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Verbeek R, Vandekerckhove L, Van Cleemput J. Update on human herpesvirus 7 pathogenesis and clinical aspects as a roadmap for future research. J Virol 2024; 98:e0043724. [PMID: 38717112 DOI: 10.1128/jvi.00437-24] [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] [Indexed: 06/14/2024] Open
Abstract
Human herpesvirus 7 (HHV-7) is a common virus that is associated with various human diseases including febrile syndromes, dermatological lesions, neurological defects, and transplant complications. Still, HHV-7 remains one of the least studied members of all human betaherpesviruses. In addition, HHV-7-related research is mostly confined to case reports, while in vitro or in vivo studies unraveling basic virology, transmission mechanisms, and viral pathogenesis are sparse. Here, we discuss HHV-7-related literature linking clinical syndromes to the viral life cycle, epidemiology, and viral immunopathogenesis. Based on our review, we propose a hypothetical model of HHV-7 pathogenesis inside its host. Furthermore, we identify important knowledge gaps and recommendations for future research to better understand HHV-7 diseases and improve therapeutic interventions.
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Affiliation(s)
- Rianne Verbeek
- HIV Cure Research Center, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Linos Vandekerckhove
- HIV Cure Research Center, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Jolien Van Cleemput
- HIV Cure Research Center, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
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Characterization of the HHV-6B U20 Immunoevasin. J Virol 2023; 97:e0189022. [PMID: 36688652 PMCID: PMC9973003 DOI: 10.1128/jvi.01890-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Roseoloviruses (human herpesvirus 6A [HHV-6A], -6B, and -7) infect >90% of the human population during early childhood and are thought to remain latent or persistent throughout the life of the host. As such, these viruses are among the most pervasive and stealthy of all viruses; they must necessarily excel at escaping immune detection throughout the life of the host, and yet, very little is known about how these viruses so successfully escape host defenses. Here, we characterize the expression, trafficking, and posttranslational modifications of the HHV6B U20 gene product, which is encoded within a block of genes unique to the roseoloviruses. HHV-6B U20 trafficked slowly through the secretory system, receiving several posttranslational modifications to its N-linked glycans, indicative of surface-expressed glycoproteins, and eventually reaching the cell surface before being internalized. Interestingly, U20 is also phosphorylated on at least one Ser, Thr, or Tyr residue. These results provide a framework to understand the role(s) of U20 in evading host defenses. IMPORTANCE The roseolovirus U20 proteins are virus-encoded integral membrane glycoproteins possessing class I major histocompatibility complex (MHC)-like folds. Surprisingly, although U20 proteins from HHV-6A and -6B share 92% identity, recent studies ascribe different functions to HHV6A U20 and HHV6B U20. HHV6A U20 was shown to downregulate NKG2D ligands, while HHV6B U20 was shown to inhibit tumor necrosis factor alpha (TNF-α)-induced apoptosis during nonproductive infection with HHV6B (E. Kofod-Olsen, K. Ross-Hansen, M. H. Schleimann, D. K. Jensen, et al., J Virol 86:11483-11492, 2012, https://doi.org/10.1128/jvi.00847-12; A. E. Chaouat, B. Seliger, O. Mandelboim, D. Schmiedel, Front Immunol 12:714799, 2021, https://doi.org/10.3389/fimmu.2021.714799). Here, we have performed cell biological and biochemical characterization of the trafficking, glycosylation, and posttranslational modifications occurring on HHV6B U20.
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Studying the Interactions of U24 from HHV-6 in Order to Further Elucidate Its Potential Role in MS. Viruses 2022; 14:v14112384. [PMID: 36366483 PMCID: PMC9696605 DOI: 10.3390/v14112384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/27/2022] [Accepted: 10/27/2022] [Indexed: 01/31/2023] Open
Abstract
A number of studies have suggested that human herpesvirus 6A (HHV-6A) may play a role in multiple sclerosis (MS). Three possible hypotheses have been investigated: (1) U24 from HHV-6A (U24-6A) mimics myelin basic protein (MBP) through analogous phosphorylation and interaction with Fyn-SH3; (2) U24-6A affects endocytic recycling by binding human neural precursor cell (NPC) expressed developmentally down-regulated protein 4-like WW3* domain (hNedd4L-WW3*); and (3) MS patients who express Killer Cell Immunoglobulin Like Receptor 2DL2 (KIR2DL2) on natural killer (NK) cells are more susceptible to HHV-6 infection. In this contribution, we examined the validity of these propositions by investigating the interactions of U24 from HHV-6B (U24-6B), a variant less commonly linked to MS, with Fyn-SH3 and hNedd4L-WW3* using heteronuclear single quantum coherence (HSQC) nuclear magnetic resonance (NMR) titrations and isothermal titration calorimetry (ITC). In addition, the importance of phosphorylation and the specific role of U24 in NK cell activation in MS patients were examined. Overall, the findings allowed us to shed light into the models linking HHV-6 to MS and the involvement of U24.
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Weaver GC, Arya R, Schneider CL, Hudson AW, Stern LJ. Structural Models for Roseolovirus U20 And U21: Non-Classical MHC-I Like Proteins From HHV-6A, HHV-6B, and HHV-7. Front Immunol 2022; 13:864898. [PMID: 35444636 PMCID: PMC9013968 DOI: 10.3389/fimmu.2022.864898] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Accepted: 03/08/2022] [Indexed: 01/08/2023] Open
Abstract
Human roseolovirus U20 and U21 are type I membrane glycoproteins that have been implicated in immune evasion by interfering with recognition of classical and non-classical MHC proteins. U20 and U21 are predicted to be type I glycoproteins with extracytosolic immunoglobulin-like domains, but detailed structural information is lacking. AlphaFold and RoseTTAfold are next generation machine-learning-based prediction engines that recently have revolutionized the field of computational three-dimensional protein structure prediction. Here, we review the structural biology of viral immunoevasins and the current status of computational structure prediction algorithms. We use these computational tools to generate structural models for U20 and U21 proteins, which are predicted to adopt MHC-Ia-like folds with closed MHC platforms and immunoglobulin-like domains. We evaluate these structural models and place them within current understanding of the structural basis for viral immune evasion of T cell and natural killer cell recognition.
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Affiliation(s)
- Grant C. Weaver
- Immunology and Microbiology Graduate Program, Morningside Graduate School of Biomedical Sciences, UMass Chan Medical School, Worcester, MA, United States
- Department of Pathology, UMass Chan Medical School, Worcester, MA, United States
| | - Richa Arya
- Department of Pathology, UMass Chan Medical School, Worcester, MA, United States
| | | | - Amy W. Hudson
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Lawrence J. Stern
- Immunology and Microbiology Graduate Program, Morningside Graduate School of Biomedical Sciences, UMass Chan Medical School, Worcester, MA, United States
- Department of Pathology, UMass Chan Medical School, Worcester, MA, United States
- Department of Biochemistry and Molecular Biotechnology, UMass Chan Medical School, Worcester, MA, United States
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5
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Viral Proteins with PxxP and PY Motifs May Play a Role in Multiple Sclerosis. Viruses 2022; 14:v14020281. [PMID: 35215874 PMCID: PMC8879583 DOI: 10.3390/v14020281] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/19/2022] [Accepted: 01/26/2022] [Indexed: 02/04/2023] Open
Abstract
Multiple sclerosis (MS) is a debilitating disease that arises from immune system attacks to the protective myelin sheath that covers nerve fibers and ensures optimal communication between brain and body. Although the cause of MS is unknown, a number of factors, which include viruses, have been identified as increasing the risk of displaying MS symptoms. Specifically, the ubiquitous and highly prevalent Epstein–Barr virus, human herpesvirus 6, cytomegalovirus, varicella–zoster virus, and other viruses have been identified as potential triggering agents. In this review, we examine the specific role of proline-rich proteins encoded by these viruses and their potential role in MS at a molecular level.
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Abstract
Like all herpesviruses, the roseoloviruses (HHV6A, -6B, and -7) establish lifelong infection within their host, requiring these viruses to evade host antiviral responses. One common host-evasion strategy is the downregulation of host-encoded, surface-expressed glycoproteins. Roseoloviruses have been shown to evade the host immune response by downregulating NK-activating ligands, class I MHC, and the TCR/CD3 complex. To more globally identify glycoproteins that are differentially expressed on the surface of HHV6A-infected cells, we performed cell surface capture of N-linked glycoproteins present on the surface of T cells infected with HHV6A, and compared these to proteins present on the surface of uninfected T cells. We found that the protein tyrosine phosphatase CD45 is downregulated in T cells infected with HHV6A. We also demonstrated that CD45 is similarly downregulated in cells infected with HHV7. CD45 is essential for signaling through the T cell receptor and, as such, is necessary for developing a fully functional immune response. Interestingly, the closely related betaherpesviruses human cytomegalovirus (HCMV) and murine cytomegalovirus (MCMV) have also separately evolved unique mechanisms to target CD45. While HCMV and MCMV target CD45 signaling and trafficking, HHV6A acts to downregulate CD45 transcripts. IMPORTANCE Human herpesviruses-6 and -7 infect essentially 100% of the world's population before the age of 5 and then remain latent or persistent in their host throughout life. As such, these viruses are among the most pervasive and stealthy of all viruses. Host immune cells rely on the presence of surface-expressed proteins to identify and target virus-infected cells. Here, we investigated the changes that occur to proteins expressed on the cell surface of T cells after infection with human herpesvirus-6A. We discovered that HHV-6A infection results in a reduction of CD45 on the surface of infected T cells and impaired activation in response to T cell receptor stimulation.
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Bhavsar T, Crane GM. Immunodeficiency-Related Lymphoid Proliferations: New Insights With Relevance to Practice. Curr Hematol Malig Rep 2020; 15:360-371. [PMID: 32535851 DOI: 10.1007/s11899-020-00594-1] [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] [Indexed: 12/19/2022]
Abstract
PURPOSE OF REVIEW Our understanding of risk factors and mechanisms underlying immunosuppression-related lymphoproliferative disorders continues to evolve. An increasing number of patients are living with altered immune status due to HIV, solid organ or hematopoietic stem cell transplant, treatment of autoimmune disease, or advanced age. This review covers advances in understanding, emerging trends, and revisions to diagnostic guidelines. RECENT FINDINGS The tumor microenvironment, including interactions between the host immune system and tumor cells, is of increasing interest in the setting of immunosuppression. While some forms of lymphoproliferative disease are associated with unique risk factors, common mechanisms are also emerging. Indolent forms, such as Epstein-Barr virus positive mucocutaneous ulcer, are important to recognize. As methods to modulate the immune system evolve, more data are needed to understand and minimize lymphoproliferative disease risk. A better understanding of individual risk factors and common mechanisms underlying immunosuppression-related lymphoproliferations will ultimately enable improved prevention and treatment of these disorders.
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Affiliation(s)
- Tapan Bhavsar
- Department of Pathology and Laboratory Medicine, George Washington School of Medicine, Washington, DC, USA
| | - Genevieve M Crane
- Robert J. Tomsich Pathology and Laboratory Medicine Institute, Cleveland Clinic, Cleveland, OH, USA.
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8
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Abstract
The WW domain is a modular protein structure that recognizes the proline-rich Pro-Pro-x-Tyr (PPxY) motif contained in specific target proteins. The compact modular nature of the WW domain makes it ideal for mediating interactions between proteins in complex networks and signaling pathways of the cell (e.g. the Hippo pathway). As a result, WW domains play key roles in a plethora of both normal and disease processes. Intriguingly, RNA and DNA viruses have evolved strategies to hijack cellular WW domain-containing proteins and thereby exploit the modular functions of these host proteins for various steps of the virus life cycle, including entry, replication, and egress. In this review, we summarize key findings in this rapidly expanding field, in which new virus-host interactions continue to be identified. Further unraveling of the molecular aspects of these crucial virus-host interactions will continue to enhance our fundamental understanding of the biology and pathogenesis of these viruses. We anticipate that additional insights into these interactions will help support strategies to develop a new class of small-molecule inhibitors of viral PPxY-host WW-domain interactions that could be used as antiviral therapeutics.
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Affiliation(s)
- Ariel Shepley-McTaggart
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Hao Fan
- Bioinformatics Institute, Agency for Science, Technology, and Research (A*STAR), 30 Biopolis Street, Matrix #07-01, Singapore 138671.,Department of Biological Sciences (DBS), National University of Singapore, Singapore 119077.,Center for Computational Biology, DUKE-NUS Medical School, Singapore 169857
| | - Marius Sudol
- Department of Physiology, National University of Singapore, Singapore 119077.,Laboratory of Cancer Signaling and Domainopathies, Yong Loo Li School of Medicine, Block MD9, 2 Medical Drive #04-01, Singapore 117597.,Mechanobiology Institute, T-Lab, 5A Engineering Drive 1, Singapore 117411.,Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Ronald N Harty
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
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Morgens DW, Chan C, Kane AJ, Weir NR, Li A, Dubreuil MM, Tsui CK, Hess GT, Lavertu A, Han K, Polyakov N, Zhou J, Handy EL, Alabi P, Dombroski A, Yao D, Altman RB, Sello JK, Denic V, Bassik MC. Retro-2 protects cells from ricin toxicity by inhibiting ASNA1-mediated ER targeting and insertion of tail-anchored proteins. eLife 2019; 8:48434. [PMID: 31674906 PMCID: PMC6858068 DOI: 10.7554/elife.48434] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 10/28/2019] [Indexed: 12/11/2022] Open
Abstract
The small molecule Retro-2 prevents ricin toxicity through a poorly-defined mechanism of action (MOA), which involves halting retrograde vesicle transport to the endoplasmic reticulum (ER). CRISPRi genetic interaction analysis revealed Retro-2 activity resembles disruption of the transmembrane domain recognition complex (TRC) pathway, which mediates post-translational ER-targeting and insertion of tail-anchored (TA) proteins, including SNAREs required for retrograde transport. Cell-based and in vitro assays show that Retro-2 blocks delivery of newly-synthesized TA-proteins to the ER-targeting factor ASNA1 (TRC40). An ASNA1 point mutant identified using CRISPR-mediated mutagenesis abolishes both the cytoprotective effect of Retro-2 against ricin and its inhibitory effect on ASNA1-mediated ER-targeting. Together, our work explains how Retro-2 prevents retrograde trafficking of toxins by inhibiting TA-protein targeting, describes a general CRISPR strategy for predicting the MOA of small molecules, and paves the way for drugging the TRC pathway to treat broad classes of viruses known to be inhibited by Retro-2.
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Affiliation(s)
- David W Morgens
- Department of Genetics, Stanford University, Stanford, United States
| | - Charlene Chan
- Department of Molecular and Cellular Biology, Northwest Labs, Harvard University, Cambridge, United States
| | - Andrew J Kane
- Department of Molecular and Cellular Biology, Northwest Labs, Harvard University, Cambridge, United States
| | - Nicholas R Weir
- Department of Molecular and Cellular Biology, Northwest Labs, Harvard University, Cambridge, United States
| | - Amy Li
- Department of Genetics, Stanford University, Stanford, United States
| | | | - C Kimberly Tsui
- Department of Genetics, Stanford University, Stanford, United States
| | - Gaelen T Hess
- Department of Genetics, Stanford University, Stanford, United States
| | - Adam Lavertu
- Biomedical Informatics Training Program, Stanford University, Stanford, United States
| | - Kyuho Han
- Department of Genetics, Stanford University, Stanford, United States
| | - Nicole Polyakov
- Department of Molecular and Cellular Biology, Northwest Labs, Harvard University, Cambridge, United States
| | - Jing Zhou
- Department of Molecular and Cellular Biology, Northwest Labs, Harvard University, Cambridge, United States
| | - Emma L Handy
- Department of Chemistry, Brown University, Providence, United States
| | - Philip Alabi
- Department of Chemistry, Brown University, Providence, United States
| | - Amanda Dombroski
- Department of Chemistry, Brown University, Providence, United States
| | - David Yao
- Department of Genetics, Stanford University, Stanford, United States
| | - Russ B Altman
- Department of Genetics, Stanford University, Stanford, United States.,Bioengineering, Stanford University, Stanford, United States
| | - Jason K Sello
- Department of Chemistry, Brown University, Providence, United States
| | - Vladimir Denic
- Department of Molecular and Cellular Biology, Northwest Labs, Harvard University, Cambridge, United States
| | - Michael C Bassik
- Department of Genetics, Stanford University, Stanford, United States.,Program in Cancer Biology, Stanford University, Stanford, United States.,Stanford University Chemistry, Engineering, and Medicine for Human Health (ChEM-H), Stanford, United States
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10
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Tiwari S, Lapierre J, Ojha CR, Martins K, Parira T, Dutta RK, Caobi A, Garbinski L, Ceyhan Y, Esteban-Lopez M, El-Hage N. Signaling pathways and therapeutic perspectives related to environmental factors associated with multiple sclerosis. J Neurosci Res 2018; 96:1831-1846. [PMID: 30204260 PMCID: PMC7167107 DOI: 10.1002/jnr.24322] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 08/09/2018] [Accepted: 08/13/2018] [Indexed: 12/16/2022]
Abstract
Multiple sclerosis (MS) is an immune-mediated demyelinating disorder of unknown etiology. Both genetic-susceptibility and environment exposures, including vitamin D deficiency, Epstein-Barr viral and Herpesvirus (HHV-6) infections are strongly implicated in the activation of T cells and MS-pathogenesis. Despite precise knowledge of how these factors could be operating alone or in combination to facilitate and aggravate the disease progression, it is clear that prolonged induction of inflammatory molecules and recruitment of other immune cells by the activated T cells results in demyelination and axonal damage. It is imperative to understand the risk factors associated with MS progression and how these factors contribute to disease pathology. Understanding of the underlying mechanisms of what factors triggers activation of T cells to attack myelin antigen are important to strategize therapeutics and therapies against MS. Current review provides a detailed literature to understand the role of both pathogenic and non-pathogenic factors on the impact of MS.
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Affiliation(s)
- Sneham Tiwari
- Departments of Immunology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida
| | - Jessica Lapierre
- Departments of Immunology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida
| | - Chet Raj Ojha
- Departments of Immunology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida
| | - Kyle Martins
- Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida
| | - Tiyash Parira
- Departments of Immunology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida
| | - Rajib Kumar Dutta
- Departments of Immunology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida
| | - Allen Caobi
- Departments of Immunology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida
| | - Luis Garbinski
- Cell Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida
| | - Yasemin Ceyhan
- Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida
| | - Maria Esteban-Lopez
- Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida
| | - Nazira El-Hage
- Departments of Immunology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida
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Abstract
Nedd4 is a family of ubiquitin E3 ligases that regulate numerous cellular processes. In this report, we showed that alpha- and beta-herpesviruses have membrane proteins that regulate the function of the Nedd4 family members. Although the homology search score was quite low, UL56 of herpes simplex virus type 1 and 2, ORF0 of varicella-zoster virus, UL42 of human cytomegalovirus, and U24 of human herpesvirus 6A, 6B, and 7 all possess at least one PPxY (PY) motif in their cytoplasmic domain, and are able to bind with Itch, a member of the Nedd4 family. These viral proteins altered the localization of Itch and decreased Itch expression in co-expressing cells. In addition, these viral proteins reduced the production of retrovirus vectors through the regulation of the Nedd4 family of proteins. U24, but not the other proteins, effectively reduced CD3ε expression on the T cell surface. These viral molecules are thought to contribute to the specific function of each virus through the regulation of Nedd4 family activity.
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Telford M, Navarro A, Santpere G. Whole genome diversity of inherited chromosomally integrated HHV-6 derived from healthy individuals of diverse geographic origin. Sci Rep 2018; 8:3472. [PMID: 29472617 PMCID: PMC5823862 DOI: 10.1038/s41598-018-21645-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 01/31/2018] [Indexed: 12/13/2022] Open
Abstract
Human herpesviruses 6-A and -B (HHV-6A, HHV-6B) are ubiquitous in human populations worldwide. These viruses have been associated with several diseases such as multiple sclerosis, Hodgkin's lymphoma or encephalitis. Despite of the need to understand the genetic diversity and geographic stratification of these viruses, the availability of complete viral sequences from different populations is still limited. Here, we present nine new inherited chromosomally integrated HHV-6 sequences from diverse geographical origin which were generated through target DNA enrichment on lymphoblastoid cell lines derived from healthy individuals. Integration with available HHV-6 sequences allowed the assessment of HHV-6A and -6B phylogeny, patterns of recombination and signatures of natural selection. Analysis of the intra-species variability showed differences between A and B diversity levels and revealed that the HHV-6B reference (Z29) is an uncommon sequence, suggesting the need for an alternative reference sequence. Signs of geographical variation are present and more defined in HHV-6A, while they appear partly masked by recombination in HHV-6B. Finally, we conducted a scan for signatures of selection in protein coding genes that yielded at least 6 genes (4 and 2 respectively for the A and B species) showing significant evidence for accelerated evolution, and 1 gene showing evidence of positive selection in HHV-6A.
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Affiliation(s)
- Marco Telford
- Institute of Evolutionary Biology (UPF-CSIC), Departament de Ciències Experimentals i la Salut, Universitat Pompeu Fabra, PRBB, Barcelona, Catalonia, Spain
| | - Arcadi Navarro
- Institute of Evolutionary Biology (UPF-CSIC), Departament de Ciències Experimentals i la Salut, Universitat Pompeu Fabra, PRBB, Barcelona, Catalonia, Spain.
- National Institute for Bioinformatics (INB), PRBB, Barcelona, Catalonia, Spain.
- Institució Catalana de Recerca i Estudis Avançats (ICREA), PRBB, Barcelona, Catalonia, Spain.
- Center for Genomic Regulation (CRG), PRBB, Barcelona, Catalonia, Spain.
| | - Gabriel Santpere
- Institute of Evolutionary Biology (UPF-CSIC), Departament de Ciències Experimentals i la Salut, Universitat Pompeu Fabra, PRBB, Barcelona, Catalonia, Spain.
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, 06510, USA.
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13
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Liu L, Zhou Q, Xie Y, Zuo L, Zhu F, Lu J. Extracellular vesicles: novel vehicles in herpesvirus infection. Virol Sin 2017; 32:349-356. [PMID: 29116589 PMCID: PMC6704204 DOI: 10.1007/s12250-017-4073-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 10/09/2017] [Indexed: 12/12/2022] Open
Abstract
Herpesviruses are remarkable pathogens that have evolved multiple mechanisms to evade host immunity, ensuring their proliferation and egress. Among these mechanisms, herpesviruses utilize elaborate extracellular vesicles, including exosomes, for the intricate interplay between infected host and recipient cells. Herpesviruses incorporate genome expression products and direct cellular products into exosomal cargoes. These components alter the content and function of exosomes released from donor cells, thus affecting the downstream signalings of recipient cells. In this way, herpesviruses hijack exosomal pathways to ensure their survival and persistence, and exosomes are emerging as critical mediators for virus infection-associated intercellular communication and microenvironment alteration. In this review, the function and effects of exosomes in herpesvirus infection will be discussed, so that we will have a better understanding about the pathogenesis of herpesviruses.
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Affiliation(s)
- Lingzhi Liu
- The Key Laboratory of Carcinogenesis of the Chinese Ministry of Health, Xiangya Hospital, Central South University, Changsha, 410080, China
- Cancer Research Institute, Central South University, Changsha, 410078, China
- Department of Microbiology, School of Basic Medical Science, Central South University, Changsha, 410078, China
| | - Quan Zhou
- Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian, 116024, China
| | - Yan Xie
- The Key Laboratory of Carcinogenesis of the Chinese Ministry of Health, Xiangya Hospital, Central South University, Changsha, 410080, China
- Cancer Research Institute, Central South University, Changsha, 410078, China
- Department of Microbiology, School of Basic Medical Science, Central South University, Changsha, 410078, China
| | - Lielian Zuo
- The Key Laboratory of Carcinogenesis of the Chinese Ministry of Health, Xiangya Hospital, Central South University, Changsha, 410080, China
- Cancer Research Institute, Central South University, Changsha, 410078, China
- Department of Microbiology, School of Basic Medical Science, Central South University, Changsha, 410078, China
| | - Fanxiu Zhu
- The Key Laboratory of Carcinogenesis of the Chinese Ministry of Health, Xiangya Hospital, Central South University, Changsha, 410080, China
- Department of Biological Science, Florida State University, Tallahassee, 32306, USA
| | - Jianhong Lu
- The Key Laboratory of Carcinogenesis of the Chinese Ministry of Health, Xiangya Hospital, Central South University, Changsha, 410080, China.
- Cancer Research Institute, Central South University, Changsha, 410078, China.
- Department of Microbiology, School of Basic Medical Science, Central South University, Changsha, 410078, China.
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14
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Abstract
The release of membrane-bound vesicles from cells is being increasingly recognized as a mechanism of intercellular communication. Extracellular vesicles (EVs) or exosomes are produced by virus-infected cells and are thought to be involved in intercellular communication between infected and uninfected cells. Viruses, in particular oncogenic viruses and viruses that establish chronic infections, have been shown to modulate the production and content of EVs. Viral microRNAs, proteins and even entire virions can be incorporated into EVs, which can affect the immune recognition of viruses or modulate neighbouring cells. In this Review, we discuss the roles that EVs have during viral infection to either promote or restrict viral replication in target cells. We will also discuss our current understanding of the molecular mechanisms that underlie these roles, the potential consequences for the infected host and possible future diagnostic applications.
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15
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Sang Y, Zhang R, Creagh AL, Haynes CA, Straus SK. Interactions of U24 from Roseolovirus with WW domains: canonical vs noncanonical. Biochem Cell Biol 2017; 95:350-358. [PMID: 28314105 DOI: 10.1139/bcb-2016-0250] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
U24 is a C-terminal membrane-anchored protein found in both human herpes virus type 6 and 7 (HHV-6 and HHV-7), with an N-terminal segment that is rich in prolines (PPxY motif in both HHV-6A and 7; PxxP motif in HHV-6A). Previous work has shown that U24 interacts strongly with Nedd4 WW domains, in particular, hNedd4L-WW3*. It was also shown that this interaction depends strongly on the nature of the amino acids that are upstream from the PY motif in U24. In this contribution, data was obtained from pull-downs, isothermal titration calorimetry, and NMR to further determine what modulates U24:WW domain interactions. Specifically, 3 non-canonical WW domains from human Smad ubiquitination regulatory factor (Smurf), namely hSmurf2-WW2, hSmurf2-WW3, and a tandem construct hSmurf2-WW2 + 3, were studied. Overall, the interactions between U24 and these Smurf WW domains were found to be weaker than those in U24:Nedd4 WW domain pairs, suggesting that U24 function is tightly linked to specific E3 ubiqitin ligases.
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Affiliation(s)
- Yurou Sang
- a Department of Chemistry, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada
| | - Rui Zhang
- a Department of Chemistry, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada
| | - A Louise Creagh
- b Michael Smith Laboratories and Department of Chemical and Biological Engineering, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada
| | - Charles A Haynes
- b Michael Smith Laboratories and Department of Chemical and Biological Engineering, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada
| | - Suzana K Straus
- a Department of Chemistry, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada
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Sang Y, Zhang R, Scott WRP, Creagh AL, Haynes CA, Straus SK. U24 from Roseolovirus interacts strongly with Nedd4 WW Domains. Sci Rep 2017; 7:39776. [PMID: 28051106 PMCID: PMC5209733 DOI: 10.1038/srep39776] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 11/28/2016] [Indexed: 01/20/2023] Open
Abstract
U24 is a protein found in both roseoloviruses Human Herpes Virus type 6 and 7 (HHV-6 and HHV-7), with an N-terminus that is rich in prolines (PY motif in both HHV-6A and 7; PxxP motif in HHV-6A). Previous work has shown that the interaction between U24 and WW domains is important for endocytic recycling of T-cell receptors, but a cognate ligand was never identified. In this contribution, data was obtained from pull-downs, ITC, NMR and molecular dynamics simulations to show that a specific interaction exists between U24 and Nedd4 WW domains. ITC experiments were also carried out for U24 from HHV-6A phosphorylated at Thr6 (pU24-6A) and a peptide containing the PY motif from Nogo-A, a protein implicated in both the initial inflammatory and the neurodegenerative phases of multiple sclerosis (MS). The results suggest that phosphorylation of U24 from HHV-6A may be crucial for its potential role in MS.
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Affiliation(s)
- Yurou Sang
- Department of Chemistry, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Rui Zhang
- Department of Chemistry, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Walter R P Scott
- Department of Chemistry, The University of British Columbia, Vancouver, British Columbia, Canada
| | - A Louise Creagh
- Michael Smith Laboratories and Department of Chemical and Biological Engineering, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Charles A Haynes
- Michael Smith Laboratories and Department of Chemical and Biological Engineering, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Suzana K Straus
- Department of Chemistry, The University of British Columbia, Vancouver, British Columbia, Canada
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Koshizuka T, Tanaka K, Suzutani T. Degradation of host ubiquitin E3 ligase Itch by human cytomegalovirus UL42. J Gen Virol 2016; 97:196-208. [DOI: 10.1099/jgv.0.000336] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Affiliation(s)
- Tetsuo Koshizuka
- Department of Microbiology, Fukushima Medical University School of Medicine, 1 Hikarigaoka, Fukushima 960-1295, Japan
| | - Keiichiro Tanaka
- Department of Microbiology, Fukushima Medical University School of Medicine, 1 Hikarigaoka, Fukushima 960-1295, Japan
| | - Tatsuo Suzutani
- Department of Microbiology, Fukushima Medical University School of Medicine, 1 Hikarigaoka, Fukushima 960-1295, Japan
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Jasirwan C, Tang H, Kawabata A, Mori Y. The human herpesvirus 6 U21-U24 gene cluster is dispensable for virus growth. Microbiol Immunol 2015; 59:48-53. [PMID: 25346365 DOI: 10.1111/1348-0421.12208] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 10/01/2014] [Accepted: 10/24/2014] [Indexed: 10/24/2022]
Abstract
Human herpesvirus 6 (HHV-6) is a T-lymphotrophic virus belongs to the genus Roseolovirus within the beta herpesvirus subfamily. The U20-U24 gene cluster is unique to Roseoloviruses; however, both their function and whether they are essential for virus growth is unknown. Recently, bacterial artificial chromosome (BAC) techniques have been used to investigate HHV-6A. This study describes generation of a virus genome lacking U21-U24 (HHV-6ABACΔU21-24) and shows that infectious virus particles can be reconstituted from this BAC DNA. Our data indicate that the HHV-6 U21-U24 gene cluster is dispensable for virus propagation.
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Affiliation(s)
- Chyntia Jasirwan
- Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Hyogo, Kobe, 650-0017, Japan
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Leibovitch EC, Jacobson S. Evidence linking HHV-6 with multiple sclerosis: an update. Curr Opin Virol 2014; 9:127-33. [PMID: 25462444 PMCID: PMC4269240 DOI: 10.1016/j.coviro.2014.09.016] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 09/25/2014] [Accepted: 09/26/2014] [Indexed: 11/17/2022]
Abstract
Following reports of elevated antiviral antibodies in MS patient sera and viral DNA detection in MS plaques nearly two decades ago, the neurovirology community has actively explored how herpesviruses such as HHV-6 might be involved in MS disease pathogenesis. Though findings across the field are non-uniform, an emerging consensus of viral correlates with disease course and evidence of HHV-6-specific immune responses in the CNS provide compelling evidence for a role, direct or indirect, of this virus in MS. Ultimately, the only way to demonstrate the involvement, or lack thereof, of HHV-6 or other herpesviruses in this disease is through a controlled clinical trial of an efficacious antiviral drug.
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Affiliation(s)
- Emily C Leibovitch
- Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA; Institute for Biomedical Sciences, School of Medicine and Health Sciences of The George Washington University, Washington, DC, USA
| | - Steven Jacobson
- Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
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20
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Roseoloviruses and their modulation of host defenses. Curr Opin Virol 2014; 9:178-87. [DOI: 10.1016/j.coviro.2014.09.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 09/23/2014] [Accepted: 09/26/2014] [Indexed: 12/27/2022]
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Sang Y, Tait AR, Scott WRP, Creagh AL, Kumar P, Haynes CA, Straus SK. Probing the interaction between U24 and the SH3 domain of Fyn tyrosine kinase. Biochemistry 2014; 53:6092-102. [PMID: 25225878 DOI: 10.1021/bi500945x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The putative membrane protein U24 from HHV-6A shares a seven-residue sequence identity (which includes a PxxP motif) with myelin basic protein (MBP), a protein responsible for the compaction of the myelin sheath in the central nervous system. U24 from HHV-6A also shares a PPxY motif with U24 from the related virus HHV-7, allowing them both to block early endosomal recycling. Recently, MBP has been shown to have protein-protein interactions with a range of proteins, including proteins containing SH3 domains. Given that this interaction is mediated by the proline-rich segment in MBP, and that similar proline-rich segments are found in U24, we investigate here whether U24 also interacts with SH3 domain-containing proteins and what the nature of that interaction might be. The implications of a U24-Fyn tyrosine kinase SH3 domain interaction are discussed in terms of the hypothesis that U24 may function like MBP through molecular mimicry, potentially contributing to the disease state of multiple sclerosis or other demyelinating disorders.
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Affiliation(s)
- Yurou Sang
- Department of Chemistry, University of British Columbia , 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada
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22
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Characterization of the human herpesvirus 6A U23 gene. Virology 2013; 450-451:98-105. [PMID: 24503071 DOI: 10.1016/j.virol.2013.12.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2013] [Revised: 10/01/2013] [Accepted: 12/04/2013] [Indexed: 11/21/2022]
Abstract
Human herpesvirus 6 (HHV-6), which replicates abundantly in T cells, belongs to the Roseolovirus genus within the betaherpesvirus subfamily. Members of the Roseolovirus genus encode seven unique genes, U20, U21, U23, U24, U24A, U26, and U100. The present study focused on one of these, U23, by analyzing the characteristics of its gene product in HHV-6A-infected cells. The results indicated that the U23 protein was expressed at the late phase of infection as a glycoprotein, but was not incorporated into virions, and mostly stayed within the trans Golgi network (TGN) in HHV-6A-infected cells. Furthermore, analysis using a U23-defective mutant virus showed that the gene is nonessential for viral replication in vitro.
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23
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Tait AR, Straus SK. Overexpression and purification of U24 from human herpesvirus type-6 in E. coli: unconventional use of oxidizing environments with a maltose binding protein-hexahistine dual tag to enhance membrane protein yield. Microb Cell Fact 2011; 10:51. [PMID: 21714924 PMCID: PMC3155487 DOI: 10.1186/1475-2859-10-51] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Accepted: 06/29/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Obtaining membrane proteins in sufficient quantity for biophysical study and biotechnological applications has been a difficult task. Use of the maltose binding protein/hexahistidine dual tag system with E.coli as an expression host is emerging as a high throughput method to enhance membrane protein yield, solubility, and purity, but fails to be effective for certain proteins. Optimizing the variables in this system to fine-tune for efficiency can ultimately be a daunting task. To identify factors critical to success in this expression system, we have selected to study U24, a novel membrane protein from Human Herpesvirus type-6 with potent immunosuppressive ability and a possible role in the pathogenesis of the disease multiple sclerosis. RESULTS We expressed full-length U24 as a C-terminal fusion to a maltose binding protein/hexahistidine tag and examined the effects of temperature, growth medium type, cell strain type, oxidizing vs. reducing conditions and periplasmic vs. cytoplasmic expression location. Temperature appeared to have the greatest effect on yield; at 37°C full-length protein was either poorly expressed (periplasm) or degraded (cytoplasm) whereas at 18°C, expression was improved especially in the periplasm of C41(DE3) cells and in the cytoplasm of oxidizing Δtrx/Δgor mutant strains, Origami 2 and SHuffle. Expression of the fusion protein in these strains were estimated to be 3.2, 5.3 and 4.3 times greater, respectively, compared to commonly-used BL21(DE3) cells. We found that U24 is isolated with an intramolecular disulfide bond under these conditions, and we probed whether this disulfide bond was critical to high yield expression of full-length protein. Expression analysis of a C21SC37S cysteine-free mutant U24 demonstrated that this disulfide was not critical for full-length protein expression, but it is more likely that strained metabolic conditions favour factors which promote protein expression. This hypothesis is supported by the fact that use of minimal media could enhance protein production compared to nutrient-rich LB media. CONCLUSIONS We have found optimal conditions for heterologous expression of U24 from Human Herpesvirus type-6 in E.coli and have demonstrated that milligram quantities of pure protein can be obtained. Strained metabolic conditions such as low temperature, minimal media and an oxidizing environment appeared essential for high-level, full-length protein production and this information may be useful for expressing other membrane proteins of interest.
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Affiliation(s)
- Andrew R Tait
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, V6T 1Z1, Canada
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24
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Horst D, Favaloro V, Vilardi F, van Leeuwen HC, Garstka MA, Hislop AD, Rabu C, Kremmer E, Rickinson AB, High S, Dobberstein B, Ressing ME, Wiertz EJHJ. EBV protein BNLF2a exploits host tail-anchored protein integration machinery to inhibit TAP. THE JOURNAL OF IMMUNOLOGY 2011; 186:3594-605. [PMID: 21296983 DOI: 10.4049/jimmunol.1002656] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
EBV, the prototypic human γ(1)-herpesvirus, persists for life in infected individuals, despite the presence of vigorous antiviral immunity. CTLs play an important role in the protection against viral infections, which they detect through recognition of virus-encoded peptides presented in the context of HLA class I molecules at the cell surface. The viral peptides are generated in the cytosol and are transported into the endoplasmic reticulum (ER) by TAP. The EBV-encoded lytic-phase protein BNLF2a acts as a powerful inhibitor of TAP. Consequently, loading of antigenic peptides onto HLA class I molecules is hampered, and recognition of BNLF2a-expressing cells by cytotoxic T cells is avoided. In this study, we characterize BNLF2a as a tail-anchored (TA) protein and elucidate its mode of action. Its hydrophilic N-terminal domain is located in the cytosol, whereas its hydrophobic C-terminal domain is inserted into membranes posttranslationally. TAP has no role in membrane insertion of BNLF2a. Instead, Asna1 (also named TRC40), a cellular protein involved in posttranslational membrane insertion of TA proteins, is responsible for integration of BNLF2a into the ER membrane. Asna1 is thereby required for efficient BNLF2a-mediated HLA class I downregulation. To optimally accomplish immune evasion, BNLF2a is composed of two specialized domains: its C-terminal tail anchor ensures membrane integration and ER retention, whereas its cytosolic N terminus accomplishes inhibition of TAP function. These results illustrate how EBV exploits a cellular pathway for TA protein biogenesis to achieve immune evasion, and they highlight the exquisite adaptation of this virus to its host.
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Affiliation(s)
- Daniëlle Horst
- Department of Medical Microbiology, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
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