1
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Pickering S, Sumner J, Kerridge C, Perera M, Neil S. Differential dysregulation of β-TrCP1 and -2 by HIV-1 Vpu leads to inhibition of canonical and non-canonical NF-κB pathways in infected cells. mBio 2023; 14:e0329322. [PMID: 37341489 PMCID: PMC10470808 DOI: 10.1128/mbio.03293-22] [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: 11/25/2022] [Accepted: 04/03/2023] [Indexed: 06/22/2023] Open
Abstract
The HIV-1 Vpu protein is expressed late in the virus lifecycle to promote infectious virus production and avoid innate and adaptive immunity. This includes the inhibition of the NF-κB pathway which, when activated, leads to the induction of inflammatory responses and the promotion of antiviral immunity. Here we demonstrate that Vpu can inhibit both canonical and non-canonical NF-κB pathways, through the direct inhibition of the F-box protein β-TrCP, the substrate recognition portion of the Skp1-Cul1-F-box (SCF)β-TrCP ubiquitin ligase complex. There are two paralogues of β-TrCP (β-TrCP1/BTRC and β-TrCP2/FBXW11), encoded on different chromosomes, which appear to be functionally redundant. Vpu, however, is one of the few β-TrCP substrates to differentiate between the two paralogues. We have found that patient-derived alleles of Vpu, unlike those from lab-adapted viruses, trigger the degradation of β-TrCP1 while co-opting its paralogue β-TrCP2 for the degradation of cellular targets of Vpu, such as CD4. The potency of this dual inhibition correlates with stabilization of the classical IκBα and the phosphorylated precursors of the mature DNA-binding subunits of canonical and non-canonical NF-κB pathways, p105/NFκB1 and p100/NFκB2, in HIV-1 infected CD4+ T cells. Both precursors act as alternative IκBs in their own right, thus reinforcing NF-κB inhibition at steady state and upon activation with either selective canonical or non-canonical NF-κB stimuli. These data reveal the complex regulation of NF-κB late in the viral replication cycle, with consequences for both the pathogenesis of HIV/AIDS and the use of NF-κB-modulating drugs in HIV cure strategies. IMPORTANCE The NF-κB pathway regulates host responses to infection and is a common target of viral antagonism. The HIV-1 Vpu protein inhibits NF-κB signaling late in the virus lifecycle, by binding and inhibiting β-TrCP, the substrate recognition portion of the ubiquitin ligase responsible for inducing IκB degradation. Here we demonstrate that Vpu simultaneously inhibits and exploits the two different paralogues of β-TrCP by triggering the degradation of β-TrCP1 and co-opting β-TrCP2 for the destruction of its cellular targets. In so doing, it has a potent inhibitory effect on both the canonical and non-canonical NF-κB pathways. This effect has been underestimated in previous mechanistic studies due to the use of Vpu proteins from lab-adapted viruses. Our findings reveal previously unappreciated differences in the β-TrCP paralogues, revealing functional insights into the regulation of these proteins. This study also raises important implications for the role of NF-κB inhibition in the immunopathogenesis of HIV/AIDS and the way that this may impact on HIV latency reversal strategies based on the activation of the non-canonical NF-κB pathway.
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Affiliation(s)
- Suzanne Pickering
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King’s College London, London, United Kingdom
| | - Jonathan Sumner
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King’s College London, London, United Kingdom
| | - Claire Kerridge
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King’s College London, London, United Kingdom
| | - Marianne Perera
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King’s College London, London, United Kingdom
| | - Stuart Neil
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King’s College London, London, United Kingdom
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2
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Zhang RZ, Kane M. Insights into the role of HIV-1 Vpu in modulation of NF-ĸB signaling pathways. mBio 2023; 14:e0092023. [PMID: 37409832 PMCID: PMC10470773 DOI: 10.1128/mbio.00920-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 05/30/2023] [Indexed: 07/07/2023] Open
Abstract
HIV-1 inhibits the activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) to prevent the induction of a proinflammatory state but also activates the NF-κB pathway to promote viral transcription. Thus, optimal regulation of this pathway is important for the viral life cycle. In recent work, Pickering et al. (3) demonstrate that HIV-1 viral protein U has contrasting effects on the two distinct paralogs of β-transducin repeat-containing protein (β-TrCP1 and β-TrCP2) and that this interaction has important implications for the regulation of both the canonical and non-canonical NF-κB pathways. Additionally, the authors identified the viral requirements for the dysregulation of β-TrCP. In this commentary, we discuss how these findings further our understanding of how the NF-κB pathway functions during viral infection.
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Affiliation(s)
- Robert Z. Zhang
- Department of Pediatrics, Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Melissa Kane
- Department of Pediatrics, Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- RK Mellon Institute for Pediatric Research, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Center for Microbial Pathogenesis, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
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3
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Itell HL, Humes D, Overbaugh J. Several cell-intrinsic effectors drive type I interferon-mediated restriction of HIV-1 in primary CD4 + T cells. Cell Rep 2023; 42:112556. [PMID: 37227817 PMCID: PMC10592456 DOI: 10.1016/j.celrep.2023.112556] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 03/30/2023] [Accepted: 05/05/2023] [Indexed: 05/27/2023] Open
Abstract
Type I interferon (IFN) upregulates proteins that inhibit HIV within infected cells. Prior studies have identified IFN-stimulated genes (ISGs) that impede lab-adapted HIV in cell lines, yet the ISG(s) that mediate IFN restriction in HIV target cells, primary CD4+ T cells, are unknown. Here, we interrogate ISG restriction of primary HIV in CD4+ T cells by performing CRISPR-knockout screens with a custom library that specifically targets ISGs expressed in CD4+ T cells. Our investigation identifies previously undescribed HIV-restricting ISGs (HM13, IGFBP2, LAP3) and finds that two factors characterized in other HIV infection models (IFI16 and UBE2L6) mediate IFN restriction in T cells. Inactivation of these five ISGs in combination further diminishes IFN's protective effect against diverse HIV strains. This work demonstrates that IFN restriction of HIV is multifaceted, resulting from several effectors functioning collectively, and establishes a primary cell ISG screening model to identify both single and combinations of HIV-restricting ISGs.
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Affiliation(s)
- Hannah L Itell
- Molecular and Cellular Biology PhD Program, University of Washington, Seattle, WA 98195, USA; Division of Human Biology, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Daryl Humes
- Division of Human Biology, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Julie Overbaugh
- Division of Human Biology, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA.
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4
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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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5
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Itell HL, Humes D, Overbaugh J. Several cell-intrinsic effectors drive type I interferon-mediated restriction of HIV-1 in primary CD4 + T cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.07.527545. [PMID: 36798236 PMCID: PMC9934674 DOI: 10.1101/2023.02.07.527545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Type I interferon (IFN) upregulates proteins that inhibit HIV within infected cells. Prior studies have identified IFN-stimulated genes (ISGs) that impede lab-adapted HIV in cell lines, yet the ISG(s) that mediate IFN restriction in HIV target cells, primary CD4 + T cells, are unknown. Here, we interrogate ISG restriction of primary HIV in CD4 + T cells. We performed CRISPR-knockout screens using a custom library that specifically targets ISGs expressed in CD4 + T cells and validated top hits. Our investigation identified new HIV-restricting ISGs (HM13, IGFBP2, LAP3) and found that two previously studied factors (IFI16, UBE2L6) are IFN effectors in T cells. Inactivation of these five ISGs in combination further diminished IFN’s protective effect against six diverse HIV strains. This work demonstrates that IFN restriction of HIV is multifaceted, resulting from several effectors functioning collectively, and establishes a primary cell ISG screening model to identify both single and combinations of HIV-restricting ISGs.
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Affiliation(s)
- Hannah L. Itell
- Molecular and Cellular Biology PhD Program, University of Washington, Seattle, WA, 98109, USA
- Division of Human Biology, Fred Hutchinson Cancer Center, Seattle, WA, 98109, USA
| | - Daryl Humes
- Division of Human Biology, Fred Hutchinson Cancer Center, Seattle, WA, 98109, USA
- Present address: Tr1X Inc, La Jolla, CA, 92037, USA
| | - Julie Overbaugh
- Division of Human Biology, Fred Hutchinson Cancer Center, Seattle, WA, 98109, USA
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6
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Vollmers S, Lobermeyer A, Niehrs A, Fittje P, Indenbirken D, Nakel J, Virdi S, Brias S, Trenkner T, Sauer G, Peine S, Behrens GM, Lehmann C, Meurer A, Pauli R, Postel N, Roider J, Scholten S, Spinner CD, Stephan C, Wolf E, Wyen C, Richert L, Norman PJ, Sauter J, Schmidt AH, Hoelzemer A, Altfeld M, Körner C. Host KIR/HLA-C Genotypes Determine HIV-Mediated Changes of the NK Cell Repertoire and Are Associated With Vpu Sequence Variations Impacting Downmodulation of HLA-C. Front Immunol 2022; 13:922252. [PMID: 35911762 PMCID: PMC9334850 DOI: 10.3389/fimmu.2022.922252] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Accepted: 06/13/2022] [Indexed: 12/29/2022] Open
Abstract
NK cells play a pivotal role in viral immunity, utilizing a large array of activating and inhibitory receptors to identify and eliminate virus-infected cells. Killer-cell immunoglobulin-like receptors (KIRs) represent a highly polymorphic receptor family, regulating NK cell activity and determining the ability to recognize target cells. Human leukocyte antigen (HLA) class I molecules serve as the primary ligand for KIRs. Herein, HLA-C stands out as being the dominant ligand for the majority of KIRs. Accumulating evidence indicated that interactions between HLA-C and its inhibitory KIR2DL receptors (KIR2DL1/L2/L3) can drive HIV-1-mediated immune evasion and thus may contribute to the intrinsic control of HIV-1 infection. Of particular interest in this context is the recent observation that HIV-1 is able to adapt to host HLA-C genotypes through Vpu-mediated downmodulation of HLA-C. However, our understanding of the complex interplay between KIR/HLA immunogenetics, NK cell-mediated immune pressure and HIV-1 immune escape is still limited. Therefore, we investigated the impact of specific KIR/HLA-C combinations on the NK cell receptor repertoire and HIV-1 Vpu protein sequence variations of 122 viremic, untreated HIV-1+ individuals. Compared to 60 HIV-1- controls, HIV-1 infection was associated with significant changes within the NK cell receptor repertoire, including reduced percentages of NK cells expressing NKG2A, CD8, and KIR2DS4. In contrast, the NKG2C+ and KIR3DL2+ NK cell sub-populations from HIV-1+ individuals was enlarged compared to HIV-1- controls. Stratification along KIR/HLA-C genotypes revealed a genotype-dependent expansion of KIR2DL1+ NK cells that was ultimately associated with increased binding affinities between KIR2DL1 and HLA-C allotypes. Lastly, our data hinted to a preferential selection of Vpu sequence variants that were associated with HLA-C downmodulation in individuals with high KIR2DL/HLA-C binding affinities. Altogether, our study provides evidence that HIV-1-associated changes in the KIR repertoire of NK cells are to some extent predetermined by host KIR2DL/HLA-C genotypes. Furthermore, analysis of Vpu sequence polymorphisms indicates that differential KIR2DL/HLA-C binding affinities may serve as an additional mechanism how host genetics impact immune evasion by HIV-1.
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Affiliation(s)
| | | | | | - Pia Fittje
- Leibniz Institute of Virology, Hamburg, Germany
| | | | | | | | - Sebastien Brias
- Leibniz Institute of Virology, Hamburg, Germany
- First Department of Medicine, Division of Infectious Diseases, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Gabriel Sauer
- Department I for Internal Medicine, University Hospital of Cologne, Cologne, Germany
| | - Sven Peine
- Institute for Transfusion Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Georg M.N. Behrens
- Department for Rheumatology and Clinical Immunology, Hannover Medical School, Hannover, Germany
| | - Clara Lehmann
- Department I for Internal Medicine, Division of Infectious Diseases, University Hospital Cologne, Cologne, Germany
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Anja Meurer
- Center for Internal Medicine and Infectiology, Munich, Germany
| | - Ramona Pauli
- Medizinisches Versorgungszentrum (MVZ) am Isartor, Munich, Germany
| | - Nils Postel
- Prinzmed, Practice for Infectious Diseases, Munich, Germany
| | - Julia Roider
- Department of Internal Medicine IV, Department of Infectious Diseases, Ludwig-Maximilians University Munich, Munich, Germany
- German Center for Infection Research (DZIF), Partner Site Munich, Munich, Germany
| | | | - Christoph D. Spinner
- German Center for Infection Research (DZIF), Partner Site Munich, Munich, Germany
- Technical University of Munich, School of Medicine, University Hospital rechts der Isar, Department of Internal Medicine II, Munich, Germany
| | - Christoph Stephan
- Infectious Diseases Unit, Goethe-University Hospital Frankfurt, Frankfurt, Germany
| | | | - Christoph Wyen
- Department I for Internal Medicine, Division of Infectious Diseases, University Hospital Cologne, Cologne, Germany
- Praxis am Ebertplatz, Cologne, Germany
| | - Laura Richert
- University of Bordeaux, Inserm U1219 Bordeaux Population Health, Inria Sistm, Bordeaux, France
| | - Paul J. Norman
- Division of Biomedical Informatics and Personalized Medicine, University of Colorado, Aurora, CO, United States
- Department of Immunology and Microbiology, University of Colorado, Aurora, CO, United States
| | | | | | - Angelique Hoelzemer
- Leibniz Institute of Virology, Hamburg, Germany
- First Department of Medicine, Division of Infectious Diseases, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- German Center for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel-Riems, Hamburg, Germany
| | - Marcus Altfeld
- Leibniz Institute of Virology, Hamburg, Germany
- German Center for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel-Riems, Hamburg, Germany
| | - Christian Körner
- Leibniz Institute of Virology, Hamburg, Germany
- *Correspondence: Christian Körner,
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7
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Umviligihozo G, Mann JK, Jin SW, Mwimanzi FM, Hsieh HSA, Sudderuddin H, Lee GQ, Byakwaga H, Muzoora C, Hunt PW, Martin JN, Haberer JE, Karita E, Allen S, Hunter E, Brumme ZL, Brockman MA. Attenuated HIV-1 Nef But Not Vpu Function in a Cohort of Rwandan Long-Term Survivors. FRONTIERS IN VIROLOGY 2022; 2:917902. [PMID: 35982753 PMCID: PMC9383652 DOI: 10.3389/fviro.2022.917902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
HIV-1 accessory proteins Nef and Vpu enhance viral pathogenesis through partially overlapping immune evasion activities. Attenuated Nef or Vpu functions have been reported in individuals who display slower disease progression, but few studies have assessed the relative impact of these proteins in non-B HIV-1 subtypes or examined paired proteins from the same individuals. Here, we examined the sequence and function of matched Nef and Vpu clones isolated from 29 long-term survivors (LTS) from Rwanda living with HIV-1 subtype A and compared our results to those of 104 Nef and 62 Vpu clones isolated from individuals living with chronic untreated HIV-1 subtype A from the same geographic area. Nef and vpu coding regions were amplified from plasma HIV RNA and cloned. The function of one intact, phylogenetically-validated Nef and Vpu clone per individual was then quantified by flow cytometry following transient expression in an immortalized CD4+ T-cell line. We measured the ability of each Nef clone to downregulate CD4 and HLA class I, and of each Vpu clone to downregulate CD4 and Tetherin, from the cell surface. Results were normalized to reference clones (Nef-SF2 and Vpu-NL4.3). We observed that Nef-mediated CD4 and HLA downregulation functions were lower in LTS compared to the control cohort (Mann-Whitney p=0.03 and p<0.0001, respectively). Moreover, we found a positive correlation between Nef-mediated CD4 downregulation function and plasma viral load in LTS and controls (Spearman ρ= 0.59, p=0.03 and ρ=0.30, p=0.005, respectively). In contrast, Vpu-mediated functions were similar between groups and did not correlate with clinical markers. Further analyses identified polymorphisms at Nef codon 184 and Vpu codons 60-62 that were associated with function, which were confirmed through mutagenesis. Overall, our results support attenuated function of Nef, but not Vpu, as a contributor to slower disease progression in this cohort of long-term survivors with HIV-1 subtype A.
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Affiliation(s)
| | - Jaclyn K. Mann
- HIV Pathogenesis Programme, University of KwaZulu-Natal, Durban, South Africa
| | - Steven W. Jin
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada
| | | | - Hua-Shiuan A. Hsieh
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Hanwei Sudderuddin
- British Columbia Centre for Excellence in HIV/AIDS, Vancover, BC, Canada
| | - Guinevere Q. Lee
- Department of Medicine, Weill Cornell Medical College, New York, NY, United States
| | - Helen Byakwaga
- Department of Community Health, Mbarara University of Science and Technology, Mbarara, Uganda,Department of Medicine, University of California, San Francisco, CA, United States
| | - Conrad Muzoora
- Department of Medicine, Weill Cornell Medical College, New York, NY, United States
| | - Peter W. Hunt
- Department of Community Health, Mbarara University of Science and Technology, Mbarara, Uganda
| | - Jeff N. Martin
- Department of Community Health, Mbarara University of Science and Technology, Mbarara, Uganda
| | - Jessica E. Haberer
- Center for Global Health, Massachusetts General Hospital, Boston, MA, United States,Department of Medicine, Harvard Medical School, Boston, MA, United States
| | | | - Susan Allen
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, United States
| | - Eric Hunter
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, United States,Emory Vaccine Center at Yerkes National Primate Research Center, Atlanta, GA, United States
| | - Zabrina L. Brumme
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada,British Columbia Centre for Excellence in HIV/AIDS, Vancover, BC, Canada
| | - Mark A. Brockman
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada,Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada,British Columbia Centre for Excellence in HIV/AIDS, Vancover, BC, Canada,Correspondence: Mark A. Brockman,
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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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Khan N, Geiger JD. Role of Viral Protein U (Vpu) in HIV-1 Infection and Pathogenesis. Viruses 2021; 13:v13081466. [PMID: 34452331 PMCID: PMC8402909 DOI: 10.3390/v13081466] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/16/2021] [Accepted: 07/24/2021] [Indexed: 12/11/2022] Open
Abstract
Human immunodeficiency virus (HIV)-1 and HIV-2 originated from cross-species transmission of simian immunodeficiency viruses (SIVs). Most of these transfers resulted in limited spread of these viruses to humans. However, one transmission event involving SIVcpz from chimpanzees gave rise to group M HIV-1, with M being the principal strain of HIV-1 responsible for the AIDS pandemic. Vpu is an HIV-1 accessory protein generated from Env/Vpu encoded bicistronic mRNA and localized in cytosolic and membrane regions of cells capable of being infected by HIV-1 and that regulate HIV-1 infection and transmission by downregulating BST-2, CD4 proteins levels, and immune evasion. This review will focus of critical aspects of Vpu including its zoonosis, the adaptive hurdles to cross-species transmission, and future perspectives and broad implications of Vpu in HIV-1 infection and dissemination.
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10
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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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11
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Ficarelli M, Wilson H, Pedro Galão R, Mazzon M, Antzin-Anduetza I, Marsh M, Neil SJD, Swanson CM. KHNYN is essential for the zinc finger antiviral protein (ZAP) to restrict HIV-1 containing clustered CpG dinucleotides. eLife 2019; 8:e46767. [PMID: 31284899 PMCID: PMC6615859 DOI: 10.7554/elife.46767] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 06/10/2019] [Indexed: 12/21/2022] Open
Abstract
CpG dinucleotides are suppressed in most vertebrate RNA viruses, including HIV-1, and introducing CpGs into RNA virus genomes inhibits their replication. The zinc finger antiviral protein (ZAP) binds regions of viral RNA containing CpGs and targets them for degradation. ZAP does not have enzymatic activity and recruits other cellular proteins to inhibit viral replication. We found that KHNYN, a protein with no previously known function, interacts with ZAP. KHNYN overexpression selectively inhibits HIV-1 containing clustered CpG dinucleotides and this requires ZAP and its cofactor TRIM25. KHNYN requires both its KH-like domain and NYN endonuclease domain for antiviral activity. Crucially, depletion of KHNYN eliminated the deleterious effect of CpG dinucleotides on HIV-1 RNA abundance and infectious virus production and also enhanced the production of murine leukemia virus. Overall, we have identified KHNYN as a novel cofactor for ZAP to target CpG-containing retroviral RNA for degradation.
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Affiliation(s)
- Mattia Ficarelli
- Department of Infectious Diseases, School of Immunology and Microbial SciencesKing’s College LondonLondonUnited Kingdom
| | - Harry Wilson
- Department of Infectious Diseases, School of Immunology and Microbial SciencesKing’s College LondonLondonUnited Kingdom
| | - Rui Pedro Galão
- Department of Infectious Diseases, School of Immunology and Microbial SciencesKing’s College LondonLondonUnited Kingdom
| | - Michela Mazzon
- MRC Laboratory for Molecular Cell BiologyUniversity College LondonLondonUnited Kingdom
| | - Irati Antzin-Anduetza
- Department of Infectious Diseases, School of Immunology and Microbial SciencesKing’s College LondonLondonUnited Kingdom
| | - Mark Marsh
- MRC Laboratory for Molecular Cell BiologyUniversity College LondonLondonUnited Kingdom
| | - Stuart JD Neil
- Department of Infectious Diseases, School of Immunology and Microbial SciencesKing’s College LondonLondonUnited Kingdom
| | - Chad M Swanson
- Department of Infectious Diseases, School of Immunology and Microbial SciencesKing’s College LondonLondonUnited Kingdom
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12
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Langer S, Hammer C, Hopfensperger K, Klein L, Hotter D, De Jesus PD, Herbert KM, Pache L, Smith N, van der Merwe JA, Chanda SK, Fellay J, Kirchhoff F, Sauter D. HIV-1 Vpu is a potent transcriptional suppressor of NF-κB-elicited antiviral immune responses. eLife 2019; 8:41930. [PMID: 30717826 PMCID: PMC6372280 DOI: 10.7554/elife.41930] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 01/26/2019] [Indexed: 12/11/2022] Open
Abstract
Many viral pathogens target innate sensing cascades and/or cellular transcription factors to suppress antiviral immune responses. Here, we show that the accessory viral protein U (Vpu) of HIV-1 exerts broad immunosuppressive effects by inhibiting activation of the transcription factor NF-κB. Global transcriptional profiling of infected CD4 +T cells revealed that vpu-deficient HIV-1 strains induce substantially stronger immune responses than the respective wild type viruses. Gene set enrichment analyses and cytokine arrays showed that Vpu suppresses the expression of NF-κB targets including interferons and restriction factors. Mutational analyses demonstrated that this immunosuppressive activity of Vpu is independent of its ability to counteract the restriction factor and innate sensor tetherin. However, Vpu-mediated inhibition of immune activation required an arginine residue in the cytoplasmic domain that is critical for blocking NF-κB signaling downstream of tetherin. In summary, our findings demonstrate that HIV-1 Vpu potently suppresses NF-κB-elicited antiviral immune responses at the transcriptional level. The Human Immunodeficiency Virus (or HIV for short) has infected more than 70 million people worldwide. Although effective therapies exist to prevent the replication of the virus and the development to AIDS, there is no cure or vaccine, and the virus still spreads efficiently in human populations, infecting about 1.8 million new people every year. The unfortunate success of HIV can in part be explained by several viral proteins that trick our immune system and enable the virus to persist at high levels in the human body. For example, an HIV protein called viral protein U (Vpu) prevents infected cells from producing alarm signals such as interferons, which usually help healthy, uninfected cells to defend themselves against viruses. However, the extent to which Vpu interferes with interferons and other proteins involved in immune responses has remained unclear. To address this question, Langer, Hammer, Hopfensperger et al. compared how different variants of HIV affect immune responses in human cells. The experiments showed that cells infected with HIV variants lacking Vpu released larger amounts of interferons and other cellular proteins that are involved in immune responses compared to HIV variants with Vpu. Further experiments showed that Vpu works by inhibiting the activation of a protein called NF-κB, which usually switches on genes that encode interferons and many other proteins involved in immune responses. These findings demonstrate that Vpu has a broader impact on the human immune response than previously thought. In order to multiply efficiently, HIV initially requires the NF-κB protein to be active. Therefore, when NF-κB is inactive, HIV may adopt a dormant state that prevents current antiviral drug treatments from eradicating the virus in the human body. In the future, developing new drugs that can activate dormant HIV particles may therefore have the potential to help cure HIV infections.
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Affiliation(s)
- Simon Langer
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany.,Infectious and Inflammatory Disease Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States
| | - Christian Hammer
- School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | | | - Lukas Klein
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Dominik Hotter
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Paul D De Jesus
- Infectious and Inflammatory Disease Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States
| | - Kristina M Herbert
- Infectious and Inflammatory Disease Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States
| | - Lars Pache
- Infectious and Inflammatory Disease Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States
| | - Nikaïa Smith
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | | | - Sumit K Chanda
- Infectious and Inflammatory Disease Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States
| | - Jacques Fellay
- School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Frank Kirchhoff
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Daniel Sauter
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
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13
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OhAinle M, Helms L, Vermeire J, Roesch F, Humes D, Basom R, Delrow JJ, Overbaugh J, Emerman M. A virus-packageable CRISPR screen identifies host factors mediating interferon inhibition of HIV. eLife 2018; 7:e39823. [PMID: 30520725 PMCID: PMC6286125 DOI: 10.7554/elife.39823] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 11/13/2018] [Indexed: 12/14/2022] Open
Abstract
Interferon (IFN) inhibits HIV replication by inducing antiviral effectors. To comprehensively identify IFN-induced HIV restriction factors, we assembled a CRISPR sgRNA library of Interferon Stimulated Genes (ISGs) into a modified lentiviral vector that allows for packaging of sgRNA-encoding genomes in trans into budding HIV-1 particles. We observed that knockout of Zinc Antiviral Protein (ZAP) improved the performance of the screen due to ZAP-mediated inhibition of the vector. A small panel of IFN-induced HIV restriction factors, including MxB, IFITM1, Tetherin/BST2 and TRIM5alpha together explain the inhibitory effects of IFN on the CXCR4-tropic HIV-1 strain, HIV-1LAI, in THP-1 cells. A second screen with a CCR5-tropic primary strain, HIV-1Q23.BG505, described an overlapping, but non-identical, panel of restriction factors. Further, this screen also identifies HIV dependency factors. The ability of IFN-induced restriction factors to inhibit HIV strains to replicate in human cells suggests that these human restriction factors are incompletely antagonized. Editorial note This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that all the issues have been addressed (see decision letter).
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Affiliation(s)
- Molly OhAinle
- Divisions of Human Biology and Basic SciencesFred Hutchinson Cancer Research CenterWashingtonUnited States
| | - Louisa Helms
- Divisions of Human Biology and Basic SciencesFred Hutchinson Cancer Research CenterWashingtonUnited States
| | - Jolien Vermeire
- Divisions of Human Biology and Basic SciencesFred Hutchinson Cancer Research CenterWashingtonUnited States
| | - Ferdinand Roesch
- Divisions of Human Biology and Basic SciencesFred Hutchinson Cancer Research CenterWashingtonUnited States
| | - Daryl Humes
- Divisions of Human Biology and Basic SciencesFred Hutchinson Cancer Research CenterWashingtonUnited States
| | - Ryan Basom
- Genomics and Bioinformatics Shared ResourceFred Hutchinson Cancer Research CenterSeattleUnited States
| | - Jeffrey J Delrow
- Genomics and Bioinformatics Shared ResourceFred Hutchinson Cancer Research CenterSeattleUnited States
| | - Julie Overbaugh
- Divisions of Human Biology and Basic SciencesFred Hutchinson Cancer Research CenterWashingtonUnited States
| | - Michael Emerman
- Divisions of Human Biology and Basic SciencesFred Hutchinson Cancer Research CenterWashingtonUnited States
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14
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Bachtel ND, Umviligihozo G, Pickering S, Mota TM, Liang H, Del Prete GQ, Chatterjee P, Lee GQ, Thomas R, Brockman MA, Neil S, Carrington M, Bwana B, Bangsberg DR, Martin JN, Kallas EG, Donini CS, Cerqueira NB, O’Doherty UT, Hahn BH, Jones RB, Brumme ZL, Nixon DF, Apps R. HLA-C downregulation by HIV-1 adapts to host HLA genotype. PLoS Pathog 2018; 14:e1007257. [PMID: 30180214 PMCID: PMC6138419 DOI: 10.1371/journal.ppat.1007257] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 09/14/2018] [Accepted: 08/02/2018] [Indexed: 01/09/2023] Open
Abstract
HIV-1 can downregulate HLA-C on infected cells, using the viral protein Vpu, and the magnitude of this downregulation varies widely between primary HIV-1 variants. The selection pressures that result in viral downregulation of HLA-C in some individuals, but preservation of surface HLA-C in others are not clear. To better understand viral immune evasion targeting HLA-C, we have characterized HLA-C downregulation by a range of primary HIV-1 viruses. 128 replication competent viral isolates from 19 individuals with effective anti-retroviral therapy, show that a substantial minority of individuals harbor latent reservoir virus which strongly downregulates HLA-C. Untreated infections display no change in HLA-C downregulation during the first 6 months of infection, but variation between viral quasispecies can be detected in chronic infection. Vpu molecules cloned from plasma of 195 treatment naïve individuals in chronic infection demonstrate that downregulation of HLA-C adapts to host HLA genotype. HLA-C alleles differ in the pressure they exert for downregulation, and individuals with higher levels of HLA-C expression favor greater viral downregulation of HLA-C. Studies of primary and mutant molecules identify 5 residues in the transmembrane region of Vpu, and 4 residues in the transmembrane domain of HLA-C, which determine interactions between Vpu and HLA. The observed adaptation of Vpu-mediated downregulation to host genotype indicates that HLA-C alleles differ in likelihood of mediating a CTL response that is subverted by viral downregulation, and that preservation of HLA-C expression is favored in the absence of these responses. Finding that latent reservoir viruses can downregulate HLA-C could have implications for HIV-1 cure therapy approaches in some individuals.
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Affiliation(s)
- Nathaniel D. Bachtel
- Department of Microbiology, Immunology & Tropical Medicine, The George Washington University, Washington DC, United States of America
| | | | - Suzanne Pickering
- Department of Infectious Disease, King’s College London School of Medicine, Guy’s Hospital, London, United Kingdom
| | - Talia M. Mota
- Department of Microbiology, Immunology & Tropical Medicine, The George Washington University, Washington DC, United States of America
| | - Hua Liang
- Department of Statistics and Biostatistics, George Washington University, Washington DC, United States of America
| | - Gregory Q. Del Prete
- AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research sponsored by the National Cancer Institute, Frederick, Maryland, United States of America
| | - Pramita Chatterjee
- Cancer and Inflammation Program, HLA Immunogenetics Section, Basic Science Program, Frederick National Laboratory for Cancer Research sponsored by the National Cancer Institute, Frederick, Maryland, United States of America
| | - Guinevere Q. Lee
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, Massachusetts, United States of America
| | - Rasmi Thomas
- US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation, Bethesda, Maryland, United States of America
| | - Mark A. Brockman
- Faculty of Health Sciences, Simon Fraser University, Burnaby, Canada
- British Columbia Centre for Excellence in HIV/AIDS, Vancouver, Canada
| | - Stuart Neil
- Department of Infectious Disease, King’s College London School of Medicine, Guy’s Hospital, London, United Kingdom
| | - Mary Carrington
- Cancer and Inflammation Program, HLA Immunogenetics Section, Basic Science Program, Frederick National Laboratory for Cancer Research sponsored by the National Cancer Institute, Frederick, Maryland, United States of America
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, Massachusetts, United States of America
| | - Bosco Bwana
- Mbarara University of Science and Technology, Mbarara, Uganda
| | - David R. Bangsberg
- Mbarara University of Science and Technology, Mbarara, Uganda
- Oregon Health & Science University, Portland State University School of Public Health, Portland, Oregon, United States of America
| | - Jeffrey N. Martin
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, California, United States of America
| | | | | | | | - Una T. O’Doherty
- Departments of Medicine and Microbiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Beatrice H. Hahn
- Departments of Medicine and Microbiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - R. Brad Jones
- Department of Microbiology, Immunology & Tropical Medicine, The George Washington University, Washington DC, United States of America
| | - Zabrina L. Brumme
- Faculty of Health Sciences, Simon Fraser University, Burnaby, Canada
- British Columbia Centre for Excellence in HIV/AIDS, Vancouver, Canada
| | - Douglas F. Nixon
- Department of Microbiology, Immunology & Tropical Medicine, The George Washington University, Washington DC, United States of America
| | - Richard Apps
- Department of Microbiology, Immunology & Tropical Medicine, The George Washington University, Washington DC, United States of America
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15
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Preadaptation of Simian Immunodeficiency Virus SIVsmm Facilitated Env-Mediated Counteraction of Human Tetherin by Human Immunodeficiency Virus Type 2. J Virol 2018; 92:JVI.00276-18. [PMID: 29976668 DOI: 10.1128/jvi.00276-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 06/23/2018] [Indexed: 12/14/2022] Open
Abstract
The host restriction factor tetherin inhibits virion release from infected cells and poses a significant barrier to successful zoonotic transmission of primate lentiviruses to humans. While most simian immunodeficiency viruses (SIV), including the direct precursors of human immunodeficiency virus type 1 (HIV-1) and HIV-2, use their Nef protein to counteract tetherin in their natural hosts, they fail to antagonize the human tetherin ortholog. Pandemic HIV-1 group M and epidemic group O strains overcame this hurdle by adapting their Vpu and Nef proteins, respectively, whereas HIV-2 group A uses its envelope (Env) glycoprotein to counteract human tetherin. Whether or how the remaining eight groups of HIV-2 antagonize this antiviral factor has remained unclear. Here, we show that Nef proteins from diverse groups of HIV-2 do not or only modestly antagonize human tetherin, while their ability to downmodulate CD3 and CD4 is highly conserved. Experiments in transfected cell lines and infected primary cells revealed that not only Env proteins of epidemic HIV-2 group A but also those of a circulating recombinant form (CRF01_AB) and rare groups F and I decrease surface expression of human tetherin and significantly enhance progeny virus release. Intriguingly, we found that many SIVsmm Envs also counteract human as well as smm tetherin. Thus, Env-mediated tetherin antagonism in different groups of HIV-2 presumably stems from a preadaptation of their SIVsmm precursors to humans. In summary, we identified a phenotypic trait of SIVsmm that may have facilitated its successful zoonotic transmission to humans and the emergence of HIV-2.IMPORTANCE HIV-2 groups A to I resulted from nine independent cross-species transmission events of SIVsmm to humans and differ considerably in their prevalence and geographic spread. Thus, detailed characterization of these viruses offers a valuable means to elucidate immune evasion mechanisms and human-specific adaptations determining viral spread. In a systematic comparison of rare and epidemic HIV-2 groups and their simian SIVsmm counterparts, we found that the ability of Nef to downmodulate the primary viral entry receptor CD4 and the T cell receptor CD3 is conserved, while effects on CD28, CD74, and major histocompatibility complex class I surface expression vary considerably. Furthermore, we show that not only the Env proteins of HIV-2 groups A, AB, F, and I but also those of some SIVsmm isolates antagonize human tetherin. This finding helps to explain why SIVsmm has been able to cross the species barrier to humans on at least nine independent occasions.
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16
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Foster TL, Pickering S, Neil SJD. Inhibiting the Ins and Outs of HIV Replication: Cell-Intrinsic Antiretroviral Restrictions at the Plasma Membrane. Front Immunol 2018; 8:1853. [PMID: 29354117 PMCID: PMC5758531 DOI: 10.3389/fimmu.2017.01853] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 12/07/2017] [Indexed: 01/01/2023] Open
Abstract
Like all viruses, human immunodeficiency viruses (HIVs) and their primate lentivirus relatives must enter cells in order to replicate and, once produced, new virions need to exit to spread to new targets. These processes require the virus to cross the plasma membrane of the cell twice: once via fusion mediated by the envelope glycoprotein to deliver the viral core into the cytosol; and secondly by ESCRT-mediated scission of budding virions during release. This physical barrier thus presents a perfect location for host antiviral restrictions that target enveloped viruses in general. In this review we will examine the current understanding of innate host antiviral defences that inhibit these essential replicative steps of primate lentiviruses associated with the plasma membrane, the mechanism by which these viruses have adapted to evade such defences, and the role that this virus/host battleground plays in the transmission and pathogenesis of HIV/AIDS.
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Affiliation(s)
- Toshana L Foster
- Department of Infectious Disease, School of Immunology and Microbial Sciences, King's College London, London, United Kingdom
| | - Suzanne Pickering
- Department of Infectious Disease, School of Immunology and Microbial Sciences, King's College London, London, United Kingdom
| | - Stuart J D Neil
- Department of Infectious Disease, School of Immunology and Microbial Sciences, King's College London, London, United Kingdom
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17
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Vermeire J, Roesch F, Sauter D, Rua R, Hotter D, Van Nuffel A, Vanderstraeten H, Naessens E, Iannucci V, Landi A, Witkowski W, Baeyens A, Kirchhoff F, Verhasselt B. HIV Triggers a cGAS-Dependent, Vpu- and Vpr-Regulated Type I Interferon Response in CD4 + T Cells. Cell Rep 2017; 17:413-424. [PMID: 27705790 DOI: 10.1016/j.celrep.2016.09.023] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 07/18/2016] [Accepted: 09/08/2016] [Indexed: 02/07/2023] Open
Abstract
Several pattern-recognition receptors sense HIV-1 replication products and induce type I interferon (IFN-I) production under specific experimental conditions. However, it is thought that viral sensing and IFN induction are virtually absent in the main target cells of HIV-1 in vivo. Here, we show that activated CD4+ T cells sense HIV-1 infection through the cytosolic DNA sensor cGAS and mount a bioactive IFN-I response. Efficient induction of IFN-I by HIV-1 infection requires proviral integration and is regulated by newly expressed viral accessory proteins: Vpr potentiates, while Vpu suppresses cGAS-dependent IFN-I induction. Furthermore, Vpr also amplifies innate sensing of HIV-1 infection in Vpx-treated dendritic cells. Our results identify cGAS as mediator of an IFN-I response to HIV-1 infection in CD4+ T cells and demonstrate that this response is modulated by the viral accessory proteins Vpr and Vpu. Thus, viral innate immune evasion is incomplete in the main target cells of HIV-1.
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Affiliation(s)
- Jolien Vermeire
- Department of Clinical Chemistry, Microbiology, and Immunology, Ghent University, 9000 Ghent, Belgium
| | - Ferdinand Roesch
- Département de Virologie, Unité Virus et Immunité, Institut Pasteur, 75015 Paris, France
| | - Daniel Sauter
- Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany
| | - Réjane Rua
- Département de Virologie, Unité Virus et Immunité, Institut Pasteur, 75015 Paris, France
| | - Dominik Hotter
- Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany
| | - Anouk Van Nuffel
- Department of Clinical Chemistry, Microbiology, and Immunology, Ghent University, 9000 Ghent, Belgium
| | - Hanne Vanderstraeten
- Department of Clinical Chemistry, Microbiology, and Immunology, Ghent University, 9000 Ghent, Belgium
| | - Evelien Naessens
- Department of Clinical Chemistry, Microbiology, and Immunology, Ghent University, 9000 Ghent, Belgium
| | - Veronica Iannucci
- Department of Clinical Chemistry, Microbiology, and Immunology, Ghent University, 9000 Ghent, Belgium
| | - Alessia Landi
- Department of Clinical Chemistry, Microbiology, and Immunology, Ghent University, 9000 Ghent, Belgium
| | - Wojciech Witkowski
- Department of Clinical Chemistry, Microbiology, and Immunology, Ghent University, 9000 Ghent, Belgium
| | - Ann Baeyens
- Department of Clinical Chemistry, Microbiology, and Immunology, Ghent University, 9000 Ghent, Belgium
| | - Frank Kirchhoff
- Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany
| | - Bruno Verhasselt
- Department of Clinical Chemistry, Microbiology, and Immunology, Ghent University, 9000 Ghent, Belgium.
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18
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Abstract
It is widely held that HIV-1 Nef downmodulates HLA-A and -B to protect infected cells from CD8(+) T cells but leaves HLA-C on the cell surface to inhibit NK cells. In this issue of Cell Host & Microbe, Apps et al. (2016) revise this model by showing that the Vpu protein of primary HIV-1 isolates downmodulate HLA-C.
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Affiliation(s)
- Edward Barker
- Department of Immunology and Microbiology, Rush University Medical Center, 1735 W. Harrison Street, 620 Cohn Building, Chicago, IL 60612, USA.
| | - David T Evans
- Pathology & Laboratory Medicine, University of Wisconsin, AIDS Vaccine Research Laboratory 585 Science Drive, Madison, WI 53711, USA
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19
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Romani B, Kavyanifard A, Allahbakhshi E. Functional conservation and coherence of HIV-1 subtype A Vpu alleles. Sci Rep 2017; 7:44894. [PMID: 28317943 PMCID: PMC5357900 DOI: 10.1038/srep44894] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 02/14/2017] [Indexed: 11/09/2022] Open
Abstract
Functional studies of HIV-1 proteins are normally conducted using lab adapted strains of HIV-1. The extent of those functions in clinical strains is sometimes unknown. In this study, we amplified and sequenced HIV-1 Vpu from 10 Iranian patients infected with HIV-1. Phylogenetic analysis indicated that the Vpu alleles were closely related to the CRF35_AD from Iran and subtype A Vpu. We addressed some of the well-established functions of the HIV-1 Vpu, as well as some of its recently reported functions. Ability of the clinical strains of subtype A Vpu alleles for downregulation of CD4 was similar to that of the lab adapted NL4.3 Vpu. Majority of the subtype A Vpu alleles performed stronger than NL4.3 Vpu for downregulation of SNAT1. The Vpu alleles differentially induced downregulation of HLA-C, ranging from no effect to 88% downregulation of surface HLA-C. Downregulation of tetherin and enhancement of virus release was similar for the subtype A Vpu alleles and NL4.3. Subtype A Vpu alleles were more potent when compared with NL4.3 for inhibition of NF-κB activation. Our study shows that subtype A Vpu alleles exert the classical functions of HIV-1 Vpu.
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Affiliation(s)
- Bizhan Romani
- Cellular and Molecular Research Center (CMRC), Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences (AJUMS), Ahvaz, 61357-15794, Iran.,Department of Biology, Faculty of Science, University of Isfahan, Isfahan, 81746-73441, Iran
| | | | - Elham Allahbakhshi
- Cellular and Molecular Research Center (CMRC), Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences (AJUMS), Ahvaz, 61357-15794, Iran
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20
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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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21
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Romani B, Kavyanifard A, Allahbakhshi E. Functional conservation and coherence of HIV-1 subtype A Vpu alleles. Sci Rep 2017; 7:87. [PMID: 28273896 PMCID: PMC5428049 DOI: 10.1038/s41598-017-00222-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 02/14/2017] [Indexed: 12/19/2022] Open
Abstract
Functional studies of HIV-1 proteins are normally conducted using lab adapted strains of HIV-1. The extent of those functions in clinical strains is sometimes unknown. In this study, we amplified and sequenced HIV-1 Vpu from 10 Iranian patients infected with HIV-1. Phylogenetic analysis indicated that the Vpu alleles were closely related to the CRF35_AD from Iran and subtype A Vpu. We addressed some of the well-established functions of the HIV-1 Vpu, as well as some of its recently reported functions. Ability of the clinical strains of subtype A Vpu alleles for downregulation of CD4 was similar to that of the lab adapted NL4.3 Vpu. Majority of the subtype A Vpu alleles performed stronger than NL4.3 Vpu for downregulation of SNAT1. The Vpu alleles differentially induced downregulation of HLA-C, ranging from no effect to 88% downregulation of surface HLA-C. Downregulation of tetherin and enhancement of virus release was similar for the subtype A Vpu alleles and NL4.3. Subtype A Vpu alleles were more potent when compared with NL4.3 for inhibition of NF-κB activation. Our study shows that subtype A Vpu alleles exert the classical functions of HIV-1 Vpu.
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Affiliation(s)
- Bizhan Romani
- Cellular and Molecular Research Center (CMRC), Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences (AJUMS), Ahvaz, 61357-15794, Iran.,Department of Biology, Faculty of Science, University of Isfahan, Isfahan, 81746-73441, Iran
| | | | - Elham Allahbakhshi
- Cellular and Molecular Research Center (CMRC), Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences (AJUMS), Ahvaz, 61357-15794, Iran.
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22
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Hammonds JE, Beeman N, Ding L, Takushi S, Francis AC, Wang JJ, Melikyan GB, Spearman P. Siglec-1 initiates formation of the virus-containing compartment and enhances macrophage-to-T cell transmission of HIV-1. PLoS Pathog 2017; 13:e1006181. [PMID: 28129379 PMCID: PMC5298340 DOI: 10.1371/journal.ppat.1006181] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Revised: 02/08/2017] [Accepted: 01/12/2017] [Indexed: 11/22/2022] Open
Abstract
HIV-1 particles assemble and bud from the plasma membrane of infected T lymphocytes. Infected macrophages, in contrast, accumulate particles within an apparent intracellular compartment known as the virus-containing compartment or VCC. Many aspects of the formation and function of the VCC remain unclear. Here we demonstrate that VCC formation does not actually require infection of the macrophage, but can be reproduced through the exogenous addition of non-infectious virus-like particles or infectious virions to macrophage cultures. Particles were captured by Siglec-1, a prominent cell surface lectin that attaches to gangliosides on the lipid envelope of the virus. VCCs formed within infected macrophages were readily targeted by the addition of ganglioside-containing virus-like particles to the extracellular media. Depletion of Siglec-1 from the macrophage or depletion of gangliosides from viral particles prevented particle uptake into the VCC and resulted in substantial reductions of VCC volume. Furthermore, Siglec-1-mediated virion capture and subsequent VCC formation was required for efficient trans-infection of autologous T cells. Our results help to define the nature of this intracellular compartment, arguing that it is a compartment formed by particle uptake from the periphery, and that this compartment can readily transmit virus to target T lymphocytes. Inhibiting or eliminating the VCC may be an important component of strategies to reduce HIV transmission and to eradicate HIV reservoirs. T lymphocytes and macrophages are the two major cell types involved in HIV replication and transmission events. When a T cell is infected, virus particles assemble and bud from the plasma membrane of the cell. In contrast, infected macrophages develop an intracellular collection of viruses termed the virus-containing compartment or VCC. Many aspects of the formation and function of the VCC remain unclear. Here we show that VCC formation does not actually require infection of the macrophage, but can be reproduced through the addition of virus-like particles or infectious virions to macrophages. HIV-1 particles were captured by the cell surface carbohydrate-binding protein Siglec-1, followed by co-migration of Siglec-1 and captured viral particles to the VCC. Depletion of Siglec-1 from the macrophage prevented VCC formation, and inhibited the ability of infected macrophages to transmit HIV to T cells. Our results help to define the origin of this intracellular compartment, arguing that it is a compartment formed by particle uptake from the periphery. Inhibiting or eliminating the VCC may be an important component of strategies to reduce HIV transmission and to eradicate HIV reservoirs.
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Affiliation(s)
- Jason E. Hammonds
- Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - Neal Beeman
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Lingmei Ding
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Sarah Takushi
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Ashwanth C. Francis
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Jaang-Jiun Wang
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Gregory B. Melikyan
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Paul Spearman
- Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
- * E-mail:
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23
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Soper A, Juarez-Fernandez G, Aso H, Moriwaki M, Yamada E, Nakano Y, Koyanagi Y, Sato K. Various plus unique: Viral protein U as a plurifunctional protein for HIV-1 replication. Exp Biol Med (Maywood) 2017; 242:850-858. [PMID: 28346011 DOI: 10.1177/1535370217697384] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1), the causative agent of acquired immunodeficiency syndrome, encodes four accessory genes, one of which is viral protein U (Vpu). Recently, the study of Vpu has been of great interest. For instance, various cellular proteins are degraded (e.g. CD4) and down-modulated (e.g. tetherin) by Vpu. Vpu also antagonizes the function of tetherin and inhibits NF-κB. Moreover, Vpu is a viroporin forming ion channels and may represent a promising target for anti-HIV-1 drugs. In this review, we summarize the domains/residues that are responsible for Vpu's functions, describe the current understanding of the role of Vpu in HIV-1-infected cells, and review the effect of Vpu on HIV-1 in replication and pathogenesis. Future investigations that simultaneously assess a combination of Vpu functions are required to clearly delineate the most important functions for viral replication. Impact statement Viral protein U (Vpu) is a unique protein encoded by human immunodeficiency virus type 1 (HIV-1) and related lentiviruses, playing multiple roles in viral replication and pathogenesis. In this review, we briefly summarize the most up-to-date knowledge of HIV-1 Vpu.
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Affiliation(s)
- Andrew Soper
- 1 Laboratory of Systems Virology, Department of Biosystems Science, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 6068507, Japan
| | - Guillermo Juarez-Fernandez
- 1 Laboratory of Systems Virology, Department of Biosystems Science, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 6068507, Japan
| | - Hirofumi Aso
- 1 Laboratory of Systems Virology, Department of Biosystems Science, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 6068507, Japan.,2 Faculty of Pharmaceutical Sciences, Kyoto University, Kyoto 6068501, Japan
| | - Miyu Moriwaki
- 1 Laboratory of Systems Virology, Department of Biosystems Science, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 6068507, Japan.,3 Graduate School of Biostudies, Kyoto University, Kyoto 6068315, Japan
| | - Eri Yamada
- 1 Laboratory of Systems Virology, Department of Biosystems Science, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 6068507, Japan
| | - Yusuke Nakano
- 1 Laboratory of Systems Virology, Department of Biosystems Science, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 6068507, Japan
| | - Yoshio Koyanagi
- 1 Laboratory of Systems Virology, Department of Biosystems Science, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 6068507, Japan
| | - Kei Sato
- 1 Laboratory of Systems Virology, Department of Biosystems Science, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 6068507, Japan.,4 CREST, Japan Science and Technology Agency, Saitama 3220012, Japan
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24
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Arias JF, Colomer-Lluch M, von Bredow B, Greene JM, MacDonald J, O'Connor DH, Serra-Moreno R, Evans DT. Tetherin Antagonism by HIV-1 Group M Nef Proteins. J Virol 2016; 90:10701-10714. [PMID: 27654287 PMCID: PMC5110183 DOI: 10.1128/jvi.01465-16] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 09/12/2016] [Indexed: 12/20/2022] Open
Abstract
Although Nef is the viral gene product used by most simian immunodeficiency viruses to overcome restriction by tetherin, this activity was acquired by the Vpu protein of HIV-1 group M due to the absence of sequences in human tetherin that confer susceptibility to Nef. Thus, it is widely accepted that HIV-1 group M uses Vpu instead of Nef to counteract tetherin. Challenging this paradigm, we identified Nef alleles of HIV-1 group M isolates with significant activity against human tetherin. These Nef proteins promoted virus release and tetherin downmodulation from the cell surface and, in the context of vpu-deleted HIV-1 recombinants, enhanced virus replication and resistance to antibody-dependent cell-mediated cytotoxicity (ADCC). Further analysis revealed that the Vpu proteins from several of these viruses lack antitetherin activity, suggesting that under certain circumstances, HIV-1 group M Nef may acquire the ability to counteract tetherin to compensate for the loss of this function by Vpu. These observations illustrate the remarkable plasticity of HIV-1 in overcoming restriction by tetherin and challenge the prevailing view that all HIV-1 group M isolates use Vpu to counteract tetherin. IMPORTANCE Most viruses of HIV-1 group M, the main group of HIV-1 responsible for the global AIDS pandemic, use their Vpu proteins to overcome restriction by tetherin (BST-2 or CD317), which is a transmembrane protein that inhibits virus release from infected cells. Here we show that the Nef proteins of certain HIV-1 group M isolates can acquire the ability to counteract tetherin. These results challenge the current paradigm that HIV-1 group M exclusively uses Vpu to counteract tetherin and underscore the importance of tetherin antagonism for efficient viral replication.
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Affiliation(s)
- Juan F Arias
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Marta Colomer-Lluch
- Department of Biological Sciences, College of Arts and Sciences, Texas Tech University, Lubbock, Texas, USA
| | - Benjamin von Bredow
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | | | - Julie MacDonald
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - David H O'Connor
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Ruth Serra-Moreno
- Department of Biological Sciences, College of Arts and Sciences, Texas Tech University, Lubbock, Texas, USA
| | - David T Evans
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
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25
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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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26
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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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Vanwalscappel B, Rato S, Perez-Olmeda M, Díez Fuertes F, Casartelli N, Alcami J, Mammano F. Genetic and phenotypic analyses of sequential vpu alleles from HIV-infected IFN-treated patients. Virology 2016; 500:247-258. [PMID: 27855354 DOI: 10.1016/j.virol.2016.10.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 10/24/2016] [Accepted: 10/25/2016] [Indexed: 02/06/2023]
Abstract
Treatment of HIV-infected patients with IFN-α results in significant, but clinically insufficient, reductions of viremia. IFN induces the expression of several antiviral proteins including BST-2, which inhibits HIV by multiple mechanisms. The viral protein Vpu counteracts different effects of BST-2. We thus asked if Vpu proteins from IFN-treated patients displayed improved anti-BST-2 activities as compared to Vpu from baseline. Deep-sequencing analyses revealed that in five of seven patients treated by IFN-α for a concomitant HCV infection in the absence of antiretroviral drugs, the dominant Vpu sequences differed before and during treatment. In three patients, vpu alleles that emerged during treatment improved virus replication in the presence of IFN-α, and two of them conferred improved virus budding from cells expressing BST-2. Differences were observed for the ability to down-regulate CD4, while all Vpu variants potently down-modulated BST-2 from the cell surface. This report discloses relevant consequences of IFN-treatment on HIV properties.
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Affiliation(s)
- Bénédicte Vanwalscappel
- INSERM, U941, Paris F-75010, France; Univ Paris Diderot, Sorbonne Paris Cité, F-75475 Paris, France
| | | | - Mayte Perez-Olmeda
- AIDS Immunopathogenesis Unit, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain
| | - Francisco Díez Fuertes
- AIDS Immunopathogenesis Unit, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain
| | | | - José Alcami
- AIDS Immunopathogenesis Unit, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain.
| | - Fabrizio Mammano
- INSERM, U941, Paris F-75010, France; Univ Paris Diderot, Sorbonne Paris Cité, F-75475 Paris, France.
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28
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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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29
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Cell Surface Downregulation of NK Cell Ligands by Patient-Derived HIV-1 Vpu and Nef Alleles. J Acquir Immune Defic Syndr 2016; 72:1-10. [PMID: 26656785 DOI: 10.1097/qai.0000000000000917] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVE HIV-1 Vpu and Nef proteins downregulate cell surface levels of natural killer (NK) cell ligands but functional consequences of individual downregulation events are unclear. We tested how well-conserved NK cell ligand downregulation is among Vpu and Nef variants isolated from chronic HIV patients. METHODS Proviral vpu and nef sequences were amplified from 27 chronic HIV patients, subcloned, and tested for their ability to downregulate cell surface receptors. RESULTS Cell surface downregulation of CD4, CD317/tetherin, and major histocompatibility complex class 1 that exert biological functions other than NK cell activation were well conserved among patient-derived Vpu and Nef variants. Among NK cell ligands, NK-T-B-antigen, poliovirus receptor, and UL16-binding protein were identified as main targets for Vpu and Nef, the downregulation of which by at least 1 viral protein was highly conserved. NK cell ligands displayed specific sensitivity to Vpu (NK-T-B-antigen) or Nef (poliovirus receptor), and downregulation of cell surface UL16-binding protein was identified as a novel and highly conserved activity of HIV-1 Vpu but not Nef. CONCLUSIONS The conservation of downregulation of major NK cell ligands by either HIV-1 Vpu or Nef suggests an important pathophysiological role of this activity, which may impact the acute but not the chronic phase of HIV infection.
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30
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Abstract
The HIV genome encodes a small number of viral proteins (i.e., 16), invariably establishing cooperative associations among HIV proteins and between HIV and host proteins, to invade host cells and hijack their internal machineries. As a known example, the HIV envelope glycoprotein GP120 is closely associated with GP41 for viral entry. From a genome-wide perspective, a hypothesis can be worked out to determine whether 16 HIV proteins could develop 120 possible pairwise associations either by physical interactions or by functional associations mediated via HIV or host molecules. Here, we present the first systematic review of experimental evidence on HIV genome-wide protein associations using a large body of publications accumulated over the past 3 decades. Of 120 possible pairwise associations between 16 HIV proteins, at least 34 physical interactions and 17 functional associations have been identified. To achieve efficient viral replication and infection, HIV protein associations play essential roles (e.g., cleavage, inhibition, and activation) during the HIV life cycle. In either a dispensable or an indispensable manner, each HIV protein collaborates with another viral protein to accomplish specific activities that precisely take place at the proper stages of the HIV life cycle. In addition, HIV genome-wide protein associations have an impact on anti-HIV inhibitors due to the extensive cross talk between drug-inhibited proteins and other HIV proteins. Overall, this study presents for the first time a comprehensive overview of HIV genome-wide protein associations, highlighting meticulous collaborations between all viral proteins during the HIV life cycle.
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Affiliation(s)
- Guangdi Li
- Department of Metabolism and Endocrinology, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, Ministry of Education, National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China KU Leuven-University of Leuven, Rega Institute for Medical Research, Department of Microbiology and Immunology, Leuven, Belgium
| | - Erik De Clercq
- KU Leuven-University of Leuven, Rega Institute for Medical Research, Department of Microbiology and Immunology, Leuven, Belgium
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Abstract
Human immunodeficiency virus type 1 (HIV-1) groups M, N, O, and P are the result of independent zoonotic transmissions of simian immunodeficiency viruses (SIVs) infecting great apes in Africa. Among these, only Vpu proteins of pandemic HIV-1 group M strains evolved potent activity against the restriction factor tetherin, which inhibits virus release from infected cells. Thus, effective Vpu-mediated tetherin antagonism may have been a prerequisite for the global spread of HIV-1. To determine whether this particular function enhances primary HIV-1 replication and interferon resistance, we introduced mutations into the vpu genes of HIV-1 group M and N strains to specifically disrupt their ability to antagonize tetherin, but not other Vpu functions, such as degradation of CD4, down-modulation of CD1d and NTB-A, and suppression of NF-κB activity. Lack of particular human-specific adaptations reduced the ability of HIV-1 group M Vpu proteins to enhance virus production and release from primary CD4+ T cells at high levels of type I interferon (IFN) from about 5-fold to 2-fold. Interestingly, transmitted founder HIV-1 strains exhibited higher virion release capacity than chronic control HIV-1 strains irrespective of Vpu function, and group M viruses produced higher levels of cell-free virions than an N group HIV-1 strain. Thus, efficient virus release from infected cells seems to play an important role in the spread of HIV-1 in the human population and requires a fully functional Vpu protein that counteracts human tetherin. Understanding which human-specific adaptations allowed HIV-1 to cause the AIDS pandemic is of great importance. One feature that distinguishes pandemic HIV-1 group M strains from nonpandemic or rare group O, N, and P viruses is the acquisition of mutations in the accessory Vpu protein that confer potent activity against human tetherin. Adaptation was required because human tetherin has a deletion that renders it resistant to the Nef protein used by the SIV precursor of HIV-1 to antagonize this antiviral factor. It has been suggested that these adaptations in Vpu were critical for the effective spread of HIV-1 M strains, but direct evidence has been lacking. Here, we show that these changes in Vpu significantly enhance virus replication and release in human CD4+ T cells, particularly in the presence of IFN, thus supporting an important role in the spread of pandemic HIV-1.
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Rossenkhan R, MacLeod IJ, Brumme ZL, Magaret CA, Sebunya TK, Musonda R, Gashe BA, Edlefsen PT, Novitsky V, Essex M. Transmitted/Founder HIV-1 Subtype C Viruses Show Distinctive Signature Patterns in Vif, Vpr, and Vpu That Are Under Subsequent Immune Pressure During Early Infection. AIDS Res Hum Retroviruses 2016; 32:1031-1045. [PMID: 27349335 DOI: 10.1089/aid.2015.0330] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Viral variants that predominate during early infection may exhibit constrained diversity compared with those found during chronic infection and could contain amino acid signature patterns that may enhance transmission, establish productive infection, and influence early events that modulate the infection course. We compared amino acid distributions in 17 patients recently infected with HIV-1C with patients with chronic infection. We found significantly lower entropy in inferred transmitted/founder (t/f) compared with chronic viruses and identified signature patterns in Vif and Vpr from inferred t/f viruses. We investigated sequence evolution longitudinally up to 500 days postseroconversion and compared the impact of selected substitutions on predicted human leukocyte antigen (HLA) binding affinities of published and predicted cytotoxic T-lymphocyte epitopes. Polymorphisms in Vif and Vpr during early infection occurred more frequently at epitope-HLA anchor residues and significantly decreased predicted epitope-HLA binding. Transmission-associated sequence signatures may have implications for novel strategies to prevent HIV-1 transmission.
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Affiliation(s)
- Raabya Rossenkhan
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
- Botswana Harvard AIDS Institute, Gaborone, Botswana
- Department of Biological Sciences, University of Botswana, Gaborone, Botswana
- Vaccine and Infectious Diseases Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
| | - Iain J. MacLeod
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
- Botswana Harvard AIDS Institute, Gaborone, Botswana
| | - Zabrina L. Brumme
- Faculty of Health Sciences, Simon Fraser University, Burnaby, Canada
- British Columbia Centre for Excellence in HIV/AIDS, Vancouver, Canada
| | - Craig A. Magaret
- Vaccine and Infectious Diseases Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
| | - Theresa K. Sebunya
- Department of Biological Sciences, University of Botswana, Gaborone, Botswana
| | - Rosemary Musonda
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
- Botswana Harvard AIDS Institute, Gaborone, Botswana
| | - Berhanu A. Gashe
- Department of Biological Sciences, University of Botswana, Gaborone, Botswana
| | - Paul T. Edlefsen
- Vaccine and Infectious Diseases Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
| | - Vlad Novitsky
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
- Botswana Harvard AIDS Institute, Gaborone, Botswana
| | - M. Essex
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
- Botswana Harvard AIDS Institute, Gaborone, Botswana
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HIV Genome-Wide Protein Associations: a Review of 30 Years of Research. Microbiol Mol Biol Rev 2016; 80:679-731. [PMID: 27357278 DOI: 10.1128/mmbr.00065-15] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The HIV genome encodes a small number of viral proteins (i.e., 16), invariably establishing cooperative associations among HIV proteins and between HIV and host proteins, to invade host cells and hijack their internal machineries. As a known example, the HIV envelope glycoprotein GP120 is closely associated with GP41 for viral entry. From a genome-wide perspective, a hypothesis can be worked out to determine whether 16 HIV proteins could develop 120 possible pairwise associations either by physical interactions or by functional associations mediated via HIV or host molecules. Here, we present the first systematic review of experimental evidence on HIV genome-wide protein associations using a large body of publications accumulated over the past 3 decades. Of 120 possible pairwise associations between 16 HIV proteins, at least 34 physical interactions and 17 functional associations have been identified. To achieve efficient viral replication and infection, HIV protein associations play essential roles (e.g., cleavage, inhibition, and activation) during the HIV life cycle. In either a dispensable or an indispensable manner, each HIV protein collaborates with another viral protein to accomplish specific activities that precisely take place at the proper stages of the HIV life cycle. In addition, HIV genome-wide protein associations have an impact on anti-HIV inhibitors due to the extensive cross talk between drug-inhibited proteins and other HIV proteins. Overall, this study presents for the first time a comprehensive overview of HIV genome-wide protein associations, highlighting meticulous collaborations between all viral proteins during the HIV life cycle.
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Apps R, Del Prete GQ, Chatterjee P, Lara A, Brumme ZL, Brockman MA, Neil S, Pickering S, Schneider DK, Piechocka-Trocha A, Walker BD, Thomas R, Shaw GM, Hahn BH, Keele BF, Lifson JD, Carrington M. HIV-1 Vpu Mediates HLA-C Downregulation. Cell Host Microbe 2016; 19:686-95. [PMID: 27173934 PMCID: PMC4904791 DOI: 10.1016/j.chom.2016.04.005] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Revised: 03/08/2016] [Accepted: 04/05/2016] [Indexed: 12/31/2022]
Abstract
Many pathogens evade cytotoxic T lymphocytes (CTLs) by downregulating HLA molecules on infected cells, but the loss of HLA can trigger NK cell-mediated lysis. HIV-1 is thought to subvert CTLs while preserving NK cell inhibition by Nef-mediated downregulation of HLA-A and -B but not HLA-C molecules. We find that HLA-C is downregulated by most primary HIV-1 clones, including transmitted founder viruses, in contrast to the laboratory-adapted NL4-3 virus. HLA-C reduction is mediated by viral Vpu and reduces the ability of HLA-C restricted CTLs to suppress viral replication in CD4+ cells in vitro. HLA-A/B are unaffected by Vpu, and primary HIV-1 clones vary in their ability to downregulate HLA-C, possibly in response to whether CTLs or NK cells dominate immune pressure through HLA-C. HIV-2 also suppresses HLA-C expression through distinct mechanisms, underscoring the immune pressure HLA-C exerts on HIV. This viral immune evasion casts new light on the roles of CTLs and NK cells in immune responses against HIV.
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Affiliation(s)
- Richard Apps
- Cancer and Inflammation Program, Leidos Biomedical Research, Frederick National Laboratory, Frederick, MD 21702, USA
| | - Gregory Q Del Prete
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Frederick National Laboratory, Frederick, MD 21702, USA
| | - Pramita Chatterjee
- Cancer and Inflammation Program, Leidos Biomedical Research, Frederick National Laboratory, Frederick, MD 21702, USA
| | - Abigail Lara
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Frederick National Laboratory, Frederick, MD 21702, USA
| | - Zabrina L Brumme
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada; British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC V67 1Y6, Canada
| | - Mark A Brockman
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada; British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC V67 1Y6, Canada
| | - Stuart Neil
- Department of Infectious Disease, King's College London School of Medicine, Guy's Hospital, London SE1 9RT, UK
| | - Suzanne Pickering
- Department of Infectious Disease, King's College London School of Medicine, Guy's Hospital, London SE1 9RT, UK
| | - Douglas K Schneider
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Frederick National Laboratory, Frederick, MD 21702, USA
| | - Alicja Piechocka-Trocha
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02139-3583, USA
| | - Bruce D Walker
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02139-3583, USA
| | - Rasmi Thomas
- Host Genetics Section, US Military HIV Research Program, Silver Spring, MD 20910, USA
| | - George M Shaw
- Departments of Medicine and Microbiology, University of Pennsylvania, Philadelphia, PA 19104-6076, USA
| | - Beatrice H Hahn
- Departments of Medicine and Microbiology, University of Pennsylvania, Philadelphia, PA 19104-6076, USA
| | - Brandon F Keele
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Frederick National Laboratory, Frederick, MD 21702, USA
| | - Jeffrey D Lifson
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Frederick National Laboratory, Frederick, MD 21702, USA
| | - Mary Carrington
- Cancer and Inflammation Program, Leidos Biomedical Research, Frederick National Laboratory, Frederick, MD 21702, USA; Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02139-3583, USA.
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Zhang L, Wahba G, Yuan M. Distance shrinkage and Euclidean embedding via regularized kernel estimation. J R Stat Soc Series B Stat Methodol 2016. [DOI: 10.1111/rssb.12138] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Romani B, Baygloo NS, Hamidi-Fard M, Aghasadeghi MR, Allahbakhshi E. HIV-1 Vpr Protein Induces Proteasomal Degradation of Chromatin-associated Class I HDACs to Overcome Latent Infection of Macrophages. J Biol Chem 2015; 291:2696-711. [PMID: 26679995 DOI: 10.1074/jbc.m115.689018] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Indexed: 11/06/2022] Open
Abstract
Mechanisms underlying HIV-1 latency remain among the most crucial questions that need to be answered to adopt strategies for purging the latent viral reservoirs. Here we show that HIV-1 accessory protein Vpr induces depletion of class I HDACs, including HDAC1, 2, 3, and 8, to overcome latency in macrophages. We found that Vpr binds and depletes chromatin-associated class I HDACs through a VprBP-dependent mechanism, with HDAC3 as the most affected class I HDAC. De novo expression of Vpr in infected macrophages induced depletion of HDAC1 and 3 on the HIV-1 LTR that was associated with hyperacetylation of histones on the HIV-1 LTR. As a result of hyperacetylation of histones on HIV-1 promotor, the virus established an active promotor and this contributed to the acute infection of macrophages. Collectively, HIV-1 Vpr down-regulates class I HDACs on chromatin to counteract latent infections of macrophages.
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Affiliation(s)
- Bizhan Romani
- From the Department of Biology, Faculty of Science, University of Isfahan, Isfahan 81746-73441, Iran, Cellular and Molecular Research Center (CMRC), Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences (AJUMS), Ahvaz 61357-15794, Iran, and
| | - Nima Shaykh Baygloo
- From the Department of Biology, Faculty of Science, University of Isfahan, Isfahan 81746-73441, Iran
| | - Mojtaba Hamidi-Fard
- Hepatitis and AIDS Department, Pasteur Institute of Iran, Tehran 13169-43551, Iran
| | | | - Elham Allahbakhshi
- Cellular and Molecular Research Center (CMRC), Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences (AJUMS), Ahvaz 61357-15794, Iran, and
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Pharmacologic Inhibition of Nedd8 Activation Enzyme Exposes CD4-Induced Epitopes within Env on Cells Expressing HIV-1. J Virol 2015; 90:2486-502. [PMID: 26676780 DOI: 10.1128/jvi.02736-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 12/09/2015] [Indexed: 01/17/2023] Open
Abstract
UNLABELLED HIV-1 Vpu decreases the exposure of epitopes within the viral envelope glycoprotein (Env) on the surface of infected cells by downregulating both BST2 and CD4. To test the hypothesis that inhibiting Vpu activity would increase the exposure of these epitopes and sensitize infected cells to antibody-dependent cellular cytotoxicity (ADCC), we treated cells with the Nedd8 activation enzyme (NAE) inhibitor MLN4924, which inhibits the cullin1-based ubiquitin ligase complex coopted by Vpu to degrade cellular targets. Treatment of HeLa cells with MLN4924 or expression of a dominant negative mutant of cullin1 inhibited the Vpu-mediated downregulation of CD4 but not the downregulation of BST2. NAE inhibition also increased the surface exposure of CD4-induced epitopes within Env on HEK293 cells containing an inducible HIV genome, on infected CEM T cells, and on infected primary T cells. In contrast, the Vpu-mediated downregulation of BST2 was substantially inhibited by MLN4924 only when T cells were treated with alpha interferon (IFN-α) to induce high levels of BST2 expression. As reported previously, the absence of vpu or nef and even more so the combined absence of these two genes sensitized infected cells to ADCC. However, NAE inhibition affected ADCC minimally. Paradoxically, even in infected, IFN-treated cells in which NAE inhibition substantially rescued the surface level of BST2, the surface level of Env detected with an antibody recognizing a CD4-independent epitope (2G12) was minimally increased. Mutation of the C-terminal Vpu residue W76, which supports the ability of Vpu to stimulate virion release by displacing BST2 from assembly sites on the plasma membrane by a cullin1-independent mechanism, increased the exposure of Env detected by 2G12 on infected T cells. Thus, inhibiting the displacement function of Vpu together with its ability to degrade CD4 and BST2 may be required to sensitize infected cells to ADCC. IMPORTANCE Pathogenic viruses encode gene products that enable evasion of host immune surveillance mechanisms. One such mechanism is antibody-dependent cellular cytotoxicity (ADCC), whereby host antibodies bind envelope glycoproteins of the virus that are inserted into the cellular membrane and direct the destruction of infected cells. Targeting pharmacologically the activity of HIV-1 Vpu, which contributes to evasion of ADCC, could potentially sensitize infected cells to this immune surveillance mechanism, an outcome that would have therapeutic implications with respect to the goal of curing HIV-1 infection. The Nedd8 activation enzyme inhibitor MLN4924 blocks the activity of the host ubiquitin ligase that Vpu coopts to direct the degradation of CD4 and BST2. We observed that while MLN4924 partially reverses the activity of Vpu and could become part of a therapeutic approach by virtue of CD4-induced epitope exposure, sufficient Vpu activity as an antagonist of BST2 persists despite this drug to allow escape from ADCC.
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Mussil B, Javed A, Töpfer K, Sauermann U, Sopper S. Increased BST2 expression during simian immunodeficiency virus infection is not a determinant of disease progression in rhesus monkeys. Retrovirology 2015; 12:92. [PMID: 26554913 PMCID: PMC4641394 DOI: 10.1186/s12977-015-0219-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 10/23/2015] [Indexed: 12/21/2022] Open
Abstract
Background Bone marrow stromal cell antigen 2 (BST2), also known as tetherin, HM1.24 or CD317 represents a type 2 integral membrane protein, which has been described to restrict the production of some enveloped viruses by inhibiting the virus release from the cell surface. This innate antiviral mechanism is counteracted by the HIV-1 viral factor Vpu, targeting BST2 for cellular degradation. Since antiviral BST2 activity has been mainly confirmed by in vitro data, we investigated its role in vivo on the disease progression using the SIV/macaque model for AIDS. We determined BST2 expression in PBMC and leukocyte subsets of uninfected and SIV-infected rhesus macaques by real-time PCR and flow cytometry and correlated it with disease progression and viral load. Results Compared to pre-infection levels, we found increased BST2 expression in PBMC, purified CD4+ lymphocytes and CD14+ monocytes of SIV-infected animals, which correlated with viral load. Highest BST2 levels were found in progressors and lowest levels comparable to uninfected macaques were observed in long-term non-progressors (LTNPs). During acute viremia, BST2 mRNA increased in parallel with MX1, a prototype interferon-stimulated gene. This association was maintained during the whole disease course. Conclusion The detected relationship between BST2 expression and viral load as well as with MX1 indicate a common regulation by the interferon response and suggest rather limited influence of BST2 in vivo on the disease outcome. Electronic supplementary material The online version of this article (doi:10.1186/s12977-015-0219-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Bianka Mussil
- Unit of Infection Models, German Primate Centre, Goettingen, Germany.
| | - Aneela Javed
- Unit of Infection Models, German Primate Centre, Goettingen, Germany. .,Department of Healthcare Biotechnology, Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Science and Technology (NUST), H12, Islamabad, Pakistan.
| | - Katharina Töpfer
- Unit of Infection Models, German Primate Centre, Goettingen, Germany.
| | - Ulrike Sauermann
- Unit of Infection Models, German Primate Centre, Goettingen, Germany.
| | - Sieghart Sopper
- Department of Hematology and Oncology, Medical University Innsbruck, ZVG 7G5 009A, Anichstr. 35, 6020, Innsbruck, Austria. .,Tyrolean Cancer Research Institute, Innsbruck, Austria.
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Serine Phosphorylation of HIV-1 Vpu and Its Binding to Tetherin Regulates Interaction with Clathrin Adaptors. PLoS Pathog 2015; 11:e1005141. [PMID: 26317613 PMCID: PMC4552633 DOI: 10.1371/journal.ppat.1005141] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 08/11/2015] [Indexed: 02/07/2023] Open
Abstract
HIV-1 Vpu prevents incorporation of tetherin (BST2/ CD317) into budding virions and targets it for ESCRT-dependent endosomal degradation via a clathrin-dependent process. This requires a variant acidic dileucine-sorting motif (ExxxLV) in Vpu. Structural studies demonstrate that recombinant Vpu/tetherin fusions can form a ternary complex with the clathrin adaptor AP-1. However, open questions still exist about Vpu’s mechanism of action. Particularly, whether endosomal degradation and the recruitment of the E3 ubiquitin ligase SCFβTRCP1/2 to a conserved phosphorylated binding site, DSGNES, are required for antagonism. Re-evaluation of the phenotype of Vpu phosphorylation mutants and naturally occurring allelic variants reveals that the requirement for the Vpu phosphoserine motif in tetherin antagonism is dissociable from SCFβTRCP1/2 and ESCRT-dependent tetherin degradation. Vpu phospho-mutants phenocopy ExxxLV mutants, and can be rescued by direct clathrin interaction in the absence of SCFβTRCP1/2 recruitment. Moreover, we demonstrate physical interaction between Vpu and AP-1 or AP-2 in cells. This requires Vpu/tetherin transmembrane domain interactions as well as the ExxxLV motif. Importantly, it also requires the Vpu phosphoserine motif and adjacent acidic residues. Taken together these data explain the discordance between the role of SCFβTRCP1/2 and Vpu phosphorylation in tetherin antagonism, and indicate that phosphorylation of Vpu in Vpu/tetherin complexes regulates promiscuous recruitment of adaptors, implicating clathrin-dependent sorting as an essential first step in tetherin antagonism. Counteraction of tetherin, a host antiviral protein that blocks viral release from infected cells, is an essential attribute of HIV-1 and its related viruses. The HIV-1 accessory protein Vpu binds to tetherin, preventing its incorporation into viral particles, and targets it for ubiquitin-dependent degradation. This involves mis-trafficking of tetherin by a Vpu-dependent mechanism through the engagement of clathrin adaptor proteins. Although structural evidence exists for Vpu and tetherin interacting with clathrin adaptor 1 (AP-1), evidence that it is required for Vpu-mediated tetherin counteraction is still lacking. Tetherin degradation by Vpu also requires an E3 ubiquitin ligase, SCFβTRCP1/2 that binds to phosphorylated serine residues in the Vpu cytoplasmic tail. Again, discrepancies exist about the importance of this interaction in tetherin’s counteraction. Here we show that Vpu phosphorylation, in combination with its physical interaction with tetherin, regulates interaction with both AP-1 and the other major cellular clathrin adaptor, AP-2. These interactions can be decoupled from SCFβTRCP1/2 recruitment, thus indicating clathrin-dependent mis-trafficking as a critical step in tetherin antagonism by Vpu. Additionally, the ability to interact both with AP-1 and AP-2 in a tetherin-dependent manner indicates a redundancy in host cofactors used by Vpu that explains disparate previous observations of its mechanism of action.
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Vpu Protein: The Viroporin Encoded by HIV-1. Viruses 2015; 7:4352-68. [PMID: 26247957 PMCID: PMC4576185 DOI: 10.3390/v7082824] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 06/29/2015] [Accepted: 07/28/2015] [Indexed: 02/06/2023] Open
Abstract
Viral protein U (Vpu) is a lentiviral viroporin encoded by human immunodeficiency virus type 1 (HIV-1) and some simian immunodeficiency virus (SIV) strains. This small protein of 81 amino acids contains a single transmembrane domain that allows for supramolecular organization via homoligomerization or interaction with other proteins. The topology and trafficking of Vpu through subcellular compartments result in pleiotropic effects in host cells. Notwithstanding the high variability of its amino acid sequence, the functionality of Vpu is well conserved in pandemic virus isolates. This review outlines our current knowledge on the interactions of Vpu with the host cell. The regulation of cellular physiology by Vpu and the validity of this viroporin as a therapeutic target are also discussed.
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Mlcochova P, Apolonia L, Kluge SF, Sridharan A, Kirchhoff F, Malim MH, Sauter D, Gupta RK. Immune evasion activities of accessory proteins Vpu, Nef and Vif are conserved in acute and chronic HIV-1 infection. Virology 2015; 482:72-8. [PMID: 25827531 PMCID: PMC4503796 DOI: 10.1016/j.virol.2015.03.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 02/24/2015] [Accepted: 03/02/2015] [Indexed: 01/19/2023]
Abstract
Heterosexual HIV-1 transmission has been identified as a genetic bottleneck and a single transmitted/founder (T/F) variant with reduced sensitivity to type I interferon initiates productive infection in most cases. We hypothesized that particularly active accessory protein(s) may confer T/F viruses with a selective advantage in establishing HIV infection. Thus, we tested vpu, vif and nef alleles from six T/F and six chronic (CC) viruses in assays for 9 immune evasion activities involving the counteraction of interferon-stimulated genes and modulation of ligands known to activate innate immune cells. All functions were highly conserved with no significant differences between T/F and CC viruses, suggesting that these accessory protein functions are important throughout the course of infection.
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Affiliation(s)
- Petra Mlcochova
- Department of Infection, University College London, London, UK
| | - Luis Apolonia
- Department of Infectious Diseases, King׳s College London, London, UK
| | - Silvia F Kluge
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | | | - Frank Kirchhoff
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Michael H Malim
- Department of Infectious Diseases, King׳s College London, London, UK
| | - Daniel Sauter
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
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Ramirez PW, DePaula-Silva AB, Szaniawski M, Barker E, Bosque A, Planelles V. HIV-1 Vpu utilizes both cullin-RING ligase (CRL) dependent and independent mechanisms to downmodulate host proteins. Retrovirology 2015. [PMID: 26215564 PMCID: PMC4517359 DOI: 10.1186/s12977-015-0192-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background Hijacking of the cullin-RING E3 ubiquitin ligase (CRL) machinery is a common mechanism employed by diverse groups of viruses for the efficient counteraction and degradation of host proteins. In particular, HIV-1 Vpu usurps the SCFβ-TrCP E3 ubiquitin ligase complex to mark CD4 for degradation by the 26S proteasome. Vpu also interacts with and downmodulates a number of other host proteins, including the restriction factor BST-2. However, whether Vpu primarily relies on a cullin-dependent or -independent mechanism to antagonize its cellular targets has not been fully elucidated. Results We utilized a sulphamate AMP analog, MLN4924, to effectively block the activation of CRLs within infected primary CD4+ T cells. MLN4924 treatment, in a dose dependent manner, efficiently relieved surface downmodulation and degradation of CD4 by NL4-3 Vpu. MLN4924 inhibition was highly specific, as this inhibitor had no effect on Nef’s ability to downregulate CD4, which is accomplished by a CRL-independent mechanism. In contrast, NL4-3 Vpu’s capacity to downregulate BST-2, NTB-A and CCR7 was not inhibited by the drug. Vpu’s from both a transmitted founder (T/F) and chronic carrier (CC) virus preserved the ability to downregulate BST-2 in the presence of MLN4924. Finally, depletion of cellular pools of cullin 1 attenuated Vpu’s ability to decrease CD4 but not BST-2 surface levels. Conclusions We conclude that Vpu employs both CRL-dependent and CRL-independent modes of action against host proteins. Notably, we also establish that Vpu-mediated reduction of BST-2 from the cell surface is independent of β-TrCP and the CRL- machinery and this function is conserved by Vpu’s from primary isolates. Therefore, potential therapies aimed at antagonizing the activities of Vpu may need to address these distinct mechanisms of action in order to achieve a maximal effect.
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Affiliation(s)
- Peter W Ramirez
- Division of Microbiology and Immunology, Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT, 84112, USA.
| | - Ana Beatriz DePaula-Silva
- Division of Microbiology and Immunology, Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT, 84112, USA.
| | - Matt Szaniawski
- Division of Microbiology and Immunology, Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT, 84112, USA.
| | - Edward Barker
- Department of Immunology and Microbiology, Rush University Medical Center, Chicago, IL, 60612, USA.
| | - Alberto Bosque
- Division of Microbiology and Immunology, Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT, 84112, USA.
| | - Vicente Planelles
- Division of Microbiology and Immunology, Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT, 84112, USA.
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Iwami S, Sato K, Morita S, Inaba H, Kobayashi T, Takeuchi JS, Kimura Y, Misawa N, Ren F, Iwasa Y, Aihara K, Koyanagi Y. Pandemic HIV-1 Vpu overcomes intrinsic herd immunity mediated by tetherin. Sci Rep 2015; 5:12256. [PMID: 26184634 PMCID: PMC4505337 DOI: 10.1038/srep12256] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 06/23/2015] [Indexed: 12/26/2022] Open
Abstract
Among the four groups of HIV-1 (M, N, O, and P), HIV-1M alone is pandemic and has rapidly expanded across the world. However, why HIV-1M has caused a devastating pandemic while the other groups remain contained is unclear. Interestingly, only HIV-1M Vpu, a viral protein, can robustly counteract human tetherin, which tethers budding virions. Therefore, we hypothesize that this property of HIV-1M Vpu facilitates human-to-human viral transmission. Adopting a multilayered experimental-mathematical approach, we demonstrate that HIV-1M Vpu confers a 2.38-fold increase in the prevalence of HIV-1 transmission. When Vpu activity is lost, protected human populations emerge (i.e., intrinsic herd immunity develops) through the anti-viral effect of tetherin. We also reveal that all Vpus of transmitted/founder HIV-1M viruses maintain anti-tetherin activity. These findings indicate that tetherin plays the role of a host restriction factor, providing ‘intrinsic herd immunity’, whereas Vpu has evolved in HIV-1M as a tetherin antagonist.
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Affiliation(s)
- Shingo Iwami
- 1] Mathematical Biology Laboratory, Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka, Fukuoka 8128581, Japan [2] PRESTO, JST, Kawaguchi, Saitama 3320012, Japan [3] CREST, JST, Kawaguchi, Saitama 3320012, Japan
| | - Kei Sato
- 1] Laboratory of Viral Pathogenesis, Institute for Virus Research, Kyoto University, Kyoto, Kyoto 6068507, Japan [2] CREST, JST, Kawaguchi, Saitama 3320012, Japan
| | - Satoru Morita
- 1] Department of Mathematical and Systems Engineering, Shizuoka University, Hamamatsu, Shizuoka 4328561, Japan [2] CREST, JST, Kawaguchi, Saitama 3320012, Japan
| | - Hisashi Inaba
- 1] Graduate School of Mathematical Sciences, The University of Tokyo, Meguro-ku, Tokyo 1538914, Japan [2] CREST, JST, Kawaguchi, Saitama 3320012, Japan
| | - Tomoko Kobayashi
- Laboratory for Animal Health, Department of Animal Science, Faculty of Agriculture, Tokyo University of Agriculture, Atsugi, Kanagawa 2430034, Japan
| | - Junko S Takeuchi
- Laboratory of Viral Pathogenesis, Institute for Virus Research, Kyoto University, Kyoto, Kyoto 6068507, Japan
| | - Yuichi Kimura
- Laboratory of Viral Pathogenesis, Institute for Virus Research, Kyoto University, Kyoto, Kyoto 6068507, Japan
| | - Naoko Misawa
- Laboratory of Viral Pathogenesis, Institute for Virus Research, Kyoto University, Kyoto, Kyoto 6068507, Japan
| | - Fengrong Ren
- Department of Bioinformatics, Medical Research Institute, Tokyo Medical and Dental University, Tokyo 1138510, Japan
| | - Yoh Iwasa
- Mathematical Biology Laboratory, Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka, Fukuoka 8128581, Japan
| | - Kazuyuki Aihara
- 1] Institute of Industrial Science, The University of Tokyo, Meguro-ku, Tokyo 1538505, Japan [2] Graduate School of Information Science and Technology, The University of Tokyo, Meguro-ku, Tokyo 1138656, Japan
| | - Yoshio Koyanagi
- Laboratory of Viral Pathogenesis, Institute for Virus Research, Kyoto University, Kyoto, Kyoto 6068507, Japan
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Galão RP, Pickering S, Curnock R, Neil SJD. Retroviral retention activates a Syk-dependent HemITAM in human tetherin. Cell Host Microbe 2015; 16:291-303. [PMID: 25211072 PMCID: PMC4161388 DOI: 10.1016/j.chom.2014.08.005] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Revised: 07/18/2014] [Accepted: 08/07/2014] [Indexed: 12/27/2022]
Abstract
Tetherin (BST2/CD317) restricts the release of enveloped viral particles from infected cells. Coupled to this virion retention, hominid tetherins induce proinflammatory gene expression via activating NF-κB. We investigated the events initiating this tetherin-induced signaling and show that physical retention of retroviral particles induces the phosphorylation of conserved tyrosine residues in the cytoplasmic tails of tetherin dimers. This phosphorylation induces the recruitment of spleen tyrosine kinase (Syk), which is required for downstream NF-κB activation, indicating that the tetherin cytoplasmic tail resembles the hemi-immunoreceptor tyrosine-based activation motifs (hemITAMs) found in C-type lectin pattern recognition receptors. Retroviral-induced tetherin signaling is coupled to the cortical actin cytoskeleton via the Rac-GAP-containing protein RICH2 (ARHGAP44), and a naturally occurring tetherin polymorphism with reduced RICH2 binding exhibits decreased phosphorylation and NF-κB activation. Thus, upon virion retention, this linkage to the actin cytoskeleton likely triggers tetherin phosphorylation and subsequent signal transduction to induce an antiviral state. A hemITAM in human tetherin is phosphorylated upon viral restriction Tetherin phosphorylation recruits and is dependent upon the kinase Syk The RICH2-tetherin interaction couples tetherin signaling to the actin cytoskeleton A human polymorphism in tetherin abolishes RICH2 interactions and signal transduction
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Affiliation(s)
- Rui Pedro Galão
- Department of Infectious Disease, King's College London School of Medicine, Guy's Hospital, London SE1 9RT, UK
| | - Suzanne Pickering
- Department of Infectious Disease, King's College London School of Medicine, Guy's Hospital, London SE1 9RT, UK
| | - Rachel Curnock
- School of Biochemistry, Faculty of Medical and Veterinary Sciences, University of Bristol, Bristol BS8 1TD, UK
| | - Stuart J D Neil
- Department of Infectious Disease, King's College London School of Medicine, Guy's Hospital, London SE1 9RT, UK.
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Simon V, Bloch N, Landau NR. Intrinsic host restrictions to HIV-1 and mechanisms of viral escape. Nat Immunol 2015; 16:546-53. [PMID: 25988886 PMCID: PMC6908429 DOI: 10.1038/ni.3156] [Citation(s) in RCA: 215] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 03/24/2015] [Indexed: 02/06/2023]
Abstract
To replicate in their hosts, viruses have to navigate the complexities of the mammalian cell, co-opting mechanisms of cellular physiology while defeating restriction factors that are dedicated to halting their progression. Primate lentiviruses devote a relatively large portion of their coding capacity to counteracting restriction factors by encoding accessory proteins dedicated to neutralizing the antiviral function of these intracellular inhibitors. Research into the roles of the accessory proteins has revealed the existence of previously undetected intrinsic defenses, provided insight into the evolution of primate lentiviruses as they adapt to new species and uncovered new targets for the development of therapeutics. This Review discusses the biology of the restriction factors APOBEC3, SAMHD1 and tetherin and the viral accessory proteins that counteract them.
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Affiliation(s)
- Viviana Simon
- Department of Microbiology, The Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Nicolin Bloch
- Department of Microbiology, NYU School of Medicine, New York, New York, USA
| | - Nathaniel R Landau
- Department of Microbiology, NYU School of Medicine, New York, New York, USA
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46
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Yamada E, Yoshikawa R, Nakano Y, Misawa N, Koyanagi Y, Sato K. Impacts of humanized mouse models on the investigation of HIV-1 infection: illuminating the roles of viral accessory proteins in vivo. Viruses 2015; 7:1373-90. [PMID: 25807049 PMCID: PMC4379576 DOI: 10.3390/v7031373] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 03/10/2015] [Accepted: 03/10/2015] [Indexed: 12/26/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) encodes four accessory genes: vif, vpu, vpr, and nef. Recent investigations using in vitro cell culture systems have shed light on the roles of these HIV-1 accessory proteins, Vif, Vpr, Vpu, and Nef, in counteracting, modulating, and evading various cellular factors that are responsible for anti-HIV-1 intrinsic immunity. However, since humans are the exclusive target for HIV-1 infection, conventional animal models are incapable of mimicking the dynamics of HIV-1 infection in vivo. Moreover, the effects of HIV-1 accessory proteins on viral infection in vivo remain unclear. To elucidate the roles of HIV-1 accessory proteins in the dynamics of viral infection in vivo, humanized mouse models, in which the mice are xenotransplanted with human hematopoietic stem cells, has been utilized. This review describes the current knowledge of the roles of HIV-1 accessory proteins in viral infection, replication, and pathogenicity in vivo, which are revealed by the studies using humanized mouse models.
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Affiliation(s)
- Eri Yamada
- Laboratory of Viral Pathogenesis, Institute for Virus Research, Kyoto University, Kyoto 6068507, Japan.
| | - Rokusuke Yoshikawa
- Laboratory of Viral Pathogenesis, Institute for Virus Research, Kyoto University, Kyoto 6068507, Japan.
| | - Yusuke Nakano
- Laboratory of Viral Pathogenesis, Institute for Virus Research, Kyoto University, Kyoto 6068507, Japan.
| | - Naoko Misawa
- Laboratory of Viral Pathogenesis, Institute for Virus Research, Kyoto University, Kyoto 6068507, Japan.
| | - Yoshio Koyanagi
- Laboratory of Viral Pathogenesis, Institute for Virus Research, Kyoto University, Kyoto 6068507, Japan.
| | - Kei Sato
- Laboratory of Viral Pathogenesis, Institute for Virus Research, Kyoto University, Kyoto 6068507, Japan.
- CREST, Japan Science and Technology Agency, Saitama 3220012, Japan.
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Chen J, Tibroni N, Sauter D, Galaski J, Miura T, Alter G, Mueller B, Haller C, Walker BD, Kirchhoff F, Brumme ZL, Ueno T, Fackler OT. Modest attenuation of HIV-1 Vpu alleles derived from elite controller plasma. PLoS One 2015; 10:e0120434. [PMID: 25793728 PMCID: PMC4368696 DOI: 10.1371/journal.pone.0120434] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 01/22/2015] [Indexed: 11/19/2022] Open
Abstract
In the absence of antiretroviral therapy, infection with human immunodeficiency virus type 1 (HIV-1) can typically not be controlled by the infected host and results in the development of acquired immunodeficiency. In rare cases, however, patients spontaneously control HIV-1 replication. Mechanisms by which such elite controllers (ECs) achieve control of HIV-1 replication include particularly efficient immune responses as well as reduced fitness of the specific virus strains. To address whether polymorphisms in the accessory HIV-1 protein Vpu are associated with EC status we functionally analyzed a panel of plasma-derived vpu alleles from 15 EC and 16 chronic progressor (CP) patients. Antagonism of the HIV particle release restriction by the intrinsic immunity factor CD317/tetherin was well conserved among EC and CP Vpu alleles, underscoring the selective advantage of this Vpu function in HIV-1 infected individuals. In contrast, interference with CD317/tetherin induced NF-κB activation was little conserved in both groups. EC Vpus more frequently displayed reduced ability to downregulate cell surface levels of CD4 and MHC class I (MHC-I) molecules as well as of the NK cell ligand NTB-A. Polymorphisms potentially associated with high affinity interactions of the inhibitory killer immunoglobulin-like receptor (KIR) KIR2DL2 were significantly enriched among EC Vpus but did not account for these functional differences. Together these results suggest that in a subgroup of EC patients, some Vpu functions are modestly reduced, possibly as a result of host selection.
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Affiliation(s)
- Jingyan Chen
- Department of Infectious Diseases, Integrative Virology, University Hospital Heidelberg, INF 324, Heidelberg, Germany
- German Center for Infection Research, Heidelberg University, Heidelberg. Germany
| | - Nadine Tibroni
- Department of Infectious Diseases, Integrative Virology, University Hospital Heidelberg, INF 324, Heidelberg, Germany
- German Center for Infection Research, Heidelberg University, Heidelberg. Germany
| | - Daniel Sauter
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Johanna Galaski
- Department of Infectious Diseases, Integrative Virology, University Hospital Heidelberg, INF 324, Heidelberg, Germany
- German Center for Infection Research, Heidelberg University, Heidelberg. Germany
| | - Toshiyuki Miura
- Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | - Galit Alter
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Boston, Massachusetts, United States of America
| | - Birthe Mueller
- Department of Infectious Diseases, Integrative Virology, University Hospital Heidelberg, INF 324, Heidelberg, Germany
- German Center for Infection Research, Heidelberg University, Heidelberg. Germany
| | - Claudia Haller
- Department of Infectious Diseases, Integrative Virology, University Hospital Heidelberg, INF 324, Heidelberg, Germany
- German Center for Infection Research, Heidelberg University, Heidelberg. Germany
| | - Bruce D. Walker
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Boston, Massachusetts, United States of America
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
| | - Frank Kirchhoff
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Zabrina L. Brumme
- Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
- British Columbia Centre for Excellence in HIV/AIDS, Vancouver, British Columbia, Canada
| | - Takamasa Ueno
- Center for AIDS Research, Kumamoto University, 2–2–1 Honjo, Kumamoto, Japan
- International Research Center for Medical Sciences (IRCMS), Kumamoto University, Japan
| | - Oliver T. Fackler
- Department of Infectious Diseases, Integrative Virology, University Hospital Heidelberg, INF 324, Heidelberg, Germany
- German Center for Infection Research, Heidelberg University, Heidelberg. Germany
- * E-mail:
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48
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Sauter D, Hotter D, Van Driessche B, Stürzel CM, Kluge SF, Wildum S, Yu H, Baumann B, Wirth T, Plantier JC, Leoz M, Hahn BH, Van Lint C, Kirchhoff F. Differential regulation of NF-κB-mediated proviral and antiviral host gene expression by primate lentiviral Nef and Vpu proteins. Cell Rep 2015; 10:586-99. [PMID: 25620704 PMCID: PMC4682570 DOI: 10.1016/j.celrep.2014.12.047] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 11/28/2014] [Accepted: 12/19/2014] [Indexed: 02/06/2023] Open
Abstract
NF-κB is essential for effective transcription of primate lentiviral genomes and also activates antiviral host genes. Here, we show that the early protein Nef of most primate lentiviruses enhances NF-κB activation. In contrast, the late protein Vpu of HIV-1 and its simian precursors inhibits activation of NF-κB, even in the presence of Nef. Although this effect of Vpu did not correlate with its ability to interact with β-TrCP, it involved the stabilization of IκB and reduced nuclear translocation of p65. Interestingly, however, Vpu did not affect casein kinase II-mediated phosphorylation of p65. Lack of Vpu was associated with increased NF-κB activation and induction of interferon and interferon-stimulated genes (ISGs) in HIV-1-infected T cells. Thus, HIV-1 and its simian precursors employ Nef to boost NF-κB activation early during the viral life cycle to initiate proviral transcription, while Vpu is used to downmodulate NF-κB-dependent expression of ISGs at later stages.
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Affiliation(s)
- Daniel Sauter
- Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany.
| | - Dominik Hotter
- Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany
| | - Benoît Van Driessche
- Institute for Molecular Biology and Medicine, University of Brussels, 6041 Gosselies, Belgium
| | - Christina M Stürzel
- Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany
| | - Silvia F Kluge
- Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany
| | - Steffen Wildum
- Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany
| | - Hangxing Yu
- Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany
| | - Bernd Baumann
- Institute of Physiological Chemistry, Ulm University Medical Center, 89081 Ulm, Germany
| | - Thomas Wirth
- Institute of Physiological Chemistry, Ulm University Medical Center, 89081 Ulm, Germany
| | | | - Marie Leoz
- Laboratoire Associé au Centre National de Référence du VIH, 76031 Rouen, France
| | - Beatrice H Hahn
- Departments of Medicine and Microbiology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Carine Van Lint
- Institute for Molecular Biology and Medicine, University of Brussels, 6041 Gosselies, Belgium
| | - Frank Kirchhoff
- Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany.
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49
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Hasan Z, Kamori D, Ueno T. Role of host immune responses in sequence variability of HIV-1 Vpu. World J Immunol 2014; 4:107-115. [DOI: 10.5411/wji.v4.i2.107] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 04/19/2014] [Accepted: 06/16/2014] [Indexed: 02/05/2023] Open
Abstract
Viral protein U (Vpu) is an accessory protein associated with two main functions important in human immunodeficiency virus type 1 (HIV-1) replication and dissemination; these are down-regulation of CD4 receptor through mediating its proteasomal degradation and enhancement of virion release by antagonizing tetherin/BST2. It is also well established that Vpu is one of the most highly variable proteins in the HIV-1 proteome. However it is still unclear what drives Vpu sequence variability, whether Vpu acquires polymorphisms as a means of immune escape, functional advantage, or otherwise. It is assumed that the host-pathogen interaction is a cause of polymorphic phenotype of Vpu and that the resulting functional heterogeneity of Vpu may have critical significance in vivo. In order to comprehensively understand Vpu variability, it is important to integrate at the population level the genetic association approaches to identify specific amino acid residues and the immune escape kinetics which may impose Vpu functional constraints in vivo. This review will focus on HIV-1 accessory protein Vpu in the context of its sequence variability at population level and also bring forward evidence on the role of the host immune responses in driving Vpu sequence variability; we will also highlight the recent findings that illustrate Vpu functional implication in HIV-1 pathogenesis.
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50
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Roy N, Pacini G, Berlioz-Torrent C, Janvier K. Mechanisms underlying HIV-1 Vpu-mediated viral egress. Front Microbiol 2014; 5:177. [PMID: 24822052 PMCID: PMC4013480 DOI: 10.3389/fmicb.2014.00177] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2014] [Accepted: 03/31/2014] [Indexed: 11/13/2022] Open
Abstract
Viruses such as lentiviruses that are responsible for long lasting infections have to evade several levels of cellular immune mechanisms to persist and efficiently disseminate in the host. Over the past decades, much evidence has emerged regarding the major role of accessory proteins of primate lentiviruses, human immunodeficiency virus and simian immunodeficiency virus, in viral evasion from the host immune defense. This short review will provide an overview of the mechanism whereby the accessory protein Vpu contributes to this escape. Vpu is a multifunctional protein that was shown to contribute to viral egress by down-regulating several mediators of the immune system such as CD4, CD1d, NTB-A and the restriction factor BST2. The mechanisms underlying its activity are not fully characterized but rely on its ability to interfere with the host machinery regulating protein turnover and vesicular trafficking. This review will focus on our current understanding of the mechanisms whereby Vpu down-regulates CD4 and BST2 expression levels to favor viral egress.
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Affiliation(s)
- Nicolas Roy
- INSERM U1016, Institut Cochin Paris, France ; CNRS UMR8104 Paris, France ; Université Paris Descartes Paris, France
| | - Grégory Pacini
- INSERM U1016, Institut Cochin Paris, France ; CNRS UMR8104 Paris, France ; Université Paris Descartes Paris, France
| | - Clarisse Berlioz-Torrent
- INSERM U1016, Institut Cochin Paris, France ; CNRS UMR8104 Paris, France ; Université Paris Descartes Paris, France
| | - Katy Janvier
- INSERM U1016, Institut Cochin Paris, France ; CNRS UMR8104 Paris, France ; Université Paris Descartes Paris, France
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