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Norman RX, Chen YC, Recchia EE, Loi J, Rosemarie Q, Lesko SL, Patel S, Sherer N, Takaku M, Burkard ME, Suzuki A. One step 4x and 12x 3D-ExM: robust super-resolution microscopy in cell biology. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.13.607782. [PMID: 39185153 PMCID: PMC11343106 DOI: 10.1101/2024.08.13.607782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/27/2024]
Abstract
Super-resolution microscopy has become an indispensable tool across diverse research fields, offering unprecedented insights into biological architectures with nanometer scale resolution. Compared to traditional nanometer-scale imaging methods such as electron microscopy, super-resolution microscopy offers several advantages, including the simultaneous labeling of multiple target biomolecules with high specificity and simpler sample preparation, making it accessible to most researchers. In this study, we introduce two optimized methods of super-resolution imaging: 4-fold and 12-fold 3D-isotropic and preserved Expansion Microscopy (4x and 12x 3D-ExM). 3D-ExM is a straightforward expansion microscopy method featuring a single-step process, providing robust and reproducible 3D isotropic expansion for both 2D and 3D cell culture models. With standard confocal microscopy, 12x 3D-ExM achieves a lateral resolution of under 30 nm, enabling the visualization of nanoscale structures, including chromosomes, kinetochores, nuclear pore complexes, and Epstein-Barr virus particles. These results demonstrate that 3D-ExM provides cost-effective and user-friendly super-resolution microscopy, making it highly suitable for a wide range of cell biology research, including studies on cellular and chromatin architectures.
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Affiliation(s)
- Roshan X Norman
- Biophysics Graduate Program, University of Wisconsin-Madison, Madison, Wisconsin
- Department of Oncology, McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, Wisconsin
- Department of Medicine, Hematology/Oncology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Yu-Chia Chen
- Department of Oncology, McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, Wisconsin
- Molecular and Cellular Pharmacology Graduate Program, University of Wisconsin-Madison, Madison, Wisconsin
| | - Emma E Recchia
- Department of Oncology, McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, Wisconsin
| | - Jonathan Loi
- Biophysics Graduate Program, University of Wisconsin-Madison, Madison, Wisconsin
- Department of Oncology, McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, Wisconsin
| | - Quincy Rosemarie
- Department of Oncology, McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, Wisconsin
| | - Sydney L Lesko
- Department of Oncology, McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, Wisconsin
| | - Smit Patel
- Department of Oncology, McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, Wisconsin
| | - Nathan Sherer
- Department of Oncology, McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, Wisconsin
- UW Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin
| | - Motoki Takaku
- Department of Biomedical Science, University of North Dakota School of Medicine and Health Science, Grand Forks, North Dakota, USA
| | - Mark E Burkard
- Biophysics Graduate Program, University of Wisconsin-Madison, Madison, Wisconsin
- Department of Oncology, McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, Wisconsin
- Department of Medicine, Hematology/Oncology, University of Wisconsin-Madison, Madison, Wisconsin
- UW Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin
| | - Aussie Suzuki
- Biophysics Graduate Program, University of Wisconsin-Madison, Madison, Wisconsin
- Department of Oncology, McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, Wisconsin
- UW Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin
- Lead Contact
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2
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Virus-Like Particles as Preventive and Therapeutic Cancer Vaccines. Vaccines (Basel) 2022; 10:vaccines10020227. [PMID: 35214685 PMCID: PMC8879290 DOI: 10.3390/vaccines10020227] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 01/27/2022] [Accepted: 01/28/2022] [Indexed: 12/04/2022] Open
Abstract
Virus-like particles (VLPs) are self-assembled viral protein complexes that mimic the native virus structure without being infectious. VLPs, similarly to wild type viruses, are able to efficiently target and activate dendritic cells (DCs) triggering the B and T cell immunities. Therefore, VLPs hold great promise for the development of effective and affordable vaccines in infectious diseases and cancers. Vaccine formulations based on VLPs, compared to other nanoparticles, have the advantage of incorporating multiple antigens derived from different proteins. Moreover, such antigens can be functionalized by chemical modifications without affecting the structural conformation or the antigenicity. This review summarizes the current status of preventive and therapeutic VLP-based vaccines developed against human oncoviruses as well as cancers.
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3
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Madi JR, Outa AA, Ghannam M, Hussein HM, Shehab M, Hasan ZAKH, Fayad AA, Shirinian M, Rahal EA. Drosophila melanogaster as a Model System to Assess the Effect of Epstein-Barr Virus DNA on Inflammatory Gut Diseases. Front Immunol 2021; 12:586930. [PMID: 33828545 PMCID: PMC8019809 DOI: 10.3389/fimmu.2021.586930] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 03/03/2021] [Indexed: 01/05/2023] Open
Abstract
The Epstein-Barr virus (EBV) commonly infects humans and is highly associated with different types of cancers and autoimmune diseases. EBV has also been detected in inflamed gastrointestinal mucosa of patients suffering from prolonged inflammation of the digestive tract such as inflammatory bowel disease (IBD) with no clear role identified yet for EBV in the pathology of such diseases. Since we have previously reported immune-stimulating capabilities of EBV DNA in various models, in this study we investigated whether EBV DNA may play a role in exacerbating intestinal inflammation through innate immune and regeneration responses using the Drosophila melanogaster model. We have generated inflamed gastrointestinal tracts in adult fruit flies through the administration of dextran sodium sulfate (DSS), a sulfated polysaccharide that causes human ulcerative colitis- like pathologies due to its toxicity to intestinal cells. Intestinal damage induced by inflammation recruited plasmatocytes to the ileum in fly hindguts. EBV DNA aggravated inflammation by enhancing the immune deficiency (IMD) pathway as well as further increasing the cellular inflammatory responses manifested upon the administration of DSS. The study at hand proposes a possible immunostimulatory role of the viral DNA exerted specifically in the fly hindgut hence further developing our understanding of immune responses mounted against EBV DNA in the latter intestinal segment of the D. melanogaster gut. These findings suggest that EBV DNA may perpetuate proinflammatory processes initiated in an inflamed digestive system. Our findings indicate that D. melanogaster can serve as a model to further understand EBV-associated gastroinflammatory pathologies. Further studies employing mammalian models may validate the immunogenicity of EBV DNA in an IBD context and its role in exacerbating the disease through inflammatory mediators.
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Affiliation(s)
- Joelle R Madi
- Department of Experimental Pathology and Immunology, American University of Beirut, Faculty of Medicine, Beirut, Lebanon.,Center for Infectious Diseases Research, American University of Beirut Medical Center, Beirut, Lebanon
| | - Amani Al Outa
- Department of Anatomy, Cell Biology and Physiology, American University of Beirut, Faculty of Medicine, Beirut, Lebanon
| | - Mirna Ghannam
- Department of Experimental Pathology and Immunology, American University of Beirut, Faculty of Medicine, Beirut, Lebanon.,Center for Infectious Diseases Research, American University of Beirut Medical Center, Beirut, Lebanon
| | - Hadi M Hussein
- Department of Experimental Pathology and Immunology, American University of Beirut, Faculty of Medicine, Beirut, Lebanon.,Center for Infectious Diseases Research, American University of Beirut Medical Center, Beirut, Lebanon
| | - Marwa Shehab
- Department of Experimental Pathology and Immunology, American University of Beirut, Faculty of Medicine, Beirut, Lebanon.,Center for Infectious Diseases Research, American University of Beirut Medical Center, Beirut, Lebanon
| | - Zeinab Al Kobra Haj Hasan
- Department of Experimental Pathology and Immunology, American University of Beirut, Faculty of Medicine, Beirut, Lebanon.,Center for Infectious Diseases Research, American University of Beirut Medical Center, Beirut, Lebanon
| | - Antoine Abou Fayad
- Department of Experimental Pathology and Immunology, American University of Beirut, Faculty of Medicine, Beirut, Lebanon.,Center for Infectious Diseases Research, American University of Beirut Medical Center, Beirut, Lebanon
| | - Margret Shirinian
- Department of Experimental Pathology and Immunology, American University of Beirut, Faculty of Medicine, Beirut, Lebanon.,Center for Infectious Diseases Research, American University of Beirut Medical Center, Beirut, Lebanon
| | - Elias A Rahal
- Department of Experimental Pathology and Immunology, American University of Beirut, Faculty of Medicine, Beirut, Lebanon.,Center for Infectious Diseases Research, American University of Beirut Medical Center, Beirut, Lebanon
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4
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Liu W, Cui Y, Wang C, Li Z, Gong D, Dai X, Bi GQ, Sun R, Zhou ZH. Structures of capsid and capsid-associated tegument complex inside the Epstein-Barr virus. Nat Microbiol 2020; 5:1285-1298. [PMID: 32719506 DOI: 10.1038/s41564-020-0758-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 06/19/2020] [Indexed: 12/20/2022]
Abstract
As the first discovered human cancer virus, Epstein-Barr virus (EBV) causes Burkitt's lymphoma and nasopharyngeal carcinoma. Isolating virions for determining high-resolution structures has been hindered by latency-a hallmark of EBV infection-and atomic structures are thus available only for recombinantly expressed EBV proteins. In the present study, by symmetry relaxation and subparticle reconstruction, we have determined near-atomic-resolution structures of the EBV capsid with an asymmetrically attached DNA-translocating portal and capsid-associated tegument complexes from cryogenic electron microscopy images of just 2,048 EBV virions obtained by chemical induction. The resulting atomic models reveal structural plasticity among the 20 conformers of the major capsid protein, 2 conformers of the small capsid protein (SCP), 4 conformers of the triplex monomer proteins and 2 conformers of the triplex dimer proteins. Plasticity reaches the greatest level at the capsid-tegument interfaces involving SCP and capsid-associated tegument complexes (CATC): SCPs crown pentons/hexons and mediate tegument protein binding, and CATCs bind and rotate all five periportal triplexes, but notably only about one peri-penton triplex. These results offer insights into the EBV capsid assembly and a mechanism for recruiting cell-regulating factors into the tegument compartment as 'cargoes', and should inform future anti-EBV strategies.
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Affiliation(s)
- Wei Liu
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA, USA.,Department of Microbiology Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA, USA.,Center for Integrative Imaging, Hefei National Laboratory for Physical Sciences at the Microscale, and School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Yanxiang Cui
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA, USA
| | - Caiyan Wang
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA, USA.,Department of Microbiology Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA, USA.,International Institute for Translational Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Zihang Li
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA, USA.,Department of Microbiology Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA, USA
| | - Danyang Gong
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA, USA.,Department of Therapeutics Discovery, Amgen Research, Amgen Inc., Thousand Oaks, CA, USA
| | - Xinghong Dai
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA, USA.,Department of Microbiology Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA, USA.,Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Guo-Qiang Bi
- Center for Integrative Imaging, Hefei National Laboratory for Physical Sciences at the Microscale, and School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Ren Sun
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA, USA.,Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA, USA
| | - Z Hong Zhou
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA, USA. .,Department of Microbiology Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA, USA.
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5
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Li Z, Zhang X, Dong L, Pang J, Xu M, Zhong Q, Zeng MS, Yu X. CryoEM structure of the tegumented capsid of Epstein-Barr virus. Cell Res 2020; 30:873-884. [PMID: 32620850 PMCID: PMC7608217 DOI: 10.1038/s41422-020-0363-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Accepted: 06/16/2020] [Indexed: 12/13/2022] Open
Abstract
Epstein-Barr virus (EBV) is the primary cause of infectious mononucleosis and has been shown to be closely associated with various malignancies. Here, we present a complete atomic model of EBV, including the icosahedral capsid, the dodecameric portal and the capsid-associated tegument complex (CATC). Our in situ portal from the tegumented capsid adopts a closed conformation with its channel valve holding the terminal viral DNA and with its crown region firmly engaged by three layers of ring-like dsDNA, which, together with the penton flexibility, effectively alleviates the capsid inner pressure placed on the portal cap. In contrast, the CATCs, through binding to the flexible penton vertices in a stoichiometric manner, accurately increase the inner capsid pressure to facilitate the pressure-driven genome delivery. Together, our results provide important insights into the mechanism by which the EBV capsid, portal, packaged genome and the CATCs coordinately achieve a pressure balance to simultaneously benefit both viral genome retention and ejection.
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Affiliation(s)
- Zhihai Li
- Cryo-Electron Microscopy Research Center, The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Xiao Zhang
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Department of Experimental Research, Sun Yat-sen University Cancer Center, Sun Yat-sen University, Guangzhou, Guangdong, 510060, China
| | - Lili Dong
- Cryo-Electron Microscopy Research Center, The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Jingjing Pang
- Cryo-Electron Microscopy Research Center, The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Miao Xu
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Department of Experimental Research, Sun Yat-sen University Cancer Center, Sun Yat-sen University, Guangzhou, Guangdong, 510060, China
| | - Qian Zhong
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Department of Experimental Research, Sun Yat-sen University Cancer Center, Sun Yat-sen University, Guangzhou, Guangdong, 510060, China
| | - Mu-Sheng Zeng
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Department of Experimental Research, Sun Yat-sen University Cancer Center, Sun Yat-sen University, Guangzhou, Guangdong, 510060, China.
| | - Xuekui Yu
- Cryo-Electron Microscopy Research Center, The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China.
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6
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Brandariz-Nuñez A, Robinson SJ, Evilevitch A. Pressurized DNA state inside herpes capsids-A novel antiviral target. PLoS Pathog 2020; 16:e1008604. [PMID: 32702029 PMCID: PMC7377361 DOI: 10.1371/journal.ppat.1008604] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 05/05/2020] [Indexed: 01/25/2023] Open
Abstract
Drug resistance in viruses represents one of the major challenges of healthcare. As part of an effort to provide a treatment that avoids the possibility of drug resistance, we discovered a novel mechanism of action (MOA) and specific compounds to treat all nine human herpesviruses and animal herpesviruses. The novel MOA targets the pressurized genome state in a viral capsid, "turns off" capsid pressure, and blocks viral genome ejection into a cell nucleus, preventing viral replication. This work serves as a proof-of-concept to demonstrate the feasibility of a new antiviral target-suppressing pressure-driven viral genome ejection-that is likely impervious to developing drug resistance. This pivotal finding presents a platform for discovery of a new class of broad-spectrum treatments for herpesviruses and other viral infections with genome-pressure-dependent replication. A biophysical approach to antiviral treatment such as this is also a vital strategy to prevent the spread of emerging viruses where vaccine development is challenged by high mutation rates or other evasion mechanisms.
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Affiliation(s)
- Alberto Brandariz-Nuñez
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Scott J. Robinson
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Alex Evilevitch
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- Department of Experimental Medical Science, Lund University, Lund, Sweden
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7
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Sugimoto A, Yamashita Y, Kanda T, Murata T, Tsurumi T. Epstein-Barr virus genome packaging factors accumulate in BMRF1-cores within viral replication compartments. PLoS One 2019; 14:e0222519. [PMID: 31518362 PMCID: PMC6743757 DOI: 10.1371/journal.pone.0222519] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 09/02/2019] [Indexed: 12/26/2022] Open
Abstract
Productive replication of Epstein-Barr virus (EBV) during the lytic cycle occurs in discrete sites within nuclei, termed replication compartments. We previously proposed that replication compartments consist of two subnuclear domains: "ongoing replication foci" and "BMRF1-cores". Viral genome replication takes place in ongoing replication foci, which are enriched with viral replication proteins, such as BALF5 and BALF2. Amplified DNA and BMRF1 protein accumulate in BMRF1-cores, which are surrounded by ongoing replication foci. We here determined the locations of procapsid and genome-packaging proteins of EBV via three-dimensional (3D) surface reconstruction and correlative fluorescence microscopy-electron microscopy (FM-EM). The results revealed that viral factors required for DNA packaging, such as BGLF1, BVRF1, and BFLF1 proteins, are located in the innermost subdomains of the BMRF1-cores. In contrast, capsid structural proteins, such as BBRF1, BORF1, BDLF1, and BVRF2, were found both outside and inside the BMRF1-cores. Based on these observations, we propose a model in which viral procapsids are assembled outside the BMRF1-cores and subsequently migrate therein, where viral DNA encapsidation occurs. To our knowledge, this is the first report describing capsid assembly sites in relation to EBV replication compartments.
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Affiliation(s)
- Atsuko Sugimoto
- Division of Virology, Aichi Cancer Center Research Institute, Chikusa-ku, Nagoya, Japan
- Department of Virology, Nagoya University Graduate School of Medicine, Nagoya University, Showa-ku, Nagoya, Japan
- Department of Virology and Parasitology, Fujita Health University, School of Medicine, Toyoake, Japan
| | - Yoriko Yamashita
- Department of Experimental Pathology and Tumor Biology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Teru Kanda
- Division of Virology, Aichi Cancer Center Research Institute, Chikusa-ku, Nagoya, Japan
- Division of Microbiology, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Takayuki Murata
- Division of Virology, Aichi Cancer Center Research Institute, Chikusa-ku, Nagoya, Japan
- Department of Virology, Nagoya University Graduate School of Medicine, Nagoya University, Showa-ku, Nagoya, Japan
- Department of Virology and Parasitology, Fujita Health University, School of Medicine, Toyoake, Japan
- * E-mail:
| | - Tatsuya Tsurumi
- Division of Virology, Aichi Cancer Center Research Institute, Chikusa-ku, Nagoya, Japan
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8
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Brandariz-Nuñez A, Liu T, Du T, Evilevitch A. Pressure-driven release of viral genome into a host nucleus is a mechanism leading to herpes infection. eLife 2019; 8:47212. [PMID: 31393262 PMCID: PMC6711703 DOI: 10.7554/elife.47212] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 08/04/2019] [Indexed: 12/31/2022] Open
Abstract
Many viruses previously have been shown to have pressurized genomes inside their viral protein shell, termed the capsid. This pressure results from the tight confinement of negatively charged viral nucleic acids inside the capsid. However, the relevance of capsid pressure to viral infection has not been demonstrated. In this work, we show that the internal DNA pressure of tens of atmospheres inside a herpesvirus capsid powers ejection of the viral genome into a host cell nucleus. To our knowledge, this provides the first demonstration of a pressure-dependent mechanism of viral genome penetration into a host nucleus, leading to infection of eukaryotic cells.
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Affiliation(s)
- Alberto Brandariz-Nuñez
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, United States
| | - Ting Liu
- Department of Physics, Carnegie Mellon University, Pittsburgh, United States
| | - Te Du
- The Marjorie B. Kovler Viral Oncology Laboratories, The University of Chicago, Chicago, United States
| | - Alex Evilevitch
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, United States.,Department of Experimental Medical Sciences, Lund University, Lund, Sweden
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9
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Abstract
The Epstein-Barr virus (EBV) capsid contains a major capsid protein, VCA; two minor capsid proteins, BDLF1 and BORF1; and a small capsid protein, BFRF3. During the lytic cycle, these capsid proteins are synthesized and imported into the host nucleus for capsid assembly. This study finds that EBV capsid proteins colocalize with promyelocytic leukemia (PML) nuclear bodies (NBs) in P3HR1 cells during the viral lytic cycle, appearing as nuclear speckles under a confocal laser scanning microscope. In a glutathione S-transferase pulldown study, we show that BORF1 interacts with PML-NBs in vitro. BORF1 also colocalizes with PML-NBs in EBV-negative Akata cells after transfection and is responsible for bringing VCA and the VCA-BFRF3 complex from the cytoplasm to PML-NBs in the nucleus. Furthermore, BDLF1 is dispersed throughout the cell when expressed alone but colocalizes with PML-NBs when BORF1 is also present in the cell. In addition, this study finds that knockdown of PML expression by short hairpin RNA does not influence the intracellular levels of capsid proteins but reduces the number of viral particles produced by P3HR1 cells. Together, these results demonstrate that BORF1 plays a critical role in bringing capsid proteins to PML-NBs, which may likely be the assembly sites of EBV capsids. The mechanisms elucidated in this study are critical to understanding the process of EBV capsid assembly. IMPORTANCE Capsid assembly is an important event during the Epstein-Barr virus (EBV) lytic cycle, as this process is required for the production of virions. In this study, confocal microscopy revealed that the EBV capsid protein BORF1 interacts with promyelocytic leukemia (PML) nuclear bodies (NBs) in the host nucleus and is responsible for transporting the other EBV capsid proteins, including VCA, BDLF1, and BFRF3, to these subnuclear locations prior to initiation of capsid assembly. This study also found that knockdown of PML expression by short hairpin RNA significantly reduces EBV capsid assembly capabilities. This enhanced understanding of capsid assembly offers potential for the development of novel antiviral strategies and therapies that can prevent the propagation and spread of EBV.
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10
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Ogembo JG, Muraswki MR, McGinnes LW, Parcharidou A, Sutiwisesak R, Tison T, Avendano J, Agnani D, Finberg RW, Morrison TG, Fingeroth JD. A chimeric EBV gp350/220-based VLP replicates the virion B-cell attachment mechanism and elicits long-lasting neutralizing antibodies in mice. J Transl Med 2015; 13:50. [PMID: 25885535 PMCID: PMC4328182 DOI: 10.1186/s12967-015-0415-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 01/20/2015] [Indexed: 12/22/2022] Open
Abstract
Epstein-Barr virus (EBV), an oncogenic gammaherpesvirus, causes acute infectious mononucleosis (AIM) and is linked to the development of several human malignancies. There is an urgent need for a vaccine that is safe, prevents infection and/or limits disease. Unique among human herpesviruses, glycoprotein (gp)350/220, which initiates EBV attachment to susceptible host cells, is the major ligand on the EBV envelope and is highly conserved. Interaction between gp350/220 and complement receptor type 2 (CR2)/CD21 and/or (CR1)/CD35 on B-cells is required for infection. Potent antibody responses to gp350/220 occur in animal models and humans. Thus, gp350/220 provides an attractive candidate for prophylactic subunit vaccine development. However, in a recent Phase II clinical trial immunization with soluble recombinant gp350 reduced the incidence of AIM, but did not prevent infection. Despite various attempts to produce an EBV vaccine, no vaccine is licensed. Herein we describe a sub-unit vaccine against EBV based on a novel Newcastle disease virus (NDV)-virus-like particle (VLP) platform consisting of EBVgp350/220 ectodomain fused to NDV-fusion (F) protein. The chimeric protein EBVgp350/220-F is incorporated into the membrane of a VLP composed of the NDV matrix and nucleoprotein. The particles resemble native EBV in diameter and shape and bind CD21 and CD35. Immunization of BALB/c mice with EBVgp350/220-F VLPs elicited strong, long-lasting neutralizing antibody responses when assessed in vitro. This chimeric VLP is predicted to provide a superior safety profile as it is efficiently produced in Chinese hamster ovary (CHO) cells using a platform devoid of human nucleic acid and EBV-transforming genes.
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Affiliation(s)
- Javier Gordon Ogembo
- Department of Medicine, University of Massachusetts Medical School, 364 Plantation Street, LRB Room 323, Worcester, MA, 01605, USA.
| | - Matthew R Muraswki
- Department of Medicine, Beth Israel Deaconess Medical Center/Harvard Medical School, Boston, MA, UK.
| | - Lori W McGinnes
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, USA.
| | - Agapi Parcharidou
- Department of Medicine, Beth Israel Deaconess Medical Center/Harvard Medical School, Boston, MA, UK.
| | - Rujapak Sutiwisesak
- Department of Medicine, University of Massachusetts Medical School, 364 Plantation Street, LRB Room 323, Worcester, MA, 01605, USA.
| | - Timelia Tison
- Department of Medicine, University of Massachusetts Medical School, 364 Plantation Street, LRB Room 323, Worcester, MA, 01605, USA.
| | - Juan Avendano
- Department of Medicine, Beth Israel Deaconess Medical Center/Harvard Medical School, Boston, MA, UK.
| | - Deep Agnani
- Department of Medicine, Beth Israel Deaconess Medical Center/Harvard Medical School, Boston, MA, UK.
| | - Robert W Finberg
- Department of Medicine, University of Massachusetts Medical School, 364 Plantation Street, LRB Room 323, Worcester, MA, 01605, USA. .,Program in Immunology and Microbiology, University of Massachusetts Medical School, Worcester, MA, USA.
| | - Trudy G Morrison
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, USA. .,Program in Immunology and Microbiology, University of Massachusetts Medical School, Worcester, MA, USA.
| | - Joyce D Fingeroth
- Department of Medicine, University of Massachusetts Medical School, 364 Plantation Street, LRB Room 323, Worcester, MA, 01605, USA. .,Department of Medicine, Beth Israel Deaconess Medical Center/Harvard Medical School, Boston, MA, UK. .,Program in Immunology and Microbiology, University of Massachusetts Medical School, Worcester, MA, USA.
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Four levels of hierarchical organization, including noncovalent chainmail, brace the mature tumor herpesvirus capsid against pressurization. Structure 2014; 22:1385-98. [PMID: 25220471 DOI: 10.1016/j.str.2014.05.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2013] [Revised: 05/25/2014] [Accepted: 05/28/2014] [Indexed: 11/24/2022]
Abstract
Like many double-stranded DNA viruses, tumor gammaherpesviruses Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus withstand high internal pressure. Bacteriophage HK97 uses covalent chainmail for this purpose, but how this is achieved noncovalently in the much larger gammaherpesvirus capsid is unknown. Our cryoelectron microscopy structure of a gammaherpesvirus capsid reveals a hierarchy of four levels of organization: (1) Within a hexon capsomer, each monomer of the major capsid protein (MCP), 1,378 amino acids and six domains, interacts with its neighboring MCPs at four sites. (2) Neighboring capsomers are linked in pairs by MCP dimerization domains and in groups of three by heterotrimeric triplex proteins. (3) Small (∼280 amino acids) HK97-like domains in MCP monomers alternate with triplex heterotrimers to form a belt that encircles each capsomer. (4) One hundred sixty-two belts concatenate to form noncovalent chainmail. The triplex heterotrimer orchestrates all four levels and likely drives maturation to an angular capsid that can withstand pressurization.
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The assembly domain of the small capsid protein of Kaposi's sarcoma-associated herpesvirus. J Virol 2012; 86:11926-30. [PMID: 22915821 DOI: 10.1128/jvi.01430-12] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Self-assembly of Kaposi's sarcoma-associated herpesvirus capsids occurs when six proteins are coexpressed in insect cells using recombinant baculoviruses; however, if the small capsid protein (SCP) is omitted from the coinfection, assembly does not occur. Herein we delineate and identify precisely the assembly domain and the residues of SCP required for assembly. Hence, six residues, R14, D18, V25, R46, G66, and R70 in the assembly domain, when changed to alanine, completely abolish or reduce capsid assembly.
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