Rutuja Kulkarni
- Division of Experimental Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Shuxian Jiang
- Division of Experimental Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Jerome E. Groopman
- Division of Experimental Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
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Visualization of HIV T Cell Virological Synapses and Virus-Containing Compartments by Three-Dimensional Correlative Light and Electron Microscopy. J Virol 2017; 91:JVI.01605-16. [PMID: 27847357 PMCID: PMC5215336 DOI: 10.1128/jvi.01605-16] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 10/31/2016] [Indexed: 11/20/2022] Open
Abstract
Virological synapses (VS) are adhesive structures that form between infected and uninfected cells to enhance the spread of HIV-1. During T cell VS formation, viral proteins are actively recruited to the site of cell-cell contact where the viral material is efficiently translocated to target cells into heterogeneous, protease-resistant, antibody-inaccessible compartments. Using correlative light and electron microscopy (CLEM), we define the membrane topography of the virus-containing compartments (VCC) where HIV is found following VS-mediated transfer. Focused ion beam scanning electron microscopy (FIB-SEM) and serial sectioning transmission electron microscopy (SS-TEM) were used to better resolve the fluorescent Gag-containing structures within the VCC. We found that small punctate fluorescent signals correlated with single viral particles in enclosed vesicular compartments or surface-localized virus particles and that large fluorescent signals correlated with membranous Gag-containing structures with unknown pathological function. CLEM imaging revealed distinct pools of newly deposited viral proteins within endocytic and nonendocytic compartments in VS target T cells. IMPORTANCE This study directly correlates individual virus-associated objects observed in light microscopy with ultrastructural features seen by electron microscopy in the HIV-1 virological synapse. This approach elucidates which infection-associated ultrastructural features represent bona fide HIV protein complexes. We define the morphology of some HIV cell-to-cell transfer intermediates as true endocytic compartments and resolve unique synapse-associated viral structures created by transfer across virological synapses.
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HIV Envelope gp120 Alters T Cell Receptor Mobilization in the Immunological Synapse of Uninfected CD4 T Cells and Augments T Cell Activation. J Virol 2016; 90:10513-10526. [PMID: 27630246 DOI: 10.1128/jvi.01532-16] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 09/07/2016] [Indexed: 01/21/2023] Open
Abstract
HIV is transmitted most efficiently from cell to cell, and productive infection occurs mainly in activated CD4 T cells. It is postulated that HIV exploits immunological synapses formed between CD4 T cells and antigen-presenting cells to facilitate the targeting and infection of activated CD4 T cells. This study sought to evaluate how the presence of the HIV envelope (Env) in the CD4 T cell immunological synapse affects synapse formation and intracellular signaling to impact the downstream T cell activation events. CD4 T cells were applied to supported lipid bilayers that were reconstituted with HIV Env gp120, anti-T cell receptor (anti-TCR) monoclonal antibody, and ICAM-1 to represent the surface of HIV Env-bearing antigen-presenting cells. The results showed that the HIV Env did not disrupt immunological synapse formation. Instead, the HIV Env accumulated with TCR at the center of the synapse, altered the kinetics of TCR recruitment to the synapse and affected synapse morphology over time. The HIV Env also prolonged Lck phosphorylation at the synapse and enhanced TCR-induced CD69 upregulation, interleukin-2 secretion, and proliferation to promote virus infection. These results suggest that HIV uses the immunological synapse as a conduit not only for selective virus transmission to activated CD4 T cells but also for boosting the T cell activation state, thereby increasing its likelihood of undergoing productive replication in targeted CD4 T cells. IMPORTANCE There are about two million new HIV infections every year. A better understanding of how HIV is transmitted to susceptible cells is critical to devise effective strategies to prevent HIV infection. Activated CD4 T cells are preferentially infected by HIV, although how this is accomplished is not fully understood. This study examined whether HIV co-opts the normal T cell activation process through the so-called immunological synapse. We found that the HIV envelope is recruited to the center of the immunological synapse together with the T cell receptor and enhances the T cell receptor-induced activation of CD4 T cells. Heightened cellular activation promotes the capacity of CD4 T cells to support productive HIV replication. This study provides evidence of the exploitation of the normal immunological synapse and T cell activation process by HIV to boost the activation state of targeted CD4 T cells and promote the infection of these cells.
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44
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Cell-Free versus Cell-to-Cell Infection by Human Immunodeficiency Virus Type 1 and Human T-Lymphotropic Virus Type 1: Exploring the Link among Viral Source, Viral Trafficking, and Viral Replication. J Virol 2016; 90:7607-17. [PMID: 27334587 DOI: 10.1128/jvi.00407-16] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) and human T-lymphotropic virus type 1 (HTLV-1) are complex retroviruses mainly infecting CD4(+) T lymphocytes. In addition, antigen-presenting cells such as dendritic cells (DCs) are targeted in vivo by both viruses, although to a lesser extent. Interaction of HIV-1 with DCs plays a key role in viral dissemination from the mucosa to CD4(+) T lymphocytes present in lymphoid organs. While similar mechanisms may occur for HTLV-1 as well, most HTLV-1 data were obtained from T-cell studies, and little is known regarding the trafficking of this virus in DCs. We first compared the efficiency of cell-free versus cell-associated viral sources of both retroviruses at infecting DCs. We showed that both HIV-1 and HTLV-1 cell-free particles are poorly efficient at productively infecting DCs, except when DC-SIGN has been engaged. Furthermore, while SAMHD-1 accounts for restriction of cell-free HIV-1 infection, it is not involved in HTLV-1 restriction. In addition, cell-free viruses lead mainly to a nonproductive DC infection, leading to trans-infection of T-cells, a process important for HIV-1 spread but not for that of HTLV-1. Finally, we show that T-DC cell-to-cell transfer implies viral trafficking in vesicles that may both increase productive infection of DCs ("cis-infection") and allow viral escape from immune surveillance. Altogether, these observations allowed us to draw a model of HTLV-1 and HIV-1 trafficking in DCs.
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45
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Viruses exploit the tissue physiology of the host to spread in vivo. Curr Opin Cell Biol 2016; 41:81-90. [PMID: 27149407 DOI: 10.1016/j.ceb.2016.04.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 04/11/2016] [Accepted: 04/20/2016] [Indexed: 02/07/2023]
Abstract
Viruses are pathogens that strictly depend on their host for propagation. Over years of co-evolution viruses have become experts in exploiting the host cell biology and physiology to ensure efficient replication and spread. Here, we will first summarize the concepts that have emerged from in vitro cell culture studies to understand virus spread. We will then review the results from studies in living animals that reveal how viruses exploit the natural flow of body fluids, specific tissue architecture, and patterns of cell circulation and migration to spread within the host. Understanding tissue physiology will be critical for the design of antiviral strategies that prevent virus dissemination.
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46
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Abstract
Human immunodeficiency virus type 1 (HIV-1) gives rise to a chronic infection that progressively depletes CD4(+) T lymphocytes. CD4(+) T lymphocytes play a central coordinating role in adaptive cellular and humoral immune responses, and to do so they migrate and interact within lymphoid compartments and at effector sites to mount immune responses. While cell-free virus serves as an excellent prognostic indicator for patient survival, interactions of infected T cells or virus-scavenging immune cells with uninfected T cells can greatly enhance viral spread. HIV can induce interactions between infected and uninfected T cells that are triggered by cell surface expression of viral Env, which serves as a cell adhesion molecule that interacts with CD4 on the target cell, before it acts as the viral membrane fusion protein. These interactions are called virological synapses and promote replication in the face of selective pressure of humoral immune responses and antiretroviral therapy. Other infection-enhancing cell-cell interactions occur between virus-concentrating antigen-presenting cells and recipient T cells, called infectious synapses. The exact roles that these cell-cell interactions play in each stage of infection, from viral acquisition, systemic dissemination, to chronic persistence are still being determined. Infection-promoting immune cell interactions are likely to contribute to viral persistence and enhance the ability of HIV-1 to evade adaptive immune responses.
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Affiliation(s)
- K M Law
- Immunology Institute Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - N Satija
- Immunology Institute Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - A M Esposito
- Immunology Institute Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - B K Chen
- Immunology Institute Icahn School of Medicine at Mount Sinai, New York, NY, United States.
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47
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Chang K, Baginski J, Hassan SF, Volin M, Shukla D, Tiwari V. Filopodia and Viruses: An Analysis of Membrane Processes in Entry Mechanisms. Front Microbiol 2016; 7:300. [PMID: 27014223 PMCID: PMC4785137 DOI: 10.3389/fmicb.2016.00300] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 02/23/2016] [Indexed: 12/21/2022] Open
Abstract
Filopodia are thin, actin rich bundles protruding from cell plasma membranes, serving physiological purposes, such as probing the environment and facilitating cell-to-cell adhesion. Recent studies have highlighted that actively polymerized filopodial-protrusions are exploited during virus entry, trafficking, spread, and the development of clinical pathology of viral diseases. These observations have caused a surge in investigation of the key determinants of filopodial induction and their influence on cell topography including receptor expression for viral entry. It is now very clear that filopodia can provide unique opportunities for many viruses to invade host cells vertically during primary infection, or horizontally during virus spread from cell-to-cell. These emerging concepts can explain the unprecedented ability of viruses to invade both nearby and long-distant host cells, a feature that may directly contribute to viral tropism. In this review, we summarize the significance of filopodia in viral diseases and discuss future therapeutic possibilities to precisely target filopodial-flyovers to prevent or control infectious diseases.
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Affiliation(s)
- Kenneth Chang
- Department of Microbiology and Immunology, Chicago College of Osteopathic Medicine, Midwestern University Downers Grove, IL, USA
| | - John Baginski
- Department of Microbiology and Immunology, Chicago College of Osteopathic Medicine, Midwestern University Downers Grove, IL, USA
| | - Samer F Hassan
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago Chicago, IL, USA
| | - Michael Volin
- Department of Microbiology and Immunology, Chicago College of Osteopathic Medicine, Midwestern University Downers Grove, IL, USA
| | - Deepak Shukla
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago Chicago, IL, USA
| | - Vaibhav Tiwari
- Department of Microbiology and Immunology, Chicago College of Osteopathic Medicine, Midwestern University Downers Grove, IL, USA
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Abstract
A quiet revolution is under way in technologies used for nanoscale cellular imaging. Focused ion beams, previously restricted to the materials sciences and semiconductor fields, are rapidly becoming powerful tools for ultrastructural imaging of biological samples. Cell and tissue architecture, as preserved in plastic-embedded resin or in plunge-frozen form, can be investigated in three dimensions by scanning electron microscopy imaging of freshly created surfaces that result from the progressive removal of material using a focused ion beam. The focused ion beam can also be used as a sculpting tool to create specific specimen shapes such as lamellae or needles that can be analyzed further by transmission electron microscopy or by methods that probe chemical composition. Here we provide an in-depth primer to the application of focused ion beams in biology, including a guide to the practical aspects of using the technology, as well as selected examples of its contribution to the generation of new insights into subcellular architecture and mechanisms underlying host-pathogen interactions.
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49
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Ménager MM, Littman DR. Actin Dynamics Regulates Dendritic Cell-Mediated Transfer of HIV-1 to T Cells. Cell 2016; 164:695-709. [PMID: 26830877 DOI: 10.1016/j.cell.2015.12.036] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 10/23/2015] [Accepted: 12/14/2015] [Indexed: 10/22/2022]
Abstract
Whereas human dendritic cells (DCs) are largely resistant to productive infection with HIV-1, they have a unique ability to take up the virus and transmit it efficiently to T lymphocytes through a process of trans-infection or trans-enhancement. To elucidate the molecular and cell biological mechanism for trans-enhancement, we performed an shRNA screen of several hundred genes involved in organelle and membrane trafficking in immature human monocyte-derived dendritic cells (MDDCs). We identified TSPAN7 and DNM2, which control actin nucleation and stabilization, as having important and distinct roles in limiting HIV-1 endocytosis and in maintaining virus particles on dendrites, which is required for efficient transfer to T lymphocytes. Further characterization of this process may provide insights not only into the role of DCs in transmission and dissemination of HIV-1 but also more broadly into mechanisms controlling capture and internalization of pathogens.
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Affiliation(s)
- Mickaël M Ménager
- Molecular Pathogenesis Program, The Kimmel Center for Biology and Medicine of the Skirball Institute, New York University School of Medicine, New York, NY 10016, USA.
| | - Dan R Littman
- Molecular Pathogenesis Program, The Kimmel Center for Biology and Medicine of the Skirball Institute, New York University School of Medicine, New York, NY 10016, USA; Howard Hughes Medical Institute.
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50
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Viral Infection at High Magnification: 3D Electron Microscopy Methods to Analyze the Architecture of Infected Cells. Viruses 2015; 7:6316-45. [PMID: 26633469 PMCID: PMC4690864 DOI: 10.3390/v7122940] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 10/16/2015] [Accepted: 11/16/2015] [Indexed: 02/06/2023] Open
Abstract
As obligate intracellular parasites, viruses need to hijack their cellular hosts and reprogram their machineries in order to replicate their genomes and produce new virions. For the direct visualization of the different steps of a viral life cycle (attachment, entry, replication, assembly and egress) electron microscopy (EM) methods are extremely helpful. While conventional EM has given important information about virus-host cell interactions, the development of three-dimensional EM (3D-EM) approaches provides unprecedented insights into how viruses remodel the intracellular architecture of the host cell. During the last years several 3D-EM methods have been developed. Here we will provide a description of the main approaches and examples of innovative applications.
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