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Ghone DA, Evans EL, Bandini M, Stephenson KG, Sherer NM, Suzuki A. HIV-1 Vif disrupts phosphatase feedback regulation at the kinetochore, leading to a pronounced pseudo-metaphase arrest. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.30.605839. [PMID: 39131328 PMCID: PMC11312601 DOI: 10.1101/2024.07.30.605839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/13/2024]
Abstract
The human immunodeficiency virus type 1 (HIV-1) Virion Infectivity Factor (Vif) targets and degrades cellular APOBEC3 proteins, key regulators of intrinsic and innate antiretroviral immune responses, thereby facilitating HIV-1 infection. While Vif's role in degrading APOBEC3G is well-studied, Vif is also known to cause cell cycle arrest but the detailed nature of Vif's effects on the cell cycle has yet to be delineated. In this study, we employed high-temporal single-cell live imaging and super-resolution microscopy to monitor individual cells during Vif-induced cell cycle arrest. Our findings reveal that Vif does not affect the G2/M boundary as previously thought. Instead, Vif triggers a unique and robust pseudo-metaphase arrest, which is markedly distinct from the mild prometaphase arrest induced by the HIV-1 accessory protein, Vpr, known for modulating the cell cycle. During Vif-mediated arrest, chromosomes align properly to form a metaphase plate but later disassemble, resulting in polar chromosomes. Notably, unlike Vpr, Vif significantly reduces the levels of both Phosphatase 1 (PP1) and 2 (PP2) at kinetochores, which are key regulators of chromosome-microtubule interactions. These results reveal a novel function of Vif in kinetochore regulation that governs the spatial organization of chromosomes during mitosis.
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Affiliation(s)
- Dhaval A Ghone
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Biophysics Graduate Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
- These authors contributed equally
| | - Edward L Evans
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Cancer Biology Graduate Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Institute for Molecular Virology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
- These authors contributed equally
- Present address: Laboratory for Optical and Computational Instrumentation, University of Wisconsin-Madison, Madison, Wisconsin, 53705, USA
| | - Madison Bandini
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Cancer Biology Graduate Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Institute for Molecular Virology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Kaelyn G Stephenson
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Nathan M Sherer
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Carbone Comprehensive Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Institute for Molecular Virology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Aussie Suzuki
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Carbone Comprehensive Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
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2
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Hu Y, Delviks-Frankenberry KA, Wu C, Arizaga F, Pathak VK, Xiong Y. Structural insights into PPP2R5A degradation by HIV-1 Vif. Nat Struct Mol Biol 2024:10.1038/s41594-024-01314-6. [PMID: 38789685 DOI: 10.1038/s41594-024-01314-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 04/11/2024] [Indexed: 05/26/2024]
Abstract
HIV-1 Vif recruits host cullin-RING-E3 ubiquitin ligase and CBFβ to degrade the cellular APOBEC3 antiviral proteins through diverse interactions. Recent evidence has shown that Vif also degrades the regulatory subunits PPP2R5(A-E) of cellular protein phosphatase 2A to induce G2/M cell cycle arrest. As PPP2R5 proteins bear no functional or structural resemblance to A3s, it is unclear how Vif can recognize different sets of proteins. Here we report the cryogenic-electron microscopy structure of PPP2R5A in complex with HIV-1 Vif-CBFβ-elongin B-elongin C at 3.58 Å resolution. The structure shows PPP2R5A binds across the Vif molecule, with biochemical and cellular studies confirming a distinct Vif-PPP2R5A interface that partially overlaps with those for A3s. Vif also blocks a canonical PPP2R5A substrate-binding site, indicating that it suppresses the phosphatase activities through both degradation-dependent and degradation-independent mechanisms. Our work identifies critical Vif motifs regulating the recognition of diverse A3 and PPP2R5A substrates, whereby disruption of these host-virus protein interactions could serve as potential targets for HIV-1 therapeutics.
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Affiliation(s)
- Yingxia Hu
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Krista A Delviks-Frankenberry
- Viral Mutation Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, USA
| | - Chunxiang Wu
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Fidel Arizaga
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Vinay K Pathak
- Viral Mutation Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, USA.
| | - Yong Xiong
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA.
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3
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Vanegas-Torres CA, Schindler M. HIV-1 Vpr Functions in Primary CD4 + T Cells. Viruses 2024; 16:420. [PMID: 38543785 PMCID: PMC10975730 DOI: 10.3390/v16030420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 03/05/2024] [Accepted: 03/05/2024] [Indexed: 05/23/2024] Open
Abstract
HIV-1 encodes four accesory proteins in addition to its structural and regulatory genes. Uniquely amongst them, Vpr is abundantly present within virions, meaning it is poised to exert various biological effects on the host cell upon delivery. In this way, Vpr contributes towards the establishment of a successful infection, as evidenced by the extent to which HIV-1 depends on this factor to achieve full pathogenicity in vivo. Although HIV infects various cell types in the host organism, CD4+ T cells are preferentially targeted since they are highly permissive towards productive infection, concomitantly bringing about the hallmark immune dysfunction that accompanies HIV-1 spread. The last several decades have seen unprecedented progress in unraveling the activities Vpr possesses in the host cell at the molecular scale, increasingly underscoring the importance of this viral component. Nevertheless, it remains controversial whether some of these advances bear in vivo relevance, since commonly employed cellular models significantly differ from primary T lymphocytes. One prominent example is the "established" ability of Vpr to induce G2 cell cycle arrest, with enigmatic physiological relevance in infected primary T lymphocytes. The objective of this review is to present these discoveries in their biological context to illustrate the mechanisms whereby Vpr supports HIV-1 infection in CD4+ T cells, whilst identifying findings that require validation in physiologically relevant models.
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Affiliation(s)
| | - Michael Schindler
- Institute for Medical Virology and Epidemiology of Viral Diseases, University Hospital Tuebingen, 72076 Tuebingen, Germany;
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4
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Rausch JW, Parvez S, Pathak S, Capoferri AA, Kearney MF. HIV Expression in Infected T Cell Clones. Viruses 2024; 16:108. [PMID: 38257808 PMCID: PMC10820123 DOI: 10.3390/v16010108] [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: 12/13/2023] [Revised: 01/04/2024] [Accepted: 01/06/2024] [Indexed: 01/24/2024] Open
Abstract
The principal barrier to an HIV-1 cure is the persistence of infected cells harboring replication-competent proviruses despite antiretroviral therapy (ART). HIV-1 transcriptional suppression, referred to as viral latency, is foremost among persistence determinants, as it allows infected cells to evade the cytopathic effects of virion production and killing by cytotoxic T lymphocytes (CTL) and other immune factors. HIV-1 persistence is also governed by cellular proliferation, an innate and essential capacity of CD4+ T cells that both sustains cell populations over time and enables a robust directed response to immunological threats. However, when HIV-1 infects CD4+ T cells, this capacity for proliferation can enable surreptitious HIV-1 propagation without the deleterious effects of viral gene expression in latently infected cells. Over time on ART, the HIV-1 reservoir is shaped by both persistence determinants, with selective forces most often favoring clonally expanded infected cell populations harboring transcriptionally quiescent proviruses. Moreover, if HIV latency is incomplete or sporadically reversed in clonal infected cell populations that are replenished faster than they are depleted, such populations could both persist indefinitely and contribute to low-level persistent viremia during ART and viremic rebound if treatment is withdrawn. In this review, select genetic, epigenetic, cellular, and immunological determinants of viral transcriptional suppression and clonal expansion of HIV-1 reservoir T cells, interdependencies among these determinants, and implications for HIV-1 persistence will be presented and discussed.
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Affiliation(s)
- Jason W. Rausch
- HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA; (S.P.); (S.P.); (A.A.C.); (M.F.K.)
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5
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Zhou Y, Huang Y, Chen X, Chen T, Hu W, Hou W, Zhang Q, Xiong Y. Transcriptomic study reveals changes of lncRNAs in PBMCs from HIV-1 patients before and after ART. Sci Rep 2023; 13:22493. [PMID: 38110484 PMCID: PMC10728114 DOI: 10.1038/s41598-023-49595-z] [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: 05/21/2023] [Accepted: 12/09/2023] [Indexed: 12/20/2023] Open
Abstract
Long noncoding RNAs (lncRNAs) play important roles in regulating HIV-1 infection and virus-host interactions. However, it is unclear whether and how ART alters lncRNAs in HIV-infected patients. In the present study, we investigated changes of lncRNAs in PBMCs from HIV-1 patients pre- and post-ART. We identified a total of 974 lncRNAs whose expression was restored to normal levels after ART. Cis-acting analysis showed that six lncRNAs have cis-regulated target genes, among which RP11-290F5.1 and interferon regulatory factor 2 (IRF2) were reported to promote HIV replication. Furthermore, we found that lncRNA CTB-119C2.1, which regulates most mRNAs with differential expression in PBMCs from HIV-1 infected patients after ART, was significantly upregulated by RNA-seq and qRT-PCR assays. KEGG analysis of CTB-119C2.1-associated genes revealed that most of the genes are involved in the p53 signaling pathway and pathways related to cell cycle and DNA replication. Our findings thus reveal the dynamic change of lncRNAs in people living with HIV-1 pre- and post-ART and warrant further investigation of the role of lncRNAs in HIV-1 pathogenesis and treatment.
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Affiliation(s)
- Yingying Zhou
- Department of Infectious Diseases, Zhongnan Hospital of Wuhan University, No. 169, Donghu Road, Wuchang District, Wuhan, 430071, Hubei Province, China
| | - Yuqing Huang
- State Key Laboratory of Virology, Modern Virology Research Center, College of Life Sciences, Wuhan University, Wuhan, 430071, Hubei Province, China
| | - Xiaoping Chen
- Department of Infectious Diseases, Zhongnan Hospital of Wuhan University, No. 169, Donghu Road, Wuchang District, Wuhan, 430071, Hubei Province, China
| | - Tielong Chen
- Department of Infectious Diseases, Zhongnan Hospital of Wuhan University, No. 169, Donghu Road, Wuchang District, Wuhan, 430071, Hubei Province, China
| | - Wenjia Hu
- Department of Infectious Diseases, Zhongnan Hospital of Wuhan University, No. 169, Donghu Road, Wuchang District, Wuhan, 430071, Hubei Province, China
| | - Wei Hou
- State Key Laboratory of Virology/Institute of Medical Virology/Hubei Province Key Laboratory of Allergy and Immunology, School of Basic Medical Sciences, Wuhan University, 185 Donghu Road, Wuhan, 430071, Hubei Province, China.
| | - Qi Zhang
- State Key Laboratory of Virology, Modern Virology Research Center, College of Life Sciences, Wuhan University, Wuhan, 430071, Hubei Province, China.
| | - Yong Xiong
- Department of Infectious Diseases, Zhongnan Hospital of Wuhan University, No. 169, Donghu Road, Wuchang District, Wuhan, 430071, Hubei Province, China.
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6
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Bjorgen JC, Dick JK, Cromarty R, Hart GT, Rhein J. NK cell subsets and dysfunction during viral infection: a new avenue for therapeutics? Front Immunol 2023; 14:1267774. [PMID: 37928543 PMCID: PMC10620977 DOI: 10.3389/fimmu.2023.1267774] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 09/25/2023] [Indexed: 11/07/2023] Open
Abstract
In the setting of viral challenge, natural killer (NK) cells play an important role as an early immune responder against infection. During this response, significant changes in the NK cell population occur, particularly in terms of their frequency, location, and subtype prevalence. In this review, changes in the NK cell repertoire associated with several pathogenic viral infections are summarized, with a particular focus placed on changes that contribute to NK cell dysregulation in these settings. This dysregulation, in turn, can contribute to host pathology either by causing NK cells to be hyperresponsive or hyporesponsive. Hyperresponsive NK cells mediate significant host cell death and contribute to generating a hyperinflammatory environment. Hyporesponsive NK cell populations shift toward exhaustion and often fail to limit viral pathogenesis, possibly enabling viral persistence. Several emerging therapeutic approaches aimed at addressing NK cell dysregulation have arisen in the last three decades in the setting of cancer and may prove to hold promise in treating viral diseases. However, the application of such therapeutics to treat viral infections remains critically underexplored. This review briefly explores several therapeutic approaches, including the administration of TGF-β inhibitors, immune checkpoint inhibitors, adoptive NK cell therapies, CAR NK cells, and NK cell engagers among other therapeutics.
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Affiliation(s)
- Jacob C. Bjorgen
- Division of Infectious Diseases and International Medicine, Department of Medicine, University of Minnesota, Minneapolis, MN, United States
| | - Jenna K. Dick
- Division of Infectious Diseases and International Medicine, Department of Medicine, University of Minnesota, Minneapolis, MN, United States
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, United States
- Center for Immunology, University of Minnesota, Minneapolis, MN, United States
| | - Ross Cromarty
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, United States
| | - Geoffrey T. Hart
- Division of Infectious Diseases and International Medicine, Department of Medicine, University of Minnesota, Minneapolis, MN, United States
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, United States
- Center for Immunology, University of Minnesota, Minneapolis, MN, United States
| | - Joshua Rhein
- Division of Infectious Diseases and International Medicine, Department of Medicine, University of Minnesota, Minneapolis, MN, United States
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7
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Jackson PEH, Holsey J, Turse L, Hammarskjold ML, Rekosh D. Rev-Rev Response Element Activity Selection Bias at the Human Immunodeficiency Virus Transmission Bottleneck. Open Forum Infect Dis 2023; 10:ofad486. [PMID: 37854107 PMCID: PMC10580148 DOI: 10.1093/ofid/ofad486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 09/27/2023] [Indexed: 10/20/2023] Open
Abstract
Background Sexual transmission of human immunodeficiency virus (HIV) is inefficient and results in selection of viral variants based on incompletely understood factors. Functional variation in the Rev-Rev response element (RRE) regulatory axis of HIV affect replication kinetics and relative expression of viral proteins. We explored whether differences in this axis among viral isolates affect transmission fitness. Methods HIV sequences were identified from nine female-to-male transmission pairs. Using a rapid flow cytometric assay, we analyzed Rev-RRE functional activity of primary isolates. Results Rev-RRE activity was significantly lower in recipient viruses compared with corresponding donor viruses. In most transmission events, recipient virus Rev-RRE activity clustered at the extreme low end of the range of donor virus activity. Conclusions These data indicate selection pressure on the Rev-RRE axis during female-to-male sexual transmission. Variation in Rev-RRE activity may permit viral adaptation to different fitness landscapes and could play an important role in HIV pathogenesis.
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Affiliation(s)
- Patrick E H Jackson
- Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, Virginia, USA
- Myles H. Thaler Center for AIDS and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia, USA
| | - Jordan Holsey
- Myles H. Thaler Center for AIDS and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia, USA
| | - Lauren Turse
- Myles H. Thaler Center for AIDS and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia, USA
| | - Marie-Louise Hammarskjold
- Myles H. Thaler Center for AIDS and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia, USA
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, USA
| | - David Rekosh
- Myles H. Thaler Center for AIDS and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia, USA
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, USA
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8
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Ikeda T, Shimizu R, Nasser H, Carpenter MA, Cheng AZ, Brown WL, Sauter D, Harris RS. APOBEC3 degradation is the primary function of HIV-1 Vif determining virion infectivity in the myeloid cell line THP-1. mBio 2023; 14:e0078223. [PMID: 37555667 PMCID: PMC10470580 DOI: 10.1128/mbio.00782-23] [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: 03/28/2023] [Accepted: 06/22/2023] [Indexed: 08/10/2023] Open
Abstract
HIV-1 must overcome multiple innate antiviral mechanisms to replicate in CD4+ T lymphocytes and macrophages. Previous studies have demonstrated that the apolipoprotein B mRNA editing enzyme polypeptide-like 3 (APOBEC3, A3) family of proteins (at least A3D, A3F, A3G, and stable A3H haplotypes) contribute to HIV-1 restriction in CD4+ T lymphocytes. Virus-encoded virion infectivity factor (Vif) counteracts this antiviral activity by degrading A3 enzymes allowing HIV-1 replication in infected cells. In addition to A3 proteins, Vif also targets other cellular proteins in CD4+ T lymphocytes, including PPP2R5 proteins. However, whether Vif primarily degrades only A3 proteins during viral replication is currently unknown. Herein, we describe the development and characterization of A3F-, A3F/A3G-, and A3A-to-A3G-null THP-1 cells. In comparison to Vif-proficient HIV-1, Vif-deficient viruses have substantially reduced infectivity in parental and A3F-null THP-1 cells, and a more modest decrease in infectivity in A3F/A3G-null cells. Remarkably, disruption of A3A-A3G protein expression completely restores the infectivity of Vif-deficient viruses in THP-1 cells. These results indicate that the primary function of Vif during infectious HIV-1 production from THP-1 cells is the targeting and degradation of A3 enzymes. IMPORTANCE HIV-1 Vif neutralizes the HIV-1 restriction activity of A3 proteins. However, it is currently unclear whether Vif has additional essential cellular targets. To address this question, we disrupted A3A to A3G genes in the THP-1 myeloid cell line using CRISPR and compared the infectivity of wild-type HIV-1 and Vif mutants with the selective A3 neutralization activities. Our results demonstrate that the infectivity of Vif-deficient HIV-1 and the other Vif mutants is fully restored by ablating the expression of cellular A3A to A3G proteins. These results indicate that A3 proteins are the only essential target of Vif that is required for fully infectious HIV-1 production from THP-1 cells.
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Affiliation(s)
- Terumasa Ikeda
- Division of Molecular Virology and Genetics, Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto, Japan
| | - Ryo Shimizu
- Division of Molecular Virology and Genetics, Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto, Japan
- Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Hesham Nasser
- Division of Molecular Virology and Genetics, Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto, Japan
- Department of Clinical Pathology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt
| | - Michael A. Carpenter
- Department of Biochemistry and Structural Biology, University of Texas Health San Antonio, San Antonio, Texas, USA
- Howard Hughes Medical Institute, University of Texas Health San Antonio, San Antonio, Texas, USA
| | - Adam Z. Cheng
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
- Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota, USA
| | - William L. Brown
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
- Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota, USA
| | - Daniel Sauter
- Institute for Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, Tübingen, Germany
| | - Reuben S. Harris
- Department of Biochemistry and Structural Biology, University of Texas Health San Antonio, San Antonio, Texas, USA
- Howard Hughes Medical Institute, University of Texas Health San Antonio, San Antonio, Texas, USA
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Eltalkhawy YM, Takahashi N, Ariumi Y, Shimizu J, Miyazaki K, Senju S, Suzu S. iPS cell-derived model to study the interaction between tissue macrophage and HIV-1. J Leukoc Biol 2023; 114:53-67. [PMID: 36976024 DOI: 10.1093/jleuko/qiad024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 01/18/2023] [Accepted: 02/13/2023] [Indexed: 03/17/2023] Open
Abstract
Despite effective antiretroviral therapy, HIV-1 persists in cells, including macrophages, which is an obstacle to cure. However, the precise role of macrophages in HIV-1 infection remains unclear because they reside in tissues that are not easily accessible. Monocyte-derived macrophages are widely used as a model in which peripheral blood monocytes are cultured and differentiated into macrophages. However, another model is needed because recent studies revealed that most macrophages in adult tissues originate from the yolk sac and fetal liver precursors rather than monocytes, and the embryonic macrophages possess a self-renewal (proliferating) capacity that monocyte-derived macrophages lack. Here, we show that human induced pluripotent stem cell-derived immortalized macrophage-like cells are a useful self-renewing macrophage model. They proliferate in a cytokine-dependent manner, retain macrophage functions, support HIV-1 replication, and exhibit infected monocyte-derived macrophage-like phenotypes, such as enhanced tunneling nanotube formation and cell motility, as well as resistance to a viral cytopathic effect. However, several differences are also observed between monocyte-derived macrophages and induced pluripotent stem cell-derived immortalized macrophage-like cells, most of which can be explained by the proliferation of induced pluripotent stem cell-derived immortalized macrophage-like cells. For instance, proviruses with large internal deletions, which increased over time in individuals receiving antiretroviral therapy, are enriched more rapidly in induced pluripotent stem cell-derived immortalized macrophage-like cells. Interestingly, inhibition of viral transcription by HIV-1-suppressing agents is more obvious in induced pluripotent stem cell-derived immortalized macrophage-like cells. Collectively, our present study proposes that the model of induced pluripotent stem cell-derived immortalized macrophage-like cells is suitable for mimicking the interplay between HIV-1 and self-renewing tissue macrophages, the newly recognized major population in most tissues that cannot be fully modeled by monocyte-derived macrophages alone.
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Affiliation(s)
- Youssef M Eltalkhawy
- Joint Research Center for Human Retrovirus Infection, Kumamoto University, Honjo 2-2-1, Kumamoto-city, Kumamoto 860-0811, Japan
| | - Naofumi Takahashi
- Joint Research Center for Human Retrovirus Infection, Kumamoto University, Honjo 2-2-1, Kumamoto-city, Kumamoto 860-0811, Japan
| | - Yasuo Ariumi
- Joint Research Center for Human Retrovirus Infection, Kumamoto University, Honjo 2-2-1, Kumamoto-city, Kumamoto 860-0811, Japan
| | - Jun Shimizu
- MiCAN Technologies Inc., Goryo-ohara 1-36, Kyoto 615-8245, Japan
| | - Kazuo Miyazaki
- MiCAN Technologies Inc., Goryo-ohara 1-36, Kyoto 615-8245, Japan
| | - Satoru Senju
- Department of Immunogenetics, Graduate School of Medical Sciences, Kumamoto University, Honjo 2-2-1, Kumamoto-city, Kumamoto 860-0811, Japan
| | - Shinya Suzu
- Joint Research Center for Human Retrovirus Infection, Kumamoto University, Honjo 2-2-1, Kumamoto-city, Kumamoto 860-0811, Japan
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10
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Shabana SM, Gad NS, Othman AI, Mohamed AF, El-Missiry MA. β-caryophyllene oxide induces apoptosis and inhibits proliferation of A549 lung cancer cells. Med Oncol 2023; 40:189. [PMID: 37233859 DOI: 10.1007/s12032-023-02022-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 04/02/2023] [Indexed: 05/27/2023]
Abstract
One of the most common cancers that result in death is lung cancer. There is new hope in the fight against lung cancer thanks to the chemopreventive properties of natural dietary substances like β-caryophyllene oxide (CPO), and research is currently being done to test this theory. CPO, a sesquiterpene isolated from medicinal plant essential oils, inhibits carcinogenesis and has been effective in treating many cancers. This study examined how CPO affected proliferation of human lung cancer A549 cells. CPO was found to have an inhibitory concentration (IC50) of 124.1 g/ml. The proliferative markers Ki67 and PCNA were significantly inhibited after cells were treated with CPO at a concentration of 50 g/ml compared to controls. CPO-treated cells expressed more P21, P53, and DNA strand breaks than controls. This was accompanied by a significant cell cycle arrest in the S and G2/M phases. In treated A549 cells, this was also associated with a significant induction of apoptosis, as shown by the upregulation of the expression of caspases 3, 7, and 9, as well as Bax, and the downregulation of Bcl-2. Furthermore, the redox status of treated A549 cells revealed a marked rise in GSH and GPx activity levels and a decline in 4-HNE levels, indicating low oxidative stress following CPO treatment of A549 cells. In conclusion, cell cycle arrest and apoptosis, which are unrelated to oxidative stress, were the mechanisms by which CPO reduced cancer lung cell growth. This finding might be a potential therapeutic target for the treatment of lung cancer. Hypothetical scheme of CPO anticancer effects (mechanism of signaling) in A549 cells; in vitro. CPO treatment increases expression of p21, p53 and DNA fragmentation. These events cause arrest of cell cycle which was associated with significant induction in apoptosis via increase expression of caspases (-3,-7,-9), and Bax and downregulation of Bcl-2.
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Affiliation(s)
- Sameh M Shabana
- Department of Zoology, Faculty of Science, Mansoura University, Mansoura, 35516, Egypt.
| | - Nahla S Gad
- Department of Zoology, Faculty of Science, Mansoura University, Mansoura, 35516, Egypt
| | - Azza I Othman
- Department of Zoology, Faculty of Science, Mansoura University, Mansoura, 35516, Egypt
| | - Aly Fahmy Mohamed
- The International Center for Advanced Researches (ICTAR-Egypt), Al-Azhar University, Cairo, 307422, Egypt
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11
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Ikeda T, Shimizu R, Nasser H, Carpenter MA, Cheng AZ, Brown WL, Sauter D, Harris RS. APOBEC3 degradation is the primary function of HIV-1 Vif for virus replication in the myeloid cell line THP-1. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.28.534666. [PMID: 37034786 PMCID: PMC10081227 DOI: 10.1101/2023.03.28.534666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
HIV-1 must overcome multiple innate antiviral mechanisms to replicate in CD4 + T lymphocytes and macrophages. Previous studies have demonstrated that the APOBEC3 (A3) family of proteins (at least A3D, A3F, A3G, and stable A3H haplotypes) contribute to HIV-1 restriction in CD4 + T lymphocytes. Virus-encoded virion infectivity factor (Vif) counteracts this antiviral activity by degrading A3 enzymes allowing HIV-1 replication in infected cells. In addition to A3 proteins, Vif also targets other cellular proteins in CD4 + T lymphocytes, including PPP2R5 proteins. However, whether Vif primarily degrades only A3 proteins or has additional essential targets during viral replication is currently unknown. Herein, we describe the development and characterization of A3F -, A3F/A3G -, and A3A -to- A3G -null THP-1 cells. In comparison to Vif-proficient HIV-1, Vif-deficient viruses have substantially reduced infectivity in parental and A3F -null THP-1 cells, and a more modest decrease in infectivity in A3F/A3G -null cells. Remarkably, disruption of A3Aâ€"A3G protein expression completely restores the infectivity of Vif-deficient viruses in THP-1 cells. These results indicate that the primary function of Vif during HIV-1 replication in THP-1 cells is the targeting and degradation of A3 enzymes. Importance HIV-1 Vif neutralizes the HIV-1 restriction activity of A3 proteins. However, it is currently unclear whether Vif has additional essential cellular targets. To address this question, we disrupted A3A to A3G genes in the THP-1 myeloid cell line using CRISPR and compared the infectivity of wildtype HIV-1 and Vif mutants with the selective A3 neutralization activities. Our results demonstrate that the infectivity of Vif-deficient HIV-1 and the other Vif mutants is fully restored by ablating the expression of cellular A3A to A3G proteins. These results indicate that A3 proteins are the only essential target of Vif that is required for HIV-1 replication in THP-1 cells.
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Affiliation(s)
- Terumasa Ikeda
- Division of Molecular Virology and Genetics, Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto 8600811, Japan
| | - Ryo Shimizu
- Division of Molecular Virology and Genetics, Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto 8600811, Japan
- Graduate School of Medical Sciences, Kumamoto University, Kumamoto 8600811, Japan
| | - Hesham Nasser
- Division of Molecular Virology and Genetics, Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto 8600811, Japan
- Department of Clinical Pathology, Faculty of Medicine, Suez Canal University, Ismailia 41511, Egypt
| | - Michael A. Carpenter
- Department of Biochemistry and Structural Biology, University of Texas Health San Antonio, San Antonio, Texas 78229, USA
- Howard Hughes Medical Institute, University of Texas Health San Antonio, San Antonio, Texas 78229, USA
| | - Adam Z. Cheng
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA
- Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - William L. Brown
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA
- Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Daniel Sauter
- Institute for Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, Tübingen 72076, Germany
| | - Reuben S. Harris
- Department of Biochemistry and Structural Biology, University of Texas Health San Antonio, San Antonio, Texas 78229, USA
- Howard Hughes Medical Institute, University of Texas Health San Antonio, San Antonio, Texas 78229, USA
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12
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Chen M, Li M, Budai MM, Rice AP, Kimata JT, Mohan M, Wang J. Clearance of HIV-1 or SIV reservoirs by promotion of apoptosis and inhibition of autophagy: Targeting intracellular molecules in cure-directed strategies. J Leukoc Biol 2022; 112:1245-1259. [PMID: 35362118 PMCID: PMC9522917 DOI: 10.1002/jlb.4mr0222-606] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 03/15/2022] [Indexed: 12/24/2022] Open
Abstract
The reservoirs of the HIV display cellular properties resembling long-lived immune memory cells that could be exploited for viral clearance. Our interest in developing a cure for HIV stems from the studies of immunologic memory against infections. We and others have found that long-lived immune memory cells employ prosurvival autophagy and antiapoptotic mechanisms to protect their longevity. Here, we describe the rationale for the development of an approach to clear HIV-1 by selective elimination of host cells harboring replication-competent HIV (SECH). While reactivation of HIV-1 in the host cells with latency reversing agents (LRAs) induces viral gene expression leading to cell death, LRAs also simultaneously up-regulate prosurvival antiapoptotic molecules and autophagy. Mechanistically, transcription factors that promote HIV-1 LTR-directed gene expression, such as NF-κB, AP-1, and Hif-1α, can also enhance the expression of cellular genes essential for cell survival and metabolic regulation, including Bcl-xL, Mcl-1, and autophagy genes. In the SECH approach, we inhibit the prosurvival antiapoptotic molecules and autophagy induced by LRAs, thereby allowing maximum killing of host cells by the induced HIV-1 proteins. SECH treatments cleared HIV-1 infections in humanized mice in vivo and in HIV-1 patient PBMCs ex vivo. SECH also cleared infections by the SIV in rhesus macaque PBMCs ex vivo. Research efforts are underway to improve the efficacy and safety of SECH and to facilitate the development of SECH as a therapeutic approach for treating people with HIV.
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Affiliation(s)
- Min Chen
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas, USA
| | - Min Li
- Immunobiology and Transplant Science Center, Department of Surgery, Houston Methodist Research Institute, Houston, Texas, USA
| | - Marietta M. Budai
- Immunobiology and Transplant Science Center, Department of Surgery, Houston Methodist Research Institute, Houston, Texas, USA
| | - Andrew P. Rice
- Department of Molecular Virology & Microbiology, Baylor College of Medicine, Houston, Texas, USA
| | - Jason T. Kimata
- Department of Molecular Virology & Microbiology, Baylor College of Medicine, Houston, Texas, USA
| | - Mahesh Mohan
- Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, Texas, USA
| | - Jin Wang
- Immunobiology and Transplant Science Center, Department of Surgery, Houston Methodist Research Institute, Houston, Texas, USA
- Department of Surgery, Weill Cornell Medical College, Cornell University, New York, New York, USA
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13
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Nef Suppresses LINE-1 Retrotransposition through Two Distinct Mechanisms. J Virol 2022; 96:e0114822. [PMID: 36197106 DOI: 10.1128/jvi.01148-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Long interspersed element type 1 (LINE-1) is the only known type of retroelement that can replicate autonomously, and its retrotransposition activity can trigger interferon (IFN) production. IFN production suppresses the infectivity of exogenous viruses, such as human immunodeficiency virus (HIV). As a counteraction, HIV has been reported to use multiple proteins and mechanisms to suppress LINE-1 replication. However, the mechanisms of HIV-mediated LINE-1 regulation are not fully understood. In this study, we discovered that Nef protein, which is expressed by HIV and is important for HIV pathogenesis, inhibits LINE-1 retrotransposition. Two distinct mechanisms have been uncovered for Nef-induced LINE-1 suppression. Without direct interaction with LINE-1 DNA, Nef potently inhibits the promoter activity of the LINE-1 5'-untranslated region (5'-UTR) and reduces the expression levels of LINE-1 RNA and proteins. Alternatively, although Nef does not bind to the LINE-1 open reading frame 1 protein (ORF1p) or LINE-1 RNA, it significantly compromises the ORF1p-LINE-1 RNA interaction, which is essential for LINE-1 retrotransposition. Both mechanisms can be suppressed by the G2A mutation, which abolishes myristoylation of Nef, suggesting that membrane attachment is essential for Nef to suppress LINE-1. Consequently, through LINE-1 inhibition, Nef downregulates IFN production in host cells. Therefore, our data revealed that Nef is a potent LINE-1 suppressor and an effective innate immune regulator, which not only provides new information on the intricate interaction between HIV, LINE-1, and IFN signaling systems but also strengthens the importance of Nef in HIV infection and highlights the potential of designing novel Nef-targeting anti-HIV drugs. IMPORTANCE Human immunodeficiency viruses are pathogens of AIDS that were first discovered almost 40 years ago and continue to threaten human lives to date. While currently used anti-HIV drugs are sufficient to suppress viral loads in HIV-infected patients, both drug-resistant HIV strains and adverse side effects triggered by the long-term use of these drugs highlight the need to develop novel anti-HIV drugs targeting different viral proteins and/or different steps in viral replication. To achieve this, more information is required regarding HIV pathogenesis and especially its impact on cellular activities in host cells. In this study, we discovered that the Nef protein expressed by HIV potently inhibits LINE-1 retrotransposition. During our attempt to determine the mechanism of Nef-mediated LINE-1 suppression, two additional functions of Nef were uncovered. Nef effectively repressed the promoter activity of LINE-1 5'-UTR and destabilized the interaction between ORF1p and LINE-1 RNA. Consequently, Nef not only compromises LINE-1 replication but also reduces LINE-1-triggered IFN production. The reduction in IFN production, in theory, promotes HIV infectivity. Together with its previously known functions, these findings indicate that Nef is a potential target for the development of novel anti-HIV drugs. Notably, the G2 residue, which has been reported to be essential for most Nef functions, was found to be critical in the regulation of innate immune activation by Nef, suggesting that compromising myristoylation or membrane attachment of Nef may be a good strategy for the inhibition of HIV infection.
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14
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Pedersen SF, Collora JA, Kim RN, Yang K, Razmi A, Catalano AA, Yeh YHJ, Mounzer K, Tebas P, Montaner LJ, Ho YC. Inhibition of a Chromatin and Transcription Modulator, SLTM, Increases HIV-1 Reactivation Identified by a CRISPR Inhibition Screen. J Virol 2022; 96:e0057722. [PMID: 35730977 PMCID: PMC9278143 DOI: 10.1128/jvi.00577-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 05/27/2022] [Indexed: 12/24/2022] Open
Abstract
Despite effective antiretroviral therapy, HIV-1 persistence in latent reservoirs remains a major obstacle to a cure. We postulate that HIV-1 silencing factors suppress HIV-1 reactivation and that inhibition of these factors will increase HIV-1 reactivation. To identify HIV-1 silencing factors, we conducted a genome-wide CRISPR inhibition (CRISPRi) screen using four CRISPRi-ready, HIV-1-d6-GFP-infected Jurkat T cell clones with distinct integration sites. We sorted cells with increased green fluorescent protein (GFP) expression and captured single guide RNAs (sgRNAs) via targeted deep sequencing. We identified 18 HIV-1 silencing factors that were significantly enriched in HIV-1-d6-GFPhigh cells. Among them, SLTM (scaffold attachment factor B-like transcription modulator) is an epigenetic and transcriptional modulator having both DNA and RNA binding capacities not previously known to affect HIV-1 transcription. Knocking down SLTM by CRISPRi significantly increased HIV-1-d6-GFP expression (by 1.9- to 4.2-fold) in three HIV-1-d6-GFP-Jurkat T cell clones. Furthermore, SLTM knockdown increased the chromatin accessibility of HIV-1 and the gene in which HIV-1 is integrated but not the housekeeping gene POLR2A. To test whether SLTM inhibition can reactivate HIV-1 and further induce cell death of HIV-1-infected cells ex vivo, we established a small interfering RNA (siRNA) knockdown method that reduced SLTM expression in CD4+ T cells from 10 antiretroviral therapy (ART)-treated, virally suppressed, HIV-1-infected individuals ex vivo. Using limiting dilution culture, we found that SLTM knockdown significantly reduced the frequency of HIV-1-infected cells harboring inducible HIV-1 by 62.2% (0.56/106 versus 1.48/106 CD4+ T cells [P = 0.029]). Overall, our study indicates that SLTM inhibition reactivates HIV-1 in vitro and induces cell death of HIV-1-infected cells ex vivo. Our study identified SLTM as a novel therapeutic target. IMPORTANCE HIV-1-infected cells, which can survive drug treatment and immune cell killing, prevent an HIV-1 cure. Immune recognition of infected cells requires HIV-1 protein expression; however, HIV-1 protein expression is limited in infected cells after long-term therapy. The ways in which the HIV-1 provirus is blocked from producing protein are unknown. We identified a new host protein that regulates HIV-1 gene expression. We also provided a new method of studying HIV-1-host factor interactions in cells from infected individuals. These improvements may enable future strategies to reactivate HIV-1 in infected individuals so that infected cells can be killed by immune cells, drug treatment, or the virus itself.
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Affiliation(s)
- Savannah F. Pedersen
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Jack A. Collora
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Rachel N. Kim
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Kerui Yang
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Anya Razmi
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Allison A. Catalano
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Yang-Hui Jimmy Yeh
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Karam Mounzer
- Philadelphia FIGHT Community Health Centers, Philadelphia, Pennsylvania, USA
| | - Pablo Tebas
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | - Ya-Chi Ho
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
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15
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Rausch JW, Le Grice SFJ. Characterizing the Latent HIV-1 Reservoir in Patients with Viremia Suppressed on cART: Progress, Challenges, and Opportunities. Curr HIV Res 2021; 18:99-113. [PMID: 31889490 PMCID: PMC7475929 DOI: 10.2174/1570162x18666191231105438] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 12/05/2019] [Accepted: 12/09/2019] [Indexed: 02/07/2023]
Abstract
Modern combination antiretroviral therapy (cART) can bring HIV-1 in blood plasma to level undetectable by standard tests, prevent the onset of acquired immune deficiency syndrome (AIDS), and allow a near-normal life expectancy for HIV-infected individuals. Unfortunately, cART is not curative, as within a few weeks of treatment cessation, HIV viremia in most patients rebounds to pre-cART levels. The primary source of this rebound, and the principal barrier to a cure, is the highly stable reservoir of latent yet replication-competent HIV-1 proviruses integrated into the genomic DNA of resting memory CD4+ T cells. In this review, prevailing models for how the latent reservoir is established and maintained, residual viremia and viremic rebound upon withdrawal of cART, and the types and characteristics of cells harboring latent HIV-1 will be discussed. Selected technologies currently being used to advance our understanding of HIV latency will also be presented, as will a perspective on which areas of advancement are most essential for producing the next generation of HIV-1 therapeutics.
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Affiliation(s)
- Jason W Rausch
- Basic Research Laboratory, Center for Cancer Research, National Cancer Institute, National Institute of Health, Frederick, MD 21702, United States
| | - Stuart F J Le Grice
- Basic Research Laboratory, Center for Cancer Research, National Cancer Institute, National Institute of Health, Frederick, MD 21702, United States
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16
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Salamango DJ, Harris RS. Demystifying Cell Cycle Arrest by HIV-1 Vif. Trends Microbiol 2021; 29:381-384. [PMID: 33478820 DOI: 10.1016/j.tim.2021.01.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/28/2020] [Accepted: 01/04/2021] [Indexed: 11/26/2022]
Abstract
Although APOBEC3 degradation is the canonical function of HIV-1 Vif, this viral protein also induces potent cell cycle arrest through a newly defined mechanism. Here, we review recent advances in this area and propose that the scope of this activity may go beyond subversion of the host cell cycle.
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Affiliation(s)
- Daniel J Salamango
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA; Institute for Molecular Virology, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Reuben S Harris
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA; Howard Hughes Medical Institute, University of Minnesota, Minneapolis, MN 55455, USA.
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17
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Schank M, Zhao J, Moorman JP, Yao ZQ. The Impact of HIV- and ART-Induced Mitochondrial Dysfunction in Cellular Senescence and Aging. Cells 2021; 10:cells10010174. [PMID: 33467074 PMCID: PMC7830696 DOI: 10.3390/cells10010174] [Citation(s) in RCA: 68] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 01/12/2021] [Accepted: 01/14/2021] [Indexed: 02/07/2023] Open
Abstract
According to the WHO, 38 million individuals were living with human immunodeficiency virus (HIV), 25.4 million of which were using antiretroviral therapy (ART) at the end of 2019. Despite ART-mediated suppression of viral replication, ART is not a cure and is associated with viral persistence, residual inflammation, and metabolic disturbances. Indeed, due to the presence of viral reservoirs, lifelong ART therapy is required to control viremia and prevent disease progression into acquired immune deficiency syndrome (AIDS). Successful ART treatment allows people living with HIV (PLHIV) to achieve a similar life expectancy to uninfected individuals. However, recent studies have illustrated the presence of increased comorbidities, such as accelerated, premature immune aging, in ART-controlled PLHIV compared to uninfected individuals. Studies suggest that both HIV-infection and ART-treatment lead to mitochondrial dysfunction, ultimately resulting in cellular exhaustion, senescence, and apoptosis. Since mitochondria are essential cellular organelles for energy homeostasis and cellular metabolism, their compromise leads to decreased oxidative phosphorylation (OXPHOS), ATP synthesis, gluconeogenesis, and beta-oxidation, abnormal cell homeostasis, increased oxidative stress, depolarization of the mitochondrial membrane potential, and upregulation of mitochondrial DNA mutations and cellular apoptosis. The progressive mitochondrial damage induced by HIV-infection and ART-treatment likely contributes to accelerated aging, senescence, and cellular dysfunction in PLHIV. This review discusses the connections between mitochondrial compromise and cellular dysfunction associated with HIV- and ART-induced toxicities, providing new insights into how HIV and current ART directly impact mitochondrial functions and contribute to cellular senescence and aging in PLHIV. Identifying this nexus and potential mechanisms may be beneficial in developing improved therapeutics for treating PLHIV.
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Affiliation(s)
- Madison Schank
- Center of Excellence in Inflammation, Infectious Disease and Immunity, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA; (M.S.); (J.Z.); (J.P.M.)
- Division of Infectious, Inflammatory and Immunologic Diseases, Department of Internal Medicine, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA
| | - Juan Zhao
- Center of Excellence in Inflammation, Infectious Disease and Immunity, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA; (M.S.); (J.Z.); (J.P.M.)
- Division of Infectious, Inflammatory and Immunologic Diseases, Department of Internal Medicine, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA
| | - Jonathan P. Moorman
- Center of Excellence in Inflammation, Infectious Disease and Immunity, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA; (M.S.); (J.Z.); (J.P.M.)
- Division of Infectious, Inflammatory and Immunologic Diseases, Department of Internal Medicine, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA
- Hepatitis (HCV/HBV/HIV) Program, James H. Quillen VA Medical Center, Department of Veterans Affairs, Johnson City, TN 37614, USA
| | - Zhi Q. Yao
- Center of Excellence in Inflammation, Infectious Disease and Immunity, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA; (M.S.); (J.Z.); (J.P.M.)
- Division of Infectious, Inflammatory and Immunologic Diseases, Department of Internal Medicine, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA
- Hepatitis (HCV/HBV/HIV) Program, James H. Quillen VA Medical Center, Department of Veterans Affairs, Johnson City, TN 37614, USA
- Correspondence: ; Tel.: +423-439-8063; Fax: +423-439-7010
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18
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Salamango DJ, Harris RS. Dual Functionality of HIV-1 Vif in APOBEC3 Counteraction and Cell Cycle Arrest. Front Microbiol 2021; 11:622012. [PMID: 33510734 PMCID: PMC7835321 DOI: 10.3389/fmicb.2020.622012] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 12/11/2020] [Indexed: 01/02/2023] Open
Abstract
Accessory proteins are a key feature that distinguishes primate immunodeficiency viruses such as human immunodeficiency virus type I (HIV-1) from other retroviruses. A prime example is the virion infectivity factor, Vif, which hijacks a cellular co-transcription factor (CBF-β) to recruit a ubiquitin ligase complex (CRL5) to bind and degrade antiviral APOBEC3 enzymes including APOBEC3D (A3D), APOBEC3F (A3F), APOBEC3G (A3G), and APOBEC3H (A3H). Although APOBEC3 antagonism is essential for viral pathogenesis, and a more than sufficient functional justification for Vif’s evolution, most viral proteins have evolved multiple functions. Indeed, Vif has long been known to trigger cell cycle arrest and recent studies have shed light on the underlying molecular mechanism. Vif accomplishes this function using the same CBF-β/CRL5 ubiquitin ligase complex to degrade a family of PPP2R5 phospho-regulatory proteins. These advances have helped usher in a new era of accessory protein research and fresh opportunities for drug development.
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Affiliation(s)
- Daniel J Salamango
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, United States.,Masonic Cancer Center, University of Minnesota, Minneapolis, MN, United States.,Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, United States
| | - Reuben S Harris
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, United States.,Masonic Cancer Center, University of Minnesota, Minneapolis, MN, United States.,Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, United States.,Howard Hughes Medical Institute, University of Minnesota, Minneapolis, MN, United States
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19
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Functional and Structural Insights into a Vif/PPP2R5 Complex Elucidated Using Patient HIV-1 Isolates and Computational Modeling. J Virol 2020; 94:JVI.00631-20. [PMID: 32847850 DOI: 10.1128/jvi.00631-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 08/17/2020] [Indexed: 02/06/2023] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) Vif recruits a cellular ubiquitin ligase complex to degrade antiviral APOBEC3 enzymes (APOBEC3C-H) and PP2A phosphatase regulators (PPP2R5A to PPP2R5E). While APOBEC3 antagonism is the canonical function of HIV-1 Vif, this viral accessory protein is also known to trigger G2/M cell cycle arrest. Vif initiates G2/M arrest by degrading multiple PPP2R5 family members, an activity prevalent among diverse HIV-1 and simian immunodeficiency virus (SIV) isolates. Here, computational protein-protein docking was used to delineate a Vif/CBF-β/PPP2R5 complex in which Vif is predicted to bind the same PPP2R5 surface as physiologic phosphatase targets. This model was tested using targeted mutagenesis of amino acid residues within or adjacent to the putative interface to show loss or retention, respectively, of Vif-induced PPP2R5 degradation activity. Additionally, expression of a peptide that mimics cellular targets of PPP2R5s robustly inhibited Vif-mediated degradation of PPP2R5A but not APOBEC3G. Moreover, live-cell imaging studies examining Vif-mediated degradation of PPP2R5A and APOBEC3G within the same cell revealed that PPP2R5A degradation kinetics are comparable to those of APOBEC3G with a half-life of roughly 6 h postinfection, demonstrating that Vif can concurrently mediate the degradation of distinct cellular substrates. Finally, experiments with a panel of patient-derived Vif isolates indicated that PPP2R5A degradation activity is common in patient-derived isolates. Taken together, these results support a model in which PPP2R5 degradation and global changes in the cellular phosphoproteome are likely to be advantageous for viral pathogenesis.IMPORTANCE A critical function of HIV-1 Vif is to counteract the family of APOBEC3 innate immune proteins. It is also widely accepted that Vif induces G2/M cell cycle arrest in several different cell types. Recently, it has been shown that Vif degrades multiple PPP2R5 phosphoregulators to induce the G2/M arrest phenotype. Here, computational approaches are used to test a structural model of the Vif/PPP2R5 complex. In addition, imaging studies are used to show that Vif degrades these PPP2R5 substrates in roughly the same time frame as APOBEC3 degradation and that this activity is prevalent in patient-derived Vif isolates. These studies are important by further defining PPP2R5 proteins as a bona fide substrate of HIV-1 Vif.
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20
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HIV-1 Vif Triggers Cell Cycle Arrest by Degrading Cellular PPP2R5 Phospho-regulators. Cell Rep 2020; 29:1057-1065.e4. [PMID: 31665623 PMCID: PMC6903395 DOI: 10.1016/j.celrep.2019.09.057] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 07/10/2019] [Accepted: 09/18/2019] [Indexed: 02/07/2023] Open
Abstract
HIV-1 Vif hijacks a cellular ubiquitin ligase complex to degrade antiviral APOBEC3 enzymes and PP2A phosphatase regulators (PPP2R5A–E). APOBEC3 counteraction is essential for viral pathogenesis. However, Vif also functions through an unknown mechanism to induce G2 cell cycle arrest. Here, deep mutagenesis is used to define the Vif surface required for PPP2R5 degradation and isolate a panel of separation-of-function mutants (PPP2R5 degradation-deficient and APOBEC3G degradation-proficient). Functional studies with Vif and PPP2R5 mutants were combined to demonstrate that PPP2R5 is, in fact, the target Vif degrades to induce G2 arrest. Pharmacologic and genetic approaches show that direct modulation of PP2A function or depletion of specific PPP2R5 proteins causes an indistinguishable arrest phenotype. Vif function in the cell cycle checkpoint is present in common HIV-1 subtypes worldwide and likely advantageous for viral pathogenesis. Salamango et al. discovered that the HIV-1 accessory protein Vif degrades several PP2A phospho-regulators to induce G2 cell cycle arrest. This activity is prevalent among diverse HIV-1 subtypes and global viral populations, suggesting that virus-induced G2 arrest is advantageous for pathogenesis.
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21
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Li M, Liu W, Bauch T, Graviss EA, Arduino RC, Kimata JT, Chen M, Wang J. Clearance of HIV infection by selective elimination of host cells capable of producing HIV. Nat Commun 2020; 11:4051. [PMID: 32792548 PMCID: PMC7426846 DOI: 10.1038/s41467-020-17753-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Accepted: 07/15/2020] [Indexed: 02/07/2023] Open
Abstract
The RNA genome of the human immunodeficiency virus (HIV) is reverse-transcribed into DNA and integrated into the host genome, resulting in latent infections that are difficult to clear. Here we show an approach to eradicate HIV infections by selective elimination of host cells harboring replication-competent HIV (SECH), which includes viral reactivation, induction of cell death, inhibition of autophagy and the blocking of new infections. Viral reactivation triggers cell death specifically in HIV-1-infected T cells, which is promoted by agents that induce apoptosis and inhibit autophagy. SECH treatments can clear HIV-1 in >50% mice reconstituted with a human immune system, as demonstrated by the lack of viral rebound after withdrawal of treatments, and by adoptive transfer of treated lymphocytes into uninfected humanized mice. Moreover, SECH clears HIV-1 in blood samples from HIV-1-infected patients. Our results suggest a strategy to eradicate HIV infections by selectively eliminating host cells capable of producing HIV.
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Affiliation(s)
- Min Li
- Immunobiology and Transplant Science Center, Houston Methodist Research Institute, Houston, TX, 77030, USA
| | - Wei Liu
- Immunobiology and Transplant Science Center, Houston Methodist Research Institute, Houston, TX, 77030, USA
| | - Tonya Bauch
- Immunobiology and Transplant Science Center, Houston Methodist Research Institute, Houston, TX, 77030, USA
| | - Edward A Graviss
- Department of Pathology and Genomic Medicine, Houston Methodist Research Institute, Houston, TX, 77030, USA
| | - Roberto C Arduino
- Division of Infectious Diseases, Department of Internal Medicine, McGovern Medical School at The University of Texas Health Science Center, Houston, TX, 77030, USA
| | - Jason T Kimata
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Min Chen
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Jin Wang
- Immunobiology and Transplant Science Center, Houston Methodist Research Institute, Houston, TX, 77030, USA.
- Department of Surgery, Weill Cornell Medical College, Cornell University, New York, NY, 10065, USA.
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22
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Ferreira IATM, Porterfield JZ, Gupta RK, Mlcochova P. Cell Cycle Regulation in Macrophages and Susceptibility to HIV-1. Viruses 2020; 12:v12080839. [PMID: 32751972 PMCID: PMC7472357 DOI: 10.3390/v12080839] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 07/24/2020] [Accepted: 07/28/2020] [Indexed: 02/07/2023] Open
Abstract
Macrophages are the first line of defence against invading pathogens. They play a crucial role in immunity but also in regeneration and homeostasis. Their remarkable plasticity in their phenotypes and function provides them with the ability to quickly respond to environmental changes and infection. Recent work shows that macrophages undergo cell cycle transition from a G0/terminally differentiated state to a G1 state. This G0-to-G1 transition presents a window of opportunity for HIV-1 infection. Macrophages are an important target for HIV-1 but express high levels of the deoxynucleotide-triphosphate hydrolase SAMHD1, which restricts viral DNA synthesis by decreasing levels of dNTPs. While the G0 state is non-permissive to HIV-1 infection, a G1 state is very permissive to HIV-1 infection. This is because macrophages in a G1 state switch off the antiviral restriction factor SAMHD1 by phosphorylation, thereby allowing productive HIV-1 infection. Here, we explore the macrophage cell cycle and the interplay between its regulation and permissivity to HIV-1 infection.
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Affiliation(s)
- Isabella A. T. M. Ferreira
- Cambridge Institute of Therapeutic Immunology & Infectious Disease (CITIID), Cambridge CB20AW, UK; (I.A.T.M.F.); (R.K.G.)
- Department of Medicine, University of Cambridge, Cambridge CB20QQ, UK
| | - J. Zachary Porterfield
- Department of Microbiology, University of Kentucky, Lexington, KY 40536, USA;
- Africa Health Research Institute, Durban 4001, South Africa
| | - Ravindra K. Gupta
- Cambridge Institute of Therapeutic Immunology & Infectious Disease (CITIID), Cambridge CB20AW, UK; (I.A.T.M.F.); (R.K.G.)
- Department of Medicine, University of Cambridge, Cambridge CB20QQ, UK
- Africa Health Research Institute, Durban 4001, South Africa
| | - Petra Mlcochova
- Cambridge Institute of Therapeutic Immunology & Infectious Disease (CITIID), Cambridge CB20AW, UK; (I.A.T.M.F.); (R.K.G.)
- Department of Medicine, University of Cambridge, Cambridge CB20QQ, UK
- Correspondence:
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Critical role of PP2A-B56 family protein degradation in HIV-1 Vif mediated G2 cell cycle arrest. Biochem Biophys Res Commun 2020; 527:257-263. [DOI: 10.1016/j.bbrc.2020.04.123] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 04/22/2020] [Indexed: 11/21/2022]
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24
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Marelli S, Williamson JC, Protasio AV, Naamati A, Greenwood EJD, Deane JE, Lehner PJ, Matheson NJ. Antagonism of PP2A is an independent and conserved function of HIV-1 Vif and causes cell cycle arrest. eLife 2020; 9:e53036. [PMID: 32292164 PMCID: PMC7920553 DOI: 10.7554/elife.53036] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 03/17/2020] [Indexed: 01/01/2023] Open
Abstract
The seminal description of the cellular restriction factor APOBEC3G and its antagonism by HIV-1 Vif has underpinned two decades of research on the host-virus interaction. We recently reported that HIV-1 Vif is also able to degrade the PPP2R5 family of regulatory subunits of key cellular phosphatase PP2A (PPP2R5A-E; Greenwood et al., 2016; Naamati et al., 2019). We now identify amino acid polymorphisms at positions 31 and 128 of HIV-1 Vif which selectively regulate the degradation of PPP2R5 family proteins. These residues covary across HIV-1 viruses in vivo, favouring depletion of PPP2R5A-E. Through analysis of point mutants and naturally occurring Vif variants, we further show that degradation of PPP2R5 family subunits is both necessary and sufficient for Vif-dependent G2/M cell cycle arrest. Antagonism of PP2A by HIV-1 Vif is therefore independent of APOBEC3 family proteins, and regulates cell cycle progression in HIV-infected cells.
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Affiliation(s)
- Sara Marelli
- Department of Medicine, University of CambridgeCambridgeUnited Kingdom
- Cambridge Institute of Therapeutic Immunology and Infectious Disease (CITIID), University of CambridgeCambridgeUnited Kingdom
| | - James C Williamson
- Department of Medicine, University of CambridgeCambridgeUnited Kingdom
- Cambridge Institute of Therapeutic Immunology and Infectious Disease (CITIID), University of CambridgeCambridgeUnited Kingdom
| | - Anna V Protasio
- Department of Medicine, University of CambridgeCambridgeUnited Kingdom
- Cambridge Institute of Therapeutic Immunology and Infectious Disease (CITIID), University of CambridgeCambridgeUnited Kingdom
| | - Adi Naamati
- Department of Medicine, University of CambridgeCambridgeUnited Kingdom
- Cambridge Institute of Therapeutic Immunology and Infectious Disease (CITIID), University of CambridgeCambridgeUnited Kingdom
| | - Edward JD Greenwood
- Department of Medicine, University of CambridgeCambridgeUnited Kingdom
- Cambridge Institute of Therapeutic Immunology and Infectious Disease (CITIID), University of CambridgeCambridgeUnited Kingdom
| | - Janet E Deane
- Department of Clinical Neuroscience, University of CambridgeCambridgeUnited Kingdom
- Cambridge Institute for Medical Research (CIMR), University of CambridgeCambridgeUnited Kingdom
| | - Paul J Lehner
- Department of Medicine, University of CambridgeCambridgeUnited Kingdom
- Cambridge Institute of Therapeutic Immunology and Infectious Disease (CITIID), University of CambridgeCambridgeUnited Kingdom
| | - Nicholas J Matheson
- Department of Medicine, University of CambridgeCambridgeUnited Kingdom
- Cambridge Institute of Therapeutic Immunology and Infectious Disease (CITIID), University of CambridgeCambridgeUnited Kingdom
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25
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Majer C, Schüssler JM, König R. Intertwined: SAMHD1 cellular functions, restriction, and viral evasion strategies. Med Microbiol Immunol 2019; 208:513-529. [PMID: 30879196 DOI: 10.1007/s00430-019-00593-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 03/08/2019] [Indexed: 01/01/2023]
Abstract
SAMHD1 was initially described for its ability to efficiently restrict HIV-1 replication in myeloid cells and resting CD4+ T cells. However, a growing body of evidence suggests that SAMHD1-mediated restriction is by far not limited to lentiviruses, but seems to be a general concept that applies to most retroviruses and at least a number of DNA viruses. SAMHD1 anti-viral activity was long believed to be solely due to its ability to deplete cellular dNTPs by enzymatic degradation. However, since its discovery, several new functions have been attributed to SAMHD1. It has been demonstrated to bind nucleic acids, to modulate innate immunity, as well as to participate in the DNA damage response and resolution of stalled replication forks. Consequently, it is likely that SAMHD1-mediated anti-viral activity is not or not exclusively mediated through its dNTPase activity. Therefore, in this review, we summarize current knowledge on SAMHD1 cellular functions and systematically discuss how these functions could contribute to the restriction of a broad range of viruses besides retroviruses: herpesviruses, poxviruses and hepatitis B virus. Furthermore, we aim to highlight different ways how viruses counteract SAMHD1-mediated restriction to bypass the SAMHD1-mediated block to viral infection.
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Affiliation(s)
- Catharina Majer
- Host-Pathogen Interactions, Paul-Ehrlich-Institute, 63225, Langen, Germany
| | | | - Renate König
- Host-Pathogen Interactions, Paul-Ehrlich-Institute, 63225, Langen, Germany. .,Immunity and Pathogenesis Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA. .,German Center for Infection Research (DZIF), 63225, Langen, Germany. .,Host-Pathogen Interactions, Paul-Ehrlich-Institute, 63225, Langen, Germany.
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26
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Du J, Rui Y, Zheng W, Li P, Kang J, Zhao K, Sun T, Yu XF. Vif-CBFβ interaction is essential for Vif-induced cell cycle arrest. Biochem Biophys Res Commun 2019; 511:910-915. [PMID: 30851937 DOI: 10.1016/j.bbrc.2019.02.136] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 02/25/2019] [Indexed: 10/27/2022]
Abstract
Interaction between HIV-1 Vif and host factor CBFβ leads to the assembly of the Vif-Cul5-EloB/C ubiquitin ligase (E3 complex). By inducing the formation of E3 complex, Vif depletes host APOBEC3 restriction factors and promotes HIV-1 infection. In addition, Vif is known to arrest host cells at G2/M phase (G2 arrest), benefiting HIV-1 replication and contributing to the depletion of CD4+ T cells. However, whether CBFβ is also involved in Vif-induced cell cycle arrest remains unclear. In the present study, we report that CBFβ is an essential factor for Vif-induced G2 arrest. Reducing endogenous CBFβ expression significantly compromised Vif's potency in cell cycle regulation. In addition, tests with CBFβ and Vif mutants indicated that Vif-CBFβ interaction is crucial for Vif to induce G2 arrest. Furthermore, suppressors against Vif-hijacked E3 complex or proteasome-mediated proteolysis also abolished Vif's ability to cause G2 arrest. In general, our data indicated that Vif induces G2 arrest through depletion of a yet-unknown cellular factor, where the involvement of CBFβ is essential. On the other hand, our data also suggested that, antiviral drugs targeting the Vif-CBFβ interaction have the potential to abolish Vif's ability to cause APOBEC3 degradation as well as G2 arrest in host cells, thus reducing both HIV-1 replication and Vif-induced CD4+ T-cell depletion.
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Affiliation(s)
- Juan Du
- Institute of Virology and AIDS Research, The First Hospital of Jilin University, Changchun, Jilin, 130061, China
| | - Yajuan Rui
- Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education), Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310009, China
| | - Wenwen Zheng
- Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education), Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310009, China
| | - Peng Li
- Institute of Virology and AIDS Research, The First Hospital of Jilin University, Changchun, Jilin, 130061, China
| | - Jian Kang
- Institute of Virology and AIDS Research, The First Hospital of Jilin University, Changchun, Jilin, 130061, China
| | - Ke Zhao
- Institute of Virology and AIDS Research, The First Hospital of Jilin University, Changchun, Jilin, 130061, China.
| | - Tianmeng Sun
- Institute of Immunology, The First Hospital of Jilin University, Changchun, Jilin, 130061, China; International Center of Future Science, Jilin University, Changchun, Jilin, 130061, China; National-local Joint Engineering Laboratory of Animal Models for Human Diseases, Changchun, Jilin, 130061, China.
| | - Xiao-Fang Yu
- Institute of Virology and AIDS Research, The First Hospital of Jilin University, Changchun, Jilin, 130061, China; Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education), Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310009, China.
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27
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Kumar NA, van der Sluis RM, Mota T, Pascoe R, Evans VA, Lewin SR, Cameron PU. Myeloid Dendritic Cells Induce HIV Latency in Proliferating CD4 + T Cells. THE JOURNAL OF IMMUNOLOGY 2018; 201:1468-1477. [PMID: 30030324 DOI: 10.4049/jimmunol.1701233] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 06/27/2018] [Indexed: 02/04/2023]
Abstract
HIV latency occurs predominantly in long-lived resting CD4+ T cells; however, latent infection also occurs in T cell subsets, including proliferating CD4+ T cells. We compared the establishment and maintenance of latent infection in nonproliferating and proliferating human CD4+ T cells cocultured with syngeneic myeloid dendritic cells (mDC). Resting CD4+ T cells were labeled with the proliferation dye eFluor 670 and cultured alone or with mDC, plasmacytoid dendritic cells, or monocytes in the presence of staphylococcal enterotoxin B (SEB). Cells were cultured for 24 h and infected with CCR5-tropic enhanced GFP (EGFP) reporter HIV. Five days postinfection, nonproductively infected EGFP- CD4+ T cells that were either nonproliferating (eFluor 670hi) or proliferating (eFluor 670lo) were sorted and cultured for an additional 7 d (day 12) with IL-7 and antiretrovirals. At day 5 postinfection, sorted, nonproductively infected T cells were stimulated with anti-CD3/CD28, and induced expression of EGFP was measured to determine the frequency of latent infection. Integrated HIV in these cells was confirmed using quantitative PCR. By these criteria, latent infection was detected at day 5 and 12 in proliferating T cells cocultured with mDC and monocytes but not plasmacytoid dendritic cells, where CD4+ T cells at day 12 were poor. At day 5 postinfection, nonproliferating T cells expressing SEB-specific TCR Vβ-17 were enriched in latent infection compared with non-SEB-specific TCR Vβ-8.1. Together, these data show that both nonproliferating and proliferating CD4+ T cells can harbor latent infection during SEB-stimulated T cell proliferation and that the establishment of HIV latency in nonproliferating T cells is linked to expression of specific TCR that respond to SEB.
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Affiliation(s)
- Nitasha A Kumar
- The Peter Doherty Institute for Infection and Immunity, University of Melbourne and Royal Melbourne Hospital, Melbourne, Victoria 3010, Australia
| | - Renee M van der Sluis
- The Peter Doherty Institute for Infection and Immunity, University of Melbourne and Royal Melbourne Hospital, Melbourne, Victoria 3010, Australia
| | - Talia Mota
- The Peter Doherty Institute for Infection and Immunity, University of Melbourne and Royal Melbourne Hospital, Melbourne, Victoria 3010, Australia
| | - Rachel Pascoe
- The Peter Doherty Institute for Infection and Immunity, University of Melbourne and Royal Melbourne Hospital, Melbourne, Victoria 3010, Australia
| | - Vanessa A Evans
- The Peter Doherty Institute for Infection and Immunity, University of Melbourne and Royal Melbourne Hospital, Melbourne, Victoria 3010, Australia
| | - Sharon R Lewin
- The Peter Doherty Institute for Infection and Immunity, University of Melbourne and Royal Melbourne Hospital, Melbourne, Victoria 3010, Australia.,Department of Infectious Diseases, Alfred Hospital and Monash University, Melbourne, Victoria 3004, Australia; and.,Centre for Biomedical Research, Burnet Institute, Melbourne, Victoria 3004, Australia
| | - Paul U Cameron
- The Peter Doherty Institute for Infection and Immunity, University of Melbourne and Royal Melbourne Hospital, Melbourne, Victoria 3010, Australia; .,Department of Infectious Diseases, Alfred Hospital and Monash University, Melbourne, Victoria 3004, Australia; and.,Centre for Biomedical Research, Burnet Institute, Melbourne, Victoria 3004, Australia
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28
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Sengupta S, Siliciano RF. Targeting the Latent Reservoir for HIV-1. Immunity 2018; 48:872-895. [PMID: 29768175 PMCID: PMC6196732 DOI: 10.1016/j.immuni.2018.04.030] [Citation(s) in RCA: 236] [Impact Index Per Article: 39.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 04/26/2018] [Accepted: 04/26/2018] [Indexed: 02/07/2023]
Abstract
Antiretroviral therapy can effectively block HIV-1 replication and prevent or reverse immunodeficiency in HIV-1-infected individuals. However, viral replication resumes within weeks of treatment interruption. The major barrier to a cure is a small pool of resting memory CD4+ T cells that harbor latent HIV-1 proviruses. This latent reservoir is now the focus of an intense international research effort. We describe how the reservoir is established, challenges involved in eliminating it, and pharmacologic and immunologic strategies for targeting this reservoir. The development of a successful cure strategy will most likely require understanding the mechanisms that maintain HIV-1 proviruses in a latent state and pathways that drive the proliferation of infected cells, which slows reservoir decay. In addition, a cure will require the development of effective immunologic approaches to eliminating infected cells. There is renewed optimism about the prospect of a cure, and the interventions discussed here could pave the way.
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Affiliation(s)
- Srona Sengupta
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Graduate Program in Immunology and Medical Scientist Training Program, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Robert F Siliciano
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Howard Hughes Medical Institute, Baltimore, MD 21205, USA.
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29
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Evans EL, Becker JT, Fricke SL, Patel K, Sherer NM. HIV-1 Vif's Capacity To Manipulate the Cell Cycle Is Species Specific. J Virol 2018; 92:e02102-17. [PMID: 29321323 PMCID: PMC5972884 DOI: 10.1128/jvi.02102-17] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 01/02/2018] [Indexed: 02/06/2023] Open
Abstract
Cells derived from mice and other rodents exhibit profound blocks to HIV-1 virion production, reflecting species-specific incompatibilities between viral Tat and Rev proteins and essential host factors cyclin T1 (CCNT1) and exportin-1 (XPO1, also known as CRM1), respectively. To determine if mouse cell blocks other than CCNT1 and XPO1 affect HIV's postintegration stages, we studied HIV-1NL4-3 gene expression in mouse NIH 3T3 cells modified to constitutively express HIV-1-compatible versions of CCNT1 and XPO1 (3T3.CX cells). 3T3.CX cells supported both Rev-independent and Rev-dependent viral gene expression and produced relatively robust levels of virus particles, confirming that CCNT1 and XPO1 represent the predominant blocks to these stages. Unexpectedly, however, 3T3.CX cells were remarkably resistant to virus-induced cytopathic effects observed in human cell lines, which we mapped to the viral protein Vif and its apparent species-specific capacity to induce G2/M cell cycle arrest. Vif was able to mediate rapid degradation of human APOBEC3G and the PPP2R5D regulatory B56 subunit of the PP2A phosphatase holoenzyme in mouse cells, thus demonstrating that VifNL4-3's modulation of the cell cycle can be functionally uncoupled from some of its other defined roles in CUL5-dependent protein degradation. Vif was also unable to induce G2/M cell cycle arrest in other nonhuman cell types, including cells derived from nonhuman primates, leading us to propose that one or more human-specific cofactors underpin Vif's ability to modulate the cell cycle.IMPORTANCE Cells derived from mice and other rodents exhibit profound blocks to HIV-1 replication, thus hindering the development of a low-cost small-animal model for studying HIV/AIDS. Here, we engineered otherwise-nonpermissive mouse cells to express HIV-1-compatible versions of two species-specific host dependency factors, cyclin T1 (CCNT1) and exportin-1 (XPO1) (3T3.CX cells). We show that 3T3.CX cells rescue HIV-1 particle production but, unexpectedly, are completely resistant to virus-induced cytopathic effects. We mapped these effects to the viral accessory protein Vif, which induces a prolonged G2/M cell cycle arrest followed by apoptosis in human cells. Combined, our results indicate that one or more additional human-specific cofactors govern HIV-1's capacity to modulate the cell cycle, with potential relevance to viral pathogenesis in people and existing animal models.
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Affiliation(s)
- Edward L Evans
- McArdle Laboratory for Cancer Research, Institute for Molecular Virology, & Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Jordan T Becker
- McArdle Laboratory for Cancer Research, Institute for Molecular Virology, & Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Stephanie L Fricke
- McArdle Laboratory for Cancer Research, Institute for Molecular Virology, & Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Kishan Patel
- McArdle Laboratory for Cancer Research, Institute for Molecular Virology, & Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Nathan M Sherer
- McArdle Laboratory for Cancer Research, Institute for Molecular Virology, & Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
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30
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Murray AJ, Kwon KJ, Farber DL, Siliciano RF. The Latent Reservoir for HIV-1: How Immunologic Memory and Clonal Expansion Contribute to HIV-1 Persistence. THE JOURNAL OF IMMUNOLOGY 2017; 197:407-17. [PMID: 27382129 DOI: 10.4049/jimmunol.1600343] [Citation(s) in RCA: 107] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 04/12/2016] [Indexed: 12/15/2022]
Abstract
Combination antiretroviral therapy (ART) for HIV-1 infection reduces plasma virus levels to below the limit of detection of clinical assays. However, even with prolonged suppression of viral replication with ART, viremia rebounds rapidly after treatment interruption. Thus, ART is not curative. The principal barrier to cure is a remarkably stable reservoir of latent HIV-1 in resting memory CD4(+) T cells. In this review, we consider explanations for the remarkable stability of the latent reservoir. Stability does not appear to reflect replenishment from new infection events but rather normal physiologic processes that provide for immunologic memory. Of particular importance are proliferative processes that drive clonal expansion of infected cells. Recent evidence suggests that in some infected cells, proliferation is a consequence of proviral integration into host genes associated with cell growth. Efforts to cure HIV-1 infection by targeting the latent reservoir may need to consider the potential of latently infected cells to proliferate.
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Affiliation(s)
- Alexandra J Murray
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Kyungyoon J Kwon
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Donna L Farber
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY 10032; Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032; Department of Surgery, Columbia University Medical Center, New York, NY 10032; and
| | - Robert F Siliciano
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205; Howard Hughes Medical Institute, Baltimore MD 21250
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31
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Hosmane NN, Kwon KJ, Bruner KM, Capoferri AA, Beg S, Rosenbloom DIS, Keele BF, Ho YC, Siliciano JD, Siliciano RF. Proliferation of latently infected CD4 + T cells carrying replication-competent HIV-1: Potential role in latent reservoir dynamics. J Exp Med 2017; 214:959-972. [PMID: 28341641 PMCID: PMC5379987 DOI: 10.1084/jem.20170193] [Citation(s) in RCA: 303] [Impact Index Per Article: 43.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Revised: 02/14/2017] [Accepted: 02/15/2017] [Indexed: 12/16/2022] Open
Abstract
A latent reservoir for HIV-1 in resting CD4+ T lymphocytes precludes cure. Mechanisms underlying reservoir stability are unclear. Recent studies suggest an unexpected degree of infected cell proliferation in vivo. T cell activation drives proliferation but also reverses latency, resulting in productive infection that generally leads to cell death. In this study, we show that latently infected cells can proliferate in response to mitogens without producing virus, generating progeny cells that can release infectious virus. Thus, assays relying on one round of activation underestimate reservoir size. Sequencing of independent clonal isolates of replication-competent virus revealed that 57% had env sequences identical to other isolates from the same patient. Identity was confirmed by full-genome sequencing and was not attributable to limited viral diversity. Phylogenetic and statistical analysis suggested that identical sequences arose from in vivo proliferation of infected cells, rather than infection of multiple cells by a dominant viral species. The possibility that much of the reservoir arises by cell proliferation presents challenges to cure.
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Affiliation(s)
- Nina N Hosmane
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Kyungyoon J Kwon
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Katherine M Bruner
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Adam A Capoferri
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Subul Beg
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Daniel I S Rosenbloom
- Department of Biomedical Informatics, Columbia University Medical Center, New York, NY 10032
| | - Brandon F Keele
- AIDS and Cancer Virus Program, Leidos Biomedical Research Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702
| | - Ya-Chi Ho
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Janet D Siliciano
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Robert F Siliciano
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205
- Howard Hughes Medical Institute, Baltimore, MD 21205
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32
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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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33
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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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Okumura F, Joo-Okumura A, Nakatsukasa K, Kamura T. The role of cullin 5-containing ubiquitin ligases. Cell Div 2016; 11:1. [PMID: 27030794 PMCID: PMC4812663 DOI: 10.1186/s13008-016-0016-3] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 03/02/2016] [Indexed: 01/01/2023] Open
Abstract
The suppressor of cytokine signaling (SOCS) box consists of the BC box and the cullin 5 (Cul5) box, which interact with Elongin BC and Cul5, respectively. SOCS box-containing proteins have ubiquitin ligase activity mediated by the formation of a complex with the scaffold protein Cul5 and the RING domain protein Rbx2, and are thereby members of the cullin RING ligase superfamily. Cul5-type ubiquitin ligases have a variety of substrates that are targeted for polyubiquitination and proteasomal degradation. Here, we review the current knowledge on the identification of Cul5 and the regulation of its expression, as well as the signaling pathways regulated by Cul5 and how viruses highjack the Cul5 system to overcome antiviral responses.
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Affiliation(s)
- Fumihiko Okumura
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602 Japan
| | - Akiko Joo-Okumura
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602 Japan
| | - Kunio Nakatsukasa
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602 Japan
| | - Takumi Kamura
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602 Japan
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Zhao K, Du J, Rui Y, Zheng W, Kang J, Hou J, Wang K, Zhang W, Simon VA, Yu XF. Evolutionarily conserved pressure for the existence of distinct G2/M cell cycle arrest and A3H inactivation functions in HIV-1 Vif. Cell Cycle 2015; 14:838-47. [PMID: 25590520 DOI: 10.1080/15384101.2014.1000212] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
HIV-1 Vif assembles the Cul5-EloB/C E3 ubiquitin ligase to induce proteasomal degradation of the cellular antiviral APOBEC3 proteins. Detailed structural studies have confirmed critical functional domains in Vif that we have previously identified as important for the interaction of EloB/C, Cul5, and CBFβ. However, the mechanism by which Vif recognizes substrates remains poorly understood. Specific regions of Vif have been identified as being responsible for binding and depleting APOBEC3G and APOBEC3F. Interestingly, we have now identified distinct yet overlapping domains that are required for HIV-1 Vif-mediated G2/M-phase cell cycle arrest and APOBEC3H degradation, but not for the inactivation of APOBEC3G or APOBEC3F. Surprisingly, Vif molecules from primary HIV-1 variants that caused G2/M arrest were unable to inactivate APOBEC3H; on the other hand, HIV-1 Vif variants that could inactivate APOBEC3H were unable to induce G2/M arrest. All of these Vif variants still maintained the ability to inactivate APOBEC3G/F. Thus, primary HIV-1 variants have evolved to possess distinct functional activities that allow them to suppress APOBEC3H or cause G2 cell cycle arrest, using mutually exclusive interface domains. APOBEC3H depletion and G2 arrest are apparently evolutionary selected features that cannot co-exist on a single Vif molecule. The existence and persistence of both types of HIV-1 Vif variant suggests the importance of APOBEC3H suppression and cell cycle regulation for HIV-1's survival in vivo.
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Affiliation(s)
- Ke Zhao
- a Institute of Virology and AIDS Research ; First Hospital of Jilin University ; Changchun , Jilin , China
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Remion A, Delord M, Hance AJ, Saragosti S, Mammano F. Kinetics of the establishment of HIV-1 viral interference and comprehensive analysis of the contribution of viral genes. Virology 2015; 487:59-67. [PMID: 26499042 DOI: 10.1016/j.virol.2015.09.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 07/01/2015] [Accepted: 09/26/2015] [Indexed: 10/22/2022]
Abstract
Viral interference defines the reduced susceptibility of an infected cell to reinfection. For HIV-1, both receptor-dependent and independent pathways were described. The relative importance of different receptor-independent pathways has not been addressed. We have used reporter viruses to quantify the percentage of single- and double-infected cells, as a function of the delay between the two infections. For co-infection experiments, the frequency of double infected cells was higher than expected for independent events. By delaying the second infection, this frequency progressively diminished, resulting in significant interference after 18h. Interference measured here was largely receptor-independent. By individually deleting viral genes or expressing them in isolation, we demonstrate that the viral protein Rev plays a dominant role, while other viral proteins contributes to optimal interference. Our study defines the kinetics of early HIV-1 interference, describing the transition from higher susceptibility to double-infection to viral interference, and identifies Rev as its dominant effector.
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Affiliation(s)
- Azaria Remion
- INSERM, U941, Paris, France; Univ Paris Diderot, Sorbonne Paris Cité, Paris, France; Institut Universitaire d'Hématologie, Hôpital Saint-Louis, Paris, France
| | - Marc Delord
- Univ Paris Diderot, Sorbonne Paris Cité, Paris, France; Institut Universitaire d'Hématologie, Hôpital Saint-Louis, Paris, France
| | - Allan J Hance
- INSERM, U941, Paris, France; Univ Paris Diderot, Sorbonne Paris Cité, Paris, France; Institut Universitaire d'Hématologie, Hôpital Saint-Louis, Paris, France
| | - Sentob Saragosti
- INSERM, U941, Paris, France; Univ Paris Diderot, Sorbonne Paris Cité, Paris, France; Institut Universitaire d'Hématologie, Hôpital Saint-Louis, Paris, France
| | - Fabrizio Mammano
- INSERM, U941, Paris, France; Univ Paris Diderot, Sorbonne Paris Cité, Paris, France; Institut Universitaire d'Hématologie, Hôpital Saint-Louis, Paris, France.
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Interactions of HIV-1 proteins as targets for developing anti-HIV-1 peptides. Future Med Chem 2015; 7:1055-77. [DOI: 10.4155/fmc.15.46] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Protein–protein interactions (PPI) are essential in every step of the HIV replication cycle. Mapping the interactions between viral and host proteins is a fundamental target for the design and development of new therapeutics. In this review, we focus on rational development of anti-HIV-1 peptides based on mapping viral–host and viral–viral protein interactions all across the HIV-1 replication cycle. We also discuss the mechanism of action, specificity and stability of these peptides, which are designed to inhibit PPI. Some of these peptides are excellent tools to study the mechanisms of PPI in HIV-1 replication cycle and for the development of anti-HIV-1 drug leads that modulate PPI.
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de Castro FL, Junqueira DM, de Medeiros RM, da Silva TR, Costenaro JG, Knak MB, de Matos Almeida SE, Campos FS, Roehe PM, Franco AC. Analysis of single-nucleotide polymorphisms in the APOBEC3H gene of domestic cats (Felis catus) and their association with the susceptibility to feline immunodeficiency virus and feline leukemia virus infections. INFECTION GENETICS AND EVOLUTION 2014; 27:389-94. [DOI: 10.1016/j.meegid.2014.08.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Revised: 08/20/2014] [Accepted: 08/21/2014] [Indexed: 10/24/2022]
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da Costa KS, Leal E, dos Santos AM, Lima e Lima AH, Alves CN, Lameira J. Structural analysis of viral infectivity factor of HIV type 1 and its interaction with A3G, EloC and EloB. PLoS One 2014; 9:e89116. [PMID: 24586532 PMCID: PMC3935857 DOI: 10.1371/journal.pone.0089116] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2013] [Accepted: 01/15/2014] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND The virion infectivity factor (Vif) is an accessory protein, which is essential for HIV replication in host cells. Vif neutralizes the antiviral host protein APOBEC3 through recruitment of the E3 ubiquitin ligase complex. METHODOLOGY Fifty thousand Vif models were generated using the ab initio relax protocol of the Rosetta algorithm from sets of three- and nine-residue fragments using the fragment Monte Carlo insertion-simulated annealing strategy, which favors protein-like features, followed by an all-atom refinement. In the protocol, a constraints archive was used to define the spatial relationship between the side chains from Cys/His residues and zinc ions that formed the zinc-finger motif that is essential for Vif function. We also performed centroids analysis and structural analysis with respect to the formation of the zinc-finger, and the residue disposal in the protein binding domains. Additionally, molecular docking was used to explore details of Vif-A3G and Vif-EloBC interactions. Furthermore, molecular dynamics simulation was used to evaluate the stability of the complexes Vif-EloBC-A3G and Vif-EloC. PRINCIPAL FINDINGS The zinc in the HCCH domain significantly alters the folding of Vif and changes the structural dynamics of the HCCH region. Ab initio modeling indicated that the Vif zinc-finger possibly displays tetrahedral geometry as suggested by Mehle et al. (2006). Our model also showed that the residues L146 and L149 of the BC-box motif bind to EloC by hydrophobic interactions, and the residue P162 of the PPLP motif is important to EloB binding. CONCLUSIONS/SIGNIFICANCE The model presented here is the first complete three-dimensional structure of the Vif. The interaction of Vif with the A3G protein and the EloBC complex is in agreement with empirical data that is currently available in the literature and could therefore provide valuable structural information for advances in rational drug design.
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Affiliation(s)
- Kauê Santana da Costa
- Laboratório de Planejamento e Desenvolvimento de Fármacos, Instituto de Ciências Exatas e Naturais– ICEN e Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Brazil
| | - Elcio Leal
- Faculdade de Biotecnologia, Universidade Federal do Pará, Belém, Brazil
| | - Alberto Monteiro dos Santos
- Laboratório de Planejamento e Desenvolvimento de Fármacos, Instituto de Ciências Exatas e Naturais– ICEN e Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Brazil
| | - Anderson Henrique Lima e Lima
- Laboratório de Planejamento e Desenvolvimento de Fármacos, Instituto de Ciências Exatas e Naturais– ICEN e Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Brazil
| | - Cláudio Nahum Alves
- Laboratório de Planejamento e Desenvolvimento de Fármacos, Instituto de Ciências Exatas e Naturais– ICEN e Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Brazil
| | - Jerônimo Lameira
- Laboratório de Planejamento e Desenvolvimento de Fármacos, Instituto de Ciências Exatas e Naturais– ICEN e Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Brazil
- Faculdade de Biotecnologia, Universidade Federal do Pará, Belém, Brazil
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Cycling memory CD4+ T cells in HIV disease have a diverse T cell receptor repertoire and a phenotype consistent with bystander activation. J Virol 2014; 88:5369-80. [PMID: 24522925 DOI: 10.1128/jvi.00017-14] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
UNLABELLED The mechanisms of increased memory CD4+ T cell cycling in HIV disease are incompletely understood but have been linked to antigen stimulation, homeostatic signals, or exposure to microbial products and the inflammatory cytokines that they induce. We examined the phenotype and Vβ family distribution in cycling memory CD4+ T cells among 52 healthy and 59 HIV-positive (HIV+) donors. Cycling memory CD4+ T cells were proportionally more frequent in subjects with HIV infection than in controls, more often expressed CD38 and PD-1, and less frequently expressed OX40 and intracellular CD40L. OX40 expression on memory CD4+ T cells was induced in vitro by anti-CD3, interleukin-2 (IL-2), IL-7, or IL-15 but not by Toll-like receptor ligands. In HIV+ donors, memory CD4+ T cell cycling was directly related to plasma lipopolysaccharide (LPS) levels, to plasma HIV RNA levels, and to memory CD8+ T cell cycling and was inversely related to peripheral blood CD4+ T cell counts but not to the levels of IL-2, IL-7, or IL-15, while in HIV-negative donors, memory CD4+ T cell cycling was related to IL-7 levels and negatively related to the plasma levels of LPS. In both controls and HIV+ donors, cycling memory CD4+ T cells had a broad distribution of Vβ families comparable to that of noncycling cells. Increased memory CD4+ T cell cycling in HIV disease is reflective of generalized immune activation and not driven primarily by cognate peptide stimulation or exposure to common gamma-chain cytokines. This cycling may be a consequence of exposure to microbial products, to plasma viremia, or, otherwise, to proinflammatory cytokines. IMPORTANCE This work provides evidence that the increased memory CD4+ T cell cycling in HIV infection is not a result of cognate peptide recognition but, rather, is more likely related to the inflammatory environment of HIV infection.
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Murakami T, Aida Y. Visualizing Vpr-induced G2 arrest and apoptosis. PLoS One 2014; 9:e86840. [PMID: 24466265 PMCID: PMC3899331 DOI: 10.1371/journal.pone.0086840] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Accepted: 12/13/2013] [Indexed: 12/05/2022] Open
Abstract
Vpr is an accessory protein of human immunodeficiency virus type 1 (HIV-1) with multiple functions. The induction of G2 arrest by Vpr plays a particularly important role in efficient viral replication because the transcriptional activity of the HIV-1 long terminal repeat is most active in G2 phase. The regulation of apoptosis by Vpr is also important for immune suppression and pathogenesis during HIV infection. However, it is not known whether Vpr-induced apoptosis depends on the ability of Vpr to induce G2 arrest, and the dynamics of Vpr-induced G2 arrest and apoptosis have not been visualized. We performed time-lapse imaging to examine the temporal relationship between Vpr-induced G2 arrest and apoptosis using HeLa cells containing the fluorescent ubiquitination-based cell cycle indicator2 (Fucci2). The dynamics of G2 arrest and subsequent long-term mitotic cell rounding in cells transfected with the Vpr-expression vector were visualized. These cells underwent nuclear mis-segregation after prolonged mitotic processes and then entered G1 phase. Some cells subsequently displayed evidence of apoptosis after prolonged mitotic processes and nuclear mis-segregation. Interestingly, Vpr-induced apoptosis was seldom observed in S or G2 phase. Likewise, visualization of synchronized HeLa/Fucci2 cells infected with an adenoviral vector expressing Vpr clearly showed that Vpr arrests the cell cycle at G2 phase, but does not induce apoptosis at S or G2 phase. Furthermore, time-lapse imaging of HeLa/Fucci2 cells expressing SCAT3.1, a caspase-3-sensitive fusion protein, clearly demonstrated that Vpr induces caspase-3-dependent apoptosis. Finally, to examine whether the effects of Vpr on G2 arrest and apoptosis were reversible, we performed live-cell imaging of a destabilizing domain fusion Vpr, which enabled rapid stabilization and destabilization by Shield1. The effects of Vpr on G2 arrest and subsequent apoptosis were reversible. This study is the first to characterize the dynamics of the morphological changes that occur during Vpr-induced G2 arrest and apoptosis.
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Affiliation(s)
- Tomoyuki Murakami
- Viral Infectious Diseases Unit, RIKEN, Wako, Saitama, Japan
- Laboratory of Viral Infectious Diseases, Department of Medical Genome Sciences, Graduate School of Frontier Science, The University of Tokyo, Wako, Saitama, Japan
| | - Yoko Aida
- Viral Infectious Diseases Unit, RIKEN, Wako, Saitama, Japan
- Laboratory of Viral Infectious Diseases, Department of Medical Genome Sciences, Graduate School of Frontier Science, The University of Tokyo, Wako, Saitama, Japan
- * E-mail:
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HIV-1 Vpr accelerates viral replication during acute infection by exploitation of proliferating CD4+ T cells in vivo. PLoS Pathog 2013; 9:e1003812. [PMID: 24339781 PMCID: PMC3855622 DOI: 10.1371/journal.ppat.1003812] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Accepted: 10/22/2013] [Indexed: 11/28/2022] Open
Abstract
The precise role of viral protein R (Vpr), an HIV-1-encoded protein, during HIV-1 infection and its contribution to the development of AIDS remain unclear. Previous reports have shown that Vpr has the ability to cause G2 cell cycle arrest and apoptosis in HIV-1-infected cells in vitro. In addition, vpr is highly conserved in transmitted/founder HIV-1s and in all primate lentiviruses, which are evolutionarily related to HIV-1. Although these findings suggest an important role of Vpr in HIV-1 pathogenesis, its direct evidence in vivo has not been shown. Here, by using a human hematopoietic stem cell-transplanted humanized mouse model, we demonstrated that Vpr causes G2 cell cycle arrest and apoptosis predominantly in proliferating CCR5+ CD4+ T cells, which mainly consist of regulatory CD4+ T cells (Tregs), resulting in Treg depletion and enhanced virus production during acute infection. The Vpr-dependent enhancement of virus replication and Treg depletion is observed in CCR5-tropic but not CXCR4-tropic HIV-1-infected mice, suggesting that these effects are dependent on the coreceptor usage by HIV-1. Immune activation was observed in CCR5-tropic wild-type but not in vpr-deficient HIV-1-infected humanized mice. When humanized mice were treated with denileukin diftitox (DD), to deplete Tregs, DD-treated humanized mice showed massive activation/proliferation of memory T cells compared to the untreated group. This activation/proliferation enhanced CCR5 expression in memory CD4+ T cells and rendered them more susceptible to CCR5-tropic wild-type HIV-1 infection than to vpr-deficient virus. Taken together, these results suggest that Vpr takes advantage of proliferating CCR5+ CD4+ T cells for enhancing viremia of CCR5-tropic HIV-1. Because Tregs exist in a higher cycling state than other T cell subsets, Tregs appear to be more vulnerable to exploitation by Vpr during acute HIV-1 infection. HIV-1 encodes nine genes, five of which (gag, pol, env, tat, and rev) are essential for viral replication, and four, termed accessory genes (vif, vpu, nef, and vpr), appear to aid virus infection. Of the four accessory proteins, Vpr is the most enigmatic. It is well known that Vpr has the potential to cause G2 cell cycle arrest and apoptosis in vitro. Moreover, it has been reported that Vpr-mediated G2 arrest increases HIV-1 production in vitro. However, the role of Vpr in HIV-1 propagation in vivo remains unclear. Here, by using a humanized mouse model, we demonstrate that Vpr enhances CCR5-tropic but not CXCR4-tropic HIV-1 replication in vivo by exploiting Tregs during acute infection. In CCR5-tropic HIV-1-infected humanized mice, Vpr-dependent G2 cell cycle arrest and apoptosis are predominantly observed in infected Tregs, and wild-type but not vpr-deficient HIV-1-infected mice displayed acute Treg depletion. This Vpr-dependent Treg depletion may lead to immune activation and provide a pool of activated/proliferating CD4+ T cells, which supports subsequent HIV-1 expansion in vivo. This is the first report demonstrating the role of Vpr in HIV-1 infection in vivo.
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Nekorchuk MD, Sharifi HJ, Furuya AKM, Jellinger R, de Noronha CMC. HIV relies on neddylation for ubiquitin ligase-mediated functions. Retrovirology 2013; 10:138. [PMID: 24245672 PMCID: PMC3842660 DOI: 10.1186/1742-4690-10-138] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 11/07/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND HIV and SIV defeat antiviral proteins by usurping Cullin-RING E3 ubiquitin ligases (CRLs) and likely influence other cellular processes through these as well. HIV-2 viral protein X (Vpx) engages the cullin4-containing CRL4 complex to deplete the antiviral protein SAMHD1. Vif expressed by HIV-1 and HIV-2 taps a cullin5 ubiquitin ligase complex to mark the antiviral protein APOBEC3G for destruction. Viral Protein R of HIV-1 (Vpr) assembles with the CRL4 ubiquitin ligase complex to deplete uracil-N-glycosylase2 (UNG2). Covalent attachment of the ubiquitin-like protein side-chain NEDD8 functionally activates cullins which are common to all of these processes. RESULTS The requirement for neddylation in HIV-1 and HIV-2 infectivity was tested in the presence of APOBEC3G and SAMHD1 respectively. Further the need for neddylation in HIV-1 Vpr-mediated depletion of UNG2 was probed. Treatment with MLN4924, an adenosine sulfamate analog which hinders the NEDD8 activating enzyme NAE1, blocked neddylation of cullin4A (CUL4A). The inhibitor hindered HIV-1 infection in the presence of APOBEC3G, even when Vif was expressed, and it stopped HIV-2 infection in the presence of SAMHD1 and Vpx. Consistent with these findings, MLN4924 prevented Vpx-mediated depletion of SAMHD1 in macrophages infected with Vpx-expressing HIV-2, as well as HIV-1 Vif-mediated destruction of APOBEC3G. It also stemmed Vpr-mediated UNG2 elimination from cells infected with HIV-1. CONCLUSIONS Neddylation plays an important role in HIV-1 and HIV-2 infection. This observation is consistent with the essential parts that cullin-based ubiquitin ligases play in overcoming cellular anti-viral defenses.
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Affiliation(s)
| | | | | | | | - Carlos M C de Noronha
- Center for Immunology and Microbial Disease, Albany Medical College, 43 New Scotland Avenue, Albany, NY 12208, USA.
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Abstract
Type 1 long-interspersed nuclear elements (L1s) are autonomous retrotransposable elements that retain the potential for activity in the human genome but are suppressed by host factors. Retrotransposition of L1s into chromosomal DNA can lead to genomic instability, whereas reverse transcription of L1 in the cytosol has the potential to activate innate immune sensors. We hypothesized that HIV-1 infection would compromise cellular control of L1 elements, resulting in the induction of retrotransposition events. Here, we show that HIV-1 infection enhances L1 retrotransposition in Jurkat cells in a Vif- and Vpr-dependent manner. In primary CD4(+) cells, HIV-1 infection results in the accumulation of L1 DNA, at least the majority of which is extrachromosomal. These data expose an unrecognized interaction between HIV-1 and endogenous retrotransposable elements, which may have implications for the innate immune response to HIV-1 infection, as well as for HIV-1-induced genomic instability and cytopathicity.
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Shan L, Siliciano RF. From reactivation of latent HIV-1 to elimination of the latent reservoir: the presence of multiple barriers to viral eradication. Bioessays 2013; 35:544-52. [PMID: 23613347 DOI: 10.1002/bies.201200170] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The discovery of a stable latent reservoir for HIV-1 in resting memory CD4(+) T cells provides a mechanism for lifelong persistence of HIV-1. The long-lived latently infected cells persist in spite of prolonged highly active antiretroviral therapy and present a major barrier to a cure of HIV-1 infection. In this review, we discuss the current understanding of HIV-1 persistence and latent viral infection in the context of effective antiretroviral therapy and the recent progress in purging latent viral reservoirs. Recent studies demonstrate that reactivation of latent HIV-1 is a promising strategy for the depletion of these viral reservoirs. A thorough evaluation of the anti-latency activity of drug candidates should include the measurement of changes in intracellular viral RNA, plasma virus levels, and the size of latent viral reservoirs, as well as potential adverse effects. Currently, there are several technical barriers to the evaluation of anti-latency drugs in vivo. We also discuss these challenging issues that remain unresolved.
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Affiliation(s)
- Liang Shan
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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De Maio FA, Rocco CA, Aulicino PC, Bologna R, Mangano A, Sen L. Unusual substitutions in HIV-1 vif from children infected perinatally without progression to AIDS for more than 8 years without therapy. J Med Virol 2013; 84:1844-52. [PMID: 23080486 DOI: 10.1002/jmv.23261] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The HIV-1 vif gene encodes for an accessory protein that is central for virus replication due mainly to its capacity to counteract the antiviral action of host APOBEC3 restriction factors. In order to evaluate whether HIV-1 vif alterations account for a delayed progression to AIDS in children infected perinatally, the vif genes from a group of 11 patients who exhibited an extremely slow disease progression (slow progressors) were studied by direct sequencing. In addition, the vif genes from a group of 93 children with typical disease progression (typical progressors) were analyzed for comparison. Phylogenetic analysis indicated that sequences from slow progressors did not have a common origin, discarding a shared ancestor of reduced virulence. There were no differences in the diversity between the vif genes from slow and typical progressors. No gross defects showing a clear distinction among sequences from both groups of children were found. However, in the deduced Vif proteins, changes V13I, V55T, and L81M were observed only in sequences from slow progressors. By analyzing sequences stored in databases, these mutations were determined as unusual substitutions occurring at highly conserved Vif sites across different HIV-1 clades, but were observed with an increased frequency in sequences from elite controllers. These mutations were in the Vif regions reported as relevant for protein activity. These findings suggest that the Vif sequences from slow progressors carry unusual substitutions, which may alter the protein function and may contribute to viral attenuation.
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Affiliation(s)
- Federico A De Maio
- Cellular Biology and Retroviruses Laboratory-CONICET, Juan P. Garrahan, Pediatric Hospital, Buenos Aires, Argentina
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Takaori-Kondo A, Shindo K. HIV-1 Vif: a guardian of the virus that opens up a new era in the research field of restriction factors. Front Microbiol 2013; 4:34. [PMID: 23430691 PMCID: PMC3576844 DOI: 10.3389/fmicb.2013.00034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 02/07/2013] [Indexed: 11/13/2022] Open
Abstract
The research on virion infectivity factor (Vif) protein had started in late 1980s right after HIV-1 was cloned, and the function of Vif had been a mystery for a long time. However, the research on Vif has finally lead to the identification of APOBEC3G, which opens up a new era in the research field of host restriction factors in HIV-1 infection followed by TRIM5α, Tetherin/BST-2, and SAMHD1. This suggests that continuation of basic research on fundamental questions is quite important. We still have many questions on Vif and APOBEC3 and should continue to work on these proteins in the future in order to better regulate HIV-1. We will discuss not only the history but also recent advances in Vif research.
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Affiliation(s)
- Akifumi Takaori-Kondo
- Department of Hematology and Oncology, Graduate School of Medicine, Kyoto University Kyoto, Japan
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Evidence for Vpr-dependent HIV-1 replication in human CD4+ CEM.NKR T-cells. Retrovirology 2012; 9:93. [PMID: 23134572 PMCID: PMC3528630 DOI: 10.1186/1742-4690-9-93] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2012] [Accepted: 10/11/2012] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Vpr is exclusively expressed in primate lentiviruses and contributes to viral replication and disease progression in vivo. HIV-1 Vpr has two major activities in vitro: arrest of cell cycle in the G2 phase (G2 arrest), and enhancement of viral replication in macrophages. Previously, we reported a potent HIV-1 restriction in the human CD4+ CEM.NKR (NKR) T cells, where wild-type (WT) HIV-1 replication was inhibited by almost 1,000-fold. From the parental NKR cells, we isolated eight clones by limiting dilution. These clones showed three levels of resistance to the WT HIV-1 infection: non-permissive (NP), semi-permissive (SP), and permissive (P). Here, we compared the replication of WT, Vif-defective, Vpr-defective, and Vpu-defective viruses in these cells. RESULTS Although both WT and Vpu-defective viruses could replicate in the permissive and semi-permissive clones, the replication of Vif-defective and Vpr-defective viruses was completely restricted. The expression of APOBEC3G (A3G) cytidine deaminase in NKR cells explains why Vif, but not Vpr, was required for HIV-1 replication. When the Vpr-defective virus life cycle was compared with the WT virus life cycle in the semi-permissive cells, it was found that the Vpr-defective virus could enter the cell and produce virions containing properly processed Gag and Env proteins, but these virions showed much less efficiency for reverse transcription during the next-round of infection. In addition, although viral replication was restricted in the non-permissive cells, treatment with arsenic trioxide (As2O3) could completely restore WT, but not Vpr-defective virus replication. Moreover, disruption of Vpr binding to its cofactor DCAF1 and/or induction of G2 arrest activity did not disrupt the Vpr activity in enhancing HIV-1 replication in NKR cells. CONCLUSIONS These results demonstrate that HIV-1 replication in NKR cells is Vpr-dependent. Vpr promotes HIV-1 replication from the 2nd cycle likely by overcoming a block at early stage of viral replication; and this activity does not require DCAF1 and G2 arrest. Further studies of this mechanism should provide new understanding of Vpr function in the HIV-1 life cycle.
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Poli A, Tozon N, Guidi G, Pistello M. Renal alterations in feline immunodeficiency virus (FIV)-infected cats: a natural model of lentivirus-induced renal disease changes. Viruses 2012; 4:1372-1389. [PMID: 23170163 PMCID: PMC3499810 DOI: 10.3390/v4091372] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Revised: 08/15/2012] [Accepted: 08/16/2012] [Indexed: 01/19/2023] Open
Abstract
Human immunodeficiency virus (HIV) is associated with several renal syndromes including acute and chronic renal failures, but the underlying pathogenic mechanisms are unclear. HIV and feline immunodeficiency virus (FIV) share numerous biological and pathological features, including renal alterations. We investigated and compared the morphological changes of renal tissue of 51 experimentally and 21 naturally infected cats. Compared to the latter, the experimentally infected cats exhibited some mesangial widening and glomerulonephritis, milder proteinuria, and lower tubular and interstitial alterations. The numbers of giant protein tubular casts and tubular microcysts were also lower. In contrast, diffuse interstitial infiltrates and glomerular and interstitial amyloidosis were detected only in naturally infected cats. Similar alterations are found in HIV infected patients, thus supporting the idea of a causative role of FIV infection in renal disease, and underlining the relevance of the FIV and its natural host as an animal model for investigating lentivirus-associated nephropathy.
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Affiliation(s)
- Alessandro Poli
- Department of Animal Pathology, Prophylaxis and Food Hygiene, Veterinary Faculty, University of Pisa, Viale delle Piagge 2, Pisa 56124, Italy;
| | - Natasa Tozon
- Clinic for Small Animal Medicine and Surgery, Veterinary Faculty, University of Ljubljana, Gerbičeva 60, Ljubljana 1000, Slovenia;
| | - Grazia Guidi
- Department of Veterinary Clinic, Veterinary Faculty, University of Pisa, Via Livornese, San Piero a Grado, Pisa 56122, Italy;
| | - Mauro Pistello
- Department of Experimental Pathology, University of Pisa, Via S. Zeno, 35/39, Pisa 56127, Italy
- Author to whom correspondence should be addressed; ; Tel.: +39-050-221-3781; Fax: +39-050-221-3524
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