1
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Liu S, Großkopf AK, Yang X, Mannheim ME, Backovic M, Scribano S, Schlagowski S, Ensser A, Hahn AS. Kaposi's sarcoma-associated herpesvirus glycoprotein K8.1 is critical for infection in a cell-specific manner and functions at the attachment step on keratinocytes. J Virol 2023; 97:e0083223. [PMID: 37796128 PMCID: PMC10617506 DOI: 10.1128/jvi.00832-23] [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: 06/02/2023] [Accepted: 06/12/2023] [Indexed: 10/06/2023] Open
Abstract
IMPORTANCE Kaposi's sarcoma-associated herpesvirus (KSHV) is the causative agent of several B cell malignancies and Kaposi's sarcoma. We analyzed the function of K8.1, the major antigenic component of the KSHV virion in the infection of different cells. To do this, we deleted K8.1 from the viral genome. It was found that K8.1 is critical for the infection of certain epithelial cells, e.g., a skin model cell line but not for infection of many other cells. K8.1 was found to mediate attachment of the virus to cells where it plays a role in infection. In contrast, we did not find K8.1 or a related protein from a closely related monkey virus to activate fusion of the viral and cellular membranes, at least not under the conditions tested. These findings suggest that K8.1 functions in a highly cell-specific manner during KSHV entry, playing a crucial role in the attachment of KSHV to, e.g., skin epithelial cells.
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Affiliation(s)
- Shanchuan Liu
- Junior Research Group Herpesviruses, Infection Biology Unit, German Primate Center – Leibniz Institute for Primate Research, Göttingen, Germany
| | - Anna K. Großkopf
- Junior Research Group Herpesviruses, Infection Biology Unit, German Primate Center – Leibniz Institute for Primate Research, Göttingen, Germany
| | - Xiaoliang Yang
- Junior Research Group Herpesviruses, Infection Biology Unit, German Primate Center – Leibniz Institute for Primate Research, Göttingen, Germany
| | - Maximilian E. Mannheim
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, Unité de Virologie Structurale, Paris, France
| | - Marija Backovic
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, Unité de Virologie Structurale, Paris, France
| | - Stefano Scribano
- Junior Research Group Herpesviruses, Infection Biology Unit, German Primate Center – Leibniz Institute for Primate Research, Göttingen, Germany
| | - Sarah Schlagowski
- Junior Research Group Herpesviruses, Infection Biology Unit, German Primate Center – Leibniz Institute for Primate Research, Göttingen, Germany
| | - Armin Ensser
- Institute for Clinical and Molecular Virology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Alexander S. Hahn
- Junior Research Group Herpesviruses, Infection Biology Unit, German Primate Center – Leibniz Institute for Primate Research, Göttingen, Germany
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2
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Lu ZZ, Sun C, Zhang X, Peng Y, Wang Y, Zeng Y, Zhu N, Yuan Y, Zeng MS. Neuropilin 1 is an entry receptor for KSHV infection of mesenchymal stem cell through TGFBR1/2-mediated macropinocytosis. SCIENCE ADVANCES 2023; 9:eadg1778. [PMID: 37224259 DOI: 10.1126/sciadv.adg1778] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 04/19/2023] [Indexed: 05/26/2023]
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) has been implicated in the pathogenesis of Kaposi's sarcoma (KS) and other malignancies. The cellular origin of KS has been suggested to be either mesenchymal stem cells (MSCs) or endothelial cells. However, receptor(s) for KSHV to infect MSCs remains unknown. By combining bioinformatics analysis and shRNA screening, we identify neuropilin 1 (NRP1) as an entry receptor for KSHV infection of MSCs. Functionally, NRP1 knockout and overexpression in MSCs significantly reduce and promote, respectively, KSHV infection. Mechanistically, NRP1 facilitated the binding and internalization of KSHV by interacting with KSHV glycoprotein B (gB), which was blocked by soluble NRP1 protein. Furthermore, NRP1 interacts with TGF-β receptor type 2 (TGFBR2) through their respective cytoplasmic domains and thus activates the TGFBR1/2 complex, which facilitates the macropinocytosis-mediated KSHV internalization via the small GTPases Cdc42 and Rac1. Together, these findings implicate that KSHV has evolved a strategy to invade MSCs by harnessing NRP1 and TGF-beta receptors to stimulate macropinocytosis.
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Affiliation(s)
- Zheng-Zhou Lu
- State Key Laboratory of Oncology in South China, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Sun Yat-sen University Cancer Center and Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Cong Sun
- State Key Laboratory of Oncology in South China, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Sun Yat-sen University Cancer Center and Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Xiaolin Zhang
- State Key Laboratory of Oncology in South China, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Sun Yat-sen University Cancer Center and Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Yingying Peng
- Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Yan Wang
- Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Yan Zeng
- Precision clinical laboratory, Central People's Hospital of Zhanjiang, Zhanjiang, Guangdong 524037, China
- Key Laboratory of Xinjiang Endemic and Ethnic Disease, School of Medicine, Shihezi University, Shihezi 832000, China
| | - Nannan Zhu
- State Key Laboratory of Oncology in South China, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Sun Yat-sen University Cancer Center and Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Yan Yuan
- State Key Laboratory of Oncology in South China, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Sun Yat-sen University Cancer Center and Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
- Institute for Advanced Medical Research, Shandong University, Jinan, Shandong, China
| | - Mu-Sheng Zeng
- State Key Laboratory of Oncology in South China, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Sun Yat-sen University Cancer Center and Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
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3
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Zhong L, Zhang W, Krummenacher C, Chen Y, Zheng Q, Zhao Q, Zeng MS, Xia N, Zeng YX, Xu M, Zhang X. Targeting herpesvirus entry complex and fusogen glycoproteins with prophylactic and therapeutic agents. Trends Microbiol 2023:S0966-842X(23)00077-X. [DOI: 10.1016/j.tim.2023.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 02/28/2023] [Accepted: 03/01/2023] [Indexed: 04/03/2023]
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4
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Li X, Wang F, Zhang X, Sun Q, Kuang E. Suppression of KSHV lytic replication and primary effusion lymphoma by selective RNF5 inhibition. PLoS Pathog 2023; 19:e1011103. [PMID: 36656913 PMCID: PMC9888681 DOI: 10.1371/journal.ppat.1011103] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 01/31/2023] [Accepted: 01/06/2023] [Indexed: 01/20/2023] Open
Abstract
Primary effusion lymphoma (PEL), a rare aggressive B-cell lymphoma in immunosuppressed patients, is etiologically associated with oncogenic γ-herpesvirus infection. Chemotherapy is commonly used to treat PEL but usually results in poor prognosis and survival; thus, novel therapies and drug development are urgently needed for PEL treatment. Here, we demonstrated that inhibition of Ring finger protein 5 (RNF5), an ER-localized E3 ligase, suppresses multiple cellular pathways and lytic replication of Kaposi sarcoma-associated herpesvirus (KSHV) in PEL cells. RNF5 interacts with and induces Ephrin receptors A3 (EphA3) and EphA4 ubiquitination and degradation. RNF5 inhibition increases the levels of EphA3 and EphA4, thereby reducing ERK and Akt activation and KSHV lytic replication. RNF5 inhibition decreased PEL xenograft tumor growth and downregulated viral gene expression, cell cycle gene expression, and hedgehog signaling in xenograft tumors. Our study suggests that RNF5 plays the critical roles in KSHV lytic infection and tumorigenesis of primary effusion lymphoma.
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Affiliation(s)
- Xiaojuan Li
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
- College of Clinical Medicine, Hubei University of Chinese Medicine, Wuhan, China
| | - Fan Wang
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
| | - Xiaolin Zhang
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
| | - Qinqin Sun
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
| | - Ersheng Kuang
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
- Key Laboratory of Tropical Disease Control (Sun Yat-Sen University), Ministry of Education, Guangzhou, China
- * E-mail:
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5
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Casper C, Corey L, Cohen JI, Damania B, Gershon AA, Kaslow DC, Krug LT, Martin J, Mbulaiteye SM, Mocarski ES, Moore PS, Ogembo JG, Phipps W, Whitby D, Wood C. KSHV (HHV8) vaccine: promises and potential pitfalls for a new anti-cancer vaccine. NPJ Vaccines 2022; 7:108. [PMID: 36127367 PMCID: PMC9488886 DOI: 10.1038/s41541-022-00535-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 09/02/2022] [Indexed: 01/25/2023] Open
Abstract
Seven viruses cause at least 15% of the total cancer burden. Viral cancers have been described as the "low-hanging fruit" that can be potentially prevented or treated by new vaccines that would alter the course of global human cancer. Kaposi sarcoma herpesvirus (KSHV or HHV8) is the sole cause of Kaposi sarcoma, which primarily afflicts resource-poor and socially marginalized populations. This review summarizes a recent NIH-sponsored workshop's findings on the epidemiology and biology of KSHV as an overlooked but potentially vaccine-preventable infection. The unique epidemiology of this virus provides opportunities to prevent its cancers if an effective, inexpensive, and well-tolerated vaccine can be developed and delivered.
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Affiliation(s)
- Corey Casper
- Infectious Disease Research Institute, 1616 Eastlake Ave. East, Suite 400, Seattle, WA, 98102, USA
| | - Lawrence Corey
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N, Seattle, WA, 98109, USA
| | - Jeffrey I Cohen
- Laboratory of Infectious Diseases, National Institutes of Health, Bldg. 50, Room 6134, 50 South Drive, MSC8007, Bethesda, MD, 20892-8007, USA
| | - Blossom Damania
- Lineberger Comprehensive Cancer Center & Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, US
| | - Anne A Gershon
- Department of Pediatrics, Vagelos College of Physicians & Surgeons, Columbia University, 630 West 168th Street, New York, NY10032, US
| | - David C Kaslow
- PATH Essential Medicines, PATH, 2201 Westlake Avenue, Suite 200, Seattle, WA, USA
| | - Laurie T Krug
- HIV and AIDS Malignancy Branch, National Cancer Institute, Bethesda, MD, 20892, USA
| | - Jeffrey Martin
- Department of Epidemiology and Biostatistics, University of California, San Francisco, CA, USA
| | - Sam M Mbulaiteye
- Division of Cancer Epidemiology & Genetics, National Cancer Institute, NIH, HHS, 9609 Medical Center Dr, Rm. 6E118 MSC 3330, Bethesda, MD, 20892, USA
| | | | - Patrick S Moore
- Cancer Virology Program, Hillman Cancer Center, University of Pittsburgh, Pittsburgh, PA, 15213, USA.
| | - Javier Gordon Ogembo
- Department of Immuno-Oncology, Beckman Research Institute of City of Hope, Duarte, CA, 91010, USA
| | - Warren Phipps
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center; Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA, USA
| | - Denise Whitby
- AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Charles Wood
- Department of Interdisciplinary Oncology, Louisiana State University Health Sciences Center, New Orleans, LA, 70112, USA
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6
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Suzuki S, Geri JB, Knutson SD, Bell-Temin H, Tamura T, Fernández DF, Lovett GH, Till NA, Heller BL, Guo J, MacMillan DWC, Ploss A. Photochemical Identification of Auxiliary Severe Acute Respiratory Syndrome Coronavirus 2 Host Entry Factors Using μMap. J Am Chem Soc 2022; 144:16604-16611. [PMID: 36049228 PMCID: PMC9469761 DOI: 10.1021/jacs.2c06806] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Indexed: 12/20/2022]
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the infectious agent of the COVID-19 pandemic, remains a global medical problem. Angiotensin-converting enzyme 2 (ACE2) was identified as the primary viral entry receptor, and transmembrane serine protease 2 primes the spike protein for membrane fusion. However, ACE2 expression is generally low and variable across tissues, suggesting that auxiliary receptors facilitate viral entry. Identifying these factors is critical for understanding SARS-Cov-2 pathophysiology and developing new countermeasures. However, profiling host-virus interactomes involves extensive genetic screening or complex computational predictions. Here, we leverage the photocatalytic proximity labeling platform μMap to rapidly profile the spike interactome in human cells and identify eight novel candidate receptors. We systemically validate their functionality in SARS-CoV-2 pseudoviral uptake assays with both Wuhan and Delta spike variants and show that dual expression of ACE2 with either neuropilin-2, ephrin receptor A7, solute carrier family 6 member 15, or myelin and lymphocyte protein 2 significantly enhances viral uptake. Collectively, our data show that SARS-CoV-2 synergistically engages several host factors for cell entry and establishes μMap as a powerful tool for rapidly interrogating host-virus interactomes.
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Affiliation(s)
- Saori Suzuki
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Jacob B. Geri
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Steve D. Knutson
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | | | - Tomokazu Tamura
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | | | - Gabby H. Lovett
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Nicholas A. Till
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Brigitte L. Heller
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Jinchao Guo
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - David W. C. MacMillan
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
- Merck Center for Catalysis at Princeton University, Princeton, NJ 08544, USA
| | - Alexander Ploss
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
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7
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Antibodies Targeting KSHV gH/gL Reveal Distinct Neutralization Mechanisms. Viruses 2022; 14:v14030541. [PMID: 35336948 PMCID: PMC8953146 DOI: 10.3390/v14030541] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/01/2022] [Accepted: 03/02/2022] [Indexed: 02/06/2023] Open
Abstract
Kaposi’s sarcoma herpesvirus (KSHV) is associated with a significant disease burden, in particular in Sub-Sahara Africa. A KSHV vaccine would be highly desirable, but the mechanisms underlying neutralizing antibody responses against KSHV remain largely unexplored. The complex made of glycoproteins H and L (gH/gL) activates gB for the fusion of viral and cellular membranes in all herpesviruses. KSHV gH/gL also interacts with cellular Eph family receptors. To identify optimal antigens for vaccination and to elucidate neutralization mechanisms, we primed mice with recombinantly expressed, soluble gH/gL (gHecto/gL) that was either wildtype (WT), lacking defined glycosylation sites or bearing modified glycosylation, followed by boosts with WT gHecto/gL. We also immunized with a gL-gHecto fusion protein or a gHecto-ferritin/gL nanoparticle. Immune sera neutralized KSHV and inhibited EphA2 receptor binding. None of the regimens was superior to immunization with WT gHecto/gL with regard to neutralizing activity and EphA2 blocking activity, the gL-gHecto fusion protein was equally effective, and the ferritin construct was inferior. gH/gL-targeting sera inhibited gB-mediated membrane fusion and inhibited infection also independently from receptor binding and gL, as demonstrated by neutralization of a novel KSHV mutant that does not or only marginally incorporate gL into the gH/gL complex and infects through an Eph-independent route.
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8
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Interferon-Induced Transmembrane Proteins Inhibit Infection by the Kaposi's Sarcoma-Associated Herpesvirus and the Related Rhesus Monkey Rhadinovirus in a Cell-Specific Manner. mBio 2021; 12:e0211321. [PMID: 34933450 PMCID: PMC8689460 DOI: 10.1128/mbio.02113-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The interferon-induced transmembrane proteins (IFITMs) are broad-spectrum antiviral proteins that inhibit the entry of enveloped viruses. We analyzed the effect of IFITMs on the gamma-2 herpesviruses Kaposi's sarcoma-associated herpesvirus (KSHV) and the closely related rhesus monkey rhadinovirus (RRV). We used CRISPR/Cas9-mediated gene knockout to generate A549 cells, human foreskin fibroblasts (HFF), and human umbilical vein endothelial cells (HUVEC) with combined IFITM1/2/3 knockout and identified IFITMs as cell-dependent inhibitors of KSHV and RRV infection in A549 cells and HFF but not HUVEC. IFITM overexpression revealed IFITM1 as the relevant IFITM that inhibits KSHV and RRV infection. Fluorescent KSHV particles did not pronouncedly colocalize with IFITM-positive compartments. However, we found that KSHV and RRV glycoprotein-mediated cell-cell fusion is enhanced upon IFITM1/2/3 knockout. Taken together, we identified IFITM1 as a cell-dependent restriction factor of KSHV and RRV that acts at the level of membrane fusion. Of note, our results indicate that recombinant IFITM overexpression may lead to results that are not representative for the situation at endogenous levels. Strikingly, we observed that the endotheliotropic KSHV circumvents IFITM-mediated restriction in HUVEC despite high IFITM expression, while influenza A virus (IAV) glycoprotein-driven entry into HUVEC is potently restricted by IFITMs even in the absence of interferon. Mechanistically, we found that KSHV colocalizes less with IFITM1 and IFITM2 in HUVEC than in A549 cells immediately after attachment, potentially contributing to the observed difference in restriction. IMPORTANCE IFITM proteins are the first line of defense against infection by many pathogens and may also have therapeutic importance, as they, among other effectors, mediate the antiviral effect of interferons. Neither their function against herpesviruses nor their mechanism of action is well understood. We report here that in some cells but not in, for example, primary umbilical vein endothelial cells, IFITM1 restricts KSHV and RRV and that, mechanistically, this is likely effected by reducing the fusogenicity of the cell membrane. Further, we demonstrate potent inhibition of IAV glycoprotein-driven infection of cells of extrapulmonary origin by high constitutive IFITM expression.
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9
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Rani A, Jakhmola S, Karnati S, Parmar HS, Chandra Jha H. Potential entry receptors for human γ-herpesvirus into epithelial cells: A plausible therapeutic target for viral infections. Tumour Virus Res 2021; 12:200227. [PMID: 34800753 PMCID: PMC8628264 DOI: 10.1016/j.tvr.2021.200227] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 10/28/2021] [Accepted: 11/15/2021] [Indexed: 12/14/2022] Open
Abstract
Herpesviruses are ubiquitous viruses, specifically the Epstein Barr virus (EBV). EBV and Kaposi's sarcoma-associated herpesvirus (KSHV) establish their latency for a long period in B-cells and their reactivation instigates dreadful diseases from cancer to neurological modalities. The envelope glycoprotein of these viruses makes an attachment with several host receptors. For instance; glycoprotein 350/220, gp42, gHgL and gB of EBV establish an attachment with CD21, HLA-DR, Ephs, and other receptor molecules to hijack the B- and epithelial cell machinery. Ephs are reported recently as potent receptors for EBV entry into epithelial cells. Eph receptors play a role in the maintenance and control of various cellular processes including morphology, adhesion, proliferation, survival and differentiation. Alterations in the structure and expression of Eph and ephrin (Eph ligands) molecules is entangled with various pathologies including tumours and neurological complications. Along with Eph, integrins, NRP, NMHC are also key players in viral infections as they are possibly involved in viral transmission, replication and persistence. Contrarily, KSHV gH is known to interact with EphA2 and -A4 molecules, whereas in the case of EBV only EphA2 receptors are being reported to date. The ELEFN region of KSHV gH was involved in the interaction with EphA2, however, the interacting region of EBV gH is elusive. Further, the gHgL of KSHV and EBV form a complex with the EphA2 ligand-binding domain (LBD). Primarily by using gL both KSHV and EBV gHgL bind to the peripheral regions of LBD. In addition to γ-herpesviruses, several other viruses like Nipah virus, Cedar virus, Hepatitis C virus and Rhesus macaque rhadinovirus (RRV) also access the host cells via Eph receptors. Therefore, we summarise the possible roles of Eph and ephrins in virus-mediated infection and these molecules could serve as potential therapeutic targets. Crucial understanding of human γ-herpesviruses entry mechanism. Eph receptors relate to changed biomolecular profile upon EBV infection. EBV association with neurological disorders. Eph receptors could be an elegant drug for human γ-herpesviruses.
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Affiliation(s)
- Annu Rani
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, India
| | - Shweta Jakhmola
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, India
| | - Srikanth Karnati
- Department of Medical Cell Biology, Julius Maximilians University, Wuerzburg, Germany
| | - Hamendra Singh Parmar
- School of Biotechnology, Devi Ahilya University, Takshashila Campus, Khandwa Road, Indore, 452001, MP, India
| | - Hem Chandra Jha
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, India.
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10
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Light TP, Brun D, Guardado-Calvo P, Pederzoli R, Haouz A, Neipel F, Rey FA, Hristova K, Backovic M. Human herpesvirus 8 molecular mimicry of ephrin ligands facilitates cell entry and triggers EphA2 signaling. PLoS Biol 2021; 19:e3001392. [PMID: 34499637 PMCID: PMC8454987 DOI: 10.1371/journal.pbio.3001392] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 09/21/2021] [Accepted: 08/16/2021] [Indexed: 01/19/2023] Open
Abstract
Human herpesvirus 8 (HHV-8) is an oncogenic virus that enters cells by fusion of the viral and endosomal cellular membranes in a process mediated by viral surface glycoproteins. One of the cellular receptors hijacked by HHV-8 to gain access to cells is the EphA2 tyrosine kinase receptor, and the mechanistic basis of EphA2-mediated viral entry remains unclear. Using X-ray structure analysis, targeted mutagenesis, and binding studies, we here show that the HHV-8 envelope glycoprotein complex H and L (gH/gL) binds with subnanomolar affinity to EphA2 via molecular mimicry of the receptor’s cellular ligands, ephrins (Eph family receptor interacting proteins), revealing a pivotal role for the conserved gH residue E52 and the amino-terminal peptide of gL. Using FSI-FRET and cell contraction assays, we further demonstrate that the gH/gL complex also functionally mimics ephrin ligand by inducing EphA2 receptor association via its dimerization interface, thus triggering receptor signaling for cytoskeleton remodeling. These results now provide novel insight into the entry mechanism of HHV-8, opening avenues for the search of therapeutic agents that could interfere with HHV-8–related diseases. Herpesviruses are known to hijack cellular receptors to enter cells, but this study shows that human herpesvirus 8 takes this to another level by using its envelope glycoprotein complex gH/gL to mimic the EphA2 receptor’s natural ligands, ephrins.
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Affiliation(s)
- Taylor P Light
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America.,Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Delphine Brun
- Department of Virology, Structural Virology Unit, Institut Pasteur, Paris, France.,CNRS, UMR 3569, Paris, France
| | - Pablo Guardado-Calvo
- Department of Virology, Structural Virology Unit, Institut Pasteur, Paris, France.,CNRS, UMR 3569, Paris, France
| | - Riccardo Pederzoli
- Department of Virology, Structural Virology Unit, Institut Pasteur, Paris, France.,CNRS, UMR 3569, Paris, France
| | - Ahmed Haouz
- CNRS, UMR 3569, Paris, France.,Crystallography Platform C2RT, Institut Pasteur, Paris, France
| | - Frank Neipel
- Crystallography Platform C2RT, Institut Pasteur, Paris, France
| | - Félix A Rey
- Department of Virology, Structural Virology Unit, Institut Pasteur, Paris, France.,CNRS, UMR 3569, Paris, France
| | - Kalina Hristova
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America.,Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Marija Backovic
- Department of Virology, Structural Virology Unit, Institut Pasteur, Paris, France.,CNRS, UMR 3569, Paris, France
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11
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Tan X, Ren S, Fu MZ, Ren S, Yang C, Wu X, Chen T, Latham PS, Meltzer SJ, Fu SW. microRNA-196b promotes esophageal squamous cell carcinogenesis and chemoradioresistance by inhibiting EPHA7, thereby restoring EPHA2 activity. Am J Cancer Res 2021; 11:3594-3610. [PMID: 34354862 PMCID: PMC8332861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 04/17/2021] [Indexed: 06/13/2023] Open
Abstract
Esophageal cancer (EC) is extremely aggressive and has a very poor survival rate. Esophageal squamous cell carcinoma (ESCC) accounts for 80% of all ECs worldwide, with the majority of the remaining 20% being esophageal adenocarcinoma (EAC). Due to its occult and insidious presentation, ESCC is typically diagnosed and treated in its advanced stages, thereby limiting the success of present therapeutic modalities. microRNAs (miRNAs) can function as tumor suppressors or oncogenes, playing critical roles in cancer initiation and progression by regulating target genes in oncogenic pathways. In the current study, we demonstrated that microRNA-196b (miR-196b) is one of the most upregulated miRNAs in both ESCC and EAC. miR-196b was overexpressed in ESCC and EAC cell lines, cellular exosomal RNAs, and ESCC tissue samples. Functional studies revealed that miR-196b acted as an oncomiR by directly targeting a tumor suppressor, ephrin type-A receptor 7 (EPHA7). EPHA7 abrogates the activity of ephrin type-A receptor 2 (EPHA2), a key molecule involved in the epithelial-to-mesenchymal transition (EMT) and MAPK/ERK pathways, mediating resistance to UV and chemoradiotherapy in both ESCC and EAC. Taken together, these findings suggest that miR-196b is a strong candidate molecular target for EC treatment.
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Affiliation(s)
- Xiaohui Tan
- Department of Medicine, Division of Genomic Medicine, Department of Microbiology, Immunology and Tropical Medicine, The George Washington University School of Medicine and Health SciencesWashington, DC, USA
| | - Shuchang Ren
- Department of Medicine, Division of Genomic Medicine, Department of Microbiology, Immunology and Tropical Medicine, The George Washington University School of Medicine and Health SciencesWashington, DC, USA
| | - Melinda Z Fu
- Department of Medicine, Division of Genomic Medicine, Department of Microbiology, Immunology and Tropical Medicine, The George Washington University School of Medicine and Health SciencesWashington, DC, USA
| | - Shuyang Ren
- Department of Medicine, Division of Genomic Medicine, Department of Microbiology, Immunology and Tropical Medicine, The George Washington University School of Medicine and Health SciencesWashington, DC, USA
| | - Canyuan Yang
- Department of Medicine, Division of Genomic Medicine, Department of Microbiology, Immunology and Tropical Medicine, The George Washington University School of Medicine and Health SciencesWashington, DC, USA
| | - Xiaoling Wu
- Department of Medicine, Chengdu Military General HospitalChengdu, Sichuan, China
| | - Tao Chen
- Department of Medicine, Chengdu Military General HospitalChengdu, Sichuan, China
| | - Patricia S Latham
- Department of Pathology, The George Washington University School of Medicine and Health SciencesWashington, DC, USA
| | - Stephen J Meltzer
- Departments of Medicine and Oncology, The Johns Hopkins University School of Medicine and Sidney Kimmel Comprehensive Cancer CenterBaltimore, MD, USA
| | - Sidney W Fu
- Department of Medicine, Division of Genomic Medicine, Department of Microbiology, Immunology and Tropical Medicine, The George Washington University School of Medicine and Health SciencesWashington, DC, USA
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12
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Hörnich BF, Großkopf AK, Schlagowski S, Tenbusch M, Kleine-Weber H, Neipel F, Stahl-Hennig C, Hahn AS. SARS-CoV-2 and SARS-CoV Spike-Mediated Cell-Cell Fusion Differ in Their Requirements for Receptor Expression and Proteolytic Activation. J Virol 2021; 95:e00002-21. [PMID: 33608407 PMCID: PMC8104116 DOI: 10.1128/jvi.00002-21] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 02/14/2021] [Indexed: 02/07/2023] Open
Abstract
Severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) infects cells through interaction of its spike protein (SARS2-S) with angiotensin-converting enzyme 2 (ACE2) and activation by proteases, in particular transmembrane protease serine 2 (TMPRSS2). Viruses can also spread through fusion of infected with uninfected cells. We compared the requirements of ACE2 expression, proteolytic activation, and sensitivity to inhibitors for SARS2-S-mediated and SARS-CoV-S (SARS1-S)-mediated cell-cell fusion. SARS2-S-driven fusion was moderately increased by TMPRSS2 and strongly by ACE2, while SARS1-S-driven fusion was strongly increased by TMPRSS2 and less so by ACE2 expression. In contrast to that of SARS1-S, SARS2-S-mediated cell-cell fusion was efficiently activated by batimastat-sensitive metalloproteases. Mutation of the S1/S2 proteolytic cleavage site reduced effector cell-target cell fusion when ACE2 or TMPRSS2 was limiting and rendered SARS2-S-driven cell-cell fusion more dependent on TMPRSS2. When both ACE2 and TMPRSS2 were abundant, initial target cell-effector cell fusion was unaltered compared to that of wild-type (wt) SARS2-S, but syncytia remained smaller. Mutation of the S2 cleavage (S2') site specifically abrogated activation by TMPRSS2 for both cell-cell fusion and SARS2-S-driven pseudoparticle entry but still allowed for activation by metalloproteases for cell-cell fusion and by cathepsins for particle entry. Finally, we found that the TMPRSS2 inhibitor bromhexine, unlike the inhibitor camostat, was unable to reduce TMPRSS2-activated cell-cell fusion by SARS1-S and SARS2-S. Paradoxically, bromhexine enhanced cell-cell fusion in the presence of TMPRSS2, while its metabolite ambroxol exhibited inhibitory activity under some conditions. On Calu-3 lung cells, ambroxol weakly inhibited SARS2-S-driven lentiviral pseudoparticle entry, and both substances exhibited a dose-dependent trend toward weak inhibition of authentic SARS-CoV-2.IMPORTANCE Cell-cell fusion allows viruses to infect neighboring cells without the need to produce free virus and contributes to tissue damage by creating virus-infected syncytia. Our results demonstrate that the S2' cleavage site is essential for activation by TMPRSS2 and unravel important differences between SARS-CoV and SARS-CoV-2, among those, greater dependence of SARS-CoV-2 on ACE2 expression and activation by metalloproteases for cell-cell fusion. Bromhexine, reportedly an inhibitor of TMPRSS2, is currently being tested in clinical trials against coronavirus disease 2019. Our results indicate that bromhexine enhances fusion under some conditions. We therefore caution against the use of bromhexine in high dosages until its effects on SARS-CoV-2 spike activation are better understood. The related compound ambroxol, which similarly to bromhexine is clinically used as an expectorant, did not exhibit activating effects on cell-cell fusion. Both compounds exhibited weak inhibitory activity against SARS-CoV-2 infection at high concentrations, which might be clinically attainable for ambroxol.
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Affiliation(s)
- Bojan F Hörnich
- Nachwuchsgruppe Herpesviren, Abteilung Infektionsbiologie, Deutsches Primatenzentrum-Leibniz-Institut für Primatenforschung, Göttingen, Germany
| | - Anna K Großkopf
- Nachwuchsgruppe Herpesviren, Abteilung Infektionsbiologie, Deutsches Primatenzentrum-Leibniz-Institut für Primatenforschung, Göttingen, Germany
| | - Sarah Schlagowski
- Nachwuchsgruppe Herpesviren, Abteilung Infektionsbiologie, Deutsches Primatenzentrum-Leibniz-Institut für Primatenforschung, Göttingen, Germany
| | - Matthias Tenbusch
- Virologisches Institut, Universitätsklinikum Erlangen, Erlangen, Germany
| | - Hannah Kleine-Weber
- Abteilung Infektionsbiologie, Deutsches Primatenzentrum-Leibniz-Institut für Primatenforschung, Göttingen, Germany
| | - Frank Neipel
- Virologisches Institut, Universitätsklinikum Erlangen, Erlangen, Germany
| | - Christiane Stahl-Hennig
- Abteilung Infektionsmodelle, Deutsches Primatenzentrum-Leibniz-Institut für Primatenforschung, Göttingen, Germany
| | - Alexander S Hahn
- Nachwuchsgruppe Herpesviren, Abteilung Infektionsbiologie, Deutsches Primatenzentrum-Leibniz-Institut für Primatenforschung, Göttingen, Germany
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13
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Großkopf AK, Schlagowski S, Fricke T, Ensser A, Desrosiers RC, Hahn AS. Plxdc family members are novel receptors for the rhesus monkey rhadinovirus (RRV). PLoS Pathog 2021; 17:e1008979. [PMID: 33657166 PMCID: PMC7959344 DOI: 10.1371/journal.ppat.1008979] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 03/15/2021] [Accepted: 02/04/2021] [Indexed: 12/30/2022] Open
Abstract
The rhesus monkey rhadinovirus (RRV), a γ2-herpesvirus of rhesus macaques, shares many biological features with the human pathogenic Kaposi's sarcoma-associated herpesvirus (KSHV). Both viruses, as well as the more distantly related Epstein-Barr virus, engage cellular receptors from the Eph family of receptor tyrosine kinases (Ephs). However, the importance of the Eph interaction for RRV entry varies between cell types suggesting the existence of Eph-independent entry pathways. We therefore aimed to identify additional cellular receptors for RRV by affinity enrichment and mass spectrometry. We identified an additional receptor family, the Plexin domain containing proteins 1 and 2 (Plxdc1/2) that bind the RRV gH/gL glycoprotein complex. Preincubation of RRV with soluble Plxdc2 decoy receptor reduced infection by ~60%, while overexpression of Plxdc1 and 2 dramatically enhanced RRV susceptibility and cell-cell fusion of otherwise marginally permissive Raji cells. While the Plxdc2 interaction is conserved between two RRV strains, 26-95 and 17577, Plxdc1 specifically interacts with RRV 26-95 gH. The Plxdc interaction is mediated by a short motif at the N-terminus of RRV gH that is partially conserved between isolate 26-95 and isolate 17577, but absent in KSHV gH. Mutation of this motif abrogated the interaction with Plxdc1/2 and reduced RRV infection in a cell type-specific manner. Taken together, our findings characterize Plxdc1/2 as novel interaction partners and entry receptors for RRV and support the concept of the N-terminal domain of the gammaherpesviral gH/gL complex as a multifunctional receptor-binding domain. Further, Plxdc1/2 usage defines an important biological difference between KSHV and RRV.
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Affiliation(s)
- Anna K. Großkopf
- German Primate Center - Leibniz Institute for Primate Research, Göttingen, Germany
| | - Sarah Schlagowski
- German Primate Center - Leibniz Institute for Primate Research, Göttingen, Germany
| | - Thomas Fricke
- German Primate Center - Leibniz Institute for Primate Research, Göttingen, Germany
| | - Armin Ensser
- Universitätsklinikum Erlangen, Institute for Clinical and Molecular Virology, Erlangen, Germany
| | | | - Alexander S. Hahn
- German Primate Center - Leibniz Institute for Primate Research, Göttingen, Germany
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14
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Cellular Receptors Involved in KSHV Infection. Viruses 2021; 13:v13010118. [PMID: 33477296 PMCID: PMC7829929 DOI: 10.3390/v13010118] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 01/08/2021] [Accepted: 01/13/2021] [Indexed: 12/13/2022] Open
Abstract
The process of Kaposi’s Sarcoma Herpes Virus’ (KSHV) entry into target cells is complex and engages several viral glycoproteins which bind to a large range of host cell surface molecules. Receptors for KSHV include heparan sulphate proteoglycans (HSPGs), several integrins and Eph receptors, cystine/glutamate antiporter (xCT) and Dendritic Cell-Specific Intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN). This diverse range of potential binding and entry sites allows KSHV to have a broad cell tropism, and entry into specific cells is dependent on the available receptor repertoire. Several molecules involved in KSHV entry have been well characterized, particularly those postulated to be associated with KSHV-associated pathologies such as Kaposi’s Sarcoma (KS). In this review, KSHV infection of specific cell types pertinent to its pathogenesis will be comprehensively summarized with a focus on the specific cell surface binding and entry receptors KSHV exploits to gain access to a variety of cell types. Gaps in the current literature regarding understanding interactions between KSHV glycoproteins and cellular receptors in virus infection are identified which will lead to the development of virus infection intervention strategies.
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15
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Aalam F, Totonchy J. Molecular Virology of KSHV in the Lymphocyte Compartment-Insights From Patient Samples and De Novo Infection Models. Front Cell Infect Microbiol 2020; 10:607663. [PMID: 33344267 PMCID: PMC7746649 DOI: 10.3389/fcimb.2020.607663] [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: 09/17/2020] [Accepted: 11/09/2020] [Indexed: 12/26/2022] Open
Abstract
The incidence of Kaposi’s sarcoma-associated herpesvirus (KSHV)-associated Kaposi Sarcoma has declined precipitously in the present era of effective HIV treatment. However, KSHV-associated lymphoproliferative disorders although rare, have not seen a similar decline. Lymphoma is now a leading cause of death in people living with HIV (PLWH), indicating that the immune reconstitution provided by antiretroviral therapy is not sufficient to fully correct the lymphomagenic immune dysregulation perpetrated by HIV infection. As such, novel insights into the mechanisms of KSHV-mediated pathogenesis in the immune compartment are urgently needed in order to develop novel therapeutics aimed at prevention and treatment of KSHV-associated lymphoproliferations. In this review, we will discuss our current understanding of KSHV molecular virology in the lymphocyte compartment, concentrating on studies which explore mechanisms unique to infection in B lymphocytes.
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Affiliation(s)
- Farizeh Aalam
- Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, CA, United States
| | - Jennifer Totonchy
- Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, CA, United States
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16
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Su C, Wu L, Chai Y, Qi J, Tan S, Gao GF, Song H, Yan J. Molecular basis of EphA2 recognition by gHgL from gammaherpesviruses. Nat Commun 2020; 11:5964. [PMID: 33235207 PMCID: PMC7687889 DOI: 10.1038/s41467-020-19617-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 10/19/2020] [Indexed: 01/07/2023] Open
Abstract
The human γ-herpesviruses Kaposi sarcoma associated herpesvirus (KSHV) and Epstein-Barr virus (EBV) are associated with many human malignancies. Viral glycoprotein H (gH) and glycoprotein L (gL) are crucial for the cell tropism by binding to specific receptors. Recently, EphA2 was identified as the specific entry receptor for both KSHV and EBV. Here, we characterized the crystal structures of KSHV gHgL or EBV gHgL in complex with the ligand binding domain (LBD) of EphA2. Both KSHV and EBV gHgL bind to the channel and peripheral regions of LBD primarily using gL. Extensive interactions with more contacts contribute to the higher affinity of KSHV gHgL to LBD than that of EBV gHgL. These binding characteristics were verified using cell-based fusion assays with mutations in key EphA2 residues. Our experiments suggest that multiple animal γ-herpesviruses could use EphA2 as an entry receptor, implying a potential threat to human health.
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Affiliation(s)
- Chao Su
- grid.22935.3f0000 0004 0530 8290College of Veterinary Medicine, China Agricultural University, Beijing, 100193 China
| | - Lili Wu
- grid.9227.e0000000119573309CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101 China ,grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Yan Chai
- grid.9227.e0000000119573309CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101 China
| | - Jianxun Qi
- grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, Beijing, 100049 China ,grid.9227.e0000000119573309CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101 China
| | - Shuguang Tan
- grid.9227.e0000000119573309CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101 China
| | - George F. Gao
- grid.22935.3f0000 0004 0530 8290College of Veterinary Medicine, China Agricultural University, Beijing, 100193 China ,grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, Beijing, 100049 China ,grid.9227.e0000000119573309CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101 China ,grid.9227.e0000000119573309Research Network of Immunity and Health (RNIH), Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, 100101 China
| | - Hao Song
- grid.9227.e0000000119573309Research Network of Immunity and Health (RNIH), Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, 100101 China
| | - Jinghua Yan
- grid.9227.e0000000119573309CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101 China ,grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, Beijing, 100049 China
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17
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Aalam F, Nabiee R, Castano JR, Totonchy J. Analysis of KSHV B lymphocyte lineage tropism in human tonsil reveals efficient infection of CD138+ plasma cells. PLoS Pathog 2020; 16:e1008968. [PMID: 33075105 PMCID: PMC7595638 DOI: 10.1371/journal.ppat.1008968] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 10/29/2020] [Accepted: 09/07/2020] [Indexed: 02/08/2023] Open
Abstract
Despite 25 years of research, the basic virology of Kaposi Sarcoma Herpesviruses (KSHV) in B lymphocytes remains poorly understood. This study seeks to fill critical gaps in our understanding by characterizing the B lymphocyte lineage-specific tropism of KSHV. Here, we use lymphocytes derived from 40 human tonsil specimens to determine the B lymphocyte lineages targeted by KSHV early during de novo infection in our ex vivo model system. We characterize the immunological diversity of our tonsil specimens and determine that overall susceptibility of tonsil lymphocytes to KSHV infection varies substantially between donors. We demonstrate that a variety of B lymphocyte subtypes are susceptible to KSHV infection and identify CD138+ plasma cells as a highly targeted cell type for de novo KSHV infection. We determine that infection of tonsil B cell lineages is primarily latent with few lineages contributing to lytic replication. We explore the use of CD138 and heparin sulfate proteoglycans as attachment factors for the infection of B lymphocytes and conclude that they do not play a substantial role. Finally, we determine that the host T cell microenvironment influences the course of de novo infection in B lymphocytes. These results improve our understanding of KSHV transmission and the biology of early KSHV infection in a naïve human host, and lay a foundation for further characterization of KSHV molecular virology in B lymphocyte lineages. KSHV infection is associated with cancer in B cells and endothelial cells, particularly in the context of immune suppression. Very little is known about how KSHV is transmitted and how it initially establishes infection in a new host. Saliva is thought to be the primary route of person-to-person transmission for KSHV, making the tonsil a likely first site for KSHV replication in a new human host. Our study examines KSHV infection in B cells extracted from the tonsils of 40 human donors in order to determine what types of B cells are initially targeted for infection and examine how the presence (or absence) of other immune cells influence the initial stages of KSHV infection. We found that a variety of B cell subtypes derived from tonsils can be infected with KSHV. Interestingly, plasma cells (mature antibody-secreting B cells) were a highly targeted cell type. These results lay the foundation for further studies into the specific biology of KSHV in different types of B cells, an effort that may help us ultimately discover how to prevent the establishment of infection in these cells or reveal new ways to halt the progression of B cell cancers associated with KSHV infection.
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Affiliation(s)
- Farizeh Aalam
- School of Pharmacy, Chapman University, Irvine, California, United States of America
| | - Romina Nabiee
- School of Pharmacy, Chapman University, Irvine, California, United States of America
| | - Jesus Ramirez Castano
- School of Pharmacy, Chapman University, Irvine, California, United States of America
| | - Jennifer Totonchy
- School of Pharmacy, Chapman University, Irvine, California, United States of America
- * E-mail:
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18
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Epstein-Barr Virus gH/gL and Kaposi's Sarcoma-Associated Herpesvirus gH/gL Bind to Different Sites on EphA2 To Trigger Fusion. J Virol 2020; 94:JVI.01454-20. [PMID: 32847853 DOI: 10.1128/jvi.01454-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 08/18/2020] [Indexed: 12/22/2022] Open
Abstract
Both Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) are human gammaherpesviruses and are important in a variety of malignancies. Eph family receptor tyrosine kinase A2 (EphA2) is a cellular receptor for KSHV and EBV. Previous studies identified five conserved residues (ELEFN50-54) in the N-terminal domain of KSHV gH that are critical for Eph binding and KSHV infection. However, the specific domains of EBV gH/gL important for EphA2 binding are not well described. We found that the KSHV gH (ELEFN50-54) motif is important for higher KSHV fusion and that EBV gH/gL does not utilize a similar motif for fusion activity. We previously identified that an EBV gL N-glycosylation mutant (gL-N69L/S71V) was hyperfusogenic in epithelial cells but not in B cells. To determine whether this glycosylation site may be the binding region for EphA2, we compared the EphA2 binding activity of EBV gH/gL and the EBV gH/gL-N69L/S71V mutant. We found that EBV gH/gL-N69L/S71V had higher binding affinity for EphA2, indicating that the EBV gL N-glycosylation site might be responsible for inhibiting the binding of gH/gL to EphA2. Loss of N-glycosylation at this site may remove steric hindrance that reduces EBV gH/gL binding to EphA2. In addition, the mutations located in the large groove of EBV gH/gL (R152A and G49C) also have decreased binding with EphA2. Taken together, our data indicate that the binding site of EphA2 on EBV gH/gL is at least in part proximal to the EBV gL glycosylation site, which in part accounts for differences in EphA2 binding affinity by KSHV.IMPORTANCE Virus entry into target cells is the first step for virus infection. Understanding the overall entry mechanism, including the binding mechanism of specific virus glycoproteins with cellular receptors, can be useful for the design of small molecule inhibitors and vaccine development. Recently, EphA2 was identified as an important entry receptor for both KSHV and EBV. In the present study, we investigated the required binding sites within EphA2 and EBV gH/gL that mediate the interaction of these two proteins allowing entry into epithelial cells and found that it differed in compared to the interaction of KSHV gH/gL with EphA2. Our discoveries may uncover new potential interventional strategies that block EBV and KSHV infection of target epithelial cells.
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19
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Wang J, Zheng X, Peng Q, Zhang X, Qin Z. Eph receptors: the bridge linking host and virus. Cell Mol Life Sci 2020; 77:2355-2365. [PMID: 31893311 PMCID: PMC7275029 DOI: 10.1007/s00018-019-03409-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 11/17/2019] [Accepted: 12/02/2019] [Indexed: 02/06/2023]
Abstract
Eph (erythropoietin-producing hepatoma) receptors and Ephrin ligands constitute the largest subfamily of receptor tyrosine kinase (RTK), which were first discovered in tumors. Heretofore, Eph protein has been shown to be involved in various tumor biological behaviors including proliferation and progression. The occurrence of specific types of tumor is closely related to the virus infection. Virus entry is a complex process characterized by a series of events. The entry into target cells is an essential step for virus to cause diseases, which requires the fusion of the viral envelope and host cellular membrane mediated by viral glycoproteins and cellular receptors. Integrin molecules are well known as entry receptors for most herpes viruses. However, in recent years, Eph receptors and their Ephrin ligands have been reported to be involved in virus infections. The main mechanism may be the interaction between Eph receptors and conserved viral surface glycoprotein, such as the gH/gL or gB protein of the herpesviridae. This review focuses on the relationship between Eph receptor family and virus infection that summarize the processes of viruses such as EBV, KSHV, HCV, RRV, etc., infecting target cells through Eph receptors and activating its downstream signaling pathways resulting in malignancies. Finally, we discussed the perspectives to block virus infection, prevention, and treatment of viral-related tumors via Eph receptor family.
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Affiliation(s)
- Jia Wang
- Department of Immunology, Changzhi Medical College, Changzhi, 046000, Shanxi, China
| | - Xiang Zheng
- Department of Pathology, Affiliated Hospital of Guilin Medical University, Guilin, 541001, Guangxi, China
| | - Qiu Peng
- School of Basic Medical Science, Cancer Research Institute, Central South University, Changsha, 410008, Hunan, China
| | - Xuemei Zhang
- Department of Pathology, Affiliated Hospital of Guilin Medical University, Guilin, 541001, Guangxi, China.
| | - Zailong Qin
- Laboratory of Genetics and Metabolism, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Guangxi Birth Defects Research And Prevention Institute, Nanning, 530003, Guangxi, China.
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20
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Eason AB, Sin SH, Shah M, Yuan H, Phillips DJ, Droste M, Shamshiev A, Dittmer DP. DLX1008 (brolucizumab), a single-chain anti-VEGF-A antibody fragment with low picomolar affinity, leads to tumor involution in an in vivo model of Kaposi Sarcoma. PLoS One 2020; 15:e0233116. [PMID: 32407363 PMCID: PMC7224538 DOI: 10.1371/journal.pone.0233116] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 04/28/2020] [Indexed: 12/17/2022] Open
Abstract
Kaposi Sarcoma (KS) is among the most angiogenic cancers in humans and an AIDS-defining condition. KS-associated herpesvirus (KSHV) is necessary for KS development, as is vascular endothelial growth factor (VEGF-A). DLX1008 is a novel anti-VEGF-A antibody single-chain variable fragment (scFv) with low picomolar affinity for VEGF-A. In vivo imaging techniques were used to establish the efficacy of DLX1008 and to establish the mechanism of action; this included non-invasive imaging by ultrasound and optical fluorescence, verified by post-mortem histochemistry. The results showed that DLX1008 was efficacious in a KS mouse model. The NSG mouse xenografts suffered massive internal necrosis or involution, consistent with a lack of blood supply. We found that imaging by ultrasound was superior to external caliper measurements in the validation of the angiogenesis inhibitor DLX1008. Further development of DLX1008 against VEGF-dependent sarcomas is warranted.
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Affiliation(s)
- Anthony B. Eason
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, United States of America
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, United States of America
| | - Sang-Hoon Sin
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, United States of America
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, United States of America
| | - Mohsin Shah
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, United States of America
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, United States of America
| | - Hong Yuan
- Biomedical Research Imaging Center, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, United States of America
| | | | | | | | - Dirk P. Dittmer
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, United States of America
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, United States of America
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21
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A Recombinant Rhesus Monkey Rhadinovirus Deleted of Glycoprotein L Establishes Persistent Infection of Rhesus Macaques and Elicits Conventional T Cell Responses. J Virol 2020; 94:JVI.01093-19. [PMID: 31645449 DOI: 10.1128/jvi.01093-19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 09/30/2019] [Indexed: 12/19/2022] Open
Abstract
A replication-competent, recombinant strain of rhesus monkey rhadinovirus (RRV) expressing the Gag protein of SIVmac239 was constructed in the context of a glycoprotein L (gL) deletion mutation. Deletion of gL detargets the virus from Eph family receptors. The ability of this gL-minus Gag recombinant RRV to infect, persist, and elicit immune responses was evaluated after intravenous inoculation of two Mamu-A*01 + RRV-naive rhesus monkeys. Both monkeys responded with an anti-RRV antibody response, and quantitation of RRV DNA in peripheral blood mononuclear cells (PBMC) by real-time PCR revealed levels similar to those in monkeys infected with recombinant gL+ RRV. Comparison of RRV DNA levels in sorted CD3+ versus CD20+ versus CD14+ PBMC subpopulations indicated infection of the CD20+ subpopulation by the gL-minus RRV. This contrasts with results obtained with transformed B cell lines in vitro, in which deletion of gL resulted in markedly reduced infectivity. Over a period of 20 weeks, Gag-specific CD8+ T cell responses were documented by major histocompatibility complex class I (MHC-I) tetramer staining. Vaccine-induced CD8+ T cell responses, which were predominantly directed against the Mamu-A*01-restricted Gag181-189CM9 epitope, could be inhibited by blockade of MHC-I presentation. Our results indicate that gL and the interaction with Eph family receptors are dispensable for the colonization of the B cell compartment following high-dose infection by the intravenous route, which suggests the existence of alternative receptors. Further, gL-minus RRV elicits cellular immune responses that are predominantly canonical in nature.IMPORTANCE Kaposi's sarcoma-associated herpesvirus (KSHV) is associated with a substantial disease burden in sub-Saharan Africa, often in the context of human immunodeficiency virus (HIV) infection. The related rhesus monkey rhadinovirus (RRV) has shown potential as a vector to immunize monkeys with antigens from simian immunodeficiency virus (SIV), the macaque model for HIV. KSHV and RRV engage cellular receptors from the Eph family via the viral gH/gL glycoprotein complex. We have now generated a recombinant RRV that expresses the SIV Gag antigen and does not express gL. This recombinant RRV was infectious by the intravenous route, established persistent infection in the B cell compartment, and elicited strong immune responses to the SIV Gag antigen. These results argue against a role for gL and Eph family receptors in B cell infection by RRV in vivo and have implications for the development of a live-attenuated KSHV vaccine or vaccine vector.
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Dollery SJ. Towards Understanding KSHV Fusion and Entry. Viruses 2019; 11:E1073. [PMID: 31752107 PMCID: PMC6893419 DOI: 10.3390/v11111073] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/10/2019] [Accepted: 11/14/2019] [Indexed: 02/06/2023] Open
Abstract
How viruses enter cells is of critical importance to pathogenesis in the host and for treatment strategies. Over the last several years, the herpesvirus field has made numerous and thoroughly fascinating discoveries about the entry of alpha-, beta-, and gamma-herpesviruses, giving rise to knowledge of entry at the amino acid level and the realization that, in some cases, researchers had overlooked whole sets of molecules essential for entry into critical cell types. Herpesviruses come equipped with multiple envelope glycoproteins which have several roles in many aspects of infection. For herpesvirus entry, it is usual that a collective of glycoproteins is involved in attachment to the cell surface, specific interactions then take place between viral glycoproteins and host cell receptors, and then molecular interactions and triggers occur, ultimately leading to viral envelope fusion with the host cell membrane. The fact that there are multiple cell and virus molecules involved with the build-up to fusion enhances the diversity and specificity of target cell types, the cellular entry pathways the virus commandeers, and the final triggers of fusion. This review will examine discoveries relating to how Kaposi's sarcoma-associated herpesvirus (KSHV) encounters and binds to critical cell types, how cells internalize the virus, and how the fusion may occur between the viral membrane and the host cell membrane. Particular focus is given to viral glycoproteins and what is known about their mechanisms of action.
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Großkopf AK, Schlagowski S, Hörnich BF, Fricke T, Desrosiers RC, Hahn AS. EphA7 Functions as Receptor on BJAB Cells for Cell-to-Cell Transmission of the Kaposi's Sarcoma-Associated Herpesvirus and for Cell-Free Infection by the Related Rhesus Monkey Rhadinovirus. J Virol 2019; 93:e00064-19. [PMID: 31118261 PMCID: PMC6639272 DOI: 10.1128/jvi.00064-19] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 05/15/2019] [Indexed: 12/18/2022] Open
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) is the causative agent of Kaposi's sarcoma and is associated with two B cell malignancies, primary effusion lymphoma (PEL) and the plasmablastic variant of multicentric Castleman's disease. On several adherent cell types, EphA2 functions as a cellular receptor for the gH/gL glycoprotein complex of KSHV. KSHV gH/gL also has previously been found to interact weakly with other members of the Eph family of receptor tyrosine kinases (Ephs), and other A-type Ephs have been shown to be able to compensate for the absence of EphA2 using overexpression systems. However, whether these interactions are of functional consequence at endogenous protein levels has remained unclear so far. Here, we demonstrate for the first time that endogenously expressed EphA7 in BJAB B cells is critical for the cell-to-cell transmission of KSHV from producer iSLK cells to BJAB target cells. The BJAB lymphoblastoid cell line often serves as a model for B cell infection and expresses only low levels of all Eph family receptors other than EphA7. Endogenous EphA7 could be precipitated from the cellular lysate of BJAB cells using recombinant gH/gL, and knockout of EphA7 significantly reduced transmission of KSHV into BJAB target cells. Knockout of EphA5, the second most expressed A-type Eph in BJAB cells, had a similar, although less pronounced, effect on KSHV infection. Receptor function of EphA7 was conserved for cell-free infection by the related rhesus monkey rhadinovirus (RRV), which is relatively even more dependent on EphA7 for infection of BJAB cells.IMPORTANCE Infection of B cells is relevant for two KSHV-associated malignancies, the plasmablastic variant of multicentric Castleman's disease and PEL. Therefore, elucidating the process of B cell infection is important for the understanding of KSHV pathogenesis. While the high-affinity receptor for the gH/gL glycoprotein complex, EphA2, has been shown to function as an entry receptor for various types of adherent cells, the gH/gL complex can also interact with other Eph receptor tyrosine kinases with lower avidity. We analyzed the Eph interactions required for infection of BJAB cells, a model for B cell infection by KSHV. We identified EphA7 as the principal Eph receptor for infection of BJAB cells by KSHV and the related rhesus monkey rhadinovirus. While two analyzed PEL cell lines exhibited high EphA2 and low EphA7 expression, a third PEL cell line, BCBL-1, showed high EphA7 and low EphA2 expression, indicating a possible relevance for KSHV pathology.
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MESH Headings
- Animals
- B-Lymphocytes/metabolism
- B-Lymphocytes/pathology
- B-Lymphocytes/virology
- Cell Line, Tumor
- Herpesvirus 8, Human/genetics
- Herpesvirus 8, Human/metabolism
- Herpesvirus 8, Human/physiology
- Humans
- Lymphoma, Primary Effusion/metabolism
- Lymphoma, Primary Effusion/pathology
- Macaca mulatta
- Receptor, EphA7/genetics
- Receptor, EphA7/metabolism
- Receptors, Virus/genetics
- Receptors, Virus/metabolism
- Rhadinovirus/genetics
- Rhadinovirus/metabolism
- Rhadinovirus/physiology
- Viral Envelope Proteins/genetics
- Viral Envelope Proteins/metabolism
- Virus Internalization
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Affiliation(s)
- Anna K Großkopf
- Junior Research Group Herpesviruses, German Primate Center-Leibniz Institute for Primate Research, Göttingen, Germany
| | - Sarah Schlagowski
- Junior Research Group Herpesviruses, German Primate Center-Leibniz Institute for Primate Research, Göttingen, Germany
| | - Bojan F Hörnich
- Junior Research Group Herpesviruses, German Primate Center-Leibniz Institute for Primate Research, Göttingen, Germany
| | - Thomas Fricke
- Junior Research Group Herpesviruses, German Primate Center-Leibniz Institute for Primate Research, Göttingen, Germany
| | - Ronald C Desrosiers
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Alexander S Hahn
- Junior Research Group Herpesviruses, German Primate Center-Leibniz Institute for Primate Research, Göttingen, Germany
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Kaposi Sarcoma-Associated Herpesvirus Glycoprotein H Is Indispensable for Infection of Epithelial, Endothelial, and Fibroblast Cell Types. J Virol 2019; 93:JVI.00630-19. [PMID: 31142670 DOI: 10.1128/jvi.00630-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 05/15/2019] [Indexed: 02/07/2023] Open
Abstract
Kaposi sarcoma-associated herpesvirus (KSHV) is an emerging pathogen and is the causative infectious agent of Kaposi sarcoma and two malignancies of B cell origin. To date, there is no licensed KSHV vaccine. Development of an effective vaccine against KSHV continues to be limited by a poor understanding of how the virus initiates acute primary infection in vivo in diverse human cell types. The role of glycoprotein H (gH) in herpesvirus entry mechanisms remains largely unresolved. To characterize the requirement for KSHV gH in the viral life cycle and in determination of cell tropism, we generated and characterized a mutant KSHV in which expression of gH was abrogated. Using a bacterial artificial chromosome containing a complete recombinant KSHV genome and recombinant DNA technology, we inserted stop codons into the gH coding region. We used electron microscopy to reveal that the gH-null mutant virus assembled and exited from cells normally, compared to wild-type virus. Using purified virions, we assessed infectivity of the gH-null mutant in diverse mammalian cell types in vitro Unlike wild-type virus or a gH-containing revertant, the gH-null mutant was unable to infect any of the epithelial, endothelial, or fibroblast cell types tested. However, its ability to infect B cells was equivocal and remains to be investigated in vivo due to generally poor infectivity in vitro Together, these results suggest that gH is critical for KSHV infection of highly permissive cell types, including epithelial, endothelial, and fibroblast cells.IMPORTANCE All homologues of herpesvirus gH studied to date have been implicated in playing an essential role in viral infection of diverse permissive cell types. However, the role of gH in the mechanism of KSHV infection remains largely unresolved. In this study, we generated a gH-null mutant KSHV and provided evidence that deficiency of gH expression did not affect viral particle assembly or egress. Using the gH-null mutant, we showed that gH was indispensable for KSHV infection of epithelial, endothelial, and fibroblast cells in vitro This suggests that gH is an important target for the development of a KSHV prophylactic vaccine to prevent initial viral infection.
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Gammaherpesvirus entry and fusion: A tale how two human pathogenic viruses enter their host cells. Adv Virus Res 2019; 104:313-343. [PMID: 31439152 DOI: 10.1016/bs.aivir.2019.05.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The prototypical human γ-herpesviruses Epstein-Barr virus (EBV) and Kaposi Sarcoma-associated herpesvirus (KSHV) are involved in the development of malignancies. Like all herpesviruses, they share the establishment of latency, the typical architecture, and the conserved fusion machinery to initiate infection. The fusion machinery reflects virus-specific adaptations due to the requirements of the respective herpesvirus. For example, EBV evolved a tropism switch involving either the B- or epithelial cell-tropism complexes to activate fusion driven by gB. Most of the EBV entry proteins and their cellular receptors have been crystallized providing molecular details of the initial steps of infection. For KSHV, a variety of entry and binding receptors has also been reported but the mechanism how receptor binding activates gB-driven fusion is not as well understood as that for EBV. However, the downstream signaling pathways that promote the early steps of KSHV entry are well described. This review summarizes the current knowledge of the key players involved in EBV and KSHV entry and the cell-type specific mechanisms that allow infection of a wide variety of cell types.
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