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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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2
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Anastasopoulou S, Georgakopoulos T, Mouzaki A. HIV-1 Transcriptional Activator Tat Inhibits IL2 Expression by Preventing the Presence of Pol II on the IL2 Promoter. Biomolecules 2023; 13:881. [PMID: 37371461 DOI: 10.3390/biom13060881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 05/20/2023] [Accepted: 05/22/2023] [Indexed: 06/29/2023] Open
Abstract
HIV-1 infection leads to a gradual loss of T helper cells, chronic immune activation, and eventual immune system breakdown. HIV-1 causes deregulation of the expression of IL-2, a cytokine important for T helper cell growth and survival, which is downregulated in HIV-1 patients. The present study addresses the regulation of IL2 expression via HIV-1 Tat transcriptional activator. We used J-LAT cells, a T cell line that serves as a latency model for studies of HIV-1 expression in T cells, and as controls a T cell line lacking HIV-1 elements and a T cell line with a stably integrated copy of the HIV-1-LTR promoter. We show that endogenously expressed Tat inhibits IL2 transcription in J-Lat cells via its presence in the ARRE-1/2 elements of the IL2 promoter and that the inhibition of IL2 expression is mediated by Tat inhibiting Pol II activity at the IL2 promoter, which is mediated by preventing the presence of Pol II at the ARRE-1/2 elements. Overall, Tat is present at the IL2 promoter, apart from its cognate HIV-1 LTR target. This supports our current knowledge of how HIV-1 affects the host transcriptional machinery and reflects the potential of Tat to disrupt transcriptional regulation of host genes to manipulate cell responses.
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Affiliation(s)
- Spyridoula Anastasopoulou
- Laboratory of Immunohematology, Division of Hematology, Department of Internal Medicine, Medical School, University of Patras, GR-26500 Patras, Greece
| | - Tassos Georgakopoulos
- Laboratory of Immunohematology, Division of Hematology, Department of Internal Medicine, Medical School, University of Patras, GR-26500 Patras, Greece
| | - Athanasia Mouzaki
- Laboratory of Immunohematology, Division of Hematology, Department of Internal Medicine, Medical School, University of Patras, GR-26500 Patras, Greece
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Olety B, Usami Y, Wu Y, Peters P, Göttlinger H. AP-2 Adaptor Complex-Dependent Enhancement of HIV-1 Replication by Nef in the Absence of the Nef/AP-2 Targets SERINC5 and CD4. mBio 2023; 14:e0338222. [PMID: 36622146 PMCID: PMC9973267 DOI: 10.1128/mbio.03382-22] [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: 12/02/2022] [Accepted: 12/08/2022] [Indexed: 01/10/2023] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) Nef hijacks the clathrin adaptor complex 2 (AP-2) to downregulate the viral receptor CD4 and the antiviral multipass transmembrane proteins SERINC3 and SERINC5, which inhibit the infectivity of progeny virions when incorporated. In Jurkat Tag T lymphoid cells lacking SERINC3 and SERINC5, Nef is no longer required for full progeny virus infectivity and for efficient viral replication. However, in MOLT-3 T lymphoid cells, HIV-1 replication remains highly dependent on Nef even in the absence of SERINC3 and SERINC5. Using a knockout (KO) approach, we now show that the Nef-mediated enhancement of HIV-1 replication in MOLT-3 cells does not depend on the Nef-interacting kinases LCK and PAK2. Furthermore, Nef substantially enhanced HIV-1 replication even in triple-KO MOLT-3 cells that simultaneously lacked the three Nef/AP-2 targets, SERINC3, SERINC5, and CD4, and were reconstituted with a Nef-resistant CD4 to permit HIV-1 entry. Nevertheless, the ability of Nef mutants to promote HIV-1 replication in the triple-KO cells correlated strictly with the ability to bind AP-2. In addition, knockdown and reconstitution experiments confirmed the involvement of AP-2. These observations raise the possibility that MOLT-3 cells express a novel antiviral factor that is downregulated by Nef in an AP-2-dependent manner. IMPORTANCE The HIV-1 Nef protein hijacks a component of the cellular endocytic machinery called AP-2 to downregulate the viral receptor CD4 and the antiviral cellular membrane proteins SERINC3 and SERINC5. In the absence of Nef, SERINC3 and SERINC5 are taken up into viral particles, which reduces their infectivity. Surprisingly, in a T cell line called MOLT-3, Nef remains crucial for HIV-1 spreading in the absence of SERINC3 and SERINC5. We now show that this effect of Nef also does not depend on the cellular signaling molecules and Nef interaction partners LCK and PAK2. Nef was required for efficient HIV-1 spreading even in triple-knockout cells that completely lacked Nef/AP-2-sensitive CD4, in addition to the Nef/AP-2 targets SERINC3 and SERINC5. Nevertheless, our results indicate that the enhancement of HIV-1 spreading by Nef in the triple-knockout cells remained AP-2 dependent, which suggests the presence of an unknown antiviral factor that is sensitive to Nef/AP-2-mediated downregulation.
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Affiliation(s)
- Balaji Olety
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Yoshiko Usami
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Yuanfei Wu
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Paul Peters
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Heinrich Göttlinger
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
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Chen YC, He XL, Qi L, Shi W, Yuan LW, Huang MY, Xu YL, Chen X, Gu L, Zhang LL, Lu JJ. Myricetin inhibits interferon-γ-induced PD-L1 and IDO1 expression in lung cancer cells. Biochem Pharmacol 2022; 197:114940. [PMID: 35120895 DOI: 10.1016/j.bcp.2022.114940] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 01/26/2022] [Accepted: 01/27/2022] [Indexed: 11/02/2022]
Abstract
Programmed death ligand-1 (PD-L1) and indoleamine 2, 3-dioxygenase 1 (IDO1) are immune checkpoints induced by interferon-γ (IFN-γ) in the tumor microenvironment, leading to immune escape of tumors. Myricetin (MY) is a flavonoid distributed in many edible and medicinal plants. In this study, MY was identified to inhibit IFN-γ-induced PD-L1 expression in human lung cancer cells. It also reduced the expression of IDO1 and the production of kynurenine which is the product catalyzed by IDO1, while didn't show obvious effect on the expression of major histocompatibility complex-I (MHC-I), a crucial molecule for antigen presentation. In addition, the function of T cells was evaluated using a co-culture system consist of lung cancer cells and the Jurkat-PD-1 T cell line overexpressing PD-1. MY restored the survival, proliferation, CD69 expression and interleukin-2 (IL-2) secretion of Jurkat-PD-1 T cells suppressed by IFN-γ-treated lung cancer cells. Mechanistically, IFN-γ up-regulated PD-L1 and IDO1 at the transcriptional level through the JAK-STAT-IRF1 axis, which was targeted and inhibited by MY. Together, our research revealed a new mechanism of MY mediated anti-tumor activity and highlighted the potential implications of MY in tumor immunotherapy.
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Affiliation(s)
- Yu-Chi Chen
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Xin-Ling He
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Lu Qi
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Wei Shi
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Luo-Wei Yuan
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Mu-Yang Huang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Yu-Lian Xu
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Xiuping Chen
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Lei Gu
- Epigenetics Laboratory, Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany; Cardiopulmonary Institute (CPI), 61231 Bad Nauheim, Germany
| | - Le-Le Zhang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Jin-Jian Lu
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China; Department of Pharmaceutical Sciences, Faculty of Health Sciences, University of Macau, Macao, China; MoE Frontiers Science Center for Precision Oncology, University of Macau, Macao, China; Guangdong-Hong Kong-Macau Joint Lab on Chinese Medicine and Immune Disease Research, University of Macau, Macao, China.
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Synergy and allostery in ligand binding by HIV-1 Nef. Biochem J 2021; 478:1525-1545. [PMID: 33787846 PMCID: PMC8079166 DOI: 10.1042/bcj20201002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 03/29/2021] [Accepted: 03/31/2021] [Indexed: 11/27/2022]
Abstract
The Nef protein of human and simian immunodeficiency viruses boosts viral pathogenicity through its interactions with host cell proteins. By combining the polyvalency of its large unstructured regions with the binding selectivity and strength of its folded core domain, Nef can associate with many different host cell proteins, thereby disrupting their functions. For example, the combination of a linear proline-rich motif and hydrophobic core domain surface allows Nef to bind tightly and specifically to SH3 domains of Src family kinases. We investigated whether the interplay between Nef's flexible regions and its core domain could allosterically influence ligand selection. We found that the flexible regions can associate with the core domain in different ways, producing distinct conformational states that alter the way in which Nef selects for SH3 domains and exposes some of its binding motifs. The ensuing crosstalk between ligands might promote functionally coherent Nef-bound protein ensembles by synergizing certain subsets of ligands while excluding others. We also combined proteomic and bioinformatics analyses to identify human proteins that select SH3 domains in the same way as Nef. We found that only 3% of clones from a whole-human fetal library displayed Nef-like SH3 selectivity. However, in most cases, this selectivity appears to be achieved by a canonical linear interaction rather than by a Nef-like ‘tertiary' interaction. Our analysis supports the contention that Nef's mode of hijacking SH3 domains is a virus-specific adaptation with no or very few cellular counterparts. Thus, the Nef tertiary binding surface is a promising virus-specific drug target.
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Mastrogiovanni M, Juzans M, Alcover A, Di Bartolo V. Coordinating Cytoskeleton and Molecular Traffic in T Cell Migration, Activation, and Effector Functions. Front Cell Dev Biol 2020; 8:591348. [PMID: 33195256 PMCID: PMC7609836 DOI: 10.3389/fcell.2020.591348] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 09/24/2020] [Indexed: 12/28/2022] Open
Abstract
Dynamic localization of receptors and signaling molecules at the plasma membrane and within intracellular vesicular compartments is crucial for T lymphocyte sensing environmental cues, triggering membrane receptors, recruiting signaling molecules, and fine-tuning of intracellular signals. The orchestrated action of actin and microtubule cytoskeleton and intracellular vesicle traffic plays a key role in all these events that together ensure important steps in T cell physiology. These include extravasation and migration through lymphoid and peripheral tissues, T cell interactions with antigen-presenting cells, T cell receptor (TCR) triggering by cognate antigen–major histocompatibility complex (MHC) complexes, immunological synapse formation, cell activation, and effector functions. Cytoskeletal and vesicle traffic dynamics and their interplay are coordinated by a variety of regulatory molecules. Among them, polarity regulators and membrane–cytoskeleton linkers are master controllers of this interplay. Here, we review the various ways the T cell plasma membrane, receptors, and their signaling machinery interplay with the actin and microtubule cytoskeleton and with intracellular vesicular compartments. We highlight the importance of this fine-tuned crosstalk in three key stages of T cell biology involving cell polarization: T cell migration in response to chemokines, immunological synapse formation in response to antigen cues, and effector functions. Finally, we discuss two examples of perturbation of this interplay in pathological settings, such as HIV-1 infection and mutation of the polarity regulator and tumor suppressor adenomatous polyposis coli (Apc) that leads to familial polyposis and colorectal cancer.
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Affiliation(s)
- Marta Mastrogiovanni
- Ligue Nationale Contre le Cancer - Equipe Labellisée LIGUE 2018, Lymphocyte Cell Biology Unit, INSERM-U1221, Department of Immunology, Institut Pasteur, Paris, France.,Collège Doctoral, Sorbonne Université, Paris, France
| | - Marie Juzans
- Ligue Nationale Contre le Cancer - Equipe Labellisée LIGUE 2018, Lymphocyte Cell Biology Unit, INSERM-U1221, Department of Immunology, Institut Pasteur, Paris, France
| | - Andrés Alcover
- Ligue Nationale Contre le Cancer - Equipe Labellisée LIGUE 2018, Lymphocyte Cell Biology Unit, INSERM-U1221, Department of Immunology, Institut Pasteur, Paris, France
| | - Vincenzo Di Bartolo
- Ligue Nationale Contre le Cancer - Equipe Labellisée LIGUE 2018, Lymphocyte Cell Biology Unit, INSERM-U1221, Department of Immunology, Institut Pasteur, Paris, France
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7
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Wong A, Zamel R, Yeung J, Bader GD, Dos Santos CC, Bai X, Wang Y, Keshavjee S, Liu M. Potential therapeutic targets for lung repair during human ex vivo lung perfusion. Eur Respir J 2020; 55:13993003.02222-2019. [DOI: 10.1183/13993003.02222-2019] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Accepted: 01/15/2020] [Indexed: 12/20/2022]
Abstract
IntroductionThe ex vivo lung perfusion (EVLP) technique has been developed to assess the function of marginal donor lungs and has significantly increased donor lung utilisation. EVLP has also been explored as a platform for donor lung repair through injury-specific treatments such as antibiotics or fibrinolytics. We hypothesised that actively expressed pathways shared between transplantation and EVLP may reveal common mechanisms of injury and potential therapeutic targets for lung repair prior to transplantation.Materials and methodsRetrospective transcriptomics analyses were performed with peripheral tissue biopsies from “donation after brain death” lungs, with 46 pre-/post-transplant pairs and 49 pre-/post-EVLP pairs. Pathway analysis was used to identify and compare the responses of donor lungs to transplantation and to EVLP.Results22 pathways were enriched predominantly in transplantation, including upregulation of lymphocyte activation and cell death and downregulation of metabolism. Eight pathways were enriched predominantly in EVLP, including downregulation of leukocyte functions and upregulation of vascular processes. 27 pathways were commonly enriched, including activation of innate inflammation, cell death, heat stress and downregulation of metabolism and protein synthesis. Of the inflammatory clusters, Toll-like receptor/innate immune signal transduction adaptor signalling had the greatest number of nodes and was central to inflammation. These mechanisms have been previously speculated as major mechanisms of acute lung injury in animal models.ConclusionEVLP and transplantation share common molecular features of injury including innate inflammation and cell death. Blocking these pathways during EVLP may allow for lung repair prior to transplantation.
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Serra-Peinado C, Grau-Expósito J, Luque-Ballesteros L, Astorga-Gamaza A, Navarro J, Gallego-Rodriguez J, Martin M, Curran A, Burgos J, Ribera E, Raventós B, Willekens R, Torrella A, Planas B, Badía R, Garcia F, Castellví J, Genescà M, Falcó V, Buzon MJ. Expression of CD20 after viral reactivation renders HIV-reservoir cells susceptible to Rituximab. Nat Commun 2019; 10:3705. [PMID: 31420544 PMCID: PMC6697690 DOI: 10.1038/s41467-019-11556-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 07/19/2019] [Indexed: 01/06/2023] Open
Abstract
The identification of exclusive markers to target HIV-reservoir cells will represent a significant advance in the search for therapies to cure HIV. Here, we identify the B lymphocyte antigen CD20 as a marker for HIV-infected cells in vitro and in vivo. The CD20 molecule is dimly expressed in a subpopulation of CD4-positive (CD4+) T lymphocytes from blood, with high levels of cell activation and heterogeneous memory phenotypes. In lymph node samples from infected patients, CD20 is present in productively HIV-infected cells, and ex vivo viral infection selectively upregulates the expression of CD20 during early infection. In samples from patients on antiretroviral therapy (ART) this subpopulation is significantly enriched in HIV transcripts, and the anti-CD20 monoclonal antibody Rituximab induces cell killing, which reduces the pool of HIV-expressing cells when combined with latency reversal agents. We provide a tool for targeting this active HIV-reservoir after viral reactivation in patients while on ART. Here, the authors identify B lymphocyte antigen CD20 as a marker for HIV-infected T cells and provide evidence for the potential use of anti-CD20 antibodies in combination with latency reversing agents for depletion of viral reactivated CD4 T cells in patients on antiretroviral therapy.
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Affiliation(s)
- Carla Serra-Peinado
- Infectious Disease Department, Hospital Universitari Vall d'Hebrón, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Judith Grau-Expósito
- Infectious Disease Department, Hospital Universitari Vall d'Hebrón, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Laura Luque-Ballesteros
- Infectious Disease Department, Hospital Universitari Vall d'Hebrón, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Antonio Astorga-Gamaza
- Infectious Disease Department, Hospital Universitari Vall d'Hebrón, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Jordi Navarro
- Infectious Disease Department, Hospital Universitari Vall d'Hebrón, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Jenny Gallego-Rodriguez
- Infectious Disease Department, Hospital Universitari Vall d'Hebrón, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Mario Martin
- Infectious Disease Department, Hospital Universitari Vall d'Hebrón, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Adrià Curran
- Infectious Disease Department, Hospital Universitari Vall d'Hebrón, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Joaquin Burgos
- Infectious Disease Department, Hospital Universitari Vall d'Hebrón, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Esteban Ribera
- Infectious Disease Department, Hospital Universitari Vall d'Hebrón, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Berta Raventós
- Infectious Disease Department, Hospital Universitari Vall d'Hebrón, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Rein Willekens
- Infectious Disease Department, Hospital Universitari Vall d'Hebrón, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Ariadna Torrella
- Infectious Disease Department, Hospital Universitari Vall d'Hebrón, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Bibiana Planas
- Infectious Disease Department, Hospital Universitari Vall d'Hebrón, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Rosa Badía
- Infectious Disease Department, Hospital Universitari Vall d'Hebrón, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Felipe Garcia
- Infectious Disease Department, Hospital Clínic de Barcelona, Universitat de Barcelona, Barcelona, Spain
| | - Josep Castellví
- Department of Pathology, Hospital Vall d'Hebrón, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Meritxell Genescà
- Infectious Disease Department, Hospital Universitari Vall d'Hebrón, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Vicenç Falcó
- Infectious Disease Department, Hospital Universitari Vall d'Hebrón, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Maria J Buzon
- Infectious Disease Department, Hospital Universitari Vall d'Hebrón, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain.
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Abstract
The Nef protein of HIV-1 and the unrelated glycoGag protein of a murine leukemia virus similarly prevent the uptake of antiviral host proteins called SERINC3 and SERINC5 into HIV-1 particles, which enhances their infectiousness. We now show that although both SERINC antagonists can in principle similarly enhance HIV-1 replication, glycoGag is unable to substitute for Nef in primary human cells and in a T cell line called MOLT-3. In MOLT-3 cells, Nef remained crucial for HIV-1 replication even in the absence of SERINC3 and SERINC5. The pronounced effect of Nef on HIV-1 spreading in MOLT-3 cells correlated with the ability of Nef to engage cellular endocytic machinery and to downregulate the HIV-1 receptor CD4 but nevertheless persisted in the absence of CD4 downregulation. Collectively, our results provide evidence for a potent novel restriction activity that affects even relatively SERINC-resistant HIV-1 isolates and is counteracted by Nef. It has recently emerged that HIV-1 Nef counteracts the antiviral host proteins SERINC3 and SERINC5. In particular, SERINC5 inhibits the infectivity of progeny virions when incorporated. SERINC3 and SERINC5 are also counteracted by the unrelated murine leukemia virus glycosylated Gag (glycoGag) protein, which possesses a potent Nef-like activity on HIV-1 infectivity. We now report that a minimal glycoGag termed glycoMA can fully substitute for Nef in promoting HIV-1 replication in Jurkat T lymphoid cells, indicating that Nef enhances replication in these cells mainly by counteracting SERINCs. In contrast, the SERINC antagonist glycoMA was unable to substitute for Nef in MOLT-3 T lymphoid cells, in which HIV-1 replication was highly dependent on Nef, and remained so even in the absence of SERINC3 and SERINC5. As in MOLT-3 cells, glycoMA was unable to substitute for Nef in stimulating HIV-1 replication in primary human cells. Although the ability of Nef mutants to promote HIV-1 replication in MOLT-3 cells correlated with the ability to engage endocytic machinery and to downregulate CD4, Nef nevertheless rescued virus replication under conditions where CD4 downregulation did not occur. Taken together, our observations raise the possibility that Nef triggers the endocytosis of a novel antiviral factor that is active against both laboratory-adapted and primary HIV-1 strains.
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Palmeira JDF, Argañaraz GA, de Oliveira GXLM, Argañaraz ER. Physiological relevance of ACOT8-Nef interaction in HIV infection. Rev Med Virol 2019; 29:e2057. [PMID: 31179598 DOI: 10.1002/rmv.2057] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Revised: 04/29/2019] [Accepted: 05/01/2019] [Indexed: 11/06/2022]
Abstract
During human immunodeficiency virus (HIV) infection, Nef viral protein plays a crucial role in viral pathogenesis and progression of acquired immunodeficiency syndrome. Nef is expressed in the early stages of infection and alters the cellular environment increasing infectivity, viral replication, and the evasion of host immune response through several mechanisms. Nef has numerous functional domains that allow it to interact with a number of proteins, interfering with intracellular traffic. Among these proteins, human peroxisomal thioesterase 8, ACOT8, has been shown to be an important cellular partner of Nef. It has been suggested that this interaction may be involved in Nef-dependent endocytosis and also in the modulation of lipid composition in membrane rafts. However, the actual role of this interaction, as well as the mechanisms involved, has not yet been fully elucidated. In this review, we focused on the interplay between Nef and ACOT8 proteins, highlighting the possible physiological relevance in HIV infection.
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Affiliation(s)
| | - Gustavo A Argañaraz
- Laboratory of Molecular Neurovirology, Faculty of Health Science, University of Brasília, Brazil
| | | | - Enrique R Argañaraz
- Laboratory of Molecular Neurovirology, Faculty of Health Science, University of Brasília, Brazil
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11
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Jin SW, Markle TJ, Anmole G, Rahimi A, Kuang XT, Brumme ZL, Brockman MA. Modulation of TCR-dependent NFAT signaling is impaired in HIV-1 Nef isolates from elite controllers. Virology 2019; 530:39-50. [PMID: 30780124 DOI: 10.1016/j.virol.2019.02.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 02/09/2019] [Accepted: 02/10/2019] [Indexed: 12/24/2022]
Abstract
HIV-1 Nef modulates the activation state of CD4+ T cells by altering signaling events elicited by the T cell receptor (TCR). Primary nef sequences exhibit extensive inter-individual diversity that influences their ability to downregulate CD4 and HLA class I; however, the impact of nef variation on modulation of T cell signaling is poorly characterized. Here, we measured TCR-mediated activation of NFAT transcription factor in the presence of nef alleles isolated from 45 elite controllers (EC) and 46 chronic progressors (CP). EC Nef clones displayed lower ability to inhibit NFAT signaling (median 87 [IQR 75-93]% relative to SF2 Nef) compared to CP clones (94 [IQR 89-98]%) (p < 0.001). Polymorphisms in Nef's N-terminal domain impaired its ability to inhibit NFAT signaling. Results indicate that primary nef alleles exhibit a range of abilities to modulate TCR-dependent NFAT signaling, implicating natural variation in this function as a potential contributor to differential HIV-1 pathogenesis.
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Affiliation(s)
- Steven W Jin
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Tristan J Markle
- Dept. of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Gursev Anmole
- Dept. of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Asa Rahimi
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Xiaomei T Kuang
- Dept. of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Zabrina L Brumme
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada; British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada
| | - Mark A Brockman
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada; Dept. of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada; British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada.
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12
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Patters BJ, Kumar S. The role of exosomal transport of viral agents in persistent HIV pathogenesis. Retrovirology 2018; 15:79. [PMID: 30577804 PMCID: PMC6303896 DOI: 10.1186/s12977-018-0462-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 12/18/2018] [Indexed: 02/07/2023] Open
Abstract
Human immunodeficiency virus (HIV) infection, despite great advances in antiretroviral therapy, remains a lifelong affliction. Though current treatment regimens can effectively suppress viral load to undetectable levels and preserve healthy immune function, they cannot fully alleviate all symptoms caused by the presence of the virus, such as HIV-associated neurocognitive disorders. Exosomes are small vesicles that transport cellular proteins, RNA, and small molecules between cells as a mechanism of intercellular communication. Recent research has shown that HIV proteins and RNA can be packaged into exosomes and transported between cells, to pathogenic effect. This review summarizes the current knowledge on the diverse mechanisms involved in the sorting of viral elements into exosomes and the damage those exosomal agents can inflict. In addition, potential therapeutic options to counteract exosome-mediated HIV pathogenesis are reviewed and considered.
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Affiliation(s)
- Benjamin J Patters
- Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Santosh Kumar
- Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN, USA.
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Del Río-Iñiguez I, Vázquez-Chávez E, Cuche C, Di Bartolo V, Bouchet J, Alcover A. HIV-1 Nef Hijacks Lck and Rac1 Endosomal Traffic To Dually Modulate Signaling-Mediated and Actin Cytoskeleton-Mediated T Cell Functions. THE JOURNAL OF IMMUNOLOGY 2018; 201:2624-2640. [PMID: 30282749 DOI: 10.4049/jimmunol.1800372] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 09/03/2018] [Indexed: 01/03/2023]
Abstract
Endosomal traffic of TCR and signaling molecules regulates immunological synapse formation and T cell activation. We recently showed that Rab11 endosomes regulate the subcellular localization of the tyrosine kinase Lck and of the GTPase Rac1 and control their functions in TCR signaling and actin cytoskeleton remodeling. HIV-1 infection of T cells alters their endosomal traffic, activation capacity, and actin cytoskeleton organization. The viral protein Nef is pivotal for these modifications. We hypothesized that HIV-1 Nef could jointly alter Lck and Rac1 endosomal traffic and concomitantly modulate their functions. In this study, we show that HIV-1 infection of human T cells sequesters both Lck and Rac1 in a pericentrosomal compartment in an Nef-dependent manner. Strikingly, the Nef-induced Lck compartment contains signaling-competent forms (phosphorylated on key Tyr residues) of Lck and some of its downstream effectors, TCRζ, ZAP70, SLP76, and Vav1, avoiding the proximal LAT adaptor. Importantly, Nef-induced concentration of signaling molecules was concomitant with the upregulation of several early and late T cell activation genes. Moreover, preventing the concentration of the Nef-induced Lck compartment by depleting the Rab11 effector FIP3 counteracted Nef-induced gene expression upregulation. In addition, Nef extensively sequesters Rac1 and downregulates Rac1-dependent actin cytoskeleton remodeling, thus reducing T cell spreading. Therefore, by modifying their endosomal traffic, Nef hijacks signaling and actin cytoskeleton regulators to dually modulate their functional outputs. Our data shed new light into the molecular mechanisms that modify T cell physiology during HIV-1 infection.
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Affiliation(s)
- Iratxe Del Río-Iñiguez
- Lymphocyte Cell Biology Unit, Department of Immunology, Institut Pasteur, 75724 Paris, France.,INSERM U1221, 75015 Paris, France; and.,Collège Doctoral, Sorbonne Université, 75014 Paris, France
| | - Elena Vázquez-Chávez
- Lymphocyte Cell Biology Unit, Department of Immunology, Institut Pasteur, 75724 Paris, France.,INSERM U1221, 75015 Paris, France; and
| | - Céline Cuche
- Lymphocyte Cell Biology Unit, Department of Immunology, Institut Pasteur, 75724 Paris, France.,INSERM U1221, 75015 Paris, France; and
| | - Vincenzo Di Bartolo
- Lymphocyte Cell Biology Unit, Department of Immunology, Institut Pasteur, 75724 Paris, France.,INSERM U1221, 75015 Paris, France; and
| | - Jérôme Bouchet
- Lymphocyte Cell Biology Unit, Department of Immunology, Institut Pasteur, 75724 Paris, France; .,INSERM U1221, 75015 Paris, France; and
| | - Andrés Alcover
- Lymphocyte Cell Biology Unit, Department of Immunology, Institut Pasteur, 75724 Paris, France; .,INSERM U1221, 75015 Paris, France; and
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14
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Tongo M, Harkins GW, Dorfman JR, Billings E, Tovanabutra S, de Oliveira T, Martin DP. Unravelling the complicated evolutionary and dissemination history of HIV-1M subtype A lineages. Virus Evol 2018; 4:vey003. [PMID: 29484203 PMCID: PMC5819727 DOI: 10.1093/ve/vey003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Subtype A is one of the rare HIV-1 group M (HIV-1M) lineages that is both widely distributed throughout the world and persists at high frequencies in the Congo Basin (CB), the site where HIV-1M likely originated. This, together with its high degree of diversity suggests that subtype A is amongst the fittest HIV-1M lineages. Here we use a comprehensive set of published near full-length subtype A sequences and A-derived genome fragments from both circulating and unique recombinant forms (CRFs/URFs) to obtain some insights into how frequently these lineages have independently seeded HIV-1M sub-epidemics in different parts of the world. We do this by inferring when and where the major subtype A lineages and subtype A-derived CRFs originated. Following its origin in the CB during the 1940s, we track the diversification and recombination history of subtype A sequences before and during its dissemination throughout much of the world between the 1950s and 1970s. Collectively, the timings and numbers of detectable subtype A recombination and dissemination events, the present broad global distribution of the sub-epidemics that were seeded by these events, and the high prevalence of subtype A sequences within the regions where these sub-epidemics occurred, suggest that ancestral subtype A viruses (and particularly sub-subtype A1 ancestral viruses) may have been genetically predisposed to become major components of the present epidemic.
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Affiliation(s)
- Marcel Tongo
- KwaZulu-Natal Research Innovation and Sequencing Platform (Krisp), School of Laboratory Medicine and Medical Sciences, College of Health Sciences, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, Durban 4041, South Africa
- Division of Computational Biology, Department of Integrative Biomedical Sciences and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
- Center of Research for Emerging and Re-Emerging Diseases (CREMER), Institute of Medical Research and Study of Medicinal Plants (IMPM), Yaoundé, Cameroon
| | - Gordon W Harkins
- South African MRC Bioinformatics Unit, South African National Bioinformatics Institute, University of the Western Cape, Bellville 7535, South Africa
| | - Jeffrey R Dorfman
- Division of Immunology, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
- Division of Immunology, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa
| | - Erik Billings
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD 20910–7500, USA
- Henry M. Jackson Foundation for the Advancement of Military Medicine Inc., Bethesda, MD 20910–7500, USA
| | - Sodsai Tovanabutra
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD 20910–7500, USA
- Henry M. Jackson Foundation for the Advancement of Military Medicine Inc., Bethesda, MD 20910–7500, USA
| | - Tulio de Oliveira
- KwaZulu-Natal Research Innovation and Sequencing Platform (Krisp), School of Laboratory Medicine and Medical Sciences, College of Health Sciences, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, Durban 4041, South Africa
| | - Darren P Martin
- Division of Computational Biology, Department of Integrative Biomedical Sciences and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
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15
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Kumar A, Abbas W, Colin L, Khan KA, Bouchat S, Varin A, Larbi A, Gatot JS, Kabeya K, Vanhulle C, Delacourt N, Pasquereau S, Coquard L, Borch A, König R, Clumeck N, De Wit S, Rohr O, Rouzioux C, Fulop T, Van Lint C, Herbein G. Tuning of AKT-pathway by Nef and its blockade by protease inhibitors results in limited recovery in latently HIV infected T-cell line. Sci Rep 2016; 6:24090. [PMID: 27076174 PMCID: PMC4831010 DOI: 10.1038/srep24090] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 03/18/2016] [Indexed: 12/14/2022] Open
Abstract
Akt signaling plays a central role in many biological processes, which are key players in human immunodeficiency virus 1 (HIV-1) pathogenesis. We found that Akt interacts with HIV-1 Nef protein. In primary T cells treated with exogenous Nef or acutely infected with Nef-expressing HIV-1 in vitro, Akt became phosphorylated on serine473 and threonine308. In vitro, Akt activation mediated by Nef in T-cells was blocked by HIV protease inhibitors (PI), but not by reverse transcriptase inhibitors (RTI). Ex vivo, we found that the Akt pathway is hyperactivated in peripheral blood lymphocytes (PBLs) from cART naïve HIV-1-infected patients. PBLs isolated from PI-treated patients, but not from RTI-treated patients, exhibited decreased Akt activation, T-cell proliferation and IL-2 production. We found that PI but not RTI can block HIV-1 reactivation in latently infected J-Lat lymphoid cells stimulated with various stimuli. Using luciferase measurement, we further confirmed that Nef-mediated reactivation of HIV-1 from latency in 1G5 cells was blocked by PI parallel to decreased Akt activation. Our results indicate that PI-mediated blockade of Akt activation could impact the HIV-1 reservoir and support the need to further assess the therapeutic use of HIV-1 PI in order to curtail latently infected cells in HIV-1-infected patients.
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Affiliation(s)
- Amit Kumar
- Department of Virology, Pathogens &Inflammation Laboratory, University of Franche-Comté and COMUE Bourgogne Franche-Comté University, UPRES EA4266, SFR FED 4234, CHRU Besançon, Besançon, France
| | - Wasim Abbas
- Department of Virology, Pathogens &Inflammation Laboratory, University of Franche-Comté and COMUE Bourgogne Franche-Comté University, UPRES EA4266, SFR FED 4234, CHRU Besançon, Besançon, France
| | - Laurence Colin
- Laboratory of Molecular Virology, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Kashif Aziz Khan
- Department of Virology, Pathogens &Inflammation Laboratory, University of Franche-Comté and COMUE Bourgogne Franche-Comté University, UPRES EA4266, SFR FED 4234, CHRU Besançon, Besançon, France
| | - Sophie Bouchat
- Laboratory of Molecular Virology, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Audrey Varin
- Department of Virology, Pathogens &Inflammation Laboratory, University of Franche-Comté and COMUE Bourgogne Franche-Comté University, UPRES EA4266, SFR FED 4234, CHRU Besançon, Besançon, France
| | - Anis Larbi
- Department of Medicine, University of Sherbrooke, Sherbrooke, Canada
| | - Jean-Stéphane Gatot
- Laboratory of Molecular Virology, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Kabamba Kabeya
- Department of Infectious Diseases, CHU St-Pierre, ULB, Bruxelles, Belgium
| | - Caroline Vanhulle
- Laboratory of Molecular Virology, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Nadège Delacourt
- Laboratory of Molecular Virology, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Sébastien Pasquereau
- Department of Virology, Pathogens &Inflammation Laboratory, University of Franche-Comté and COMUE Bourgogne Franche-Comté University, UPRES EA4266, SFR FED 4234, CHRU Besançon, Besançon, France
| | - Laurie Coquard
- Department of Virology, Pathogens &Inflammation Laboratory, University of Franche-Comté and COMUE Bourgogne Franche-Comté University, UPRES EA4266, SFR FED 4234, CHRU Besançon, Besançon, France
| | - Alexandra Borch
- Research Group "Host-Pathogen Interactions", Paul-Ehrlich-Institute, Langen, Germany
| | - Renate König
- Research Group "Host-Pathogen Interactions", Paul-Ehrlich-Institute, Langen, Germany.,Immunity and Pathogenesis Program, Sanford Burnham Prebys Medical Discovery Research Institute, La Jolla, CA; German Center for Infection Research (DZIF), Langen, Germany
| | - Nathan Clumeck
- Department of Infectious Diseases, CHU St-Pierre, ULB, Bruxelles, Belgium
| | - Stephane De Wit
- Department of Infectious Diseases, CHU St-Pierre, ULB, Bruxelles, Belgium
| | - Olivier Rohr
- Institut de Parasitologie et Pathologie Tropicale, University of Strasbourg, Strasbourg, France
| | - Christine Rouzioux
- Department of Virology, Paris University, EA7327 Paris Descartes, APHP Necker Hospital, Paris, France
| | - Tamas Fulop
- Department of Medicine, University of Sherbrooke, Sherbrooke, Canada
| | - Carine Van Lint
- Laboratory of Molecular Virology, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Georges Herbein
- Department of Virology, Pathogens &Inflammation Laboratory, University of Franche-Comté and COMUE Bourgogne Franche-Comté University, UPRES EA4266, SFR FED 4234, CHRU Besançon, Besançon, France
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16
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El-Far M, Ancuta P, Routy JP, Zhang Y, Bakeman W, Bordi R, DaFonseca S, Said EA, Gosselin A, Tep TS, Eichbaum Q, van Grevenynghe J, Schwartz O, Freeman GJ, Haddad EK, Chomont N, Sékaly RP. Nef promotes evasion of human immunodeficiency virus type 1-infected cells from the CTLA-4-mediated inhibition of T-cell activation. J Gen Virol 2015; 96:1463-1477. [PMID: 25626682 DOI: 10.1099/vir.0.000065] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 01/19/2015] [Indexed: 01/28/2023] Open
Abstract
CTLA-4 is a negative regulator of T-cell receptor-mediated CD4(+) T-cell activation and function. Upregulation of CTLA-4 during human immunodeficiency virus type 1 (HIV-1) infection on activated T cells, particularly on HIV-specific CD4(+) T cells, correlates with immune dysfunction and disease progression. As HIV-1 infects and replicates in activated CD4(+) T cells, we investigated mechanisms by which HIV-1 modulates CTLA-4 expression to establish productive viral infection in these cells. Here, we demonstrate that HIV-1 infection in activated CD4(+) T cells was followed by Nef-mediated downregulation of CTLA-4. This was associated with a decreased T-cell activation threshold and significant resistance to CTLA-4 triggering. In line with these in vitro results, quantification of pro-viral HIV DNA from treatment-naive HIV-infected subjects demonstrated a preferential infection of memory CD4(+)CTLA-4(+) T cells, thus identifying CTLA-4 as a biomarker for HIV-infected cells in vivo. As transcriptionally active HIV-1 and Nef expression in vivo were previously shown to take place mainly in the CD3(+)CD4(-)CD8(-) [double-negative (DN)] cells, we further quantified HIV DNA in the CTLA-4(+) and CTLA-4(-) subpopulations of these cells. Our results showed that DN T cells lacking CTLA-4 expression were enriched in HIV DNA compared with DN CTLA-4(+) cells. Together, these results suggested that HIV-1 preferential infection of CD4(+)CTLA-4(+) T cells in vivo was followed by Nef-mediated concomitant downregulation of both CD4 and CTLA-4 upon transition to productive infection. This also highlights the propensity of HIV-1 to evade restriction of the key negative immune regulator CTLA-4 on cell activation and viral replication, and therefore contributes to the overall HIV-1 pathogenesis.
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Affiliation(s)
- Mohamed El-Far
- Department of Microbiology, Infectiology and Immunology, Université de Montréal, Québec, Canada.,Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | - Petronela Ancuta
- Department of Microbiology, Infectiology and Immunology, Université de Montréal, Québec, Canada.,Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | - Jean-Pierre Routy
- Division of Hematology and Chronic Viral Illness Service, McGill University Health Centre, McGill University, Montréal, Québec, Canada
| | - Yuwei Zhang
- Vaccine & Gene Therapy Institute Florida, Port St Lucie, FL, USA.,Department of Microbiology, Infectiology and Immunology, Université de Montréal, Québec, Canada.,Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | - Wendy Bakeman
- Vaccine & Gene Therapy Institute Florida, Port St Lucie, FL, USA
| | - Rebeka Bordi
- Vaccine & Gene Therapy Institute Florida, Port St Lucie, FL, USA.,Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | - Sandrina DaFonseca
- Vaccine & Gene Therapy Institute Florida, Port St Lucie, FL, USA.,Department of Microbiology, Infectiology and Immunology, Université de Montréal, Québec, Canada.,Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | - Elias A Said
- Department of Microbiology, Infectiology and Immunology, Université de Montréal, Québec, Canada.,Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | - Annie Gosselin
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | - Tévy-Suzy Tep
- Department of Microbiology, Infectiology and Immunology, Université de Montréal, Québec, Canada.,Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | | | - Julien van Grevenynghe
- Vaccine & Gene Therapy Institute Florida, Port St Lucie, FL, USA.,Department of Microbiology, Infectiology and Immunology, Université de Montréal, Québec, Canada.,Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | - Olivier Schwartz
- Virus and Immunity Group, Department of Virology, Institut Pasteur, Paris, France
| | - Gordon J Freeman
- Dana Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Elias K Haddad
- Vaccine & Gene Therapy Institute Florida, Port St Lucie, FL, USA.,Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | - Nicolas Chomont
- Vaccine & Gene Therapy Institute Florida, Port St Lucie, FL, USA.,Department of Microbiology, Infectiology and Immunology, Université de Montréal, Québec, Canada.,Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | - Rafick-Pierre Sékaly
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada.,Case Western Reserve University, Cleveland, OH, USA.,Department of Microbiology, Infectiology and Immunology, Université de Montréal, Québec, Canada.,Vaccine & Gene Therapy Institute Florida, Port St Lucie, FL, USA
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17
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Abstract
UNLABELLED Host and viral factors influence the HIV-1 infection course. Reduced Nef function has been observed in HIV-1 controllers during the chronic phase, but the kinetics and mechanisms of Nef attenuation in such individuals remain unclear. We examined plasma RNA-derived Nef clones from 10 recently infected individuals who subsequently suppressed viremia to less than 2,000 RNA copies/ml within 1 year postinfection (acute controllers) and 50 recently infected individuals who did not control viremia (acute progressors). Nef clones from acute controllers displayed a lesser ability to downregulate CD4 and HLA class I from the cell surface and a reduced ability to enhance virion infectivity compared to those from acute progressors (all P<0.01). HLA class I downregulation activity correlated inversely with days postinfection (Spearman's R=-0.85, P=0.004) and positively with baseline plasma viral load (Spearman's R=0.81, P=0.007) in acute controllers but not in acute progressors. Nef polymorphisms associated with functional changes over time were identified in follow-up samples from six controllers. For one such individual, mutational analyses indicated that four polymorphisms selected by HLA-A*31 and B*37 acted in combination to reduce Nef steady-state protein levels and HLA class I downregulation activity. Our results demonstrate that relative control of initial HIV-1 viremia is associated with Nef clones that display reduced function, which in turn may influence the course of HIV-1 infection. Transmission of impaired Nef sequences likely contributed in part to this observation; however, accumulation of HLA-associated polymorphisms in Nef that impair function also suggests that CD8+ T-cell pressures play a role in this phenomenon. IMPORTANCE Rare individuals can spontaneously control HIV-1 viremia in the absence of antiretroviral treatment. Understanding the host and viral factors that contribute to the controller phenotype may identify new strategies to design effective vaccines or therapeutics. The HIV-1 Nef protein enhances viral pathogenesis through multiple mechanisms. We examined the function of plasma HIV-1 RNA-derived Nef clones isolated from 10 recently infected individuals who subsequently controlled HIV viremia compared to the function of those from 50 individuals who failed to control viremia. Our results demonstrate that early Nef clones from HIV controllers displayed lower HLA class I and CD4 downregulation activity, as well as a reduced ability to enhance virion infectivity. The accumulation of HLA-associated polymorphisms in Nef during the first year postinfection was associated with impaired protein function in some controllers. This report highlights the potential for host immune responses to modulate HIV pathogenicity and disease outcome by targeting cytotoxic T lymphocyte (CTL) epitopes in Nef.
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