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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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Abbas W, Herbein G. T-Cell Signaling in HIV-1 Infection. Open Virol J 2013; 7:57-71. [PMID: 23986795 PMCID: PMC3751038 DOI: 10.2174/1874357920130621001] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2013] [Revised: 05/31/2013] [Accepted: 06/04/2013] [Indexed: 12/20/2022] Open
Abstract
HIV exploits the T-cell signaling network to gain access to downstream cellular components, which serves as effective tools to break the cellular barriers. Multiple host factors and their interaction with viral proteins contribute to the complexity of HIV-1 pathogenesis and disease progression. HIV-1 proteins gp120, Nef, Tat and Vpr alter the T-cell signaling pathways by activating multiple transcription factors including NF-ĸB, Sp1 and AP-1. HIV-1 evades the immune system by developing a multi-pronged strategy. Additionally, HIV-1 encoded proteins influence the apoptosis in the host cell favoring or blocking T-cell apoptosis. Thus, T-cell signaling hijacked by viral proteins accounts for both viral persistence and immune suppression during HIV-1 infection. Here, we summarize past and present studies on HIV-1 T-cell signaling with special focus on the possible role of T cells in facilitating viral infection and pathogenesis
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Affiliation(s)
- Wasim Abbas
- Department of Virology, Pathogens & Inflammation Laboratory, UPRES EA4266, SFR FED 4234, University of Franche-Comte, CHRU Besançon, F-25030 Besançon, France
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Na H, Acharjee S, Jones G, Vivithanaporn P, Noorbakhsh F, McFarlane N, Maingat F, Ballanyi K, Pardo CA, Cohen EA, Power C. Interactions between human immunodeficiency virus (HIV)-1 Vpr expression and innate immunity influence neurovirulence. Retrovirology 2011; 8:44. [PMID: 21645334 PMCID: PMC3123635 DOI: 10.1186/1742-4690-8-44] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2011] [Accepted: 06/06/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Viral diversity and abundance are defining properties of human immunodeficiency virus (HIV)-1's biology and pathogenicity. Despite the increasing availability of antiretroviral therapy, HIV-associated dementia (HAD) continues to be a devastating consequence of HIV-1 infection of the brain although the underlying disease mechanisms remain uncertain. Herein, molecular diversity within the HIV-1 non-structural gene, Vpr, was examined in RNA sequences derived from brain and blood of HIV/AIDS patients with or without HIV-associated dementia (HAD) together with the ensuing pathobiological effects. RESULTS Cloned brain- and blood-derived full length vpr alleles revealed that amino acid residue 77 within the brain-derived alleles distinguished HAD (77Q) from non-demented (ND) HIV/AIDS patients (77R) (p < 0.05) although vpr transcripts were more frequently detected in HAD brains (p < 0.05). Full length HIV-1 clones encoding the 77R-ND residue induced higher IFN-α, MX1 and BST-2 transcript levels in human glia relative to the 77Q-HAD encoding virus (p < 0.05) but both viruses exhibited similar levels of gene expression and replication. Myeloid cells transfected with 77Q-(pVpr77Q-HAD), 77R (pVpr77R-ND) or Vpr null (pVpr(-))-containing vectors showed that the pVpr77R-ND vector induced higher levels of immune gene expression (p < 0.05) and increased neurotoxicity (p < 0.05). Vpr peptides (amino acids 70-96) containing the 77Q-HAD or 77R-ND motifs induced similar levels of cytosolic calcium activation when exposed to human neurons. Human glia exposed to the 77R-ND peptide activated higher transcript levels of IFN-α, MX1, PRKRA and BST-2 relative to 77Q-HAD peptide (p < 0.05). The Vpr 77R-ND peptide was also more neurotoxic in a concentration-dependent manner when exposed to human neurons (p < 0.05). Stereotaxic implantation of full length Vpr, 77Q-HAD or 77R-ND peptides into the basal ganglia of mice revealed that full length Vpr and the 77R-ND peptide caused greater neurobehavioral deficits and neuronal injury compared with 77Q-HAD peptide-implanted animals (p < 0.05). CONCLUSIONS These observations underscored the potent neuropathogenic properties of Vpr but also indicated viral diversity modulates innate neuroimmunity and neurodegeneration.
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Affiliation(s)
- Hong Na
- Department of Medicine University of Alberta, Edmonton, AB, T6G 2S2, Canada.
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Kogan M, Rappaport J. HIV-1 accessory protein Vpr: relevance in the pathogenesis of HIV and potential for therapeutic intervention. Retrovirology 2011; 8:25. [PMID: 21489275 PMCID: PMC3090340 DOI: 10.1186/1742-4690-8-25] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Accepted: 04/13/2011] [Indexed: 01/11/2023] Open
Abstract
The HIV protein, Vpr, is a multifunctional accessory protein critical for efficient viral infection of target CD4+ T cells and macrophages. Vpr is incorporated into virions and functions to transport the preintegration complex into the nucleus where the process of viral integration into the host genome is completed. This action is particularly important in macrophages, which as a result of their terminal differentiation and non-proliferative status, would be otherwise more refractory to HIV infection. Vpr has several other critical functions including activation of HIV-1 LTR transcription, cell-cycle arrest due to DCAF-1 binding, and both direct and indirect contributions to T-cell dysfunction. The interactions of Vpr with molecular pathways in the context of macrophages, on the other hand, support accumulation of a persistent reservoir of HIV infection in cells of the myeloid lineage. The role of Vpr in the virus life cycle, as well as its effects on immune cells, appears to play an important role in the immune pathogenesis of AIDS and the development of HIV induced end-organ disease. In view of the pivotal functions of Vpr in virus infection, replication, and persistence of infection, this protein represents an attractive target for therapeutic intervention.
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Affiliation(s)
- Michael Kogan
- Department of Neuroscience, Department of Neuroscience, Center for Neurovirology, Temple University School of Medicine, 3500 North Broad Street, Philadelphia, PA 19140, USA
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Romani B, Engelbrecht S. Human immunodeficiency virus type 1 Vpr: functions and molecular interactions. J Gen Virol 2009; 90:1795-1805. [PMID: 19458171 DOI: 10.1099/vir.0.011726-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) viral protein R (Vpr) is an accessory protein that interacts with a number of cellular and viral proteins. The functions of many of these interactions in the pathogenesis of HIV-1 have been identified. Deletion of the vpr gene reduces the virulence of HIV-1 dramatically, indicating the importance of this protein for the virus. This review describes the current findings on several established functions of HIV-1 Vpr and some possible roles proposed for this protein. Because Vpr exploits cellular proteins and pathways to influence the biology of HIV-1, understanding the functions of Vpr usually involves the study of cellular pathways. Several functions of Vpr are attributed to the virion-incorporated protein, but some of them are attributed to the expression of Vpr in HIV-1-infected cells. The structure of Vpr may be key to understanding the variety of its interactions. Due to the critical role of Vpr in HIV-1 pathogenicity, study of the interactions between Vpr and cellular proteins may help us to understand the mechanism(s) of HIV-1 pathogenicity.
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Affiliation(s)
- Bizhan Romani
- Department of Pathology, Division of Medical Virology, University of Stellenbosch, Tygerberg 7505, South Africa
| | - Susan Engelbrecht
- National Health Laboratory Services, Tygerberg 7505, South Africa.,Department of Pathology, Division of Medical Virology, University of Stellenbosch, Tygerberg 7505, South Africa
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Noursadeghi M, Katz DR, Miller RF. HIV-1 infection of mononuclear phagocytic cells: the case for bacterial innate immune deficiency in AIDS. THE LANCET. INFECTIOUS DISEASES 2006; 6:794-804. [PMID: 17123899 DOI: 10.1016/s1473-3099(06)70656-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
HIV-1 infection of mononuclear phagocytic cells, comprising monocytes, macrophages, and dendritic cells, has been the subject of extensive research over the past 20 years. The roles of mononuclear phagocytic cells in transmission of HIV-1 infection and as reservoirs of actively replicating virus have received particular attention. Experimental data have also accumulated about the effects of HIV-1 on the physiological function of mononuclear phagocytic cells, particularly their role in innate immunity to bacteria. The effects of HIV-1 on bacterial innate immune responses by mononuclear phagocytic cells are discussed here together with reports of direct interactions between HIV-encoded products and bacterial innate immune signalling pathways. These reports demonstrate mechanisms for HIV-mediated disruption of innate immune responses by mononuclear phagocytic cells that could provide novel therapeutic targets in HIV-infected patients. The clinical urgency is highlighted by greatly increased risk of invasive bacterial disease in this population, even in the era of highly active antiretroviral therapy. HIV-mediated injury to bacterial innate immunity provides an experimental paradigm that could broaden our overall understanding of innate immunity and be used to study responses to pathogens other than bacteria.
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Affiliation(s)
- Mahdad Noursadeghi
- Department of Immunology and Molecular Pathology, University College London, UK.
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Muthumani K, Choo AY, Zong WX, Madesh M, Hwang DS, Premkumar A, Thieu KP, Emmanuel J, Kumar S, Thompson CB, Weiner DB. The HIV-1 Vpr and glucocorticoid receptor complex is a gain-of-function interaction that prevents the nuclear localization of PARP-1. Nat Cell Biol 2006; 8:170-9. [PMID: 16429131 PMCID: PMC3142937 DOI: 10.1038/ncb1352] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2005] [Accepted: 12/05/2005] [Indexed: 02/06/2023]
Abstract
The Vpr protein of HIV-1 functions as a vital accessory gene by regulating various cellular functions, including cell differentiation, apoptosis, nuclear factor of kappaB (NF-kappaB) suppression and cell-cycle arrest of the host cell. Several reports have indicated that Vpr complexes with the glucocorticoid receptor (GR), but it remains unclear whether the GR pathway is required for Vpr to function. Here, we report that Vpr uses the GR pathway as a recruitment vehicle for the NF-kappaB co-activating protein, poly(ADP-ribose) polymerase-1 (PARP-1). The GR interaction with Vpr is both necessary and sufficient to facilitate this interaction by potentiating the formation of a Vpr-GR-PARP-1 complex. The recruitment of PARP-1 by the Vpr-GR complex prevents its nuclear localization, which is necessary for Vpr to suppress NF-kappaB. The association of GR with PARP-1 is not observed with steroid (glucocorticoid) treatment, indicating that the GR association with PARP-1 is a gain of function that is solely attributed to HIV-1 Vpr. These data provide important insights into Vpr biology and its role in HIV pathogenesis.
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MESH Headings
- Active Transport, Cell Nucleus
- Animals
- Antigens, Bacterial/pharmacology
- Cell Line
- Cell Nucleus/metabolism
- Chlorocebus aethiops
- Enterotoxins/pharmacology
- Female
- Gene Expression/drug effects
- Gene Expression/genetics
- Gene Products, vpr/metabolism
- Gene Products, vpr/pharmacology
- Gene Products, vpr/physiology
- HIV Infections/metabolism
- HIV Infections/physiopathology
- HeLa Cells
- Humans
- I-kappa B Kinase/metabolism
- I-kappa B Proteins/metabolism
- Interleukin-1/blood
- Interleukin-12/blood
- Jurkat Cells
- Lipopolysaccharides/pharmacology
- Mice
- Mice, Inbred BALB C
- Mifepristone/pharmacology
- Mutation/genetics
- NF-KappaB Inhibitor alpha
- NF-kappa B/genetics
- Poly (ADP-Ribose) Polymerase-1
- Poly(ADP-ribose) Polymerases/genetics
- Poly(ADP-ribose) Polymerases/metabolism
- Protein Binding/drug effects
- Protein Interaction Mapping
- RNA, Small Interfering/genetics
- Receptors, Glucocorticoid/genetics
- Receptors, Glucocorticoid/metabolism
- Transcription Factor RelA/metabolism
- Transfection
- Tumor Necrosis Factor-alpha/metabolism
- Tumor Necrosis Factor-alpha/pharmacology
- U937 Cells
- vpr Gene Products, Human Immunodeficiency Virus
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Affiliation(s)
- Karuppiah Muthumani
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Andrew Y. Choo
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Wei-Xing Zong
- Abramson Family Cancer Research Institute, Department of Cancer Biology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Muniswamy Madesh
- Abramson Family Cancer Research Institute, Department of Cancer Biology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Daniel S. Hwang
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Arumugam Premkumar
- Laboratory of Molecular Neuropharmacology, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA
| | - Khanh P. Thieu
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Joann Emmanuel
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Sanjeev Kumar
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Craig B. Thompson
- Abramson Family Cancer Research Institute, Department of Cancer Biology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - David B. Weiner
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
- Correspondence should be addressed to D.B.W.
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