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Woottum M, Yan S, Sayettat S, Grinberg S, Cathelin D, Bekaddour N, Herbeuval JP, Benichou S. Macrophages: Key Cellular Players in HIV Infection and Pathogenesis. Viruses 2024; 16:288. [PMID: 38400063 PMCID: PMC10893316 DOI: 10.3390/v16020288] [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: 01/22/2024] [Revised: 02/12/2024] [Accepted: 02/13/2024] [Indexed: 02/25/2024] Open
Abstract
Although cells of the myeloid lineages, including tissue macrophages and conventional dendritic cells, were rapidly recognized, in addition to CD4+ T lymphocytes, as target cells of HIV-1, their specific roles in the pathophysiology of infection were initially largely neglected. However, numerous studies performed over the past decade, both in vitro in cell culture systems and in vivo in monkey and humanized mouse animal models, led to growing evidence that macrophages play important direct and indirect roles as HIV-1 target cells and in pathogenesis. It has been recently proposed that macrophages are likely involved in all stages of HIV-1 pathogenesis, including virus transmission and dissemination, but above all, in viral persistence through the establishment, together with latently infected CD4+ T cells, of virus reservoirs in many host tissues, the major obstacle to virus eradication in people living with HIV. Infected macrophages are indeed found, very often as multinucleated giant cells expressing viral antigens, in almost all lymphoid and non-lymphoid tissues of HIV-1-infected patients, where they can probably persist for long period of time. In addition, macrophages also likely participate, directly as HIV-1 targets or indirectly as key regulators of innate immunity and inflammation, in the chronic inflammation and associated clinical disorders observed in people living with HIV, even in patients receiving effective antiretroviral therapy. The main objective of this review is therefore to summarize the recent findings, and also to revisit older data, regarding the critical functions of tissue macrophages in the pathophysiology of HIV-1 infection, both as major HIV-1-infected target cells likely found in almost all tissues, as well as regulators of innate immunity and inflammation during the different stages of HIV-1 pathogenesis.
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Affiliation(s)
- Marie Woottum
- Institut Cochin, Inserm U1016, CNRS UMR-8104, Université Paris Cité, 75014 Paris, France; (M.W.); (S.Y.); (S.S.)
| | - Sen Yan
- Institut Cochin, Inserm U1016, CNRS UMR-8104, Université Paris Cité, 75014 Paris, France; (M.W.); (S.Y.); (S.S.)
| | - Sophie Sayettat
- Institut Cochin, Inserm U1016, CNRS UMR-8104, Université Paris Cité, 75014 Paris, France; (M.W.); (S.Y.); (S.S.)
| | - Séverine Grinberg
- CNRS UMR-8601, Université Paris Cité, 75006 Paris, France; (S.G.); (D.C.); (N.B.); (J.-P.H.)
| | - Dominique Cathelin
- CNRS UMR-8601, Université Paris Cité, 75006 Paris, France; (S.G.); (D.C.); (N.B.); (J.-P.H.)
| | - Nassima Bekaddour
- CNRS UMR-8601, Université Paris Cité, 75006 Paris, France; (S.G.); (D.C.); (N.B.); (J.-P.H.)
| | - Jean-Philippe Herbeuval
- CNRS UMR-8601, Université Paris Cité, 75006 Paris, France; (S.G.); (D.C.); (N.B.); (J.-P.H.)
| | - Serge Benichou
- Institut Cochin, Inserm U1016, CNRS UMR-8104, Université Paris Cité, 75014 Paris, France; (M.W.); (S.Y.); (S.S.)
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Abstract
Human and simian immunodeficiency viruses (HIVs and SIVs, respectively) encode several small proteins (Vif, Vpr, Nef, Vpu, and Vpx) that are called accessory because they are not generally required for viral replication in cell culture. However, they play complex and important roles for viral immune evasion and spread in vivo. Here, we discuss the diverse functions and the relevance of the viral protein U (Vpu) that is expressed from a bicistronic RNA during the late stage of the viral replication cycle and found only in HIV-1 and closely related SIVs. It is well established that Vpu counteracts the restriction factor tetherin, mediates degradation of the primary viral CD4 receptors, and inhibits activation of the transcription factor nuclear factor kappa B. Recent studies identified additional activities and provided new insights into the sophisticated mechanisms by which Vpu enhances and prolongs the release of fully infectious viral particles. In addition, it has been shown that Vpu prevents superinfection not only by degrading CD4 but also by modulating DNA repair mechanisms to promote degradation of nuclear viral complementary DNA in cells that are already productively infected.
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Affiliation(s)
- Meta Volcic
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany;
| | - Lisa Wiesmüller
- Division of Gynecological Oncology, Department of Obstetrics and Gynecology, Ulm University Medical Center, Ulm, Germany
| | - Frank Kirchhoff
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany;
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Wang XF, Zhang X, Ma W, Li J, Wang X. Host cell restriction factors of equine infectious anemia virus. Virol Sin 2023; 38:485-496. [PMID: 37419416 PMCID: PMC10436108 DOI: 10.1016/j.virs.2023.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 07/03/2023] [Indexed: 07/09/2023] Open
Abstract
Equine infectious anemia virus (EIAV) is a member of the lentivirus genus in the Retroviridae family and is considered an animal model for HIV/AIDS research. An attenuated EIAV vaccine, which was successfully developed in the 1970s by classical serial passage techniques, is the first and only lentivirus vaccine that has been widely used to date. Restriction factors are cellular proteins that provide an early line of defense against viral replication and spread by interfering with various critical steps in the viral replication cycle. However, viruses have evolved specific mechanisms to overcome these host barriers through adaptation. The battle between the viruses and restriction factors is actually a natural part of the viral replication process, which has been well studied in human immunodeficiency virus type 1 (HIV-1). EIAV has the simplest genome composition of all lentiviruses, making it an intriguing subject for understanding how the virus employs its limited viral proteins to overcome restriction factors. In this review, we summarize the current literature on the interactions between equine restriction factors and EIAV. The features of equine restriction factors and the mechanisms by which the EIAV counteract the restriction suggest that lentiviruses employ diverse strategies to counteract innate immune restrictions. In addition, we present our insights on whether restriction factors induce alterations in the phenotype of the attenuated EIAV vaccine.
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Affiliation(s)
- Xue-Feng Wang
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Xiangmin Zhang
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Weiwei Ma
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Jiwei Li
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Xiaojun Wang
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin 150069, China.
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Kayesh MEH, Kohara M, Tsukiyama-Kohara K. Toll-like Receptor Response to Human Immunodeficiency Virus Type 1 or Co-Infection with Hepatitis B or C Virus: An Overview. Int J Mol Sci 2023; 24:ijms24119624. [PMID: 37298575 DOI: 10.3390/ijms24119624] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/29/2023] [Accepted: 05/31/2023] [Indexed: 06/12/2023] Open
Abstract
Toll-like receptors (TLRs) are evolutionarily conserved pattern recognition receptors that play important roles in the early detection of pathogen-associated molecular patterns and shaping innate and adaptive immune responses, which may influence the consequences of infection. Similarly to other viral infections, human immunodeficiency virus type 1 (HIV-1) also modulates the host TLR response; therefore, a proper understanding of the response induced by human HIV-1 or co-infection with hepatitis B virus (HBV) or hepatitis C virus (HCV), due to the common mode of transmission of these viruses, is essential for understanding HIV-1 pathogenesis during mono- or co-infection with HBV or HCV, as well as for HIV-1 cure strategies. In this review, we discuss the host TLR response during HIV-1 infection and the innate immune evasion mechanisms adopted by HIV-1 for infection establishment. We also examine changes in the host TLR response during HIV-1 co-infection with HBV or HCV; however, this type of study is extremely scarce. Moreover, we discuss studies investigating TLR agonists as latency-reverting agents and immune stimulators towards new strategies for curing HIV. This understanding will help develop a new strategy for curing HIV-1 mono-infection or co-infection with HBV or HCV.
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Affiliation(s)
- Mohammad Enamul Hoque Kayesh
- Department of Microbiology and Public Health, Faculty of Animal Science and Veterinary Medicine, Patuakhali Science and Technology University, Barishal 8210, Bangladesh
| | - Michinori Kohara
- Department of Microbiology and Cell Biology, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Kyoko Tsukiyama-Kohara
- Transboundary Animal Diseases Centre, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima 890-0065, Japan
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Judith D, Versapuech M, Bejjani F, Palaric M, Verlhac P, Kuster A, Lepont L, Gallois-Montbrun S, Janvier K, Berlioz-Torrent C. ATG5 selectively engages virus-tethered BST2/tetherin in an LC3C-associated pathway. Proc Natl Acad Sci U S A 2023; 120:e2217451120. [PMID: 37155854 PMCID: PMC10193943 DOI: 10.1073/pnas.2217451120] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 03/15/2023] [Indexed: 05/10/2023] Open
Abstract
Bone marrow stromal antigen 2 (BST2)/tetherin is a restriction factor that reduces HIV-1 dissemination by tethering virus at the cell surface. BST2 also acts as a sensor of HIV-1 budding, establishing a cellular antiviral state. The HIV-1 Vpu protein antagonizes BST2 antiviral functions via multiple mechanisms, including the subversion of an LC3C-associated pathway, a key cell intrinsic antimicrobial mechanism. Here, we describe the first step of this viral-induced LC3C-associated process. This process is initiated at the plasma membrane through the recognition and internalization of virus-tethered BST2 by ATG5, an autophagy protein. ATG5 and BST2 assemble as a complex, independently of the viral protein Vpu and ahead of the recruitment of the ATG protein LC3C. The conjugation of ATG5 with ATG12 is dispensable for this interaction. ATG5 recognizes cysteine-linked homodimerized BST2 and specifically engages phosphorylated BST2 tethering viruses at the plasma membrane, in an LC3C-associated pathway. We also found that this LC3C-associated pathway is used by Vpu to attenuate the inflammatory responses mediated by virion retention. Overall, we highlight that by targeting BST2 tethering viruses, ATG5 acts as a signaling scaffold to trigger an LC3C-associated pathway induced by HIV-1 infection.
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Affiliation(s)
- Delphine Judith
- Université Paris Cité, Institut Cochin, INSERM, CNRS, F-75014Paris, France
| | - Margaux Versapuech
- Université Paris Cité, Institut Cochin, INSERM, CNRS, F-75014Paris, France
| | - Fabienne Bejjani
- Université Paris Cité, Institut Cochin, INSERM, CNRS, F-75014Paris, France
| | - Marjory Palaric
- Université Paris Cité, Institut Cochin, INSERM, CNRS, F-75014Paris, France
| | - Pauline Verlhac
- Université Paris Cité, Institut Cochin, INSERM, CNRS, F-75014Paris, France
| | - Aurelia Kuster
- Université Paris Cité, Institut Cochin, INSERM, CNRS, F-75014Paris, France
| | - Leslie Lepont
- Université Paris Cité, Institut Cochin, INSERM, CNRS, F-75014Paris, France
| | | | - Katy Janvier
- Université Paris Cité, Institut Cochin, INSERM, CNRS, F-75014Paris, France
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Stewart H, Palmulli R, Johansen KH, McGovern N, Shehata OM, Carnell GW, Jackson HK, Lee JS, Brown JC, Burgoyne T, Heeney JL, Okkenhaug K, Firth AE, Peden AA, Edgar JR. Tetherin antagonism by SARS-CoV-2 enhances virus release: multiple mechanisms including ORF3a-mediated defective retrograde traffic. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2022:2021.01.06.425396. [PMID: 33442692 PMCID: PMC7805449 DOI: 10.1101/2021.01.06.425396] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The antiviral restriction factor, tetherin, blocks the release of several different families of enveloped viruses, including the Coronaviridae. Tetherin is an interferon-induced protein that forms parallel homodimers between the host cell and viral particles, linking viruses to the surface of infected cells and inhibiting their release. We demonstrated that SARS-CoV-2 infection causes tetherin downregulation, and that tetherin depletion from cells enhances SARS-CoV-2 viral titres. We investigated the potential viral proteins involved in abrogating tetherin function and found that SARS-CoV-2 ORF3a reduces tetherin localisation within biosynthetic organelles via reduced retrograde recycling and increases tetherin localisation to late endocytic organelles. By removing tetherin from the Coronavirus budding compartments, ORF3a enhances virus release. We also found expression of Spike protein caused a reduction in cellular tetherin levels. Our results confirm that tetherin acts as a host restriction factor for SARS-CoV-2 and highlight the multiple distinct mechanisms by which SARS-CoV-2 subverts tetherin function.
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Affiliation(s)
- Hazel Stewart
- Department of Pathology, University of Cambridge, Cambridge. CB2 1QP. UK
| | - Roberta Palmulli
- Department of Pathology, University of Cambridge, Cambridge. CB2 1QP. UK
| | - Kristoffer H. Johansen
- Department of Pathology, University of Cambridge, Cambridge. CB2 1QP. UK
- Laboratory of Immune Systems Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, USA
| | - Naomi McGovern
- Department of Pathology, University of Cambridge, Cambridge. CB2 1QP. UK
| | - Ola M. Shehata
- Department of Biomedical Science, University of Sheffield, Firth Court, Sheffield. S10 2TN. UK
| | - George W. Carnell
- Department of Veterinary Medicine, University of Cambridge, Cambridge. CB3 0ES. UK
| | - Hannah K. Jackson
- Department of Pathology, University of Cambridge, Cambridge. CB2 1QP. UK
| | - Jin S. Lee
- Department of Pathology, University of Cambridge, Cambridge. CB2 1QP. UK
| | - Jonathan C. Brown
- Department of Infectious Disease, Imperial College London, London. W2 1PG. UK
| | - Thomas Burgoyne
- Royal Brompton Hospital, Guy’s and St Thomas’ NHS Foundation Trust, London. SW3 6NP. UK
- UCL Institute of Ophthalmology, University College London, London. EC1V 9EL. UK
| | - Jonathan L. Heeney
- Department of Veterinary Medicine, University of Cambridge, Cambridge. CB3 0ES. UK
| | - Klaus Okkenhaug
- Department of Pathology, University of Cambridge, Cambridge. CB2 1QP. UK
| | - Andrew E. Firth
- Department of Pathology, University of Cambridge, Cambridge. CB2 1QP. UK
| | - Andrew A. Peden
- Department of Biomedical Science, University of Sheffield, Firth Court, Sheffield. S10 2TN. UK
| | - James R. Edgar
- Department of Pathology, University of Cambridge, Cambridge. CB2 1QP. UK
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7
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Robinson CA, Lyddon TD, Gil HM, Evans DT, Kuzmichev YV, Richard J, Finzi A, Welbourn S, Rasmussen L, Nebane NM, Gupta VV, Ananthan S, Cai Z, Wonderlich ER, Augelli-Szafran CE, Bostwick R, Ptak RG, Schader SM, Johnson MC. Novel Compound Inhibitors of HIV-1 NL4-3 Vpu. Viruses 2022; 14:v14040817. [PMID: 35458546 PMCID: PMC9024541 DOI: 10.3390/v14040817] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 04/06/2022] [Accepted: 04/09/2022] [Indexed: 12/14/2022] Open
Abstract
HIV-1 Vpu targets the host cell proteins CD4 and BST-2/Tetherin for degradation, ultimately resulting in enhanced virus spread and host immune evasion. The discovery and characterization of small molecules that antagonize Vpu would further elucidate the contribution of Vpu to pathogenesis and lay the foundation for the study of a new class of novel HIV-1 therapeutics. To identify novel compounds that block Vpu activity, we have developed a cell-based ‘gain of function’ assay that produces a positive signal in response to Vpu inhibition. To develop this assay, we took advantage of the viral glycoprotein, GaLV Env. In the presence of Vpu, GaLV Env is not incorporated into viral particles, resulting in non-infectious virions. Vpu inhibition restores infectious particle production. Using this assay, a high throughput screen of >650,000 compounds was performed to identify inhibitors that block the biological activity of Vpu. From this screen, we identified several positive hits but focused on two compounds from one structural family, SRI-41897 and SRI-42371. We developed independent counter-screens for off target interactions of the compounds and found no off target interactions. Additionally, these compounds block Vpu-mediated modulation of CD4, BST-2/Tetherin and antibody dependent cell-mediated toxicity (ADCC). Unfortunately, both SRI-41897 and SRI-42371 were shown to be specific to the N-terminal region of NL4-3 Vpu and did not function against other, more clinically relevant, strains of Vpu; however, this assay may be slightly modified to include more significant Vpu strains in the future.
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Affiliation(s)
- Carolyn A. Robinson
- Department of Molecular Microbiology and Immunology, University of Missouri, School of Medicine and the Christopher S. Bond Life Sciences Center, Columbia, MO 65211, USA; (C.A.R.); (T.D.L.); (S.W.)
| | - Terri D. Lyddon
- Department of Molecular Microbiology and Immunology, University of Missouri, School of Medicine and the Christopher S. Bond Life Sciences Center, Columbia, MO 65211, USA; (C.A.R.); (T.D.L.); (S.W.)
| | - Hwi Min Gil
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, WI 53705, USA; (H.M.G.); (D.T.E.)
| | - David T. Evans
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, WI 53705, USA; (H.M.G.); (D.T.E.)
| | - Yury V. Kuzmichev
- Infectious Disease Research, Drug Development Division, Southern Research, Frederick, MD 21701, USA; (Y.V.K.); (Z.C.); (E.R.W.); (R.G.P.); (S.M.S.)
| | - Jonathan Richard
- Centre de Recherche du CHUM, Montréal, QC HX2 0A9, Canada; (J.R.); (A.F.)
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, QC HX2 0A9, Canada
| | - Andrés Finzi
- Centre de Recherche du CHUM, Montréal, QC HX2 0A9, Canada; (J.R.); (A.F.)
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, QC HX2 0A9, Canada
| | - Sarah Welbourn
- Department of Molecular Microbiology and Immunology, University of Missouri, School of Medicine and the Christopher S. Bond Life Sciences Center, Columbia, MO 65211, USA; (C.A.R.); (T.D.L.); (S.W.)
| | - Lynn Rasmussen
- High-Throughput Screening Center, Drug Discovery Division, Southern Research, Birmingham, AL 35205, USA; (L.R.); (N.M.N.); (R.B.)
| | - N. Miranda Nebane
- High-Throughput Screening Center, Drug Discovery Division, Southern Research, Birmingham, AL 35205, USA; (L.R.); (N.M.N.); (R.B.)
| | - Vandana V. Gupta
- Department of Chemistry, Drug Discovery Division, Southern Research, Birmingham, AL 35205, USA; (V.V.G.); (S.A.); (C.E.A.-S.)
| | - Sam Ananthan
- Department of Chemistry, Drug Discovery Division, Southern Research, Birmingham, AL 35205, USA; (V.V.G.); (S.A.); (C.E.A.-S.)
| | - Zhaohui Cai
- Infectious Disease Research, Drug Development Division, Southern Research, Frederick, MD 21701, USA; (Y.V.K.); (Z.C.); (E.R.W.); (R.G.P.); (S.M.S.)
| | - Elizabeth R. Wonderlich
- Infectious Disease Research, Drug Development Division, Southern Research, Frederick, MD 21701, USA; (Y.V.K.); (Z.C.); (E.R.W.); (R.G.P.); (S.M.S.)
| | - Corinne E. Augelli-Szafran
- Department of Chemistry, Drug Discovery Division, Southern Research, Birmingham, AL 35205, USA; (V.V.G.); (S.A.); (C.E.A.-S.)
| | - Robert Bostwick
- High-Throughput Screening Center, Drug Discovery Division, Southern Research, Birmingham, AL 35205, USA; (L.R.); (N.M.N.); (R.B.)
| | - Roger G. Ptak
- Infectious Disease Research, Drug Development Division, Southern Research, Frederick, MD 21701, USA; (Y.V.K.); (Z.C.); (E.R.W.); (R.G.P.); (S.M.S.)
| | - Susan M. Schader
- Infectious Disease Research, Drug Development Division, Southern Research, Frederick, MD 21701, USA; (Y.V.K.); (Z.C.); (E.R.W.); (R.G.P.); (S.M.S.)
| | - Marc C. Johnson
- Department of Molecular Microbiology and Immunology, University of Missouri, School of Medicine and the Christopher S. Bond Life Sciences Center, Columbia, MO 65211, USA; (C.A.R.); (T.D.L.); (S.W.)
- Correspondence:
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8
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Prévost J, Richard J, Gasser R, Medjahed H, Kirchhoff F, Hahn BH, Kappes JC, Ochsenbauer C, Duerr R, Finzi A. Detection of the HIV-1 Accessory Proteins Nef and Vpu by Flow Cytometry Represents a New Tool to Study Their Functional Interplay within a Single Infected CD4 + T Cell. J Virol 2022; 96:e0192921. [PMID: 35080425 PMCID: PMC8941894 DOI: 10.1128/jvi.01929-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 01/16/2022] [Indexed: 11/20/2022] Open
Abstract
The HIV-1 Nef and Vpu accessory proteins are known to protect infected cells from antibody-dependent cellular cytotoxicity (ADCC) responses by limiting exposure of CD4-induced (CD4i) envelope (Env) epitopes at the cell surface. Although both proteins target the host receptor CD4 for degradation, the extent of their functional redundancy is unknown. Here, we developed an intracellular staining technique that permits the intracellular detection of both Nef and Vpu in primary CD4+ T cells by flow cytometry. Using this method, we show that the combined expression of Nef and Vpu predicts the susceptibility of HIV-1-infected primary CD4+ T cells to ADCC by HIV+ plasma. We also show that Vpu cannot compensate for the absence of Nef, thus providing an explanation for why some infectious molecular clones that carry a LucR reporter gene upstream of Nef render infected cells more susceptible to ADCC responses. Our method thus represents a new tool to dissect the biological activity of Nef and Vpu in the context of other host and viral proteins within single infected CD4+ T cells. IMPORTANCE HIV-1 Nef and Vpu exert several biological functions that are important for viral immune evasion, release, and replication. Here, we developed a new method allowing simultaneous detection of these accessory proteins in their native form together with some of their cellular substrates. This allowed us to show that Vpu cannot compensate for the lack of a functional Nef, which has implications for studies that use Nef-defective viruses to study ADCC responses.
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Affiliation(s)
- Jérémie Prévost
- Centre de Recherche du CHUM, Montreal, Quebec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec, Canada
| | - Jonathan Richard
- Centre de Recherche du CHUM, Montreal, Quebec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec, Canada
| | - Romain Gasser
- Centre de Recherche du CHUM, Montreal, Quebec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec, Canada
| | | | - Frank Kirchhoff
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Beatrice H. Hahn
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - John C. Kappes
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Christina Ochsenbauer
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Ralf Duerr
- Department of Microbiology, New York University School of Medicine, New York, New York, USA
| | - Andrés Finzi
- Centre de Recherche du CHUM, Montreal, Quebec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec, Canada
- Department of Microbiology and Immunology, McGill University, Montreal, Quebec, Canada
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9
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SIVgsn-99CM71 Vpu employs different amino acids to antagonize human and greater spot-nosed monkey BST-2. J Virol 2021; 96:e0152721. [PMID: 34878886 DOI: 10.1128/jvi.01527-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Viral protein U (Vpu) is an accessory protein encoded by human immunodeficiency virus type 1 (HIV-1) and certain simian immunodeficiency virus (SIV) strains. Some of these viruses were reported to use Vpu to overcome restriction by BST-2 of their natural hosts. Our own recent report revealed that Vpu of SIVgsn-99CM71 (SIVgsn71) antagonizes human BST-2 through two AxxxxxxxW motifs (A22W30 and A25W33) whereas antagonizing BST-2 of its natural host, greater spot-nosed monkey (GSN), involved only A22W30 motif. Here we show that residues A22, A25, W30, and W33 of SIVgsn71 Vpu are all essential to antagonize human BST-2, while, neither single mutation of A22 nor W30 affected the ability to antagonize GSN BST-2. Similar to A18, which is located in the middle of the A14xxxxxxxW22 motif in HIV-1 NL4-3 Vpu and is essential to antagonize human BST-2, A29, located in the middle of the A25W33 motif of SIVgsn71 Vpu was found to be necessary for antagonizing human but not GSN BST-2. Further mutational analyses revealed that residues L21 and K32 of SIVgsn71 Vpu were also essential for antagonizing human BST-2. On the other hand, the ability of SIVgsn71 Vpu to target GSN BST-2 was unaffected by single amino acid substitutions but required multiple mutations to render SIVgsn71 Vpu inactive against GSN BST-2. These results suggest additional requirements for SIVgsn71 Vpu antagonizing human BST-2, implying evolution of the bst-2 gene under strong selective pressure. Importance Genes related to survival against life-threating pathogens are important determinants of natural selection in animal evolution. For instance, BST-2, a protein showing broad-spectrum antiviral activity, shows polymorphisms entailing different phenotypes even among primate species, suggesting that the bst-2 gene of primates has been subject to strong selective pressure during evolution. At the same time, viruses readily adapt to these evolutionary changes. Thus, we found that Vpu of an SIVgsn isolate (SIVgsn-99CM71) can target BST-2 from humans as well as from its natural host thus potentially facilitating zoonosis. Here we mapped residues in SIVgsn71 Vpu potentially contributing to cross-species transmission. We found that the requirements for targeting human BST-2 are distinct from and more complex than those for targeting GSN BST-2. Our results suggest that the human bst-2 gene might have evolved to acquire more restrictive phenotype than GSN bst-2 against viral proteins after being derived from their common ancestor.
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10
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Stoneham CA, Langer S, De Jesus PD, Wozniak JM, Lapek J, Deerinck T, Thor A, Pache L, Chanda SK, Gonzalez DJ, Ellisman M, Guatelli J. A combined EM and proteomic analysis places HIV-1 Vpu at the crossroads of retromer and ESCRT complexes: PTPN23 is a Vpu-cofactor. PLoS Pathog 2021; 17:e1009409. [PMID: 34843601 PMCID: PMC8659692 DOI: 10.1371/journal.ppat.1009409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 12/09/2021] [Accepted: 10/08/2021] [Indexed: 11/21/2022] Open
Abstract
The HIV-1 accessory protein Vpu modulates membrane protein trafficking and degradation to provide evasion of immune surveillance. Targets of Vpu include CD4, HLAs, and BST-2. Several cellular pathways co-opted by Vpu have been identified, but the picture of Vpu's itinerary and activities within membrane systems remains incomplete. Here, we used fusion proteins of Vpu and the enzyme ascorbate peroxidase (APEX2) to compare the ultrastructural locations and the proximal proteomes of wild type Vpu and Vpu-mutants. The proximity-omes of the proteins correlated with their ultrastructural locations and placed wild type Vpu near both retromer and ESCRT-0 complexes. Hierarchical clustering of protein abundances across the mutants was essential to interpreting the data and identified Vpu degradation-targets including CD4, HLA-C, and SEC12 as well as Vpu-cofactors including HGS, STAM, clathrin, and PTPN23, an ALIX-like protein. The Vpu-directed degradation of BST-2 was supported by STAM and PTPN23 and to a much lesser extent by the retromer subunits Vps35 and SNX3. PTPN23 also supported the Vpu-directed decrease in CD4 at the cell surface. These data suggest that Vpu directs targets from sorting endosomes to degradation at multi-vesicular bodies via ESCRT-0 and PTPN23.
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Affiliation(s)
- Charlotte A. Stoneham
- Department of Medicine, University of California, San Diego School of Medicine and Veterans Affairs San Diego Healthcare System, La Jolla, California, United States of America
| | - Simon Langer
- Infectious and Inflammatory Disease Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
| | - Paul D. De Jesus
- Infectious and Inflammatory Disease Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
| | - Jacob M. Wozniak
- Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - John Lapek
- Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Thomas Deerinck
- National Center for Microscopy and Imaging Research, Center for Research on Biological Systems, University of California, San Diego, School of Medicine, La Jolla, California, United States of America
| | - Andrea Thor
- National Center for Microscopy and Imaging Research, Center for Research on Biological Systems, University of California, San Diego, School of Medicine, La Jolla, California, United States of America
| | - Lars Pache
- Infectious and Inflammatory Disease Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
| | - Sumit K. Chanda
- Infectious and Inflammatory Disease Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
| | - David J. Gonzalez
- Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Mark Ellisman
- National Center for Microscopy and Imaging Research, Center for Research on Biological Systems, University of California, San Diego, School of Medicine, La Jolla, California, United States of America
- Department of Neurosciences, University of California, San Diego School of Medicine, La Jolla, California, United States of America
| | - John Guatelli
- Department of Medicine, University of California, San Diego School of Medicine and Veterans Affairs San Diego Healthcare System, La Jolla, California, United States of America
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11
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Li B, Dong X, Zhang W, Chen T, Yu B, Zhao W, Yang Y, Wang X, Hu Q, Wang X. High-Throughput NanoBiT-Based Screening for Inhibitors of HIV-1 Vpu and Host BST-2 Protein Interaction. Int J Mol Sci 2021; 22:ijms22179308. [PMID: 34502213 PMCID: PMC8431494 DOI: 10.3390/ijms22179308] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Revised: 08/20/2021] [Accepted: 08/25/2021] [Indexed: 12/18/2022] Open
Abstract
Bone marrow stromal cell antigen 2 (BST-2), also known as CD317 or tetherin, has been identified as a host restriction factor that suppresses the release of enveloped viruses from host cells by physically tethering viral particles to the cell surface; however, this host defense can be subverted by multiple viruses. For example, human immunodeficiency virus (HIV)-1 encodes a specific accessory protein, viral protein U (Vpu), to counteract BST-2 by binding to it and directing its lysosomal degradation. Thus, blocking the interaction between Vpu and BST-2 will provide a promising strategy for anti-HIV therapy. Here, we report a NanoLuc Binary Technology (NanoBiT)-based high-throughput screening assay to detect inhibitors that disrupt the Vpu-BST-2 interaction. Out of more than 1000 compounds screened, four inhibitors were identified with strong activity at nontoxic concentrations. In subsequent cell-based BST-2 degradation assays, inhibitor Y-39983 HCl restored the cell-surface and total cellular level of BST-2 in the presence of Vpu. Furthermore, the Vpu-mediated enhancement of pesudotyped viral particle production was inhibited by Y-39983 HCl. Our findings indicate that our newly developed assay can be used for the discovery of potential antiviral molecules with novel mechanisms of action.
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Affiliation(s)
- Boye Li
- The Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China; (B.L.); (X.D.); (W.Z.); (T.C.); (B.Y.); (W.Z.); (Y.Y.); (X.W.)
- Center of Excellence for Environmental Safety and Biological Effects, Beijing Key Laboratory for Green Catalysis and Separation, Department of Chemistry and Biology, Beijing University of Technology, Beijing 100124, China
- Beijing International Science and Technology Cooperation Base of Antivirus Drug, Beijing University of Technology, Beijing 100124, China
| | - Xiaoxiao Dong
- The Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China; (B.L.); (X.D.); (W.Z.); (T.C.); (B.Y.); (W.Z.); (Y.Y.); (X.W.)
- Beijing International Science and Technology Cooperation Base of Antivirus Drug, Beijing University of Technology, Beijing 100124, China
| | - Wenmei Zhang
- The Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China; (B.L.); (X.D.); (W.Z.); (T.C.); (B.Y.); (W.Z.); (Y.Y.); (X.W.)
- Center of Excellence for Environmental Safety and Biological Effects, Beijing Key Laboratory for Green Catalysis and Separation, Department of Chemistry and Biology, Beijing University of Technology, Beijing 100124, China
- Beijing International Science and Technology Cooperation Base of Antivirus Drug, Beijing University of Technology, Beijing 100124, China
| | - Tian Chen
- The Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China; (B.L.); (X.D.); (W.Z.); (T.C.); (B.Y.); (W.Z.); (Y.Y.); (X.W.)
- Beijing International Science and Technology Cooperation Base of Antivirus Drug, Beijing University of Technology, Beijing 100124, China
| | - Boyang Yu
- The Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China; (B.L.); (X.D.); (W.Z.); (T.C.); (B.Y.); (W.Z.); (Y.Y.); (X.W.)
- Beijing International Science and Technology Cooperation Base of Antivirus Drug, Beijing University of Technology, Beijing 100124, China
| | - Wenyue Zhao
- The Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China; (B.L.); (X.D.); (W.Z.); (T.C.); (B.Y.); (W.Z.); (Y.Y.); (X.W.)
- Beijing International Science and Technology Cooperation Base of Antivirus Drug, Beijing University of Technology, Beijing 100124, China
| | - Yishu Yang
- The Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China; (B.L.); (X.D.); (W.Z.); (T.C.); (B.Y.); (W.Z.); (Y.Y.); (X.W.)
- Beijing International Science and Technology Cooperation Base of Antivirus Drug, Beijing University of Technology, Beijing 100124, China
| | - Xiaoli Wang
- The Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China; (B.L.); (X.D.); (W.Z.); (T.C.); (B.Y.); (W.Z.); (Y.Y.); (X.W.)
- Beijing International Science and Technology Cooperation Base of Antivirus Drug, Beijing University of Technology, Beijing 100124, China
| | - Qin Hu
- The Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China; (B.L.); (X.D.); (W.Z.); (T.C.); (B.Y.); (W.Z.); (Y.Y.); (X.W.)
- Beijing International Science and Technology Cooperation Base of Antivirus Drug, Beijing University of Technology, Beijing 100124, China
- Correspondence: (Q.H.); (X.W.)
| | - Xiayan Wang
- The Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China; (B.L.); (X.D.); (W.Z.); (T.C.); (B.Y.); (W.Z.); (Y.Y.); (X.W.)
- Center of Excellence for Environmental Safety and Biological Effects, Beijing Key Laboratory for Green Catalysis and Separation, Department of Chemistry and Biology, Beijing University of Technology, Beijing 100124, China
- Correspondence: (Q.H.); (X.W.)
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12
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Tavares LA, Januário YC, daSilva LLP. HIV-1 Hijacking of Host ATPases and GTPases That Control Protein Trafficking. Front Cell Dev Biol 2021; 9:622610. [PMID: 34307340 PMCID: PMC8295591 DOI: 10.3389/fcell.2021.622610] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 06/07/2021] [Indexed: 12/22/2022] Open
Abstract
The human immunodeficiency virus (HIV-1) modifies the host cell environment to ensure efficient and sustained viral replication. Key to these processes is the capacity of the virus to hijack ATPases, GTPases and the associated proteins that control intracellular protein trafficking. The functions of these energy-harnessing enzymes can be seized by HIV-1 to allow the intracellular transport of viral components within the host cell or to change the subcellular distribution of antiviral factors, leading to immune evasion. Here, we summarize how energy-related proteins deviate from their normal functions in host protein trafficking to aid the virus in different phases of its replicative cycle. Recent discoveries regarding the interplay among HIV-1 and host ATPases and GTPases may shed light on potential targets for pharmacological intervention.
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Affiliation(s)
- Lucas A Tavares
- Department of Cell and Molecular Biology, Center for Virology Research, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Yunan C Januário
- Department of Cell and Molecular Biology, Center for Virology Research, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Luis L P daSilva
- Department of Cell and Molecular Biology, Center for Virology Research, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
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13
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Retroviral Restriction Factors and Their Viral Targets: Restriction Strategies and Evolutionary Adaptations. Microorganisms 2020; 8:microorganisms8121965. [PMID: 33322320 PMCID: PMC7764263 DOI: 10.3390/microorganisms8121965] [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: 10/30/2020] [Revised: 11/30/2020] [Accepted: 12/08/2020] [Indexed: 12/17/2022] Open
Abstract
The evolutionary conflict between retroviruses and their vertebrate hosts over millions of years has led to the emergence of cellular innate immune proteins termed restriction factors as well as their viral antagonists. Evidence accumulated in the last two decades has substantially increased our understanding of the elaborate mechanisms utilized by these restriction factors to inhibit retroviral replication, mechanisms that either directly block viral proteins or interfere with the cellular pathways hijacked by the viruses. Analyses of these complex interactions describe patterns of accelerated evolution for these restriction factors as well as the acquisition and evolution of their virus-encoded antagonists. Evidence is also mounting that many restriction factors identified for their inhibition of specific retroviruses have broader antiviral activity against additional retroviruses as well as against other viruses, and that exposure to these multiple virus challenges has shaped their adaptive evolution. In this review, we provide an overview of the restriction factors that interfere with different steps of the retroviral life cycle, describing their mechanisms of action, adaptive evolution, viral targets and the viral antagonists that evolved to counter these factors.
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14
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Proulx J, Borgmann K, Park IW. Post-translational modifications inducing proteasomal degradation to counter HIV-1 infection. Virus Res 2020; 289:198142. [PMID: 32882242 DOI: 10.1016/j.virusres.2020.198142] [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: 02/01/2020] [Revised: 08/20/2020] [Accepted: 08/21/2020] [Indexed: 12/14/2022]
Abstract
Post-translational modifications (PTMs) are integral to regulating a wide variety of cellular processes in eukaryotic cells, such as regulation of protein stability, alteration of celluar location, protein activity modulation, and regulation of protein interactions. HIV-1, like other eukaryotic viruses, and its infected host exploit the proteasomal degradation system for their respective proliferation and survival, using various PTMs, including but not limited to ubiquitination, SUMOylation, NEDDylation, interferon-stimulated gene (ISG)ylation. Essentially all viral proteins within the virions -- and in the HIV-1-infected cells -- interact with their cellular counterparts for this degradation, utilizing ubiquitin (Ub), and the Ub-like (Ubl) modifiers less frequently, to eliminate the involved proteins throughout the virus life cycle, from the entry step to release of the assembled virus particles. Such interplay is pivotal for, on the one hand, the cell to restrict proliferation of the infecting virus, and on the other, for molecular counteraction by the virus to overcome this cellular protein-imposed restriction. Recent reports indicate that not only viral/cellular proteins but also viral/viral protein interactions play vital roles in regulating viral protein stability. We hence give an overview of the molecular processes of PTMs involved in proteasomal degradation of the viral and cellular proteins, and the viral/viral and viral/cellular protein interplay in restriction and competition for HIV-1 vs. host cell survival. Insights in this realm could open new avenues for developing therapeutics against HIV-1 via targeting specific steps of the proteasome degradation pathway during the HIV-1 life cycle.
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Affiliation(s)
- Jessica Proulx
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, 76107, United States
| | - Kathleen Borgmann
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, 76107, United States
| | - In-Woo Park
- Microbiology, Immunology, and Genetics, University of North Texas Health Science Center, Fort Worth, TX, 76107, United States.
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15
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Umviligihozo G, Cobarrubias KD, Chandrarathna S, Jin SW, Reddy N, Byakwaga H, Muzoora C, Bwana MB, Lee GQ, Hunt PW, Martin JN, Brumme CJ, Bangsberg DR, Karita E, Allen S, Hunter E, Ndung'u T, Brumme ZL, Brockman MA. Differential Vpu-Mediated CD4 and Tetherin Downregulation Functions among Major HIV-1 Group M Subtypes. J Virol 2020; 94:e00293-20. [PMID: 32376625 PMCID: PMC7343213 DOI: 10.1128/jvi.00293-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Accepted: 04/30/2020] [Indexed: 12/12/2022] Open
Abstract
Downregulation of BST-2/tetherin and CD4 by HIV-1 viral protein U (Vpu) promotes viral egress and allows infected cells to evade host immunity. Little is known however about the natural variability in these Vpu functions among the genetically diverse viral subtypes that contribute to the HIV-1 pandemic. We collected Vpu isolates from 332 treatment-naive individuals living with chronic HIV-1 infection in Uganda, Rwanda, South Africa, and Canada. Together, these Vpu isolates represent four major HIV-1 group M subtypes (A [n = 63], B [n = 84], C [n = 94], and D [n = 59]) plus intersubtype recombinants and uncommon strains (n = 32). The ability of each Vpu clone to downregulate endogenous CD4 and tetherin was quantified using flow cytometry following transfection into an immortalized T-cell line and compared to that of a reference Vpu clone derived from HIV-1 subtype B NL4.3. Overall, the median CD4 downregulation function of natural Vpu isolates was similar to that of NL4.3 (1.01 [interquartile range {IQR}, 0.86 to 1.18]), while the median tetherin downregulation function was moderately lower than that of NL4.3 (0.90 [0.79 to 0.97]). Both Vpu functions varied significantly among HIV-1 subtypes (Kruskal-Wallis P < 0.0001). Specifically, subtype C clones exhibited the lowest CD4 and tetherin downregulation activities, while subtype D and B clones were most functional for both activities. We also identified Vpu polymorphisms associated with CD4 or tetherin downregulation function and validated six of these using site-directed mutagenesis. Our results highlight the marked extent to which Vpu function varies among global HIV-1 strains, raising the possibility that natural variation in this accessory protein may contribute to viral pathogenesis and/or spread.IMPORTANCE The HIV-1 accessory protein Vpu enhances viral spread by downregulating CD4 and BST-2/tetherin on the surface of infected cells. Natural variability in these Vpu functions may contribute to HIV-1 pathogenesis, but this has not been investigated among the diverse viral subtypes that contribute to the HIV-1 pandemic. In this study, we found that Vpu function differs significantly among HIV-1 subtypes A, B, C, and D. On average, subtype C clones displayed the lowest ability to downregulate both CD4 and tetherin, while subtype B and D clones were more functional. We also identified Vpu polymorphisms that associate with functional differences among HIV-1 isolates and subtypes. Our study suggests that genetic diversity in Vpu may play an important role in the differential pathogenesis and/or spread of HIV-1.
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Affiliation(s)
- Gisele Umviligihozo
- Faculty of Health Sciences, Simon Fraser University, Vancouver, British Columbia, Canada
| | - Kyle D Cobarrubias
- Faculty of Health Sciences, Simon Fraser University, Vancouver, British Columbia, Canada
| | - Sandali Chandrarathna
- Faculty of Health Sciences, Simon Fraser University, Vancouver, British Columbia, Canada
| | - Steven W Jin
- Faculty of Health Sciences, Simon Fraser University, Vancouver, British Columbia, Canada
| | - Nicole Reddy
- University of KwaZulu-Natal, Durban, South Africa
- Africa Health Research Institute, Durban, South Africa
| | - Helen Byakwaga
- Mbarara University of Science and Technology, Mbarara, Uganda
- University of California, San Francisco, California, USA
| | - Conrad Muzoora
- Mbarara University of Science and Technology, Mbarara, Uganda
| | - Mwebesa B Bwana
- Mbarara University of Science and Technology, Mbarara, Uganda
| | - Guinevere Q Lee
- British Columbia Centre for Excellence in HIV/AIDS, Vancouver, British Columbia, Canada
| | - Peter W Hunt
- University of California, San Francisco, California, USA
| | - Jeff N Martin
- University of California, San Francisco, California, USA
| | - Chanson J Brumme
- British Columbia Centre for Excellence in HIV/AIDS, Vancouver, British Columbia, Canada
- University of British Columbia, Vancouver, British Columbia, Canada
| | - David R Bangsberg
- Oregon Health and Science University-Portland State University School of Public Health, Portland, Oregon, USA
| | - Etienne Karita
- Rwanda Zambia HIV Research Group-Projet San Francisco, Kigali, Rwanda
| | - Susan Allen
- Rwanda Zambia HIV Research Group-Projet San Francisco, Kigali, Rwanda
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia, USA
- Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
| | - Eric Hunter
- Rwanda Zambia HIV Research Group-Projet San Francisco, Kigali, Rwanda
- Emory Vaccine Center at Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, USA
| | - Thumbi Ndung'u
- University of KwaZulu-Natal, Durban, South Africa
- Africa Health Research Institute, Durban, South Africa
- Max Planck Institute for Infection Biology, Berlin, Germany
- Division of Infection and Immunity, University College London, London, United Kingdom
| | - Zabrina L Brumme
- Faculty of Health Sciences, Simon Fraser University, Vancouver, British Columbia, Canada
- British Columbia Centre for Excellence in HIV/AIDS, Vancouver, British Columbia, Canada
| | - Mark A Brockman
- Faculty of Health Sciences, Simon Fraser University, Vancouver, British Columbia, Canada
- British Columbia Centre for Excellence in HIV/AIDS, Vancouver, British Columbia, Canada
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16
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Prévost J, Edgar CR, Richard J, Trothen SM, Jacob RA, Mumby MJ, Pickering S, Dubé M, Kaufmann DE, Kirchhoff F, Neil SJD, Finzi A, Dikeakos JD. HIV-1 Vpu Downregulates Tim-3 from the Surface of Infected CD4 + T Cells. J Virol 2020; 94:e01999-19. [PMID: 31941771 PMCID: PMC7081912 DOI: 10.1128/jvi.01999-19] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 01/12/2020] [Indexed: 01/26/2023] Open
Abstract
Along with other immune checkpoints, T cell immunoglobulin and mucin domain-containing protein 3 (Tim-3) is expressed on exhausted CD4+ and CD8+ T cells and is upregulated on the surface of these cells upon infection by human immunodeficiency virus type 1 (HIV-1). Recent reports have suggested an antiviral role for Tim-3. However, the molecular determinants of HIV-1 which modulate cell surface Tim-3 levels have yet to be determined. Here, we demonstrate that HIV-1 Vpu downregulates Tim-3 from the surface of infected primary CD4+ T cells, thus attenuating HIV-1-induced upregulation of Tim-3. We also provide evidence that the transmembrane domain of Vpu is required for Tim-3 downregulation. Using immunofluorescence microscopy, we determined that Vpu is in close proximity to Tim-3 and alters its subcellular localization by directing it to Rab 5-positive (Rab 5+) vesicles and targeting it for sequestration within the trans- Golgi network (TGN). Intriguingly, Tim-3 knockdown and Tim-3 blockade increased HIV-1 replication in primary CD4+ T cells, thereby suggesting that Tim-3 expression might represent a natural immune mechanism limiting viral spread.IMPORTANCE HIV infection modulates the surface expression of Tim-3, but the molecular determinants remain poorly understood. Here, we show that HIV-1 Vpu downregulates Tim-3 from the surface of infected primary CD4+ T cells through its transmembrane domain and alters its subcellular localization. Tim-3 blockade increases HIV-1 replication, suggesting a potential negative role of this protein in viral spread that is counteracted by Vpu.
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Affiliation(s)
- Jérémie Prévost
- Centre de Recherche du CHUM, Montreal, Quebec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec, Canada
| | - Cassandra R Edgar
- Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Jonathan Richard
- Centre de Recherche du CHUM, Montreal, Quebec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec, Canada
| | - Steven M Trothen
- Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Rajesh Abraham Jacob
- Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Mitchell J Mumby
- Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Suzanne Pickering
- Department of Infectious Disease, King's College London School of Life Sciences and Medicine, Guy's Hospital, London, United Kingdom
| | - Mathieu Dubé
- Centre de Recherche du CHUM, Montreal, Quebec, Canada
| | - Daniel E Kaufmann
- Centre de Recherche du CHUM, Montreal, Quebec, Canada
- Department of Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - Frank Kirchhoff
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Stuart J D Neil
- Department of Infectious Disease, King's College London School of Life Sciences and Medicine, Guy's Hospital, London, United Kingdom
| | - Andrés Finzi
- Centre de Recherche du CHUM, Montreal, Quebec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec, Canada
- Department of Microbiology and Immunology, McGill University, Montreal, Quebec, Canada
| | - Jimmy D Dikeakos
- Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
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17
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Rashamuse TJ, Njengele Z, Coyanis EM, Sayed Y, Mosebi S, Bode ML. Design, synthesis and biological evaluation of novel 2-(5-aryl-1H-imidazol-1-yl) derivatives as potential inhibitors of the HIV-1 Vpu and host BST-2 protein interaction. Eur J Med Chem 2020; 190:112111. [PMID: 32058240 DOI: 10.1016/j.ejmech.2020.112111] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 01/17/2020] [Accepted: 01/31/2020] [Indexed: 02/07/2023]
Abstract
Novel ethyl 2-(5-aryl-1H-imidazol-1-yl)-acetates 17 and propionates 18, together with their acetic acid 19 and acetohydrazide 20 derivatives, were designed and synthesized using TosMIC chemistry. Biological evaluation of these newly synthesized scaffolds in the HIV-1 Vpu- Host BST-2 ELISA assay identified seven hits (17a, 17b, 17c, 17g, 18a, 20f and 20g) with greater than 50% inhibitory activity. These hits were validated in the HIV-1 Vpu- Host BST-2 AlphaScreen™ and six of the seven compounds were found to have comparable percentage inhibitory activities to those of the ELISA assay. Compounds 17b and 20g, with consistent percentage inhibitory activities across the two assays, had IC50 values of 11.6 ± 1.1 μM and 17.6 ± 0.9 μM in a dose response AlphaScreen™ assay. In a cell-based HIV-1 antiviral assay, compound 17b exhibited an EC50 = 6.3 ± 0.7 μM at non-toxic concentrations (CC50 = 184.5 ± 0.8 μM), whereas compound 20g displayed antiviral activity roughly equivalent to its toxicity (CC50 = 159.5 ± 0.9 μM). This data suggests that compound 17b, active in both cell-based and biochemical assays, provides a good starting point for the design of possible lead compounds for prevention of HIV-1 Vpu and host BST-2 protein binding in new anti-HIV therapeutics.
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Affiliation(s)
- Thompho J Rashamuse
- Centre for Metal-based Drug Discovery, Advanced Materials Division, Mintek, 200 Malibongwe Drive, Randburg, 2125, South Africa; Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Private Bag 3, PO WITS, 2050, South Africa
| | - Zikhona Njengele
- Centre for Metal-based Drug Discovery, Advanced Materials Division, Mintek, 200 Malibongwe Drive, Randburg, 2125, South Africa; Protein Structure-Function Research Unit, School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg, 2050, South Africa
| | - E Mabel Coyanis
- Centre for Metal-based Drug Discovery, Advanced Materials Division, Mintek, 200 Malibongwe Drive, Randburg, 2125, South Africa
| | - Yasien Sayed
- Protein Structure-Function Research Unit, School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg, 2050, South Africa
| | - Salerwe Mosebi
- Department of Life and Consumer Sciences, College of Agriculture and Environmental Sciences, University of South Africa, Private Bag X6, Florida, 1710, South Africa.
| | - Moira L Bode
- Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Private Bag 3, PO WITS, 2050, South Africa.
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18
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Vpu of a Simian Immunodeficiency Virus Isolated from Greater Spot-Nosed Monkey Antagonizes Human BST-2 via Two AxxxxxxxW Motifs. J Virol 2020; 94:JVI.01669-19. [PMID: 31666374 DOI: 10.1128/jvi.01669-19] [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: 09/30/2019] [Accepted: 10/21/2019] [Indexed: 01/20/2023] Open
Abstract
BST-2/CD317/tetherin is a host transmembrane protein that potently inhibits human immunodeficiency virus type 1 (HIV-1) virion release by tethering the nascent virions to the plasma membrane. Viral protein U (Vpu) is an accessory protein encoded by HIV-1 as well as by some simian immunodeficiency viruses (SIVs) infecting wild chimpanzees, gorillas, or monkeys (SIVcpz, SIVgor, or SIVgsn/SIVmon/SIVmus, respectively). HIV-1 Vpu directly binds to and downregulates human BST-2. The antagonism is highly species specific because the amino acid sequences of BST-2 are different among animal species. Here, we show that Vpu proteins from several SIVcpz, SIVgsn, SIVmon, or SIVmus isolates fail to antagonize human BST-2. Only Vpu from an SIVgsn isolate (SIVgsn-99CM71 [SIVgsn71]) was able to antagonize human BST-2 as well as BST-2 of its natural host, greater spot-nosed monkey (GSN). This SIVgsn Vpu interacted with human BST-2, downregulated cell surface human BST-2 expression, and facilitated HIV-1 virion release in the presence of human BST-2. While the unique 14AxxxxxxxW22 motif in the transmembrane domain of HIV-1NL4-3Vpu was reported to be important for antagonizing human BST-2, we show here that two AxxxxxxxW motifs (A22W30 and A25W33) exist in SIVgsn71 Vpu. Only the A22W30 motif was needed for SIVgsn71 Vpu to antagonize GSN BST-2, suggesting that the mechanism of this antagonism resembles that of HIV-1NL4-3 Vpu against human BST-2. Interestingly, SIVgsn71 Vpu requires two AxxxxxxxW (A22W30 and A25W33) motifs to antagonize human BST-2, suggesting an as-yet-undefined way that SIVgsn71 Vpu works against human BST-2. These results imply an evolutionary impact of primate BST-2 on lentiviral Vpu.IMPORTANCE Genetic alterations conferring a selective advantage in protecting from life-threating pathogens are maintained during evolution. In fact, the amino acid sequences of BST-2 differ among primate animals and their susceptibility to viral proteins is species specific, suggesting that such genetic diversity has arisen through the evolutionarily controlled balance between the host and pathogens. The M (main) group of HIV-1 is thought to be derived from SIVcpz, which utilizes Nef, but not Vpu, to antagonize chimpanzee BST-2. SIVcpz Nef is, however, unable to antagonize human BST-2, and Vpu was consequently chosen again as an antagonist against human BST-2 in the context of HIV-1. Studies on how Vpu lost and acquired this ability, together with the distinct mechanisms by which SIVgsn71 Vpu binds to and downregulates human or GSN BST-2, may help to explain the evolution of this lentiviral protein as a result of host-pathogen interactions.
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Hydrophobic matching of HIV-1 Vpu transmembrane helix-helix interactions is optimized for subcellular location. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:183022. [PMID: 31302078 DOI: 10.1016/j.bbamem.2019.07.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Revised: 06/06/2019] [Accepted: 07/09/2019] [Indexed: 11/21/2022]
Abstract
The HIV-1 accessory protein Vpu mediates the downregulation of several host cell proteins, an activity that is critical for viral replication in vivo. As the first step in directing cell-surface proteins to internal cellular compartments, and in many cases degradation, Vpu binds a subset of its target proteins through their transmembrane domains. Each of the known targets of Vpu are synthesized in the ER, and must traverse the different membrane environments found along the secretory pathway, thus it is important to consider how membrane composition might influence the interactions between Vpu and its targets. We have used Förster resonance energy transfer (FRET) to measure the oligomerization of Vpu with the transmembrane domains of target proteins in model membranes of varying lipid composition. Our data show that both lipid bilayer thickness and acyl chain order can significantly influence monomer-oligomer equilibria within the Vpu-target system. Changes in oligomerization levels were found to be non-specific with no single Vpu-target interaction being favored under any condition. Our analysis of the influence of the membrane environment on the strength of helix-helix interactions between Vpu and its targets in vitro suggests that the strength of Vpu-target interactions in vivo will be partially dependent on the membrane environment found in specific membrane compartments.
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Ramirez PW, Sharma S, Singh R, Stoneham CA, Vollbrecht T, Guatelli J. Plasma Membrane-Associated Restriction Factors and Their Counteraction by HIV-1 Accessory Proteins. Cells 2019; 8:E1020. [PMID: 31480747 PMCID: PMC6770538 DOI: 10.3390/cells8091020] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 08/29/2019] [Accepted: 08/30/2019] [Indexed: 02/07/2023] Open
Abstract
The plasma membrane is a site of conflict between host defenses and many viruses. One aspect of this conflict is the host's attempt to eliminate infected cells using innate and adaptive cell-mediated immune mechanisms that recognize features of the plasma membrane characteristic of viral infection. Another is the expression of plasma membrane-associated proteins, so-called restriction factors, which inhibit enveloped virions directly. HIV-1 encodes two countermeasures to these host defenses: The membrane-associated accessory proteins Vpu and Nef. In addition to inhibiting cell-mediated immune-surveillance, Vpu and Nef counteract membrane-associated restriction factors. These include BST-2, which traps newly formed virions at the plasma membrane unless counteracted by Vpu, and SERINC5, which decreases the infectivity of virions unless counteracted by Nef. Here we review key features of these two antiviral proteins, and we review Vpu and Nef, which deplete them from the plasma membrane by co-opting specific cellular proteins and pathways of membrane trafficking and protein-degradation. We also discuss other plasma membrane proteins modulated by HIV-1, particularly CD4, which, if not opposed in infected cells by Vpu and Nef, inhibits viral infectivity and increases the sensitivity of the viral envelope glycoprotein to host immunity.
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Affiliation(s)
- Peter W Ramirez
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA
- VA San Diego Healthcare System, San Diego, CA 92161, USA
| | - Shilpi Sharma
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA
- VA San Diego Healthcare System, San Diego, CA 92161, USA
| | - Rajendra Singh
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA
- VA San Diego Healthcare System, San Diego, CA 92161, USA
| | - Charlotte A Stoneham
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA
- VA San Diego Healthcare System, San Diego, CA 92161, USA
| | - Thomas Vollbrecht
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA
- VA San Diego Healthcare System, San Diego, CA 92161, USA
| | - John Guatelli
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA.
- VA San Diego Healthcare System, San Diego, CA 92161, USA.
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Wang SM, Huang KJ, Wang CT. Severe acute respiratory syndrome coronavirus spike protein counteracts BST2-mediated restriction of virus-like particle release. J Med Virol 2019; 91:1743-1750. [PMID: 31199522 PMCID: PMC7166632 DOI: 10.1002/jmv.25518] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 06/08/2019] [Indexed: 12/12/2022]
Abstract
BST2/tetherin, an interferon‐inducible antiviral factor, can block the cellular release of various enveloped viruses. We previously reported that human coronavirus 229E (HCoV‐229E) infection can alleviate the BST2 tethering of HIV‐1 virions by downregulating cell surface BST2, suggesting that coronaviruses are capable of encoding anti‐BST2 factors. Here we report our new finding that severe acute respiratory syndrome coronavirus (SARS‐CoV) spike (S) glycoprotein, similar to Vpu, is capable of antagonizing the BST2 tethering of SARS‐CoV, HCoV‐229E, and HIV‐1 virus‐like particles via BST2 downregulation. However, unlike Vpu (which downmodulates BST2 by means of proteasomal and lysosomal degradation pathways), BST2 downregulation is apparently mediated by SARS‐CoV S through the lysosomal degradation pathway only. We found that SARS‐CoV S colocalized with both BST2 and reduced cell surface BST2, suggesting an association between SARS‐CoV S and BST2 that targets the lysosomal degradation pathway. According to one recent report, SARS‐CoV ORF7a antagonizes BST2 by interfering with BST2 glycosylation1. Our data provide support for the proposal that SARS‐CoV and other enveloped viruses are capable of evolving supplementary anti‐BST2 factors in a manner that requires virus replication. Further experiments are required to determine whether the BST2‐mediated restriction of authentic SARS‐CoV virions is alleviated by the SARS‐CoV spike protein. BST2/tetherin inhibits the release of various enveloped viruses. SARS‐CoV S antagonizes the BST2 tethering of human coronavirus and HIV‐1 virus‐like particles. SARS‐CoV S colocalizes with BST2 and reduces cell surface BST2. SARS‐CoV S downregulates BST2 through lysosomal degradation pathway.
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Affiliation(s)
- Shiu-Mei Wang
- Department of Medical Research, Taipei Veterans General Hospital and Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Kuo-Jung Huang
- Department of Medical Research, Taipei Veterans General Hospital and Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Chin-Tien Wang
- Department of Medical Research, Taipei Veterans General Hospital and Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan
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Rojas VK, Park IW. Role of the Ubiquitin Proteasome System (UPS) in the HIV-1 Life Cycle. Int J Mol Sci 2019; 20:ijms20122984. [PMID: 31248071 PMCID: PMC6628307 DOI: 10.3390/ijms20122984] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 06/10/2019] [Accepted: 06/11/2019] [Indexed: 01/18/2023] Open
Abstract
Given that the ubiquitin proteasome system (UPS) is the major protein degradation process in the regulation of a wide variety of cellular processes in eukaryotic cells, including alteration of cellular location, modulation of protein activity, and regulation of protein interaction, it is reasonable to suggest that the infecting HIV-1 and the invaded hosts exploit the UPS in a contest for survival and proliferation. However, to date, regulation of the HIV-1 life cycle has been mainly explained by the stage-specific expression of HIV-1 viral genes, not by elimination processes of the synthesized proteins after completion of their duties in the infected cells, which is also quintessential for understanding the molecular processes of the virus life cycle and thereby HIV-1 pathogenesis. In fact, several previous publications have indicated that the UPS plays a critical role in the regulation of the proteasomal degradation of viral and cellular counterparts at every step of the HIV-1 life cycle, from the virus entry to release of the assembled virus particles, which is integral for the regulation of survival and proliferation of the infecting HIV-1 and to replication restriction of the invading virus in the host. However, it is unknown whether and how these individual events taking place at different stages of the HIV-1 life cycle are orchestrated as an overall strategy to overcome the restrictions conferred by the host cells. Thus, in this review, we overview the interplay between HIV-1 viral and cellular proteins for restrictions/competitions for proliferation of the virus in the infected cell, which could open a new avenue for the development of therapeutics against HIV-1 via targeting a specific step of the proteasome degradation pathway during the HIV-1 life cycle.
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Affiliation(s)
- Vivian K Rojas
- Department of Microbiology, Immunology, and Genetics, University of North Texas, Health Science Center, Fort Worth, TX 76107, USA.
| | - In-Woo Park
- Department of Microbiology, Immunology, and Genetics, University of North Texas, Health Science Center, Fort Worth, TX 76107, USA.
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23
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Prévost J, Pickering S, Mumby MJ, Medjahed H, Gendron-Lepage G, Delgado GG, Dirk BS, Dikeakos JD, Stürzel CM, Sauter D, Kirchhoff F, Bibollet-Ruche F, Hahn BH, Dubé M, Kaufmann DE, Neil SJD, Finzi A, Richard J. Upregulation of BST-2 by Type I Interferons Reduces the Capacity of Vpu To Protect HIV-1-Infected Cells from NK Cell Responses. mBio 2019; 10:e01113-19. [PMID: 31213558 PMCID: PMC6581860 DOI: 10.1128/mbio.01113-19] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 05/09/2019] [Indexed: 01/03/2023] Open
Abstract
The HIV-1 accessory protein Vpu enhances viral release by counteracting the restriction factor BST-2. Furthermore, Vpu promotes NK cell evasion by downmodulating cell surface NTB-A and PVR, known ligands of the NK cell receptors NTB-A and DNAM-1, respectively. While it has been established that Vpu's transmembrane domain (TMD) is required for the interaction and intracellular sequestration of BST-2, NTB-A, and PVR, it remains unclear how Vpu manages to target these proteins simultaneously. In this study, we show that upon upregulation, BST-2 is preferentially downregulated by Vpu over its other TMD substrates. We found that type I interferon (IFN)-mediated BST-2 upregulation greatly impairs the ability of Vpu to downregulate NTB-A and PVR. Our results suggest that occupation of Vpu by BST-2 affects its ability to downregulate other TMD substrates. Accordingly, knockdown of BST-2 increases Vpu's potency to downmodulate NTB-A and PVR in the presence of type I IFN treatment. Moreover, we show that expression of human BST-2, but not that of the macaque orthologue, decreases Vpu's capacity to downregulate NTB-A. Importantly, we show that type I IFNs efficiently sensitize HIV-1-infected cells to NTB-A- and DNAM-1-mediated direct and antibody-dependent NK cell responses. Altogether, our results reveal that type I IFNs decrease Vpu's polyfunctionality, thus reducing its capacity to protect HIV-1-infected cells from NK cell responses.IMPORTANCE The restriction factor BST-2 and the NK cell ligands NTB-A and PVR are among a growing list of membrane proteins found to be downregulated by HIV-1 Vpu. BST-2 antagonism enhances viral release, while NTB-A and PVR downmodulation contributes to NK cell evasion. However, it remains unclear how Vpu can target multiple cellular factors simultaneously. Here we provide evidence that under physiological conditions, BST-2 is preferentially targeted by Vpu over NTB-A and PVR. Specifically, we show that type I IFNs decrease Vpu's polyfunctionality by upregulating BST-2, thus reducing its capacity to protect HIV-1-infected cells from NK cell responses. This indicates that there is a hierarchy of Vpu substrates upon IFN treatment, revealing that for the virus, targeting BST-2 as part of its resistance to IFN takes precedence over evading NK cell responses. This reveals a potential weakness in HIV-1's immunoevasion mechanisms that may be exploited therapeutically to harness NK cell responses against HIV-1.
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Affiliation(s)
- Jérémie Prévost
- Centre de Recherche du CHUM, Montreal, Quebec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Québec, Canada
| | - Suzanne Pickering
- Department of Infectious Disease, King's College London School of Life Sciences and Medicine, Guy's Hospital, London, United Kingdom
| | - Mitchell J Mumby
- Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada
| | | | | | | | - Brennan S Dirk
- Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Jimmy D Dikeakos
- Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Christina M Stürzel
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Daniel Sauter
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Frank Kirchhoff
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Frederic Bibollet-Ruche
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Beatrice H Hahn
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Mathieu Dubé
- Centre de Recherche du CHUM, Montreal, Quebec, Canada
| | - Daniel E Kaufmann
- Centre de Recherche du CHUM, Montreal, Quebec, Canada
- Department of Medicine, Université de Montréal, Montreal, Quebec, Canada
- Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, California, USA
| | - Stuart J D Neil
- Department of Infectious Disease, King's College London School of Life Sciences and Medicine, Guy's Hospital, London, United Kingdom
| | - Andrés Finzi
- Centre de Recherche du CHUM, Montreal, Quebec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Québec, Canada
- Department of Microbiology and Immunology, McGill University, Montreal, Quebec, Canada
| | - Jonathan Richard
- Centre de Recherche du CHUM, Montreal, Quebec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Québec, Canada
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Sharma S, Jafari M, Bangar A, William K, Guatelli J, Lewinski MK. The C-Terminal End of HIV-1 Vpu Has a Clade-Specific Determinant That Antagonizes BST-2 and Facilitates Virion Release. J Virol 2019; 93:e02315-18. [PMID: 30867310 PMCID: PMC6532089 DOI: 10.1128/jvi.02315-18] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Accepted: 03/06/2019] [Indexed: 12/12/2022] Open
Abstract
The cellular protein bone marrow stromal antigen-2 (BST-2)/tetherin acts against a variety of enveloped viruses by restricting their release from the plasma membrane. The HIV-1 accessory protein Vpu counteracts BST-2 by downregulating it from the cell surface and displacing it from virion assembly sites. Previous comparisons of Vpus from transmitted/founder viruses and between viruses isolated during acute and chronic infection led to the identification of a tryptophan at position 76 in Vpu (W76) as a key determinant for the displacement of BST-2 from virion assembly sites. Although present in Vpus from clades B, D, and G, W76 is absent from Vpus from clades A, C, and H. Mutagenesis of the C-terminal region of Vpu from two clade C viruses led to the identification of a conserved LL sequence that is functionally analogous to W76 of clade B. Alanine substitution of these leucines partially impaired virion release. This impairment was even greater when the mutations were combined with mutations of the Vpu β-TrCP binding site, resulting in Vpu proteins that induced high surface levels of BST-2 and reduced the efficiency of virion release to less than that of virus lacking vpu Microscopy confirmed that these C-terminal leucines in clade C Vpu, like W76 in clade B, contribute to virion release by supporting the displacement of BST-2 from virion assembly sites. These results suggest that although encoded differently, the ability of Vpu to displace BST-2 from sites of virion assembly on the plasma membrane is evolutionarily conserved among clade B and C HIV-1 isolates.IMPORTANCE Although targeted by a variety of restriction mechanisms, HIV-1 establishes chronic infection in most cases, in part due to the counteraction of these host defenses by viral accessory proteins. Using conserved motifs, the accessory proteins exploit the cellular machinery to degrade or mistraffic host restriction factors, thereby counteracting them. The Vpu protein counteracts the virion-tethering factor BST-2 in part by displacing it from virion assembly sites along the plasma membrane, but a previously identified determinant of that activity is clade specific at the level of protein sequence and not found in the clade C viruses that dominate the pandemic. Here, we show that clade C Vpu provides this activity via a leucine-containing sequence rather than the tryptophan-containing sequence found in clade B Vpu. This difference seems likely to reflect the different evolutionary paths taken by clade B and clade C HIV-1 in human populations.
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Affiliation(s)
- Shilpi Sharma
- Department of Medicine, University of California San Diego, La Jolla, California, USA
| | - Moein Jafari
- Department of Medicine, University of California San Diego, La Jolla, California, USA
| | - Amandip Bangar
- Department of Medicine, University of California San Diego, La Jolla, California, USA
| | - Karen William
- Department of Medicine, University of California San Diego, La Jolla, California, USA
| | - John Guatelli
- Department of Medicine, University of California San Diego, La Jolla, California, USA
- VA San Diego Healthcare System, San Diego, California, USA
| | - Mary K Lewinski
- Department of Medicine, University of California San Diego, La Jolla, California, USA
- VA San Diego Healthcare System, San Diego, California, USA
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25
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Bego MG, Miguet N, Laliberté A, Aschman N, Gerard F, Merakos AA, Weissenhorn W, Cohen ÉA. Activation of the ILT7 receptor and plasmacytoid dendritic cell responses are governed by structurally-distinct BST2 determinants. J Biol Chem 2019; 294:10503-10518. [PMID: 31118237 DOI: 10.1074/jbc.ra119.008481] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 04/25/2019] [Indexed: 12/31/2022] Open
Abstract
Type I interferons (IFN-I) are key innate immune effectors predominantly produced by activated plasmacytoid dendritic cells (pDCs). By modulating immune responses at their foundation, IFNs can widely reshape immunity to control infectious diseases and malignancies. Nevertheless, their biological activities can also be detrimental to surrounding healthy cells, as prolonged IFN-I signaling is associated with excessive inflammation and immune dysfunction. The interaction of the human pDC receptor immunoglobulin-like transcript 7 (ILT7) with its IFN-I-regulated ligand, bone marrow stromal cell antigen 2 (BST2) plays a key role in controlling the IFN-I amounts produced by pDCs in response to Toll-like receptor (TLR) activation. However, the structural determinants and molecular features of BST2 that govern ILT7 engagement and activation are largely undefined. Using two functional assays to measure BST2-stimulated ILT7 activation as well as biophysical studies, here we identified two structurally-distinct regions of the BST2 ectodomain that play divergent roles during ILT7 activation. We found that although the coiled-coil region contains a newly defined ILT7-binding surface, the N-terminal region appears to suppress ILT7 activation. We further show that a stable BST2 homodimer binds to ILT7, but post-binding events associated with the unique BST2 coiled-coil plasticity are required to trigger receptor signaling. Hence, BST2 with an unstable or a rigid coiled-coil fails to activate ILT7, whereas substitutions in its N-terminal region enhance activation. Importantly, the biological relevance of these newly defined domains of BST2 is underscored by the identification of substitutions having opposing potentials to activate ILT7 in pathological malignant conditions.
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Affiliation(s)
- Mariana G Bego
- From the Institut de Recherches Cliniques de Montréal, Montreal, Quebec H2W 1R7, Canada
| | - Nolwenn Miguet
- the University Grenoble Alpes, Institut de Biologie Structurale (IBS), CEA, CNRS, 38044 Grenoble, France, and
| | - Alexandre Laliberté
- From the Institut de Recherches Cliniques de Montréal, Montreal, Quebec H2W 1R7, Canada
| | - Nicolas Aschman
- the University Grenoble Alpes, Institut de Biologie Structurale (IBS), CEA, CNRS, 38044 Grenoble, France, and
| | - Francine Gerard
- the University Grenoble Alpes, Institut de Biologie Structurale (IBS), CEA, CNRS, 38044 Grenoble, France, and
| | - Angelique A Merakos
- From the Institut de Recherches Cliniques de Montréal, Montreal, Quebec H2W 1R7, Canada
| | - Winfried Weissenhorn
- the University Grenoble Alpes, Institut de Biologie Structurale (IBS), CEA, CNRS, 38044 Grenoble, France, and
| | - Éric A Cohen
- From the Institut de Recherches Cliniques de Montréal, Montreal, Quebec H2W 1R7, Canada, .,the Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, Quebec H3T 1J4, Canada
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Contribution of the Cytoplasmic Determinants of Vpu to the Expansion of Virus-Containing Compartments in HIV-1-Infected Macrophages. J Virol 2019; 93:JVI.00020-19. [PMID: 30867316 DOI: 10.1128/jvi.00020-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 03/09/2019] [Indexed: 12/30/2022] Open
Abstract
HIV-1 infection of macrophages leads to the sequestration of newly formed viruses in intracellular plasma membrane-connected structures termed virus-containing compartments (VCCs), where virions remain infectious and hidden from immune surveillance. The cellular restriction factor bone marrow stromal cell antigen 2 (BST2), which prevents HIV-1 dissemination by tethering budding viral particles at the plasma membrane, can be found in VCCs. The HIV-1 accessory protein Vpu counteracts the restriction factor BST2 by downregulating its expression and removing it from viral budding sites. Numerous studies described these Vpu countermeasures in CD4+ T cells or model cell lines, but the interplay between Vpu and BST2 in VCC formation and HIV-1 production in macrophages is less explored. Here, we show that Vpu expression in HIV-1-infected macrophages enhances viral release. This effect is related to Vpu's ability to circumvent BST2 antiviral activity. We show that in absence of Vpu, BST2 is enriched in VCCs and colocalizes with capsid p24, whereas Vpu expression significantly reduces the presence of BST2 in these compartments. Furthermore, our data reveal that BST2 is dispensable for the formation of VCCs and that Vpu expression impacts the volume of these compartments. This Vpu activity partly depends on BST2 expression and requires the integrity of the Vpu transmembrane domain, the dileucine-like motif E59XXXLV64 and phosphoserines 52 and 56 of Vpu. Altogether, these results highlight that Vpu controls the volume of VCCs and promotes HIV-1 release from infected macrophages.IMPORTANCE HIV-1 infection of macrophages leads to the sequestration of newly formed viruses in virus-containing compartments (VCCs), where virions remain infectious and hidden from immune surveillance. The restriction factor BST2, which prevents HIV-1 dissemination by tethering budding viral particles, can be found in VCCs. The HIV-1 Vpu protein counteracts BST2. This study explores the interplay between Vpu and BST2 in the viral protein functions on HIV-1 release and viral particle sequestration in VCCs in macrophages. The results show that Vpu controls the volume of VCCs and favors viral particle release. These Vpu functions partly depend on Vpu's ability to antagonize BST2. This study highlights that the transmembrane domain of Vpu and two motifs of the Vpu cytoplasmic domain are required for these functions. These motifs were notably involved in the control of the volume of VCCs by Vpu but were dispensable for the prevention of the specific accumulation of BST2 in these structures.
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27
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Current advances in HIV vaccine preclinical studies using Macaque models. Vaccine 2019; 37:3388-3399. [PMID: 31088747 DOI: 10.1016/j.vaccine.2019.04.094] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 04/02/2019] [Accepted: 04/30/2019] [Indexed: 02/06/2023]
Abstract
The macaque simian or simian/human immunodeficiency virus (SIV/SHIV) challenge model has been widely used to inform and guide human vaccine trials. Substantial advances have been made recently in the application of repeated-low-dose challenge (RLD) approach to assess SIV/SHIV vaccine efficacies (VE). Some candidate HIV vaccines have shown protective effects in preclinical studies using the macaque SIV/SHIV model but the model's true predictive value for screening potential HIV vaccine candidates needs to be evaluated further. Here, we review key parameters used in the RLD approach and discuss their relevance for evaluating VE to improve preclinical studies of candidate HIV vaccines.
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28
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Sharma A, Lal SK. Is tetherin a true antiviral: The influenza a virus controversy. Rev Med Virol 2019; 29:e2036. [DOI: 10.1002/rmv.2036] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 12/17/2018] [Accepted: 12/18/2018] [Indexed: 12/21/2022]
Affiliation(s)
- Anshika Sharma
- School of ScienceMonash University, Sunway Campus Bandar Sunway Malaysia
| | - Sunil K. Lal
- School of ScienceMonash University, Sunway Campus Bandar Sunway Malaysia
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Colomer-Lluch M, Ruiz A, Moris A, Prado JG. Restriction Factors: From Intrinsic Viral Restriction to Shaping Cellular Immunity Against HIV-1. Front Immunol 2018; 9:2876. [PMID: 30574147 PMCID: PMC6291751 DOI: 10.3389/fimmu.2018.02876] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 11/22/2018] [Indexed: 01/20/2023] Open
Abstract
Antiviral restriction factors are host cellular proteins that constitute a first line of defense blocking viral replication and propagation. In addition to interfering at critical steps of the viral replication cycle, some restriction factors also act as innate sensors triggering innate responses against infections. Accumulating evidence suggests an additional role for restriction factors in promoting antiviral cellular immunity to combat viruses. Here, we review the recent progress in our understanding on how restriction factors, particularly APOBEC3G, SAMHD1, Tetherin, and TRIM5α have the cell-autonomous potential to induce cellular resistance against HIV-1 while promoting antiviral innate and adaptive immune responses. Also, we provide an overview of how these restriction factors may connect with protein degradation pathways to modulate anti-HIV-1 cellular immune responses, and we summarize the potential of restriction factors-based therapeutics. This review brings a global perspective on the influence of restrictions factors in intrinsic, innate, and also adaptive antiviral immunity opening up novel research avenues for therapeutic strategies in the fields of drug discovery, gene therapy, and vaccines to control viral infections.
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Affiliation(s)
- Marta Colomer-Lluch
- IrsiCaixa AIDS Research Institute, Germans Trias i Pujol Research Institute, Universitat Autonoma de Barcelona, Badalona, Spain
| | - Alba Ruiz
- IrsiCaixa AIDS Research Institute, Germans Trias i Pujol Research Institute, Universitat Autonoma de Barcelona, Badalona, Spain
| | - Arnaud Moris
- Sorbonne Université, INSERM U1135, CNRS ERL 8255, Centre d'Immunologie et des Maladies Infectieuses (CIMI-Paris), Paris, France
| | - Julia G Prado
- IrsiCaixa AIDS Research Institute, Germans Trias i Pujol Research Institute, Universitat Autonoma de Barcelona, Badalona, Spain
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βTrCP is Required for HIV-1 Vpu Modulation of CD4, GaLV Env, and BST-2/Tetherin. Viruses 2018; 10:v10100573. [PMID: 30347660 PMCID: PMC6212966 DOI: 10.3390/v10100573] [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: 09/27/2018] [Revised: 10/10/2018] [Accepted: 10/16/2018] [Indexed: 12/27/2022] Open
Abstract
The Human immunodeficiency virus-1 (HIV-1) accessory protein Vpu modulates numerous proteins, including the host proteins CD4 and BST-2/tetherin. Vpu interacts with the Skp, Cullin, F-Box (SCF) ubiquitin ligase through interactions with the F-Box protein βTrCP (1 and/or 2). This interaction is dependent on phosphorylation of S52,56 in Vpu. Mutation of S52,56, or inhibition of the SCF, abolishes most Vpu activity against CD4 and partly reduces activity against BST-2/tetherin. Recently, Vpu has also been reported to interact with the clathrin adapter proteins AP-1 and AP-2, and these interactions were also found to be required for BST-2/tetherin antagonism in an S52,56 -dependent manner. In assays where HIV-1 is pseudotyped with gibbon ape leukemia virus (GaLV Env), Vpu has also been found to prevent GaLV Env from being incorporated into viral particles, but the mechanism for this antagonism is not fully understood. To clarify the role of the βTrCPs in Vpu function we used CRISPR/Cas9 to generate a clonal cell line lacking both βTrCP-1 and -2. Vpu activity against CD4 and GaLV Env was abolished in this cell line, and activity against BST-2/tetherin reduced significantly. Mutation of the S52,56 residues no longer affected Vpu activity against BST-2/tetherin in this cell line. These data suggest that the primary role of the S52,56 residues in antagonism of CD4, GaLV Env, and BST-2/tetherin is to recruit the SCF/βTrCP ubiquitin ligase.
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Berry KN, Kober DL, Su A, Brett TJ. Limiting Respiratory Viral Infection by Targeting Antiviral and Immunological Functions of BST-2/Tetherin: Knowledge and Gaps. Bioessays 2018; 40:e1800086. [PMID: 30113067 PMCID: PMC6371793 DOI: 10.1002/bies.201800086] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 07/20/2018] [Indexed: 12/12/2022]
Abstract
Recent findings regarding the cellular biology and immunology of BST-2 (also known as tetherin) indicate that its function could be exploited as a universal replication inhibitor of enveloped respiratory viruses (e.g., influenza, respiratory syncytial virus, etc.). BST-2 inhibits viral replication by preventing virus budding from the plasma membrane and by inducing an antiviral state in cells adjacent to infection via unique inflammatory signaling mechanisms. This review presents the first comprehensive summary of what is currently known about BST-2 anti-viral function against respiratory viruses, how these viruses construct countermeasures to antagonize BST-2, and how BST-2 function might be targeted to develop therapies to treat respiratory virus infections. The authors address the current gaps in knowledge, including the need for mechanistic understanding of BST-2 antagonism by respiratory viruses, that should be bridged to achieve that goal.
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Affiliation(s)
- Kayla N. Berry
- Division of Pulmonary and Critical CareDepartment of Internal MedicineWashington University School of MedicineSt. Louis 63110Missouri
- Immunology ProgramWashington University School of MedicineSt. Louis 63110Missouri
- Medical Scientist Training ProgramWashington University School of MedicineSt. Louis 63110Missouri
| | - Daniel L. Kober
- Division of Pulmonary and Critical CareDepartment of Internal MedicineWashington University School of MedicineSt. Louis 63110Missouri
- Microbiology ProgramWashington University School of MedicineSt. Louis 63110Missouri
| | - Alvin Su
- Division of Pulmonary and Critical CareDepartment of Internal MedicineWashington University School of MedicineSt. Louis 63110Missouri
| | - Tom J. Brett
- Division of Pulmonary and Critical CareDepartment of Internal MedicineWashington University School of MedicineSt. Louis 63110Missouri
- Department of Medicine, and Department of Cell Biology and PhysiologyWashington University School of MedicineSt. Louis 63110Missouri
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Waheed AA, Gitzen A, Swiderski M, Freed EO. High-Mannose But Not Complex-Type Glycosylation of Tetherin Is Required for Restriction of HIV-1 Release. Viruses 2018; 10:v10010026. [PMID: 29303997 PMCID: PMC5795439 DOI: 10.3390/v10010026] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 12/28/2017] [Accepted: 12/31/2017] [Indexed: 11/16/2022] Open
Abstract
Tetherin is an interferon-inducible antiviral protein that inhibits the release of a broad spectrum of enveloped viruses by retaining virions at the surface of infected cells. While the role of specific tetherin domains in antiviral activity is clearly established, the role of glycosylation in tetherin function is not clear. In this study, we carried out a detailed investigation of this question by using tetherin variants in which one or both sites of N-linked glycosylation were mutated (N65A, N92A, and N65,92A), and chemical inhibitors that prevent glycosylation at specific stages of oligosaccharide were added or modified. The single N-linked glycosylation mutants, N65A and N92A, efficiently inhibited the release of Vpu-defective human immunodeficiency virus type 1 (HIV-1). In contrast, the non-glycosylated double mutant, N65,92A, lost its ability to block HIV-1 release. The inability of the N65,92A mutant to inhibit HIV-1 release is associated with a lack of cell-surface expression. A role for glycosylation in cell-surface tetherin expression is supported by tunicamycin treatment, which inhibits the first step of N-linked glycosylation and impairs both cell-surface expression and antiviral activity. Inhibition of complex-type glycosylation with kifunensine, an inhibitor of the oligosaccharide processing enzyme mannosidase 1, had no effect on either the cell-surface expression or antiviral activity of tetherin. These results demonstrate that high-mannose modification of a single asparagine residue is necessary and sufficient, while complex-type glycosylation is dispensable, for cell-surface tetherin expression and antiviral activity.
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Affiliation(s)
- Abdul A Waheed
- Virus-Cell Interaction Section, HIV Dynamics and Replication Program, National Cancer Institute, Bldg. 535, Room 108B, 1050 Boyles St., Frederick, MD 21702-1201, USA.
| | - Ariana Gitzen
- Virus-Cell Interaction Section, HIV Dynamics and Replication Program, National Cancer Institute, Bldg. 535, Room 108B, 1050 Boyles St., Frederick, MD 21702-1201, USA.
| | - Maya Swiderski
- Virus-Cell Interaction Section, HIV Dynamics and Replication Program, National Cancer Institute, Bldg. 535, Room 108B, 1050 Boyles St., Frederick, MD 21702-1201, USA.
| | - Eric O Freed
- Virus-Cell Interaction Section, HIV Dynamics and Replication Program, National Cancer Institute, Bldg. 535, Room 108B, 1050 Boyles St., Frederick, MD 21702-1201, USA.
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Madjo U, Leymarie O, Frémont S, Kuster A, Nehlich M, Gallois-Montbrun S, Janvier K, Berlioz-Torrent C. LC3C Contributes to Vpu-Mediated Antagonism of BST2/Tetherin Restriction on HIV-1 Release through a Non-canonical Autophagy Pathway. Cell Rep 2017; 17:2221-2233. [PMID: 27880899 DOI: 10.1016/j.celrep.2016.10.045] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 09/05/2016] [Accepted: 10/13/2016] [Indexed: 11/19/2022] Open
Abstract
BST2 (bone marrow stromal antigen 2)/tetherin is a restriction factor of enveloped viruses, which blocks the release of viral particles. HIV-1 encodes proteins that antagonize this innate barrier, including the accessory protein Vpu. Here, we investigate whether the autophagy pathway and/or ATG proteins are hijacked by HIV-1 Vpu to circumvent BST2 restriction of viral release. We report that BST2 and Vpu are present in LC3-positive compartments. We found that Vpu selectively interacts with the ATG8 ortholog LC3C through the Vpu L63VEM66 sequence. This sequence is required for Vpu to antagonize BST2 restriction. LC3C expression favors the removal of BST2 from the HIV-1 budding site, and thus HIV-1 release in BST2-expressing cells. Additionally, ATG5 and beclin 1/ATG6, but not all the components of the autophagy pathway, act with LC3C to facilitate Vpu antagonism of BST2 restriction. Altogether, our data support the view that a non-canonical autophagy pathway reminiscent of LC3-associated phagocytosis contributes to Vpu counteraction of BST2 restriction.
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Affiliation(s)
- Ursula Madjo
- Inserm, U1016, Institut Cochin, 75014 Paris, France; Cnrs, UMR8104, 75014 Paris, France; University Paris Descartes, Sorbonne Paris Cité, 75014 Paris, France
| | - Olivier Leymarie
- Inserm, U1016, Institut Cochin, 75014 Paris, France; Cnrs, UMR8104, 75014 Paris, France; University Paris Descartes, Sorbonne Paris Cité, 75014 Paris, France
| | - Stéphane Frémont
- Inserm, U1016, Institut Cochin, 75014 Paris, France; Cnrs, UMR8104, 75014 Paris, France; University Paris Descartes, Sorbonne Paris Cité, 75014 Paris, France
| | - Aurelia Kuster
- Inserm, U1016, Institut Cochin, 75014 Paris, France; Cnrs, UMR8104, 75014 Paris, France; University Paris Descartes, Sorbonne Paris Cité, 75014 Paris, France
| | - Mélanie Nehlich
- Inserm, U1016, Institut Cochin, 75014 Paris, France; Cnrs, UMR8104, 75014 Paris, France; University Paris Descartes, Sorbonne Paris Cité, 75014 Paris, France
| | - Sarah Gallois-Montbrun
- Inserm, U1016, Institut Cochin, 75014 Paris, France; Cnrs, UMR8104, 75014 Paris, France; University Paris Descartes, Sorbonne Paris Cité, 75014 Paris, France
| | - Katy Janvier
- Inserm, U1016, Institut Cochin, 75014 Paris, France; Cnrs, UMR8104, 75014 Paris, France; University Paris Descartes, Sorbonne Paris Cité, 75014 Paris, France
| | - Clarisse Berlioz-Torrent
- Inserm, U1016, Institut Cochin, 75014 Paris, France; Cnrs, UMR8104, 75014 Paris, France; University Paris Descartes, Sorbonne Paris Cité, 75014 Paris, France.
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Hijacking of the Ubiquitin/Proteasome Pathway by the HIV Auxiliary Proteins. Viruses 2017; 9:v9110322. [PMID: 29088112 PMCID: PMC5707529 DOI: 10.3390/v9110322] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 10/26/2017] [Accepted: 10/30/2017] [Indexed: 02/08/2023] Open
Abstract
The ubiquitin-proteasome system (UPS) ensures regulation of the protein pool in the cell by ubiquitination of proteins followed by their degradation by the proteasome. It plays a central role in the cell under normal physiological conditions as well as during viral infections. On the one hand, the UPS can be used by the cell to degrade viral proteins, thereby restricting the viral infection. On the other hand, it can also be subverted by the virus to its own advantage, notably to induce degradation of cellular restriction factors. This makes the UPS a central player in viral restriction and counter-restriction. In this respect, the human immunodeficiency viruses (HIV-1 and 2) represent excellent examples. Indeed, many steps of the HIV life cycle are restricted by cellular proteins, some of which are themselves components of the UPS. However, HIV itself hijacks the UPS to mediate defense against several cellular restriction factors. For example, the HIV auxiliary proteins Vif, Vpx and Vpu counteract specific restriction factors by the recruitment of cellular UPS components. In this review, we describe the interplay between HIV and the UPS to illustrate its role in the restriction of viral infections and its hijacking by viral proteins for counter-restriction.
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Dufrasne FE, Lucchetti M, Martin A, André E, Dessilly G, Kabamba B, Goubau P, Ruelle J. Modulation of the NF-κB signaling pathway by the HIV-2 envelope glycoprotein and its incomplete BST-2 antagonism. Virology 2017; 513:11-16. [PMID: 29028477 DOI: 10.1016/j.virol.2017.09.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 09/26/2017] [Accepted: 09/30/2017] [Indexed: 12/19/2022]
Abstract
The HIVs have evolved by selecting means to hijack numerous host cellular factors. HIVs exploit the transcription factor NF-κB to ensure efficient LTR-driven gene transcription. However, NF-κB is primarily known to act as a key regulator of the proinflammatory and antiviral responses. Interestingly, retroviruses activate NF-κB during early stages of infection to initiate proviral genome expression while suppressing it at later stages to restrain expression of antiviral genes. During HIV-1 infection, diverse viral proteins such as Env, Nef and Vpr have been proposed to activate NF-κB activity, whereas Vpu has been shown to inhibit NF-κB activation. It is still unclear how HIV-2 regulates NF-κB signaling pathway during its replication cycle. Here we confirm that human BST-2 and HIV-1 Env proteins can trigger potent activation of NF-κB. Importantly, we demonstrate for the first time that the HIV-2 Env induces NF-κB activation in HEΚ293T cells. Furthermore, the anti-BST-2 activity of the HIV-2 Env is not sufficient to completely inhibit NF-κB activity.
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Affiliation(s)
- François E Dufrasne
- Université catholique de Louvain, Experimental and Clinical Research Institute (IREC), Medical Microbiology Unit (MBLG), AIDS Reference Laboratory, Avenue Hippocrate 54, B-1200 Brussels, Belgium.
| | - Mara Lucchetti
- Université catholique de Louvain, Experimental and Clinical Research Institute (IREC), Medical Microbiology Unit (MBLG), AIDS Reference Laboratory, Avenue Hippocrate 54, B-1200 Brussels, Belgium
| | - Anandi Martin
- Université catholique de Louvain, Experimental and Clinical Research Institute (IREC), Medical Microbiology Unit (MBLG), AIDS Reference Laboratory, Avenue Hippocrate 54, B-1200 Brussels, Belgium.
| | - Emmanuel André
- Université catholique de Louvain, Experimental and Clinical Research Institute (IREC), Medical Microbiology Unit (MBLG), AIDS Reference Laboratory, Avenue Hippocrate 54, B-1200 Brussels, Belgium; Cliniques Universitaires Saint-Luc, Clinical Biology Department, Microbiology Unit, B-1200 Brussels, Belgium.
| | - Géraldine Dessilly
- Université catholique de Louvain, Experimental and Clinical Research Institute (IREC), Medical Microbiology Unit (MBLG), AIDS Reference Laboratory, Avenue Hippocrate 54, B-1200 Brussels, Belgium.
| | - Benoit Kabamba
- Université catholique de Louvain, Experimental and Clinical Research Institute (IREC), Medical Microbiology Unit (MBLG), AIDS Reference Laboratory, Avenue Hippocrate 54, B-1200 Brussels, Belgium; Cliniques Universitaires Saint-Luc, Clinical Biology Department, Microbiology Unit, B-1200 Brussels, Belgium.
| | - Patrick Goubau
- Université catholique de Louvain, Experimental and Clinical Research Institute (IREC), Medical Microbiology Unit (MBLG), AIDS Reference Laboratory, Avenue Hippocrate 54, B-1200 Brussels, Belgium.
| | - Jean Ruelle
- Université catholique de Louvain, Experimental and Clinical Research Institute (IREC), Medical Microbiology Unit (MBLG), AIDS Reference Laboratory, Avenue Hippocrate 54, B-1200 Brussels, Belgium.
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Canonical and Non-Canonical Autophagy in HIV-1 Replication Cycle. Viruses 2017; 9:v9100270. [PMID: 28946621 PMCID: PMC5691622 DOI: 10.3390/v9100270] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Revised: 09/19/2017] [Accepted: 09/21/2017] [Indexed: 12/11/2022] Open
Abstract
Autophagy is a lysosomal-dependent degradative process essential for maintaining cellular homeostasis, and is a key player in innate and adaptive immune responses to intracellular pathogens such as human immunodeficiency virus type 1 (HIV-1). In HIV-1 target cells, autophagy mechanisms can (i) selectively direct viral proteins and viruses for degradation; (ii) participate in the processing and presentation of viral-derived antigens through major histocompatibility complexes; and (iii) contribute to interferon production in response to HIV-1 infection. As a consequence, HIV-1 has evolved different strategies to finely regulate the autophagy pathway to favor its replication and dissemination. HIV-1 notably encodes accessory genes encoding Tat, Nef and Vpu proteins, which are able to perturb and hijack canonical and non-canonical autophagy mechanisms. This review outlines the current knowledge on the complex interplay between autophagy and HIV-1 replication cycle, providing an overview of the autophagy-mediated molecular processes deployed both by infected cells to combat the virus and by HIV-1 to evade antiviral response.
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HIV-1 Vpu Downmodulates ICAM-1 Expression, Resulting in Decreased Killing of Infected CD4 + T Cells by NK Cells. J Virol 2017; 91:JVI.02442-16. [PMID: 28148794 DOI: 10.1128/jvi.02442-16] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 01/26/2017] [Indexed: 12/20/2022] Open
Abstract
HIV-1 Vpu is known to alter the expression of numerous cell surface molecules. Given the ever-increasing list of Vpu targets identified to date, we undertook a proteomic screen to discover novel cell membrane proteins modulated by this viral protein. Plasma membrane proteome isolates from Vpu-inducible T cells were subjected to stable isotope labeling of amino acids in cell culture (SILAC)-based mass spectrometry analysis, and putative targets were validated by infection of primary CD4+ T cells. We report here that while intercellular adhesion molecule 1 (ICAM-1) and ICAM-3 are upregulated by HIV-1 infection, expression of Vpu offsets this increase by downregulating these molecules from the cell surface. Specifically, we show that Vpu is sufficient to downregulate and deplete ICAM-1 in a manner requiring the Vpu transmembrane domain and a dual-serine (S52/S56) motif necessary for recruitment of the beta-transducin repeat-containing E3 ubiquitin protein ligase (β-TrCP) component of the Skp, Cullin, F-box (SCFβ-TrCP) E3 ubiquitin ligase. Vpu interacts with ICAM-1 to induce its proteasomal degradation. Interestingly, the E3 ubiquitin ligase component β-TrCP-1 is dispensable for ICAM-1 surface downregulation yet is necessary for ICAM-1 degradation. Functionally, Vpu-mediated ICAM-1 downregulation lowers packaging of this adhesion molecule into virions, resulting in decreased infectivity. Importantly, while Vpu-mediated downregulation of ICAM-3 has a limited effect on the conjugation of NK cells to HIV-1-infected CD4+ T cells, downregulation of ICAM-1 by Vpu results in a reduced ability of NK cells to bind and kill infected T cells. Vpu-mediated ICAM-1 downregulation may therefore represent an evolutionary compromise in viral fitness by impeding the formation of cell-to-cell contacts between immune cells and infected T cells at the cost of decreased virion infectivity.IMPORTANCE The major barrier to eradicating HIV-1 infection is the establishment of treatment-resistant reservoirs early in infection. Vpu-mediated ICAM-1 downregulation may contribute to the evasion of cell-mediated immunity during acute infection to promote viral dissemination and the development of viral reservoirs. By aiding the immune system to clear infection prior to the development of reservoirs, novel treatments designed to disrupt Vpu-mediated ICAM-1 downregulation may be beneficial during acute infection or as a prophylactic treatment.
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Lukhele S, Cohen ÉA. Conserved residues within the HIV-1 Vpu transmembrane-proximal hinge region modulate BST2 binding and antagonism. Retrovirology 2017; 14:18. [PMID: 28288652 PMCID: PMC5348903 DOI: 10.1186/s12977-017-0345-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 03/05/2017] [Indexed: 11/10/2022] Open
Abstract
Background BST2 inhibits HIV-1 release by tethering nascent virions to the surface of infected cells. HIV-1 Vpu overcomes this restriction by removing BST2 from viral budding sites via BST2 intracellular trapping and sequestration, surface downregulation and/or displacement mechanisms. Vpu is composed of a short luminal tail, a transmembrane domain (TMD) and a cytoplasmic hinge region that is followed by two helices. BST2 counteraction relies on the ability of Vpu to physically bind BST2 through TMD interactions and recruit the clathrin-dependent trafficking machinery via a canonical acidic di-leucine signalling motif within the helix-2 of Vpu. The highly conserved Vpu transmembrane-proximal hinge region encompasses residues that resemble an acidic leucine-based trafficking motif, whose functional roles are currently ill-defined. In this study, we investigated the contribution of these residues towards Vpu-mediated BST2 antagonism. Results We show that while these conserved residues have no intrinsic activity on the cellular distribution of Vpu in the absence of BST2, they regulate the ability of Vpu to bind to BST2 and, consequently, govern both BST2-dependent trafficking properties of the protein as well as its co-localization with BST2. Moreover, these residues, particularly a glutamic acid residue positioned immediately following the TMD, are a determinant not only for efficient targeting of BST2, but also binding and degradation of CD4, another host membrane protein targeted by Vpu. Mechanistically, our data are consistent with a role of these residues in the maintenance of the Vpu TMD conformational configuration such that interactions with membrane-associated host targets are favoured. Conclusions Altogether, this work demonstrates an important regulatory role of the transmembrane-proximal Vpu hinge region residues towards enabling the protein to efficiently engage its target host proteins. Thus, this highly conserved, cytosolic Vpu hinge region may represent an attractive target for the development of anti-Vpu inhibitors. Electronic supplementary material The online version of this article (doi:10.1186/s12977-017-0345-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sabelo Lukhele
- Laboratory of Human Retrovirology, Institut de Recherches Cliniques de Montréal (IRCM), 110, Pine Avenue West, Montreal, QC, H2W 1R7, Canada.,Division of Experimental Medicine, McGill University, Montreal, QC, H3A 1A3, Canada
| | - Éric A Cohen
- Laboratory of Human Retrovirology, Institut de Recherches Cliniques de Montréal (IRCM), 110, Pine Avenue West, Montreal, QC, H2W 1R7, Canada. .,Division of Experimental Medicine, McGill University, Montreal, QC, H3A 1A3, Canada. .,Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, QC, H3T 1J4, Canada.
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Li SX, Barrett BS, Guo K, Santiago ML. Tetherin/BST-2: Restriction Factor or Immunomodulator? Curr HIV Res 2016; 14:235-46. [PMID: 26957198 DOI: 10.2174/1570162x14999160224102752] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 08/10/2015] [Accepted: 08/11/2015] [Indexed: 11/22/2022]
Abstract
BACKGROUND Cell-mediated immune (CMI) responses are critical for the control of HIV-1 infection and their importance was highlighted by the existence of viral proteins, particularly Vpu and Nef, that antagonize these responses. Pandemic HIV-1 Vpu counteracts Tetherin/BST-2, a host factor that could prevent the release of HIV-1 virions by tethering virions on the cell surface, but a link between Tetherin and HIV-1 CMI responses has not yet been demonstrated in vivo. In vitro, the virological and immunological impact of Tetherin-mediated accumulation of virions ranged from enhanced or diminished cell-to-cell spread to enhanced recognition by virus-specific antibodies for natural killer cellmediated lysis. However, Tetherin-restricted virions could be internalized through an endocytosis motif in the Tetherin cytoplasmic tail. METHODS Given the uncertainties on which in vitro results manifest in vivo and the dearth of knowledge on how Tetherin influences retroviral immunity, in vivo retrovirus infections in mice encoding wild-type, null and endocytosis-defective Tetherin were performed. Here, we review and highlight the results from these in vivo studies. RESULTS Current data suggests that endocytosis-defective Tetherin functions as a potent innate restriction factor. By contrast, endocytosis-competent Tetherin, the form found in most mammals including humans and the form counteracted by HIV-1 Vpu, was linked to stronger CMI responses in mice. CONCLUSION We propose that the main role of endocytosis-competent Tetherin is not to directly restrict retroviral replication, but to promote a more effective CMI response against retroviruses.
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Affiliation(s)
| | | | | | - Mario L Santiago
- Division of Infectious Diseases, University of Colorado Denver, Mail Stop B-168, 12700 E 19th Avenue, Aurora, CO 80045, USA.
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Enhancing Virion Tethering by BST2 Sensitizes Productively and Latently HIV-infected T cells to ADCC Mediated by Broadly Neutralizing Antibodies. Sci Rep 2016; 6:37225. [PMID: 27853288 PMCID: PMC5112552 DOI: 10.1038/srep37225] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 10/26/2016] [Indexed: 02/01/2023] Open
Abstract
Binding of anti-HIV antibodies (Abs) to envelope (Env) glycoproteins on infected cells can mark them for elimination via antibody-dependent cell-mediated cytotoxicity (ADCC). BST2, a type I interferon (IFN)-stimulated restriction factor that anchors nascent Env-containing virions at the surface of infected cells has been shown to enhance ADCC functions. In a comprehensive analysis of ADCC potency by neutralizing anti-HIV Abs (NAbs), we show in this study that NAbs are capable of mediating ADCC against HIV-infected T cells with 3BNC117, PGT126 and PG9 being most efficient. We demonstrate that HIV-induced BST2 antagonism effectively attenuates Ab binding and ADCC responses mediated by all classes of NAbs that were tested. Interestingly, IFNα treatment can reverse this effect in a BST2-dependent manner. Importantly, while reactivated latent T cell lines display some susceptibility to ADCC mediated by broadly NAbs, inactivating BST2 viral countermeasures and/or exogenous IFNα augment their elimination. Overall, our findings support the notion that NAbs can induce ADCC. They highlight that while BST2 antagonism by HIV promotes ADCC evasion, strategies aimed at restoring BST2 restriction could improve anti-HIV responses and potentially provide a means to eliminate reactivated cells in latent reservoirs.
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In vitro functional assessment of natural HIV-1 group M Vpu sequences using a universal priming approach. J Virol Methods 2016; 240:32-41. [PMID: 27865749 DOI: 10.1016/j.jviromet.2016.11.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 11/04/2016] [Accepted: 11/08/2016] [Indexed: 01/06/2023]
Abstract
The HIV-1 accessory protein Vpu exhibits high inter- and intra- subtype genetic diversity that may influence Vpu function and possibly contribute to HIV-1 pathogenesis. However, scalable methods to evaluate genotype/phenotype relationships in natural Vpu sequences are limited, particularly those expressing the protein in CD4+ T-cells, the natural target of HIV-1 infection. A major impediment to assay scalability is the extensive genetic diversity within, and immediately upstream of, Vpu's initial 5' coding region, which has necessitated the design of oligonucleotide primers specific for each individual HIV-1 isolate (or subtype). To address this, we developed two universal forward primers, located in relatively conserved regions 38 and 90 bases upstream of Vpu, and a single universal reverse primer downstream of Vpu, which are predicted to cover the vast majority of global HIV-1 group M sequence diversity. We show that inclusion of up to 90 upstream bases of HIV-1 genomic sequence does not significantly influence in vitro Vpu expression or function when a Rev/Rev Response Element (RRE)-dependent expression system is used. We further assess the function of four diverse HIV-1 Vpu sequences, revealing reproducible and significant differences between them. Our approach represents a scalable option to measure the in vitro function of genetically diverse natural Vpu isolates in a CD4+ T-cell line.
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Differential Control of BST2 Restriction and Plasmacytoid Dendritic Cell Antiviral Response by Antagonists Encoded by HIV-1 Group M and O Strains. J Virol 2016; 90:10236-10246. [PMID: 27581991 DOI: 10.1128/jvi.01131-16] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 08/29/2016] [Indexed: 12/15/2022] Open
Abstract
BST2/tetherin is a type I interferon (IFN-I)-stimulated host factor that restricts the release of HIV-1 by entrapping budding virions at the cell surface. This membrane-associated protein can also engage and activate the plasmacytoid dendritic cell (pDC)-specific immunoglobulin-like transcript 7 (ILT7) inhibitory receptor to downregulate the IFN-I response by pDCs. Pandemic HIV-1 group M uses Vpu (M-Vpu) to counteract the two BST2 isoforms (long and short) that are expressed in human cells. M-Vpu efficiently downregulates surface long BST2, while it displaces short BST2 molecules away from viral assembly sites. We recently found that this attribute is used by M-Vpu to activate the BST2/ILT7-dependent negative-feedback pathway and to suppress pDC IFN-I responses during sensing of infected cells. However, whether this property is conserved in endemic HIV-1 group O, which has evolved Nef (O-Nef) to counteract specifically the long BST2 isoform, remains unknown. In the present study, we validated that O-Nefs have the capacity to downregulate surface BST2 and enhance HIV-1 particle release although less efficiently than M-Vpu. In contrast to M-Vpu, O-Nef did not efficiently enhance viral spread in T cell culture or displace short BST2 from viral assembly sites to prevent its occlusion by tethered HIV-1 particles. Consequently, O-Nef impairs the ability of BST2 to activate negative ILT7 signaling to suppress the IFN-I response by pDC-containing peripheral blood mononuclear cells (PBMCs) during sensing of infected cells. These distinctive features of BST2 counteraction by O-Nefs may in part explain the limited spread of HIV-1 group O in the human population. IMPORTANCE The geographical distributions and prevalences of different HIV-1 groups show large variations. Understanding drivers of distinctive viral spread may aid in the development of therapeutic strategies for controlling the spread of HIV-1 pandemic strains. The differential spread of HIV-1 groups appears to be linked to their capacities to antagonize the long and short isoforms of the BST2 restriction factor. We found that the endemic HIV-1 group O-encoded BST2 antagonist Nef is unable to counteract the restriction mediated by short BST2, a condition that impairs its ability to activate ILT7 and suppress pDC antiviral responses. This is in contrast to the pandemic HIV-1 group M-specified BST2 countermeasure Vpu, which displays a diverse array of mechanisms to counteract short and long BST2 isoforms, an attribute that allows the effective control of pDC antiviral responses. These findings may help explain the limited spread of HIV-1 group O as well as the continued predominance of HIV-1 group M throughout the world.
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Single Amino Acid Substitution N659D in HIV-2 Envelope Glycoprotein (Env) Impairs Viral Release and Hampers BST-2 Antagonism. Viruses 2016; 8:v8100285. [PMID: 27754450 PMCID: PMC5086617 DOI: 10.3390/v8100285] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 09/30/2016] [Accepted: 10/06/2016] [Indexed: 12/11/2022] Open
Abstract
BST-2 or tetherin is a host cell restriction factor that prevents the budding of enveloped viruses at the cell surface, thus impairing the viral spread. Several countermeasures to evade this antiviral factor have been positively selected in retroviruses: the human immunodeficiency virus type 2 (HIV-2) relies on the envelope glycoprotein (Env) to overcome BST-2 restriction. The Env gp36 ectodomain seems involved in this anti-tetherin activity, however residues and regions interacting with BST-2 are not clearly defined. Among 32 HIV-2 ROD Env mutants tested, we demonstrated that the asparagine residue at position 659 located in the gp36 ectodomain is mandatory to exert the anti-tetherin function. Viral release assays in cell lines expressing BST-2 showed a loss of viral release ability for the HIV-2 N659D mutant virus compared to the HIV-2 wild type virus. In bst-2 inactivated H9 cells, those differences were lost. Subtilisin treatment of infected cells demonstrated that the N659D mutant was more tethered at the cell surface. Förster resonance energy transfer (FRET) experiments confirmed a direct molecular link between Env and BST-2 and highlighted an inability of the mutant to bind BST-2. We also tested a virus presenting a truncation of 109 amino acids at the C-terminal part of Env, a cytoplasmic tail partial deletion that is spontaneously selected in vitro. Interestingly, viral release assays and FRET experiments indicated that a full Env cytoplasmic tail was essential in BST-2 antagonism. In HIV-2 infected cells, an efficient Env-mediated antagonism of BST-2 is operated through an intermolecular link involving the asparagine 659 residue as well as the C-terminal part of the cytoplasmic tail.
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44
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Novel Acylguanidine-Based Inhibitor of HIV-1. J Virol 2016; 90:9495-508. [PMID: 27512074 DOI: 10.1128/jvi.01107-16] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 08/05/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The emergence of transmissible HIV-1 strains with resistance to antiretroviral drugs highlights a continual need for new therapies. Here we describe a novel acylguanidine-containing compound, 1-(2-(azepan-1-yl)nicotinoyl)guanidine (or SM111), that inhibits in vitro replication of HIV-1, including strains resistant to licensed protease, reverse transcriptase, and integrase inhibitors, without major cellular toxicity. At inhibitory concentrations, intracellular p24(Gag) production was unaffected, but virion release (measured as extracellular p24(Gag)) was reduced and virion infectivity was substantially impaired, suggesting that SM111 acts at a late stage of viral replication. SM111-mediated inhibition of HIV-1 was partially overcome by a Vpu I17R mutation alone or a Vpu W22* truncation in combination with Env N136Y. These mutations enhanced virion infectivity and Env expression on the surface of infected cells in the absence and presence of SM111 but also impaired Vpu's ability to downregulate CD4 and BST2/tetherin. Taken together, our results support acylguanidines as a class of HIV-1 inhibitors with a distinct mechanism of action compared to that of licensed antiretrovirals. Further research on SM111 and similar compounds may help to elucidate knowledge gaps related to Vpu's role in promoting viral egress and infectivity. IMPORTANCE New inhibitors of HIV-1 replication may be useful as therapeutics to counteract drug resistance and as reagents to perform more detailed studies of viral pathogenesis. SM111 is a small molecule that blocks the replication of wild-type and drug-resistant HIV-1 strains by impairing viral release and substantially reducing virion infectivity, most likely through its ability to prevent Env expression at the infected cell surface. Partial resistance to SM111 is mediated by mutations in Vpu and/or Env, suggesting that the compound affects host/viral protein interactions that are important during viral egress. Further characterization of SM111 and similar compounds may allow more detailed pharmacological studies of HIV-1 egress and provide opportunities to develop new treatments for HIV-1.
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45
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Liu Y, Li M, Zhang D, Zhang M, Hu Q. HSV-2 glycoprotein gD targets the CC domain of tetherin and promotes tetherin degradation via lysosomal pathway. Virol J 2016; 13:154. [PMID: 27630089 PMCID: PMC5024446 DOI: 10.1186/s12985-016-0610-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 09/08/2016] [Indexed: 11/16/2022] Open
Abstract
Background HSV-2 is the major cause of genital herpes. We previously demonstrated that the host viral restriction factor tetherin restricts HSV-2 release and is antagonized by several HSV-2 glycoproteins. However, the mechanisms underlying HSV-2 glycoproteins mediated counteraction of tetherin remain unclear. In this study, we investigated whether tetherin restricts the cell-to-cell spread of HSV-2 and the mechanisms underlying HSV-2 gD mediated antagonism of tetherin. Methods Infectious center assays were used to test whether tetherin could affect cell-to-cell spread of HSV-2. Coimmunoprecipitation assays were performed to map the tetherin domains required for HSV-2 gD-mediated downregulation. Immunoflurence assays were performed to detect the accumulation of tetherin in lysosomes or proteasomes. All experiments were repeated for at least three times and the data were performed statistical analysis. Results 1) Tetherin restricts cell-to-cell spread of HSV-2; 2) HSV-2 gD specifically interacts with the CC domain of tetherin; 3) HSV-2 gD promotes tetherin to the lysosomal degradation pathway. Conclusions Tetherin not only restricts HSV-2 release but also its cell-to-cell spread. In turn, HSV-2 gD targets the CC domain of tetherin and promotes its degradation in the lysosome. Findings in this study have increased our understanding of tetherin restriction and viral countermeasures.
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Affiliation(s)
- Yalan Liu
- State Key Laboratory of Virology, Chinese Academy of Sciences, Wuhan Institute of Virology, Wuhan, 430071, China.
| | - Mei Li
- State Key Laboratory of Virology, Chinese Academy of Sciences, Wuhan Institute of Virology, Wuhan, 430071, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Di Zhang
- State Key Laboratory of Virology, Chinese Academy of Sciences, Wuhan Institute of Virology, Wuhan, 430071, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Mudan Zhang
- State Key Laboratory of Virology, Chinese Academy of Sciences, Wuhan Institute of Virology, Wuhan, 430071, China
| | - Qinxue Hu
- State Key Laboratory of Virology, Chinese Academy of Sciences, Wuhan Institute of Virology, Wuhan, 430071, China.,Institute for Infection and Immunity, St George's University of London, London, SW17 0RE, UK
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Rapiteanu R, Davis LJ, Williamson JC, Timms RT, Paul Luzio J, Lehner PJ. A Genetic Screen Identifies a Critical Role for the WDR81-WDR91 Complex in the Trafficking and Degradation of Tetherin. Traffic 2016; 17:940-58. [PMID: 27126989 PMCID: PMC5025723 DOI: 10.1111/tra.12409] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 04/26/2016] [Accepted: 04/26/2016] [Indexed: 12/24/2022]
Abstract
Tetherin (BST2/CD317) is a viral restriction factor that anchors enveloped viruses to host cells and limits viral spread. The HIV‐1 Vpu accessory protein counteracts tetherin by decreasing its cell surface expression and targeting it for ubiquitin‐dependent endolysosomal degradation. Although the Vpu‐mediated downregulation of tetherin has been extensively studied, the molecular details are not completely elucidated. We therefore used a forward genetic screen in human haploid KBM7 cells to identify novel genes required for tetherin trafficking. Our screen identified WDR81 as a novel gene required for tetherin trafficking and degradation in both the presence and absence of Vpu. WDR81 is a BEACH‐domain containing protein that is also required for the degradation of EGF‐stimulated epidermal growth factor receptor (EGFR) and functions in a complex with the WDR91 protein. In the absence of WDR81 the endolysosomal compartment appears swollen, with enlarged early and late endosomes and reduced delivery of endocytosed dextran to cathepsin‐active lysosomes. Our data suggest a role for the WDR81‐WDR91 complex in the fusion of endolysosomal compartments and the absence of WDR81 leads to impaired receptor trafficking and degradation.
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Affiliation(s)
- Radu Rapiteanu
- Cambridge Institute for Medical Research, University of Cambridge School of Clinical Medicine, Wellcome Trust/MRC Building Biomedical Campus, Cambridge, CB2 0XY, UK
| | - Luther J Davis
- Departments of Medicine and Clinical Biochemistry, University of Cambridge School of Clinical Medicine, Wellcome Trust/MRC Building Biomedical Campus, Cambridge, CB2 0XY, UK
| | - James C Williamson
- Cambridge Institute for Medical Research, University of Cambridge School of Clinical Medicine, Wellcome Trust/MRC Building Biomedical Campus, Cambridge, CB2 0XY, UK
| | - Richard T Timms
- Cambridge Institute for Medical Research, University of Cambridge School of Clinical Medicine, Wellcome Trust/MRC Building Biomedical Campus, Cambridge, CB2 0XY, UK
| | - J Paul Luzio
- Departments of Medicine and Clinical Biochemistry, University of Cambridge School of Clinical Medicine, Wellcome Trust/MRC Building Biomedical Campus, Cambridge, CB2 0XY, UK
| | - Paul J Lehner
- Cambridge Institute for Medical Research, University of Cambridge School of Clinical Medicine, Wellcome Trust/MRC Building Biomedical Campus, Cambridge, CB2 0XY, UK
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Remodeling of the Host Cell Plasma Membrane by HIV-1 Nef and Vpu: A Strategy to Ensure Viral Fitness and Persistence. Viruses 2016; 8:67. [PMID: 26950141 PMCID: PMC4810257 DOI: 10.3390/v8030067] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Revised: 02/09/2016] [Accepted: 02/16/2016] [Indexed: 02/07/2023] Open
Abstract
The plasma membrane protects the cell from its surroundings and regulates cellular communication, homing, and metabolism. Not surprisingly, the composition of this membrane is highly controlled through the vesicular trafficking of proteins to and from the cell surface. As intracellular pathogens, most viruses exploit the host plasma membrane to promote viral replication while avoiding immune detection. This is particularly true for the enveloped human immunodeficiency virus (HIV), which assembles and obtains its lipid shell directly at the plasma membrane. HIV-1 encodes two proteins, negative factor (Nef) and viral protein U (Vpu), which function primarily by altering the quantity and localization of cell surface molecules to increase virus fitness despite host antiviral immune responses. These proteins are expressed at different stages in the HIV-1 life cycle and employ a variety of mechanisms to target both unique and redundant surface proteins, including the viral receptor CD4, host restriction factors, immunoreceptors, homing molecules, tetraspanins and membrane transporters. In this review, we discuss recent progress in the study of the Nef and Vpu targeting of host membrane proteins with an emphasis on how remodeling of the cell membrane allows HIV-1 to avoid host antiviral immune responses leading to the establishment of systemic and persistent infection.
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48
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Zhang Q, Mi Z, Huang Y, Ma L, Ding J, Wang J, Zhang Y, Chen Y, Zhou J, Guo F, Li X, Cen S. 2-thio-6-azauridine inhibits Vpu mediated BST-2 degradation. Retrovirology 2016; 13:13. [PMID: 26935098 PMCID: PMC4776379 DOI: 10.1186/s12977-016-0247-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 02/25/2016] [Indexed: 12/31/2022] Open
Abstract
Backgroud
BST-2 is an interferon-induced host restriction factor that inhibits the release of diverse mammalian enveloped viruses from infected cells by physically trapping the newly formed virions onto the host cell surface. Human Immunodeficiency Virus-1 (HIV-1) encodes an accessory protein Vpu that antagonizes BST-2 by down-regulating BST-2 from the cell surface. Results Using a cell-based ELISA screening system, we have discovered a lead compound, 2-thio-6-azauridine, that restores cell surface BST-2 level in the presence of Vpu. This compound has no effect on the expression of BST-2 and Vpu, but inhibits Vpu-mediated BST-2 down-regulation and exerts no effect on Vpu-induced down-regulation of CD4 or KSHV K5 protein induced BST-2 down-regulation. 2-thio-6-azauridine suppresses HIV-1 production in a BST-2-dependent manner. Further results indicate that 2-thio-6-azauridine does not interrupt the interaction of BST-2 with Vpu and β-TrCP2, but decreases BST-2 ubiquitination. Conclusion Our study demonstrates the feasibility of using small molecules to target Vpu function and sensitize wild type HIV-1 to BST-2-mediated host restriction. Electronic supplementary material The online version of this article (doi:10.1186/s12977-016-0247-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Quan Zhang
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China.
| | - Zeyun Mi
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China. .,Department of Biochemistry and Molecular Biology, Tianjin Medical University, Tianjin, China.
| | - Yuming Huang
- Beijing Ditan Hospital, Capital Medical University, Beijing, China.
| | - Ling Ma
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China.
| | - Jiwei Ding
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China.
| | - Jing Wang
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China.
| | - Yongxin Zhang
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China.
| | - Yang Chen
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China.
| | - Jinming Zhou
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China.
| | - Fei Guo
- Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
| | - Xiaoyu Li
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China.
| | - Shan Cen
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China.
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Dotson D, Woodruff EA, Villalta F, Dong X. Filamin A Is Involved in HIV-1 Vpu-mediated Evasion of Host Restriction by Modulating Tetherin Expression. J Biol Chem 2016; 291:4236-46. [PMID: 26742839 DOI: 10.1074/jbc.m115.708123] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Indexed: 11/06/2022] Open
Abstract
Tetherin, also known as bone marrow stromal antigen 2 (BST-2), inhibits the release of a wide range of enveloped viruses, including human immunodeficiency virus, type 1 (HIV-1) by directly tethering nascent virions to the surface of infected cells. The HIV-1 accessary protein Vpu counteracts tetherin restriction via sequestration, down-regulation, and/or displacement mechanisms to remove tetherin from sites of virus budding. However, the exact mechanism of Vpu-mediated antagonism of tetherin restriction remains to be fully understood. Here we report a novel role for the actin cross-linking regulator filamin A (FLNa) in Vpu anti-tetherin activities. We demonstrate that FLNa associates with tetherin and that FLNa modulates tetherin turnover. FLNa deficiency was found to enhance cell surface and steady-state levels of tetherin expression. In contrast, we observed that overexpression of FLNa reduced tetherin expression levels both on the plasma membrane and in intracellular compartments. Although FLNb shows high amino acid sequence similarity with FLNa, we reveal that only FLNa, but not FLNb, plays an essential role in tetherin turnover. We further showed that FLNa deficiency inhibited Vpu-mediated enhancement of virus release through interfering with the activity of Vpu to down-regulate cellular tetherin. Taken together, our studies suggest that Vpu hijacks the FLNa function in the modulation of tetherin to neutralize the antiviral factor tetherin. These findings may provide novel strategies for the treatment of HIV-1 infection.
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Affiliation(s)
- Dominique Dotson
- From the Department of Microbiology and Immunology and Center for AIDS Health Disparities Research, School of Medicine, Meharry Medical College, Nashville, Tennessee 37208
| | - Elvin A Woodruff
- From the Department of Microbiology and Immunology and Center for AIDS Health Disparities Research, School of Medicine, Meharry Medical College, Nashville, Tennessee 37208
| | - Fernando Villalta
- From the Department of Microbiology and Immunology and Center for AIDS Health Disparities Research, School of Medicine, Meharry Medical College, Nashville, Tennessee 37208
| | - Xinhong Dong
- From the Department of Microbiology and Immunology and Center for AIDS Health Disparities Research, School of Medicine, Meharry Medical College, Nashville, Tennessee 37208
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50
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Nishitsuji H, Sugiyama R, Abe M, Takaku H. ATP1B3 Protein Modulates the Restriction of HIV-1 Production and Nuclear Factor κ Light Chain Enhancer of Activated B Cells (NF-κB) Activation by BST-2. J Biol Chem 2015; 291:4754-62. [PMID: 26694617 DOI: 10.1074/jbc.m115.679357] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Indexed: 11/06/2022] Open
Abstract
Here, we identify ATP1B3 and fibrillin-1 as novel BST-2-binding proteins. ATP1B3 depletion in HeLa cells (BST-2-positive cells), but not 293T cells (BST-2-negative cells), induced the restriction of HIV-1 production in a BST-2-dependent manner. In contrast, fibrillin-1 knockdown reduced HIV-1 production in 293T and HeLa cells in a BST-2-independent manner. Moreover, NF-κB activation was enhanced by siATP1B3 treatment in HIV-1- and HIV-1ΔVpu-infected HeLa cells. In addition, ATP1B3 silencing induced high level BST-2 expression on the surface of HeLa cells. These results indicate that ATP1B3 is a co-factor that accelerates BST-2 degradation and reduces BST-2-mediated restriction of HIV-1 production and NF-κB activation.
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Affiliation(s)
- Hironori Nishitsuji
- From the Research Center for Hepatitis and Immunology, National Center for Global Health and Medicine, Ichikawa, Chiba 272-8516
| | - Ryuichi Sugiyama
- the Department of Life and Environmental Sciences and the Department of Microbiology, Yokohama City University School of Medicine, Kanagawa 236-0004, Japan
| | - Makoto Abe
- the Department of Life and Environmental Sciences and
| | - Hiroshi Takaku
- the Department of Life and Environmental Sciences and Research Institute, Chiba Institute of Technology, 2-17-1 Tsudanuma, Narashino-shi, Chiba 275-0016, Japan, and
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