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Mbonye U, Karn J. The cell biology of HIV-1 latency and rebound. Retrovirology 2024; 21:6. [PMID: 38580979 PMCID: PMC10996279 DOI: 10.1186/s12977-024-00639-w] [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] [Indexed: 04/07/2024] Open
Abstract
Transcriptionally latent forms of replication-competent proviruses, present primarily in a small subset of memory CD4+ T cells, pose the primary barrier to a cure for HIV-1 infection because they are the source of the viral rebound that almost inevitably follows the interruption of antiretroviral therapy. Over the last 30 years, many of the factors essential for initiating HIV-1 transcription have been identified in studies performed using transformed cell lines, such as the Jurkat T-cell model. However, as highlighted in this review, several poorly understood mechanisms still need to be elucidated, including the molecular basis for promoter-proximal pausing of the transcribing complex and the detailed mechanism of the delivery of P-TEFb from 7SK snRNP. Furthermore, the central paradox of HIV-1 transcription remains unsolved: how are the initial rounds of transcription achieved in the absence of Tat? A critical limitation of the transformed cell models is that they do not recapitulate the transitions between active effector cells and quiescent memory T cells. Therefore, investigation of the molecular mechanisms of HIV-1 latency reversal and LRA efficacy in a proper physiological context requires the utilization of primary cell models. Recent mechanistic studies of HIV-1 transcription using latently infected cells recovered from donors and ex vivo cellular models of viral latency have demonstrated that the primary blocks to HIV-1 transcription in memory CD4+ T cells are restrictive epigenetic features at the proviral promoter, the cytoplasmic sequestration of key transcription initiation factors such as NFAT and NF-κB, and the vanishingly low expression of the cellular transcription elongation factor P-TEFb. One of the foremost schemes to eliminate the residual reservoir is to deliberately reactivate latent HIV-1 proviruses to enable clearance of persisting latently infected cells-the "Shock and Kill" strategy. For "Shock and Kill" to become efficient, effective, non-toxic latency-reversing agents (LRAs) must be discovered. Since multiple restrictions limit viral reactivation in primary cells, understanding the T-cell signaling mechanisms that are essential for stimulating P-TEFb biogenesis, initiation factor activation, and reversing the proviral epigenetic restrictions have become a prerequisite for the development of more effective LRAs.
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Affiliation(s)
- Uri Mbonye
- Department of Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA.
| | - Jonathan Karn
- Department of Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA.
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2
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Akade E, Jalilian S. The role of high mobility group AT-hook 1 in viral infections: Implications for cancer pathogenesis. Int J Biochem Cell Biol 2024; 169:106532. [PMID: 38278412 DOI: 10.1016/j.biocel.2024.106532] [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: 06/08/2023] [Revised: 11/25/2023] [Accepted: 01/18/2024] [Indexed: 01/28/2024]
Abstract
The crucial role of high mobility group AT-hook 1 (HMGA1) proteins in nuclear processes such as gene transcription, DNA replication, and chromatin remodeling is undeniable. Elevated levels of HMGA1 have been associated with unfavorable clinical outcomes and adverse differentiation status across various cancer types. HMGA1 regulates a diverse array of biological pathways, including tumor necrosis factor-alpha/nuclear factor-kappa B (TNF-α/NF-κB), epidermal growth factor receptor (EGFR), Hippo, Rat sarcoma/extracellular signal-regulated kinase (Ras/ERK), protein kinase B (Akt), wingless-related integration site/beta-catenin (Wnt/beta-catenin), and phosphoinositide 3-kinase/protein kinase B (PI3-K/Akt). While researchers have extensively investigated tumors in the reproductive, digestive, urinary, and hematopoietic systems, mounting evidence suggests that HMGA1 plays a critical role as a tumorigenic factor in tumors across all functional systems. Given its broad interaction network, HMGA1 is an attractive target for viral manipulation. Some viruses, including herpes simplex virus type 1, human herpesvirus 8, human papillomavirus, JC virus, hepatitis B virus, human immunodeficiency virus type 1, severe acute respiratory syndrome Coronavirus 2, and influenza viruses, utilize HMGA1 influence for infection. This interaction, particularly in oncogenesis, is crucial. Apart from the direct oncogenic effect of some of the mentioned viruses, the hit-and-run theory postulates that viruses can instigate cancer even before being completely eradicated from the host cell, implying a potentially greater impact of viruses on cancer development than previously assumed. This review explores the interplay between HMGA1, viruses, and host cellular machinery, aiming to contribute to a deeper understanding of viral-induced oncogenesis, paving the way for innovative strategies in cancer research and treatment.
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Affiliation(s)
- Esma'il Akade
- Department of Medical Virology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Shahram Jalilian
- Department of Medical Virology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
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3
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Rachel G, Vembuli H, Kumar C P G, Hanna LE. Immune cell cross talk in the establishment of HIV-1 latency. AIDS Res Hum Retroviruses 2023. [PMID: 36825522 DOI: 10.1089/aid.2022.0062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023] Open
Abstract
Revolutionary progress in combinational antiretroviral therapy (cART) has transformed Human Immunodeficiency Virus (HIV) infection into a chronic manageable disease; yet there exists an uneasy truce between the virus and the immune cells, where inflammation is limited but infection continues to fester from latent reservoirs of the virus. Clinical studies have identified the major immune cell types that constitute the latent HIV-1 reservoirs as monocytes/macrophages and CD4+ T cells. Latency probing approaches have thrown some light on the interaction between the virus and the reservoir cells from the time of onset of infection. However, research combining latency reversal strategies and immunotherapies face daunting obstacles in clinical trials because of the lack of in-depth knowledge on viral pathogenesis and mechanisms of viral evasion, leaving us behind in the battle for HIV cure. This article reviews existing knowledge on the cells and mechanisms that contribute to the establishment and survival of HIV reservoirs in infected individuals.
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Affiliation(s)
- Gladys Rachel
- National Institute of Epidemiology, 29893, Laboratory Division, TNHB Colony, ICMR-NIE, Chennai, Tamil Nadu, India, 600077;
| | - Hemanathan Vembuli
- ICMR-National Institute for Research in Tuberculosis, 29888, Department of HIV/AIDS, Chennai, Tamil Nadu, India;
| | - Girish Kumar C P
- National Institute of Epidemiology, 29893, Laboratory Division, Chennai, Tamil Nadu, India;
| | - Luke Elizabeth Hanna
- ICMR-National Institute for Research in Tuberculosis, 29888, Department of HIV/AIDS, Chennai, Tamil Nadu, India;
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4
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Ta TM, Malik S, Anderson EM, Jones AD, Perchik J, Freylikh M, Sardo L, Klase ZA, Izumi T. Insights Into Persistent HIV-1 Infection and Functional Cure: Novel Capabilities and Strategies. Front Microbiol 2022; 13:862270. [PMID: 35572626 PMCID: PMC9093714 DOI: 10.3389/fmicb.2022.862270] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 02/21/2022] [Indexed: 12/23/2022] Open
Abstract
Although HIV-1 replication can be efficiently suppressed to undetectable levels in peripheral blood by combination antiretroviral therapy (cART), lifelong medication is still required in people living with HIV (PLWH). Life expectancies have been extended by cART, but age-related comorbidities have increased which are associated with heavy physiological and economic burdens on PLWH. The obstacle to a functional HIV cure can be ascribed to the formation of latent reservoir establishment at the time of acute infection that persists during cART. Recent studies suggest that some HIV reservoirs are established in the early acute stages of HIV infection within multiple immune cells that are gradually shaped by various host and viral mechanisms and may undergo clonal expansion. Early cART initiation has been shown to reduce the reservoir size in HIV-infected individuals. Memory CD4+ T cell subsets are regarded as the predominant cellular compartment of the HIV reservoir, but monocytes and derivative macrophages or dendritic cells also play a role in the persistent virus infection. HIV latency is regulated at multiple molecular levels in transcriptional and post-transcriptional processes. Epigenetic regulation of the proviral promoter can profoundly regulate the viral transcription. In addition, transcriptional elongation, RNA splicing, and nuclear export pathways are also involved in maintaining HIV latency. Although most proviruses contain large internal deletions, some defective proviruses may induce immune activation by expressing viral proteins or producing replication-defective viral-like particles. In this review article, we discuss the state of the art on mechanisms of virus persistence in the periphery and tissue and summarize interdisciplinary approaches toward a functional HIV cure, including novel capabilities and strategies to measure and eliminate the infected reservoirs and induce immune control.
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Affiliation(s)
- Tram M. Ta
- Department of Biological Sciences, Misher College of Arts and Sciences, University of the Sciences in Philadelphia, Philadelphia, PA, United States
| | - Sajjaf Malik
- Department of Biological Sciences, Misher College of Arts and Sciences, University of the Sciences in Philadelphia, Philadelphia, PA, United States
| | - Elizabeth M. Anderson
- Office of the Assistant Secretary for Health, Region 3, U.S. Department of Health and Human Services, Washington, DC, United States
| | - Amber D. Jones
- Department of Biological Sciences, Misher College of Arts and Sciences, University of the Sciences in Philadelphia, Philadelphia, PA, United States,Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Jocelyn Perchik
- Department of Biological Sciences, Misher College of Arts and Sciences, University of the Sciences in Philadelphia, Philadelphia, PA, United States
| | - Maryann Freylikh
- Department of Biological Sciences, Misher College of Arts and Sciences, University of the Sciences in Philadelphia, Philadelphia, PA, United States
| | - Luca Sardo
- Department of Infectious Disease and Vaccines, Merck & Co., Inc., Kenilworth, NJ, United States
| | - Zackary A. Klase
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, United States,Center for Neuroimmunology and CNS Therapeutics, Institute of Molecular Medicine and Infectious Diseases, Drexel University of Medicine, Philadelphia, PA, United States
| | - Taisuke Izumi
- Department of Biological Sciences, Misher College of Arts and Sciences, University of the Sciences in Philadelphia, Philadelphia, PA, United States,*Correspondence: Taisuke Izumi,
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5
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Shen Z, Wu J, Gao Z, Zhang S, Chen J, He J, Guo Y, Deng Q, Xie Y, Liu J, Zhang J. OUP accepted manuscript. Nucleic Acids Res 2022; 50:2157-2171. [PMID: 35137191 PMCID: PMC8887475 DOI: 10.1093/nar/gkac070] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 01/10/2022] [Accepted: 01/25/2022] [Indexed: 11/29/2022] Open
Abstract
Chronic infection with hepatitis B virus (HBV) is associated with liver cirrhosis and hepatocellular carcinoma. Upon infection of hepatocytes, HBV covalently closed circular DNA (cccDNA) exists as histone-bound mini-chromosome, subjected to transcriptional regulation similar to chromosomal DNA. Here we identify high mobility group AT-hook 1 (HMGA1) protein as a positive regulator of HBV transcription that binds to a conserved ATTGG site within enhancer II/core promoter (EII/Cp) and recruits transcription factors FOXO3α and PGC1α. HMGA1-mediated upregulation of EII/Cp results in enhanced viral gene expression and genome replication. Notably, expression of endogenous HMGA1 was also demonstrated to be upregulated by HBV, which involves HBV X protein (HBx) interacting with SP1 transcription factor to activate HMGA1 promoter. Consistent with these in vitro results, chronic hepatitis B patients in immune tolerant phase display both higher intrahepatic HMGA1 protein levels and higher serum HBV markers compared to patients in inactive carrier phase. Finally, using a mouse model of HBV persistence, we show that targeting endogenous HMGA1 through RNA interference facilitated HBV clearance. These data establish HMGA1 as an important positive regulator of HBV that is reciprocally upregulated by HBV via HBx and also suggest the HMGA1-HBV positive feedback loop as a potential therapeutic target.
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Affiliation(s)
- Zhongliang Shen
- To whom correspondence should be addressed. Tel: +86 021 5288 8125; Fax: +86 021 6248 9191;
| | | | | | - Shenyan Zhang
- Department of Infectious Diseases, Shanghai Key Laboratory of Infectious Diseases and Biosafety Emergency Response, Shanghai Institute of Infectious Diseases and Biosecurity,National Medical Center for Infectious Diseases, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Jingwen Chen
- Department of Infectious Diseases, Shanghai Key Laboratory of Infectious Diseases and Biosafety Emergency Response, Shanghai Institute of Infectious Diseases and Biosecurity,National Medical Center for Infectious Diseases, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Jingjing He
- Department of Infectious Diseases, Shanghai Key Laboratory of Infectious Diseases and Biosafety Emergency Response, Shanghai Institute of Infectious Diseases and Biosecurity,National Medical Center for Infectious Diseases, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Yifei Guo
- Department of Infectious Diseases, Shanghai Key Laboratory of Infectious Diseases and Biosafety Emergency Response, Shanghai Institute of Infectious Diseases and Biosecurity,National Medical Center for Infectious Diseases, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Qiang Deng
- Key Laboratory of Medical Molecular Virology (Ministry of Education/National Health Commission/Chinese Academy of Medical Sciences), Department of Microbiology and Parasitology, Shanghai Institute of Infectious Diseases and Biosecurity, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Youhua Xie
- Correspondence may also be addressed to Youhua Xie. Tel: +86 021 5423 7972; Fax: +86 021 5423 7973;
| | - Jing Liu
- Correspondence may also be addressed to Jing Liu. Tel: +86 021 5423 7972; Fax: +86 021 5423 7973;
| | - Jiming Zhang
- Correspondence may also be addressed to Jiming Zhang. Tel: +86 021 5288 8125; Fax: +86 021 6248 9191;
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Sonti S, Sharma AL, Tyagi M. HIV-1 persistence in the CNS: Mechanisms of latency, pathogenesis and an update on eradication strategies. Virus Res 2021; 303:198523. [PMID: 34314771 DOI: 10.1016/j.virusres.2021.198523] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 07/14/2021] [Accepted: 07/17/2021] [Indexed: 12/20/2022]
Abstract
Despite four decades of research into the human immunodeficiency virus (HIV-1), a successful strategy to eradicate the virus post-infection is lacking. The major reason for this is the persistence of the virus in certain anatomical reservoirs where it can become latent and remain quiescent for as long as the cellular reservoir is alive. The Central Nervous System (CNS), in particular, is an intriguing anatomical compartment that is tightly regulated by the blood-brain barrier. Targeting the CNS viral reservoir is a major challenge owing to the decreased permeability of drugs into the CNS and the cellular microenvironment that facilitates the compartmentalization and evolution of the virus. Therefore, despite effective antiretroviral (ARV) treatment, virus persists in the CNS, and leads to neurological and neurocognitive deficits. To date, viral eradication strategies fail to eliminate the virus from the CNS. To facilitate the improvement of the existing elimination strategies, as well as the development of potential therapeutic targets, the aim of this review is to provide an in-depth understanding of HIV latency in CNS and the onset of HIV-1 associated neurological disorders.
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Affiliation(s)
- Shilpa Sonti
- Center for Translational Medicine, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
| | | | - Mudit Tyagi
- Center for Translational Medicine, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA.
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Campbell GR, Spector SA. Induction of Autophagy to Achieve a Human Immunodeficiency Virus Type 1 Cure. Cells 2021; 10:cells10071798. [PMID: 34359967 PMCID: PMC8307643 DOI: 10.3390/cells10071798] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 07/13/2021] [Accepted: 07/13/2021] [Indexed: 02/06/2023] Open
Abstract
Effective antiretroviral therapy has led to significant human immunodeficiency virus type 1 (HIV-1) suppression and improvement in immune function. However, the persistence of integrated proviral DNA in latently infected reservoir cells, which drive viral rebound post-interruption of antiretroviral therapy, remains the major roadblock to a cure. Therefore, the targeted elimination or permanent silencing of this latently infected reservoir is a major focus of HIV-1 research. The most studied approach in the development of a cure is the activation of HIV-1 expression to expose latently infected cells for immune clearance while inducing HIV-1 cytotoxicity—the “kick and kill” approach. However, the complex and highly heterogeneous nature of the latent reservoir, combined with the failure of clinical trials to reduce the reservoir size casts doubt on the feasibility of this approach. This concern that total elimination of HIV-1 from the body may not be possible has led to increased emphasis on a “functional cure” where the virus remains but is unable to reactivate which presents the challenge of permanently silencing transcription of HIV-1 for prolonged drug-free remission—a “block and lock” approach. In this review, we discuss the interaction of HIV-1 and autophagy, and the exploitation of autophagy to kill selectively HIV-1 latently infected cells as part of a cure strategy. The cure strategy proposed has the advantage of significantly decreasing the size of the HIV-1 reservoir that can contribute to a functional cure and when optimised has the potential to eradicate completely HIV-1.
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Affiliation(s)
- Grant R. Campbell
- Division of Infectious Diseases, Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA;
- Correspondence: ; Tel.: +1-858-534-7477
| | - Stephen A. Spector
- Division of Infectious Diseases, Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA;
- Rady Children’s Hospital, San Diego, CA 92123, USA
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8
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Saeb S, Ravanshad M, Pourkarim MR, Daouad F, Baesi K, Rohr O, Wallet C, Schwartz C. Brain HIV-1 latently-infected reservoirs targeted by the suicide gene strategy. Virol J 2021; 18:107. [PMID: 34059075 PMCID: PMC8166011 DOI: 10.1186/s12985-021-01584-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 05/21/2021] [Indexed: 12/22/2022] Open
Abstract
Reducing the pool of HIV-1 reservoirs in patients is a must to achieve functional cure. The most prominent HIV-1 cell reservoirs are resting CD4 + T cells and brain derived microglial cells. Infected microglial cells are believed to be the source of peripheral tissues reseedings and the emergence of drug resistance. Clearing infected cells from the brain is therefore crucial. However, many characteristics of microglial cells and the central nervous system make extremely difficult their eradication from brain reservoirs. Current methods, such as the "shock and kill", the "block and lock" and gene editing strategies cannot override these difficulties. Therefore, new strategies have to be designed when considering the elimination of brain reservoirs. We set up an original gene suicide strategy using latently infected microglial cells as model cells. In this paper we provide proof of concept of this strategy.
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Affiliation(s)
- Sepideh Saeb
- Department of Virology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
- University of Strasbourg, Research Unit 7292, DHPI, IUT Louis Pasteur, Schiltigheim, France
| | - Mehrdad Ravanshad
- Department of Virology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
| | - Mahmoud Reza Pourkarim
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Division of Clinical and Epidemiological Virology, 3000, Leuven, Belgium
| | - Fadoua Daouad
- University of Strasbourg, Research Unit 7292, DHPI, IUT Louis Pasteur, Schiltigheim, France
| | - Kazem Baesi
- Hepatitis and AIDS Department, Pasteur Institute of Iran, Tehran, Iran
| | - Olivier Rohr
- University of Strasbourg, Research Unit 7292, DHPI, IUT Louis Pasteur, Schiltigheim, France
| | - Clémentine Wallet
- University of Strasbourg, Research Unit 7292, DHPI, IUT Louis Pasteur, Schiltigheim, France
| | - Christian Schwartz
- University of Strasbourg, Research Unit 7292, DHPI, IUT Louis Pasteur, Schiltigheim, France.
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Salahong T, Schwartz C, Sungthong R. Are BET Inhibitors yet Promising Latency-Reversing Agents for HIV-1 Reactivation in AIDS Therapy? Viruses 2021; 13:v13061026. [PMID: 34072421 PMCID: PMC8228869 DOI: 10.3390/v13061026] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 05/24/2021] [Accepted: 05/26/2021] [Indexed: 12/26/2022] Open
Abstract
AIDS first emerged decades ago; however, its cure, i.e., eliminating all virus sources, is still unachievable. A critical burden of AIDS therapy is the evasive nature of HIV-1 in face of host immune responses, the so-called "latency." Recently, a promising approach, the "Shock and Kill" strategy, was proposed to eliminate latently HIV-1-infected cell reservoirs. The "Shock and Kill" concept involves two crucial steps: HIV-1 reactivation from its latency stage using a latency-reversing agent (LRA) followed by host immune responses to destroy HIV-1-infected cells in combination with reinforced antiretroviral therapy to kill the progeny virus. Hence, a key challenge is to search for optimal LRAs. Looking at epigenetics of HIV-1 infection, researchers proved that some bromodomains and extra-terminal motif protein inhibitors (BETis) are able to reactivate HIV-1 from latency. However, to date, only a few BETis have shown HIV-1-reactivating functions, and none of them have yet been approved for clinical trial. In this review, we aim to demonstrate the epigenetic roles of BETis in HIV-1 infection and HIV-1-related immune responses. Possible future applications of BETis and their HIV-1-reactivating properties are summarized and discussed.
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Affiliation(s)
- Thanarat Salahong
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand;
| | - Christian Schwartz
- Research Unit 7292, DHPI, IUT Louis Pasteur, University of Strasbourg, 67300 Schiltigheim, France
- Correspondence: (C.S.); (R.S.)
| | - Rungroch Sungthong
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow G61 1QH, UK
- Laboratory of Hydrology and Geochemistry of Strasbourg, University of Strasbourg, UMR 7517 CNRS/EOST, 67084 Strasbourg CEDEX, France
- Correspondence: (C.S.); (R.S.)
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10
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Epigenetic Mechanisms of HIV-1 Persistence. Vaccines (Basel) 2021; 9:vaccines9050514. [PMID: 34067608 PMCID: PMC8156729 DOI: 10.3390/vaccines9050514] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 05/01/2021] [Accepted: 05/11/2021] [Indexed: 12/14/2022] Open
Abstract
Eradicating HIV-1 in infected individuals will not be possible without addressing the persistence of the virus in its multiple reservoirs. In this context, the molecular characterization of HIV-1 persistence is key for the development of rationalized therapeutic interventions. HIV-1 gene expression relies on the redundant and cooperative recruitment of cellular epigenetic machineries to cis-regulatory proviral regions. Furthermore, the complex repertoire of HIV-1 repression mechanisms varies depending on the nature of the viral reservoir, although, so far, few studies have addressed the specific regulatory mechanisms of HIV-1 persistence in other reservoirs than the well-studied latently infected CD4+ T cells. Here, we present an exhaustive and updated picture of the heterochromatinization of the HIV-1 promoter in its different reservoirs. We highlight the complexity, heterogeneity and dynamics of the epigenetic mechanisms of HIV-1 persistence, while discussing the importance of further understanding HIV-1 gene regulation for the rational design of novel HIV-1 cure strategies.
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11
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Ait-Ammar A, Bellefroid M, Daouad F, Martinelli V, Van Assche J, Wallet C, Rodari A, De Rovere M, Fahrenkrog B, Schwartz C, Van Lint C, Gautier V, Rohr O. Inhibition of HIV-1 gene transcription by KAP1 in myeloid lineage. Sci Rep 2021; 11:2692. [PMID: 33514850 PMCID: PMC7846785 DOI: 10.1038/s41598-021-82164-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 01/13/2021] [Indexed: 02/08/2023] Open
Abstract
HIV-1 latency generates reservoirs that prevent viral eradication by the current therapies. To find strategies toward an HIV cure, detailed understandings of the molecular mechanisms underlying establishment and persistence of the reservoirs are needed. The cellular transcription factor KAP1 is known as a potent repressor of gene transcription. Here we report that KAP1 represses HIV-1 gene expression in myeloid cells including microglial cells, the major reservoir of the central nervous system. Mechanistically, KAP1 interacts and colocalizes with the viral transactivator Tat to promote its degradation via the proteasome pathway and repress HIV-1 gene expression. In myeloid models of latent HIV-1 infection, the depletion of KAP1 increased viral gene elongation and reactivated HIV-1 expression. Bound to the latent HIV-1 promoter, KAP1 associates and cooperates with CTIP2, a key epigenetic silencer of HIV-1 expression in microglial cells. In addition, Tat and CTIP2 compete for KAP1 binding suggesting a dynamic modulation of the KAP1 cellular partners upon HIV-1 infection. Altogether, our results suggest that KAP1 contributes to the establishment and the persistence of HIV-1 latency in myeloid cells.
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Affiliation(s)
- Amina Ait-Ammar
- grid.11843.3f0000 0001 2157 9291Université de Strasbourg, UR 7292 DHPI, FMTS, IUT Louis Pasteur, 1 Allée d’Athènes, 67300 Schiltigheim, France ,grid.7886.10000 0001 0768 2743Center for Research in Infectious Diseases (CRID), School of Medicine and Medical Science (SMMS), University College Dublin (UCD), Dublin, Ireland ,grid.4989.c0000 0001 2348 0746Service of Molecular Virology, Institute for Molecular Biology and Medicine (IBMM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Maxime Bellefroid
- grid.4989.c0000 0001 2348 0746Service of Molecular Virology, Institute for Molecular Biology and Medicine (IBMM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Fadoua Daouad
- grid.11843.3f0000 0001 2157 9291Université de Strasbourg, UR 7292 DHPI, FMTS, IUT Louis Pasteur, 1 Allée d’Athènes, 67300 Schiltigheim, France
| | - Valérie Martinelli
- grid.4989.c0000 0001 2348 0746Laboratory Biology of the Nucleus, Institute for Molecular Biology and Medicine, Université Libre de Bruxelles, 6041 Charleroi, Belgium
| | - Jeanne Van Assche
- grid.11843.3f0000 0001 2157 9291Université de Strasbourg, UR 7292 DHPI, FMTS, IUT Louis Pasteur, 1 Allée d’Athènes, 67300 Schiltigheim, France
| | - Clémentine Wallet
- grid.11843.3f0000 0001 2157 9291Université de Strasbourg, UR 7292 DHPI, FMTS, IUT Louis Pasteur, 1 Allée d’Athènes, 67300 Schiltigheim, France
| | - Anthony Rodari
- grid.4989.c0000 0001 2348 0746Service of Molecular Virology, Institute for Molecular Biology and Medicine (IBMM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Marco De Rovere
- grid.11843.3f0000 0001 2157 9291Université de Strasbourg, UR 7292 DHPI, FMTS, IUT Louis Pasteur, 1 Allée d’Athènes, 67300 Schiltigheim, France
| | - Birthe Fahrenkrog
- grid.4989.c0000 0001 2348 0746Laboratory Biology of the Nucleus, Institute for Molecular Biology and Medicine, Université Libre de Bruxelles, 6041 Charleroi, Belgium
| | - Christian Schwartz
- grid.11843.3f0000 0001 2157 9291Université de Strasbourg, UR 7292 DHPI, FMTS, IUT Louis Pasteur, 1 Allée d’Athènes, 67300 Schiltigheim, France
| | - Carine Van Lint
- grid.4989.c0000 0001 2348 0746Service of Molecular Virology, Institute for Molecular Biology and Medicine (IBMM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Virginie Gautier
- grid.7886.10000 0001 0768 2743Center for Research in Infectious Diseases (CRID), School of Medicine and Medical Science (SMMS), University College Dublin (UCD), Dublin, Ireland
| | - Olivier Rohr
- grid.11843.3f0000 0001 2157 9291Université de Strasbourg, UR 7292 DHPI, FMTS, IUT Louis Pasteur, 1 Allée d’Athènes, 67300 Schiltigheim, France
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12
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Daher MT, Bausero P, Agbulut O, Li Z, Parlakian A. Bcl11b/Ctip2 in Skin, Tooth, and Craniofacial System. Front Cell Dev Biol 2020; 8:581674. [PMID: 33363142 PMCID: PMC7758212 DOI: 10.3389/fcell.2020.581674] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 11/19/2020] [Indexed: 12/20/2022] Open
Abstract
Ctip2/Bcl11b is a zinc finger transcription factor with dual action (repression/activation) that couples epigenetic regulation to gene transcription during the development of various tissues. It is involved in a variety of physiological responses under healthy and pathological conditions. Its role and mechanisms of action are best characterized in the immune and nervous systems. Furthermore, its implication in the development and homeostasis of other various tissues has also been reported. In the present review, we describe its role in skin development, adipogenesis, tooth formation and cranial suture ossification. Experimental data from several studies demonstrate the involvement of Bcl11b in the control of the balance between cell proliferation and differentiation during organ formation and repair, and more specifically in the context of stem cell self-renewal and fate determination. The impact of mutations in the coding sequences of Bcl11b on the development of diseases such as craniosynostosis is also presented. Finally, we discuss genome-wide association studies that suggest a potential influence of single nucleotide polymorphisms found in the 3’ regulatory region of Bcl11b on the homeostasis of the cardiovascular system.
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Affiliation(s)
- Marie-Thérèse Daher
- Biological Adaptation and Ageing, Inserm ERL U1164, UMR CNRS 8256, Institut de Biologie Paris-Seine, Sorbonne Université, Paris, France
| | - Pedro Bausero
- Biological Adaptation and Ageing, Inserm ERL U1164, UMR CNRS 8256, Institut de Biologie Paris-Seine, Sorbonne Université, Paris, France
| | - Onnik Agbulut
- Biological Adaptation and Ageing, Inserm ERL U1164, UMR CNRS 8256, Institut de Biologie Paris-Seine, Sorbonne Université, Paris, France
| | - Zhenlin Li
- Biological Adaptation and Ageing, Inserm ERL U1164, UMR CNRS 8256, Institut de Biologie Paris-Seine, Sorbonne Université, Paris, France
| | - Ara Parlakian
- Biological Adaptation and Ageing, Inserm ERL U1164, UMR CNRS 8256, Institut de Biologie Paris-Seine, Sorbonne Université, Paris, France
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13
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Depicting HIV-1 Transcriptional Mechanisms: A Summary of What We Know. Viruses 2020; 12:v12121385. [PMID: 33287435 PMCID: PMC7761857 DOI: 10.3390/v12121385] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 11/26/2020] [Accepted: 12/01/2020] [Indexed: 12/19/2022] Open
Abstract
Despite the introduction of combinatory antiretroviral therapy (cART), HIV-1 infection cannot be cured and is still one of the major health issues worldwide. Indeed, as soon as cART is interrupted, a rapid rebound of viremia is observed. The establishment of viral latency and the persistence of the virus in cellular reservoirs constitute the main barrier to HIV eradication. For this reason, new therapeutic approaches have emerged to purge or restrain the HIV-1 reservoirs in order to cure infected patients. However, the viral latency is a multifactorial process that depends on various cellular mechanisms. Since these new therapies mainly target viral transcription, their development requires a detailed and precise understanding of the regulatory mechanism underlying HIV-1 transcription. In this review, we discuss the complex molecular transcriptional network regulating HIV-1 gene expression by focusing on the involvement of host cell factors that could be used as potential drug targets to design new therapeutic strategies and, to a larger extent, to reach an HIV-1 functional cure.
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14
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Wallet C, Rohr O, Schwartz C. Evolution of a concept: From accessory protein to key virulence factor, the case of HIV-1 Vpr. Biochem Pharmacol 2020; 180:114128. [PMID: 32619426 DOI: 10.1016/j.bcp.2020.114128] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 06/24/2020] [Accepted: 06/25/2020] [Indexed: 12/12/2022]
Abstract
Back in 1989 some studies have shown that the viral protein Vpr was dispensable for HIV-1 replication in vitro. From then the concept of accessory or auxiliary protein for Vpr has emerged and it is still used to date. However, Vpr soon appeared to be very important for in vivo virus spread and pathogenesis. Vpr has been involved in many biological functions including regulation of reverse transcriptase activity, the nuclear import of the pre-integration complex (PIC), HIV-1 transcription, gene splicing, apoptosis and in cell cycle arrest. Thus, we might rather consider Vpr as a true virulence factor instead of just an accessory factor. At present, Vpr can be regarded as a potential and promising target in different strategies aiming to fight infected cells including latently infected cells.
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Affiliation(s)
- Clémentine Wallet
- University of Strasbourg, Research Unit7292, DHPI, IUT Louis Pasteur, Schiltigheim, France
| | - Olivier Rohr
- University of Strasbourg, Research Unit7292, DHPI, IUT Louis Pasteur, Schiltigheim, France
| | - Christian Schwartz
- University of Strasbourg, Research Unit7292, DHPI, IUT Louis Pasteur, Schiltigheim, France.
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15
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Hasler D, Meister G, Fischer U. Stabilize and connect: the role of LARP7 in nuclear non-coding RNA metabolism. RNA Biol 2020; 18:290-303. [PMID: 32401147 DOI: 10.1080/15476286.2020.1767952] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
La and La-related proteins (LARPs) are characterized by a common RNA interaction platform termed the La module. This structural hallmark allows LARPs to pervade various aspects of RNA biology. The metazoan LARP7 protein binds to the 7SK RNA as part of a 7SK small nuclear ribonucleoprotein (7SK snRNP), which inhibits the transcriptional activity of RNA polymerase II (Pol II). Additionally, recent findings revealed unanticipated roles of LARP7 in the assembly of other RNPs, as well as in the modification, processing and cellular transport of RNA molecules. Reduced levels of functional LARP7 have been linked to cancer and Alazami syndrome, two seemingly unrelated human diseases characterized either by hyperproliferation or growth retardation. Here, we review the intricate regulatory networks centered on LARP7 and assess how malfunction of these networks may relate to the etiology of LARP7-linked diseases.
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Affiliation(s)
- Daniele Hasler
- Biochemistry Center Regensburg (BZR), Laboratory for RNA Biology, University of Regensburg, Regensburg, Germany
| | - Gunter Meister
- Biochemistry Center Regensburg (BZR), Laboratory for RNA Biology, University of Regensburg, Regensburg, Germany
| | - Utz Fischer
- Department of Biochemistry, Theodor Boveri-Institute, University of Würzburg, Würzburg, Germany
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16
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Ait-Ammar A, Kula A, Darcis G, Verdikt R, De Wit S, Gautier V, Mallon PWG, Marcello A, Rohr O, Van Lint C. Current Status of Latency Reversing Agents Facing the Heterogeneity of HIV-1 Cellular and Tissue Reservoirs. Front Microbiol 2020; 10:3060. [PMID: 32038533 PMCID: PMC6993040 DOI: 10.3389/fmicb.2019.03060] [Citation(s) in RCA: 97] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 12/18/2019] [Indexed: 12/15/2022] Open
Abstract
One of the most explored therapeutic approaches aimed at eradicating HIV-1 reservoirs is the "shock and kill" strategy which is based on HIV-1 reactivation in latently-infected cells ("shock" phase) while maintaining antiretroviral therapy (ART) in order to prevent spreading of the infection by the neosynthesized virus. This kind of strategy allows for the "kill" phase, during which latently-infected cells die from viral cytopathic effects or from host cytolytic effector mechanisms following viral reactivation. Several latency reversing agents (LRAs) with distinct mechanistic classes have been characterized to reactivate HIV-1 viral gene expression. Some LRAs have been tested in terms of their potential to purge latent HIV-1 in vivo in clinical trials, showing that reversing HIV-1 latency is possible. However, LRAs alone have failed to reduce the size of the viral reservoirs. Together with the inability of the immune system to clear the LRA-activated reservoirs and the lack of specificity of these LRAs, the heterogeneity of the reservoirs largely contributes to the limited success of clinical trials using LRAs. Indeed, HIV-1 latency is established in numerous cell types that are characterized by distinct phenotypes and metabolic properties, and these are influenced by patient history. Hence, the silencing mechanisms of HIV-1 gene expression in these cellular and tissue reservoirs need to be better understood to rationally improve this cure strategy and hopefully reach clinical success.
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Affiliation(s)
- Amina Ait-Ammar
- Service of Molecular Virology, Department of Molecular Virology (DBM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Anna Kula
- Malopolska Centre of Biotechnology, Laboratory of Virology, Jagiellonian University, Krakow, Poland
| | - Gilles Darcis
- Infectious Diseases Department, Liège University Hospital, Liège, Belgium
| | - Roxane Verdikt
- Service of Molecular Virology, Department of Molecular Virology (DBM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Stephane De Wit
- Service des Maladies Infectieuses, CHU Saint-Pierre, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Virginie Gautier
- UCD Centre for Experimental Pathogen Host Research (CEPHR), School of Medicine, University College Dublin, Dublin, Ireland
| | - Patrick W G Mallon
- UCD Centre for Experimental Pathogen Host Research (CEPHR), School of Medicine, University College Dublin, Dublin, Ireland
| | - Alessandro Marcello
- Laboratory of Molecular Virology, International Centre for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy
| | - Olivier Rohr
- Université de Strasbourg, EA7292, FMTS, IUT Louis Pasteur, Schiltigheim, France
| | - Carine Van Lint
- Service of Molecular Virology, Department of Molecular Virology (DBM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
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Wallet C, De Rovere M, Van Assche J, Daouad F, De Wit S, Gautier V, Mallon PWG, Marcello A, Van Lint C, Rohr O, Schwartz C. Microglial Cells: The Main HIV-1 Reservoir in the Brain. Front Cell Infect Microbiol 2019; 9:362. [PMID: 31709195 PMCID: PMC6821723 DOI: 10.3389/fcimb.2019.00362] [Citation(s) in RCA: 212] [Impact Index Per Article: 42.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 10/07/2019] [Indexed: 12/12/2022] Open
Abstract
Despite efficient combination of the antiretroviral therapy (cART), which significantly decreased mortality and morbidity of HIV-1 infection, a definitive HIV cure has not been achieved. Hidden HIV-1 in cellular and anatomic reservoirs is the major hurdle toward a functional cure. Microglial cells, the Central Nervous system (CNS) resident macrophages, are one of the major cellular reservoirs of latent HIV-1. These cells are believed to be involved in the emergence of drugs resistance and reseeding peripheral tissues. Moreover, these long-life reservoirs are also involved in the development of HIV-1-associated neurocognitive diseases (HAND). Clearing these infected cells from the brain is therefore crucial to achieve a cure. However, many characteristics of microglial cells and the CNS hinder the eradication of these brain reservoirs. Better understandings of the specific molecular mechanisms of HIV-1 latency in microglial cells should help to design new molecules and new strategies preventing HAND and achieving HIV cure. Moreover, new strategies are needed to circumvent the limitations associated to anatomical sanctuaries with barriers such as the blood brain barrier (BBB) that reduce the access of drugs.
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Affiliation(s)
- Clementine Wallet
- Université de Strasbourg, EA7292, FMTS, IUT Louis Pasteur, Schiltigheim, France
| | - Marco De Rovere
- Université de Strasbourg, EA7292, FMTS, IUT Louis Pasteur, Schiltigheim, France
| | - Jeanne Van Assche
- Université de Strasbourg, EA7292, FMTS, IUT Louis Pasteur, Schiltigheim, France
| | - Fadoua Daouad
- Université de Strasbourg, EA7292, FMTS, IUT Louis Pasteur, Schiltigheim, France
| | - Stéphane De Wit
- Division of Infectious Diseases, Saint-Pierre University Hospital, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Virginie Gautier
- UCD Centre for Experimental Pathogen Host Research (CEPHR), School of Medicine, University College Dublin, Dublin, Ireland
| | - Patrick W G Mallon
- UCD Centre for Experimental Pathogen Host Research (CEPHR), School of Medicine, University College Dublin, Dublin, Ireland
| | - Alessandro Marcello
- Laboratory of Molecular Virology, International Centre for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy
| | - Carine Van Lint
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Olivier Rohr
- Université de Strasbourg, EA7292, FMTS, IUT Louis Pasteur, Schiltigheim, France
| | - Christian Schwartz
- Université de Strasbourg, EA7292, FMTS, IUT Louis Pasteur, Schiltigheim, France
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18
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HIV-1 Vpr mediates the depletion of the cellular repressor CTIP2 to counteract viral gene silencing. Sci Rep 2019; 9:13154. [PMID: 31511615 PMCID: PMC6739472 DOI: 10.1038/s41598-019-48689-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 08/07/2019] [Indexed: 12/15/2022] Open
Abstract
Mammals have evolved many antiviral factors impacting different steps of the viral life cycle. Associated with chromatin-modifying enzymes, the cellular cofactor CTIP2 contributes to HIV-1 gene silencing in latently infected reservoirs that constitute the major block toward an HIV cure. We report, for the first time, that the virus has developed a strategy to overcome this major transcriptional block. Productive HIV-1 infection results in a Vpr-mediated depletion of CTIP2 in microglial cells and CD4+ T cells, two of the major viral reservoirs. Associated to the Cul4A-DDB1-DCAF1 ubiquitin ligase complex, Vpr promotes CTIP2 degradation via the proteasome pathway in the nuclei of target cells and notably at the latent HIV-1 promoter. Importantly, Vpr targets CTIP2 associated with heterochromatin-promoting enzymes dedicated to HIV-1 gene silencing. Thereby, Vpr reactivates HIV-1 expression in a microglial model of HIV-1 latency. Altogether our results suggest that HIV-1 Vpr mediates the depletion of the cellular repressor CTIP2 to counteract viral gene silencing.
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19
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Wallet C, De Rovere M, Van Assche J, Daouad F, De Wit S, Gautier V, Mallon PWG, Marcello A, Van Lint C, Rohr O, Schwartz C. Microglial Cells: The Main HIV-1 Reservoir in the Brain. Front Cell Infect Microbiol 2019. [PMID: 31709195 DOI: 10.3389/fcimb.2019.00362/bibtex] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/27/2023] Open
Abstract
Despite efficient combination of the antiretroviral therapy (cART), which significantly decreased mortality and morbidity of HIV-1 infection, a definitive HIV cure has not been achieved. Hidden HIV-1 in cellular and anatomic reservoirs is the major hurdle toward a functional cure. Microglial cells, the Central Nervous system (CNS) resident macrophages, are one of the major cellular reservoirs of latent HIV-1. These cells are believed to be involved in the emergence of drugs resistance and reseeding peripheral tissues. Moreover, these long-life reservoirs are also involved in the development of HIV-1-associated neurocognitive diseases (HAND). Clearing these infected cells from the brain is therefore crucial to achieve a cure. However, many characteristics of microglial cells and the CNS hinder the eradication of these brain reservoirs. Better understandings of the specific molecular mechanisms of HIV-1 latency in microglial cells should help to design new molecules and new strategies preventing HAND and achieving HIV cure. Moreover, new strategies are needed to circumvent the limitations associated to anatomical sanctuaries with barriers such as the blood brain barrier (BBB) that reduce the access of drugs.
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Affiliation(s)
- Clementine Wallet
- Université de Strasbourg, EA7292, FMTS, IUT Louis Pasteur, Schiltigheim, France
| | - Marco De Rovere
- Université de Strasbourg, EA7292, FMTS, IUT Louis Pasteur, Schiltigheim, France
| | - Jeanne Van Assche
- Université de Strasbourg, EA7292, FMTS, IUT Louis Pasteur, Schiltigheim, France
| | - Fadoua Daouad
- Université de Strasbourg, EA7292, FMTS, IUT Louis Pasteur, Schiltigheim, France
| | - Stéphane De Wit
- Division of Infectious Diseases, Saint-Pierre University Hospital, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Virginie Gautier
- UCD Centre for Experimental Pathogen Host Research (CEPHR), School of Medicine, University College Dublin, Dublin, Ireland
| | - Patrick W G Mallon
- UCD Centre for Experimental Pathogen Host Research (CEPHR), School of Medicine, University College Dublin, Dublin, Ireland
| | - Alessandro Marcello
- Laboratory of Molecular Virology, International Centre for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy
| | - Carine Van Lint
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Olivier Rohr
- Université de Strasbourg, EA7292, FMTS, IUT Louis Pasteur, Schiltigheim, France
| | - Christian Schwartz
- Université de Strasbourg, EA7292, FMTS, IUT Louis Pasteur, Schiltigheim, France
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20
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Eichhorn CD, Yang Y, Repeta L, Feigon J. Structural basis for recognition of human 7SK long noncoding RNA by the La-related protein Larp7. Proc Natl Acad Sci U S A 2018; 115:E6457-E6466. [PMID: 29946027 PMCID: PMC6048529 DOI: 10.1073/pnas.1806276115] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The La and the La-related protein (LARP) superfamily is a diverse class of RNA binding proteins involved in RNA processing, folding, and function. Larp7 binds to the abundant long noncoding 7SK RNA and is required for 7SK ribonucleoprotein (RNP) assembly and function. The 7SK RNP sequesters a pool of the positive transcription elongation factor b (P-TEFb) in an inactive state; on release, P-TEFb phosphorylates RNA Polymerase II to stimulate transcription elongation. Despite its essential role in transcription, limited structural information is available for the 7SK RNP, particularly for protein-RNA interactions. Larp7 contains an N-terminal La module that binds UUU-3'OH and a C-terminal atypical RNA recognition motif (xRRM) required for specific binding to 7SK and P-TEFb assembly. Deletion of the xRRM is linked to gastric cancer in humans. We report the 2.2-Å X-ray crystal structure of the human La-related protein group 7 (hLarp7) xRRM bound to the 7SK stem-loop 4, revealing a unique binding interface. Contributions of observed interactions to binding affinity were investigated by mutagenesis and isothermal titration calorimetry. NMR 13C spin relaxation data and comparison of free xRRM, RNA, and xRRM-RNA structures show that the xRRM is preordered to bind a flexible loop 4. Combining structures of the hLarp7 La module and the xRRM-7SK complex presented here, we propose a structural model for Larp7 binding to the 7SK 3' end and mechanism for 7SK RNP assembly. This work provides insight into how this domain contributes to 7SK recognition and assembly of the core 7SK RNP.
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Affiliation(s)
- Catherine D Eichhorn
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095-1569
| | - Yuan Yang
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095-1569
| | - Lucas Repeta
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095-1569
| | - Juli Feigon
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095-1569
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Lin X, Ammosova T, Kumari N, Nekhai S. Protein Phosphatase-1 -targeted Small Molecules, Iron Chelators and Curcumin Analogs as HIV-1 Antivirals. Curr Pharm Des 2018; 23:4122-4132. [PMID: 28677499 DOI: 10.2174/1381612823666170704123620] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 06/14/2017] [Accepted: 06/22/2017] [Indexed: 02/07/2023]
Abstract
BACKGROUND Despite efficient suppression of HIV-1 replication, current antiviral drugs are not able to eradicate HIV-1 infection. Permanent HIV-1 suppression or complete eradication requires novel biological approaches and therapeutic strategies. Our previous studies showed that HIV-1 transcription is regulated by host cell protein phosphatase-1. We also showed that HIV-1 transcription is sensitive to the reduction of intracellular iron that affects cell cycle-dependent kinase 2. We developed protein phosphatase 1-targeting small molecules that inhibited HIV-1 transcription. We also found an additional class of protein phosphatase-1-targeting molecules that activated HIV-1 transcription and reported HIV-1 inhibitory iron chelators and novel curcumin analogs that inhibit HIV-1. Here, we review HIV-1 transcription and replication with focus on its regulation by protein phosphatase 1 and cell cycle dependent kinase 2 and describe novel small molecules that can serve as future leads for anti-HIV drug development. RESULTS Our review describes in a non-exhaustive manner studies in which HIV-1 transcription and replication are targeted with small molecules. Previously, published studies show that HIV-1 can be inhibited with protein phosphatase-1-targeting and iron chelating compounds and curcumin analogs. These results are significant in light of the current efforts to eradicate HIV-1 through permanent inhibition. Also, HIV-1 activating compounds can be useful for "kick and kill" therapy in which the virus is reactivated prior to its inhibition by the combination antiretroviral therapy. CONCLUSION The studies described in our review point to protein phosphatase-1 as a new drug target, intracellular iron as subject for iron chelation and novel curcumin analogs that can be developed for novel HIV-1 transcription- targeting therapeutics.
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Affiliation(s)
- Xionghao Lin
- Center for Sickle Cell Disease, 1840 7th Street, N.W. HURB1, Suite 202, Washington DC 20001. United States
| | - Tatyana Ammosova
- Center for Sickle Cell Disease, 1840 7th Street, N.W. HURB1, Suite 202, Washington DC 20001. United States
| | - Namita Kumari
- Center for Sickle Cell Disease, 1840 7th Street, N.W. HURB1, Suite 202, Washington DC 20001. United States
| | - Sergei Nekhai
- Center for Sickle Cell Disease, 1840 7th Street, N.W. HURB1, Suite 202, Washington DC 20001. United States
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22
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Abstract
BACKGROUND The viral transactivator Tat protein is a key modulator of HIV-1 replication, as it regulates transcriptional elongation from the integrated proviral genome. Tat recruits the human transcription elongation factor b, and other host proteins, such as the super elongation complex, to activate the cellular RNA polymerase II, normally stalled shortly after transcription initiation at the HIV promoter. By means of a complex set of interactions with host cellular factors, Tat determines the fate of viral activity within the infected cell. The virus will either actively replicate to promote dissemination in blood and tissues, or become dormant mostly in memory CD4+ T cells, as part of a small but long-living latent reservoir, the main obstacle for HIV eradication. OBJECTIVE In this review, we summarize recent advances in the understanding of the multi-step mechanism that regulates Tat-mediated HIV-1 transcription and RNA polymerase II release, to promote viral transcription elongation. Early events of the human transcription elongation factor b release from the inhibitory 7SK small nuclear ribonucleoprotein complex and its recruitment to the HIV promoter will be discussed. Specific roles of the super elongation complex subunits during transcription elongation, and insight on recently identified cellular factors and mechanisms regulating HIV latency will be detailed. CONCLUSION Understanding the complexity of HIV transcriptional regulation by host factors may open the door for development of novel strategies to eradicate the resilient latent reservoir.
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Affiliation(s)
- Guillaume Mousseau
- The Scripps Research Institute, Department of Immunology and Microbiology, 130 Scripps Way, Jupiter, FL 33458. United States
| | - Susana T Valente
- The Scripps Research Institute, Department of Immunology and Microbiology, 130 Scripps Way, Jupiter, FL 33458. United States
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23
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Vicenzi E, Poli G. The interferon-stimulated gene TRIM22: A double-edged sword in HIV-1 infection. Cytokine Growth Factor Rev 2018; 40:40-47. [PMID: 29650252 DOI: 10.1016/j.cytogfr.2018.02.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 02/07/2018] [Indexed: 12/17/2022]
Abstract
Infection of target cells by the human immunodeficiency virus type-1 (HIV-1) is hampered by constitutively expressed host cell proteins preventing or curtailing virus replication and therefore defined as "restriction factors". Among them, members of the tripartite motif (TRIM) family have emerged as important players endowed with both antiviral effects and modulatory capacity of the innate immune response. TRIM5α and TRIM19 (i.e. promyelocytic leukemia, PML) are among the best-characterized family members; however, in this review we will focus on the potential role of another family member, i.e. TRIM22, a factor strongly induced by interferon stimulation, in HIV infection in vivo and in vitro in the context of its broader antiviral effects. We will also focus on the potential role of TRIM22 in HIV-1-infected individuals speculating on its dual role in controlling virus replication and more complex role in chronic infection. At the molecular levels, we will review the evidence in favor of a relevant role of TRIM22 as epigenetic inhibitor of HIV-1 transcription acting by preventing the binding of the host cell transcription factor Sp1 to the viral promoter. These evidences suggest that TRIM22 should be considered a potential new player in either the establishment or maintenance of HIV-1 reservoirs of latently infected cells unaffected by combination antiretroviral therapy.
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Affiliation(s)
- Elisa Vicenzi
- Viral Pathogens and Biosafety Unit, P2-P3 Laboratories, DIBIT, Via Olgettina n. 58, 20132, Milano, Italy.
| | - Guido Poli
- AIDS Immunopathogenesis Unit, San Raffaele Scientific Institute, Milan, Italy; Vita-Salute San Raffaele University, School of Medicine, Milan, Italy
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24
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Eilebrecht S, Benecke BJ, Benecke AG. Latent HIV-1 TAR Regulates 7SK-responsive P-TEFb Target Genes and Targets Cellular Immune Responses in the Absence of Tat. GENOMICS PROTEOMICS & BIOINFORMATICS 2017; 15:313-323. [PMID: 29037489 PMCID: PMC5673678 DOI: 10.1016/j.gpb.2017.05.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Revised: 05/10/2017] [Accepted: 05/24/2017] [Indexed: 01/04/2023]
Abstract
The transactivating response element (TAR) structure of the nascent HIV-1 transcript is critically involved in the recruitment of inactive positive transcription elongation factor b (P-TEFb) to the promoter proximal paused RNA polymerase II. The viral transactivator Tat is responsible for subsequent P-TEFb activation in order to start efficient viral transcription elongation. In the absence of the viral transactivator of transcription (Tat), e.g., during latency or in early stages of HIV transcription, TAR mediates an interaction of P-TEFb with its inhibitor hexamethylene bis-acetamide-inducible protein 1 (HEXIM1), keeping P-TEFb in its inactive form. In this study, we address the function of HIV-1 TAR in the absence of Tat by analyzing consequences of HIV-1 TAR overexpression on host cellular gene expression. An RNA chimera consisting of Epstein-Barr virus-expressed RNA 2 (EBER2) and HIV-1 TAR was developed to assure robust overexpression of TAR in HEK293 cells. The overexpression results in differential expression of more than 800 human genes. A significant proportion of these genes is involved in the suppression of cellular immune responses, including a significant set of 7SK-responsive P-TEFb target genes. Our findings identify a novel role for HIV-1 TAR in the absence of Tat, involving the interference with host cellular immune responses by targeting 7SK RNA-mediated gene expression and P-TEFb inactivation.
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Affiliation(s)
- Sebastian Eilebrecht
- CNRS UMR8246, Université Pierre et Marie Curie, Paris 75005, France; ACSIOMA GmbH, Technologiezentrum Ruhr, Bochum 44799, Germany.
| | | | - Arndt G Benecke
- CNRS UMR8246, Université Pierre et Marie Curie, Paris 75005, France; Center for Innate Immunity and Immune Disease, University of Washington School of Medicine, Seattle, WA 98195, USA.
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Egloff S, Studniarek C, Kiss T. 7SK small nuclear RNA, a multifunctional transcriptional regulatory RNA with gene-specific features. Transcription 2017; 9:95-101. [PMID: 28820318 DOI: 10.1080/21541264.2017.1344346] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The 7SK small nuclear RNA is a multifunctional transcriptional regulatory RNA that controls the nuclear activity of the positive transcription elongation factor b (P-TEFb), specifically targets P-TEFb to the promoter regions of selected protein-coding genes and promotes transcription of RNA polymerase II-specific spliceosomal small nuclear RNA genes.
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Affiliation(s)
- Sylvain Egloff
- a Laboratoire de Biologie Moléculaire Eucaryote du CNRS, UMR5099, Centre de Biologie Intégrative, Université Paul Sabatier , Toulouse , France
| | - Cécilia Studniarek
- a Laboratoire de Biologie Moléculaire Eucaryote du CNRS, UMR5099, Centre de Biologie Intégrative, Université Paul Sabatier , Toulouse , France
| | - Tamás Kiss
- a Laboratoire de Biologie Moléculaire Eucaryote du CNRS, UMR5099, Centre de Biologie Intégrative, Université Paul Sabatier , Toulouse , France.,b Biological Research Centre , Hungarian Academy of Sciences , Szeged , Hungary
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26
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Schwartz C, Bouchat S, Marban C, Gautier V, Van Lint C, Rohr O, Le Douce V. On the way to find a cure: Purging latent HIV-1 reservoirs. Biochem Pharmacol 2017; 146:10-22. [PMID: 28687465 DOI: 10.1016/j.bcp.2017.07.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 07/03/2017] [Indexed: 12/29/2022]
Abstract
Introduction of cART in 1996 has drastically increased the life expectancy of people living with HIV-1. However, this treatment has not allowed cure as cessation of cART is associated with a rapid viral rebound. The main barrier to the eradication of the virus is related to the persistence of latent HIV reservoirs. Evidence is now accumulating that purging the HIV-1 reservoir might lead to a cure or a remission. The most studied strategy is the so called "shock and kill" therapy. This strategy is based on reactivation of dormant viruses from the latently-infected reservoirs (the shock) followed by the eradication of the reservoirs (the kill). This review focuses mainly on the recent advances made in the "shock and kill" therapy. We believe that a cure or a remission will come from combinatorial approaches i.e. combination of drugs to reactivate the dormant virus from all the reservoirs including the one located in sanctuaries, and combination of strategies boosting the immune system. Alternative strategies based on cell and gene therapy or based in inducing deep latency, which are evoked in this review reinforce the idea that at least a remission is attainable.
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Affiliation(s)
- Christian Schwartz
- University of Strasbourg, EA7292, DHPI, Institute of Parasitology and Tropical Pathology, Strasbourg, France; University of Strasbourg, IUT Louis Pasteur, Schiltigheim, France.
| | - Sophie Bouchat
- Université Libre de Bruxelles (ULB), Service of Molecular Virology, Institute for Molecular Biology and Medicine (IBMM), 12 rue des Profs Jeener et Brachet, 6041 Gosselies, Belgium
| | - Céline Marban
- University of Strasbourg, Inserm UMR 1121 Faculté de Chirurgie Dentaire Pavillon Leriche 1, place de l'Hôpital Strasbourg, France
| | - Virginie Gautier
- UCD, Centre for Research in Infectious Diseases (CRID), School of Medicine University College Dublin, Belfield, Dublin 4, Ireland
| | - Carine Van Lint
- Université Libre de Bruxelles (ULB), Service of Molecular Virology, Institute for Molecular Biology and Medicine (IBMM), 12 rue des Profs Jeener et Brachet, 6041 Gosselies, Belgium
| | - Olivier Rohr
- University of Strasbourg, EA7292, DHPI, Institute of Parasitology and Tropical Pathology, Strasbourg, France; University of Strasbourg, IUT Louis Pasteur, Schiltigheim, France
| | - Valentin Le Douce
- UCD, Centre for Research in Infectious Diseases (CRID), School of Medicine University College Dublin, Belfield, Dublin 4, Ireland
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Darcis G, Van Driessche B, Van Lint C. HIV Latency: Should We Shock or Lock? Trends Immunol 2017; 38:217-228. [PMID: 28073694 DOI: 10.1016/j.it.2016.12.003] [Citation(s) in RCA: 120] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 12/09/2016] [Accepted: 12/12/2016] [Indexed: 11/24/2022]
Abstract
Combinatory antiretroviral therapy (cART) increases the survival and quality of life of HIV-1-infected patients. However, interruption of therapy almost invariably leads to the re-emergence of detectable viral replication because HIV-1 persists in viral latent reservoirs. Improved understanding of the molecular mechanisms involved in HIV-1 latency has paved the way for innovative strategies that attempt to purge latent virus. In this article we discuss the results of the broadly explored 'shock and kill' strategy, and also highlight the major hurdles facing this approach. Finally, we present recent innovative works suggesting that locking out latent proviruses could be a potential alternative therapeutic strategy.
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Affiliation(s)
- Gilles Darcis
- Service of Molecular Virology, Département de Biologie Moléculaire (DBM), Université Libre de Bruxelles (ULB), Rue des Professeurs Jeener et Brachet 12, 6041 Gosselies, Belgium; Service des Maladies Infectieuses, Université de Liège, Centre Hospitalier Universitaire (CHU) de Liège, Domaine Universitaire du Sart-Tilman, B35, 4000 Liège, Belgium
| | - Benoit Van Driessche
- Service of Molecular Virology, Département de Biologie Moléculaire (DBM), Université Libre de Bruxelles (ULB), Rue des Professeurs Jeener et Brachet 12, 6041 Gosselies, Belgium
| | - Carine Van Lint
- Service of Molecular Virology, Département de Biologie Moléculaire (DBM), Université Libre de Bruxelles (ULB), Rue des Professeurs Jeener et Brachet 12, 6041 Gosselies, Belgium.
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Darcis G, Van Driessche B, Bouchat S, Kirchhoff F, Van Lint C. Molecular Control of HIV and SIV Latency. Curr Top Microbiol Immunol 2017; 417:1-22. [PMID: 29071474 DOI: 10.1007/82_2017_74] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The HIV latent reservoirs are considered as the main hurdle to viral eradication. Numerous mechanisms lead to the establishment of HIV latency and act at the transcriptional and post-transcriptional levels. A better understanding of latency is needed in order to ultimately achieve a cure for HIV. The mechanisms underlying latency vary between patients, tissues, anatomical compartments, and cell types. From this point of view, simian immunodeficiency virus (SIV) infection and the use of nonhuman primate (NHP) models that recapitulate many aspects of HIV-associated latency establishment and disease progression are essential tools since they allow extensive tissue sampling as well as a control of infection parameters (virus type, dose, route, and time).
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Affiliation(s)
- Gilles Darcis
- Service of Molecular Virology, Département de Biologie Moléculaire (DBM), Université Libre de Bruxelles (ULB), Rue des Professeurs Jeener et Brachet 12, 6041, Gosselies, Belgium.,Service des Maladies Infectieuses, Université de Liège, CHU de Liège, Domaine Universitaire du Sart-Tilman, B35, 4000, Liège, Belgium.,Laboratory of Experimental Virology, Department of Medical Microbiology, Academic Medical Center of the University of Amsterdam, Meibergdreef 15, 1105, AZ, Amsterdam, The Netherlands
| | - Benoit Van Driessche
- Service of Molecular Virology, Département de Biologie Moléculaire (DBM), Université Libre de Bruxelles (ULB), Rue des Professeurs Jeener et Brachet 12, 6041, Gosselies, Belgium
| | - Sophie Bouchat
- Service of Molecular Virology, Département de Biologie Moléculaire (DBM), Université Libre de Bruxelles (ULB), Rue des Professeurs Jeener et Brachet 12, 6041, Gosselies, Belgium
| | - Frank Kirchhoff
- Institute of Molecular Virology, Ulm University Medical Center, Meyerhofstraße 1, 89081, Ulm, Germany
| | - Carine Van Lint
- Service of Molecular Virology, Département de Biologie Moléculaire (DBM), Université Libre de Bruxelles (ULB), Rue des Professeurs Jeener et Brachet 12, 6041, Gosselies, Belgium.
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Le Douce V, Forouzanfar F, Eilebrecht S, Van Driessche B, Ait-Ammar A, Verdikt R, Kurashige Y, Marban C, Gautier V, Candolfi E, Benecke AG, Van Lint C, Rohr O, Schwartz C. HIC1 controls cellular- and HIV-1- gene transcription via interactions with CTIP2 and HMGA1. Sci Rep 2016; 6:34920. [PMID: 27725726 PMCID: PMC5057145 DOI: 10.1038/srep34920] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 09/21/2016] [Indexed: 02/06/2023] Open
Abstract
Among many cellular transcriptional regulators, Bcl11b/CTIP2 and HGMA1 have been described to control the establishment and the persistence of HIV-1 latency in microglial cells, the main viral reservoir in the brain. In this present work, we identify and characterize a transcription factor i.e. HIC1, which physically interacts with both Bcl11b/CTIP2 and HMGA1 to co-regulate specific subsets of cellular genes and the viral HIV-1 gene. Our results suggest that HIC1 represses Tat dependent HIV-1 transcription. Interestingly, this repression of Tat function is linked to HIC1 K314 acetylation status and to SIRT1 deacetylase activity. Finally, we show that HIC1 interacts and cooperates with HGMA1 to regulate Tat dependent HIV-1 transcription. Our results also suggest that HIC1 repression of Tat function happens in a TAR dependent manner and that this TAR element may serve as HIC1 reservoir at the viral promoter to facilitate HIC1/TAT interaction.
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Affiliation(s)
- Valentin Le Douce
- University of Strasbourg, EA7292, DHPI, Institut of Parasitology and tropical pathology Strasbourg, France.,University of Strasbourg, IUT Louis Pasteur, Schiltigheim, France.,Institut des Hautes Etudes Scientifiques-Centre National de la Recherche Scientifique, 35 route de Chartres, 91440 Bures sur Yvette, France
| | - Faezeh Forouzanfar
- University of Strasbourg, EA7292, DHPI, Institut of Parasitology and tropical pathology Strasbourg, France
| | - Sebastian Eilebrecht
- Institut Universitaire de France, Paris, France.,Université Libre de Bruxelles (ULB), Service of Molecular Virology, Institute for Molecular Biology and Medicine (IBMM), 12 rue des Profs Jeener et Brachet, 6041 Gosselies, Belgium
| | - Benoit Van Driessche
- Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 242, Heidelberg 69120, Germany
| | - Amina Ait-Ammar
- University of Strasbourg, EA7292, DHPI, Institut of Parasitology and tropical pathology Strasbourg, France
| | - Roxane Verdikt
- Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 242, Heidelberg 69120, Germany
| | - Yoshihito Kurashige
- CNRS UMR 7224, Université Pierre et Marie Curie, 7 quai Saint Bernard, 75005 Paris, France
| | - Céline Marban
- CNRS UMR 7224, Université Pierre et Marie Curie, 7 quai Saint Bernard, 75005 Paris, France
| | - Virginie Gautier
- Institut des Hautes Etudes Scientifiques-Centre National de la Recherche Scientifique, 35 route de Chartres, 91440 Bures sur Yvette, France
| | - Ermanno Candolfi
- University of Strasbourg, EA7292, DHPI, Institut of Parasitology and tropical pathology Strasbourg, France
| | - Arndt G Benecke
- Université Libre de Bruxelles (ULB), Service of Molecular Virology, Institute for Molecular Biology and Medicine (IBMM), 12 rue des Profs Jeener et Brachet, 6041 Gosselies, Belgium.,UCD Centre for Research in Infectious Diseases (CRID) School of Medicine and Medical Science University College Dublin, Ireland
| | - Carine Van Lint
- Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 242, Heidelberg 69120, Germany
| | - Olivier Rohr
- University of Strasbourg, EA7292, DHPI, Institut of Parasitology and tropical pathology Strasbourg, France.,University of Strasbourg, IUT Louis Pasteur, Schiltigheim, France.,Inserm UMR 1121 Faculté de Chirurgie Dentaire Pavillon Leriche 1, place de l'Hôpital Strasbourg, France
| | - Christian Schwartz
- University of Strasbourg, EA7292, DHPI, Institut of Parasitology and tropical pathology Strasbourg, France.,University of Strasbourg, IUT Louis Pasteur, Schiltigheim, France
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Marban C, Forouzanfar F, Ait-Ammar A, Fahmi F, El Mekdad H, Daouad F, Rohr O, Schwartz C. Targeting the Brain Reservoirs: Toward an HIV Cure. Front Immunol 2016; 7:397. [PMID: 27746784 PMCID: PMC5044677 DOI: 10.3389/fimmu.2016.00397] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 09/20/2016] [Indexed: 12/23/2022] Open
Abstract
One of the top research priorities of the international AIDS society by the action “Towards an HIV Cure” is the purge or the decrease of the pool of all latently infected cells. This strategy is based on reactivation of latently reservoirs (the shock) followed by an intensifying combination antiretroviral therapy (cART) to kill them (the kill). The central nervous system (CNS) has potential latently infected cells, i.e., perivascular macrophages, microglial cells, and astrocytes that will need to be eliminated. However, the CNS has several characteristics that may preclude the achievement of a cure. In this review, we discuss several limitations to the eradication of brain reservoirs and how we could circumvent these limitations by making it efforts in four directions: (i) designing efficient latency-reversal agents for CNS-cell types, (ii) improving cART by targeting HIV transcription, (iii) improving delivery of HIV drugs in the CNS and in the CNS-cell types, and (iv) developing therapeutic immunization. As a prerequisite to these efforts, we also believe that a better comprehension of molecular mechanisms involved in establishment and persistence of HIV latency in brain reservoirs are essential to design new molecules for strategies aiming to achieve a cure for instance the “shock and kill” strategy.
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Affiliation(s)
- Céline Marban
- INSERM UMR 1121 Faculté de Chirurgie Dentaire, Université de Strasbourg , Strasbourg , France
| | | | - Amina Ait-Ammar
- EA7292, DHPI, Université de Strasbourg , Strasbourg , France
| | - Faiza Fahmi
- EA7292, DHPI, Université de Strasbourg , Strasbourg , France
| | - Hala El Mekdad
- EA7292, DHPI, Université de Strasbourg, Strasbourg, France; IUT Louis Pasteur de Schiltigheim, Université de Strasbourg, Schiltigheim, France
| | - Fadoua Daouad
- EA7292, DHPI, Université de Strasbourg , Strasbourg , France
| | - Olivier Rohr
- EA7292, DHPI, Université de Strasbourg, Strasbourg, France; IUT Louis Pasteur de Schiltigheim, Université de Strasbourg, Schiltigheim, France; Institut Universitaire de France, Paris, France
| | - Christian Schwartz
- EA7292, DHPI, Université de Strasbourg, Strasbourg, France; IUT Louis Pasteur de Schiltigheim, Université de Strasbourg, Schiltigheim, France
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Eichhorn CD, Chug R, Feigon J. hLARP7 C-terminal domain contains an xRRM that binds the 3' hairpin of 7SK RNA. Nucleic Acids Res 2016; 44:9977-9989. [PMID: 27679474 PMCID: PMC5175362 DOI: 10.1093/nar/gkw833] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 09/02/2016] [Accepted: 09/10/2016] [Indexed: 12/21/2022] Open
Abstract
The 7SK small nuclear ribonucleoprotein (snRNP) sequesters and inactivates the positive transcription elongation factor b (P-TEFb), an essential eukaryotic mRNA transcription factor. The human La-related protein group 7 (hLARP7) is a constitutive component of the 7SK snRNP and localizes to the 3' terminus of the 7SK long noncoding RNA. hLARP7, and in particular its C-terminal domain (CTD), is essential for 7SK RNA stability and assembly with P-TEFb. The hLARP7 N-terminal La module binds and protects the 3' end from degradation, but the structural and functional role of its CTD is unclear. We report the solution NMR structure of the hLARP7 CTD and show that this domain contains an xRRM, a class of atypical RRM first identified in the Tetrahymena thermophila telomerase LARP7 protein p65. The xRRM binds the 3' end of 7SK RNA at the top of stem-loop 4 (SL4) and interacts with both unpaired and base-paired nucleotides. This study confirms that the xRRM is general to the LARP7 family of proteins and defines the binding site for hLARP7 on the 7SK RNA, providing insight into function.
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Affiliation(s)
- Catherine D Eichhorn
- Department of Chemistry and Biochemistry, P.O. Box 951569, University of California, Los Angeles, CA 90095-1569, USA
| | - Rahul Chug
- Department of Chemistry and Biochemistry, P.O. Box 951569, University of California, Los Angeles, CA 90095-1569, USA
| | - Juli Feigon
- Department of Chemistry and Biochemistry, P.O. Box 951569, University of California, Los Angeles, CA 90095-1569, USA
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32
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C Quaresma AJ, Bugai A, Barboric M. Cracking the control of RNA polymerase II elongation by 7SK snRNP and P-TEFb. Nucleic Acids Res 2016; 44:7527-39. [PMID: 27369380 PMCID: PMC5027500 DOI: 10.1093/nar/gkw585] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 06/17/2016] [Indexed: 01/01/2023] Open
Abstract
Release of RNA polymerase II (Pol II) from promoter-proximal pausing has emerged as a critical step regulating gene expression in multicellular organisms. The transition of Pol II into productive elongation requires the kinase activity of positive transcription elongation factor b (P-TEFb), which is itself under a stringent control by the inhibitory 7SK small nuclear ribonucleoprotein (7SK snRNP) complex. Here, we provide an overview on stimulating Pol II pause release by P-TEFb and on sequestering P-TEFb into 7SK snRNP. Furthermore, we highlight mechanisms that govern anchoring of 7SK snRNP to chromatin as well as means that release P-TEFb from the inhibitory complex, and propose a unifying model of P-TEFb activation on chromatin. Collectively, these studies shine a spotlight on the central role of RNA binding proteins (RBPs) in directing the inhibition and activation of P-TEFb, providing a compelling paradigm for controlling Pol II transcription with a non-coding RNA.
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Affiliation(s)
- Alexandre J C Quaresma
- Medicum, Department of Biochemistry and Developmental Biology, University of Helsinki, Helsinki FIN-00014, Finland
| | - Andrii Bugai
- Medicum, Department of Biochemistry and Developmental Biology, University of Helsinki, Helsinki FIN-00014, Finland
| | - Matjaz Barboric
- Medicum, Department of Biochemistry and Developmental Biology, University of Helsinki, Helsinki FIN-00014, Finland
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Le Douce V, Ait-Amar A, Forouzan Far F, Fahmi F, Quiel J, El Mekdad H, Daouad F, Marban C, Rohr O, Schwartz C. Improving combination antiretroviral therapy by targeting HIV-1 gene transcription. Expert Opin Ther Targets 2016; 20:1311-1324. [PMID: 27266557 DOI: 10.1080/14728222.2016.1198777] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
INTRODUCTION Combination Antiretroviral Therapy (cART) has not allowed the cure of HIV. The main obstacle to HIV eradication is the existence of quiescent reservoirs. Several other limitations of cART have been described, such as strict life-long treatment and high costs, restricting it to Western countries, as well as the development of multidrug resistance. Given these limitations and the impetus to find a cure, the development of new treatments is necessary. Areas covered: In this review, we discuss the current status of several efficient molecules able to suppress HIV gene transcription, including NF-kB and Tat inhibitors. We also assess the potential of new proteins belonging to the intriguing DING family, which have been reported to have potential anti-HIV-1 activity by inhibiting HIV gene transcription. Expert opinion: Targeting HIV-1 gene transcription is an alternative approach, which could overcome cART-related issues, such as the emergence of multidrug resistance. Improving cART will rely on the identification and characterization of new actors inhibiting HIV-1 transcription. Combining such efforts with the use of new technologies, the development of new models for preclinical studies, and improvement in drug delivery will considerably reduce drug toxicity and thus increase patient adherence.
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Affiliation(s)
- Valentin Le Douce
- a Institut de Parasitologie et de Pathologie Tropicale, EA7292 , Université de Strasbourg , Strasbourg , France.,b IUT de Schiltigheim , Schiltigheim , France.,c UCD Centre for Research in Infectious Diseases (CRID) School of Medicine and Medical Science , University College Dublin , Dublin 4 , Ireland
| | - Amina Ait-Amar
- a Institut de Parasitologie et de Pathologie Tropicale, EA7292 , Université de Strasbourg , Strasbourg , France
| | - Faezeh Forouzan Far
- a Institut de Parasitologie et de Pathologie Tropicale, EA7292 , Université de Strasbourg , Strasbourg , France
| | - Faiza Fahmi
- a Institut de Parasitologie et de Pathologie Tropicale, EA7292 , Université de Strasbourg , Strasbourg , France
| | - Jose Quiel
- a Institut de Parasitologie et de Pathologie Tropicale, EA7292 , Université de Strasbourg , Strasbourg , France
| | - Hala El Mekdad
- a Institut de Parasitologie et de Pathologie Tropicale, EA7292 , Université de Strasbourg , Strasbourg , France
| | - Fadoua Daouad
- a Institut de Parasitologie et de Pathologie Tropicale, EA7292 , Université de Strasbourg , Strasbourg , France
| | - Céline Marban
- d Faculté de Chirurgie Dentaire , Inserm UMR 1121 , Strasbourg , France
| | - Olivier Rohr
- a Institut de Parasitologie et de Pathologie Tropicale, EA7292 , Université de Strasbourg , Strasbourg , France.,b IUT de Schiltigheim , Schiltigheim , France.,e Institut Universitaire de France , Paris , France
| | - Christian Schwartz
- a Institut de Parasitologie et de Pathologie Tropicale, EA7292 , Université de Strasbourg , Strasbourg , France.,b IUT de Schiltigheim , Schiltigheim , France
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White CH, Moesker B, Ciuffi A, Beliakova-Bethell N. Systems biology applications to study mechanisms of human immunodeficiency virus latency and reactivation. World J Clin Infect Dis 2016; 6:6-21. [DOI: 10.5495/wjcid.v6.i2.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 01/15/2016] [Accepted: 03/09/2016] [Indexed: 02/06/2023] Open
Abstract
Eradication of human immunodeficiency virus (HIV) in infected individuals is currently not possible because of the presence of the persistent cellular reservoir of latent infection. The identification of HIV latency biomarkers and a better understanding of the molecular mechanisms contributing to regulation of HIV expression might provide essential tools to eliminate these latently infected cells. This review aims at summarizing gene expression profiling and systems biology applications to studies of HIV latency and eradication. Studies comparing gene expression in latently infected and uninfected cells identify candidate latency biomarkers and novel mechanisms of latency control. Studies that profiled gene expression changes induced by existing latency reversing agents (LRAs) highlight uniting themes driving HIV reactivation and novel mechanisms that contribute to regulation of HIV expression by different LRAs. Among the reviewed gene expression studies, the common approaches included identification of differentially expressed genes and gene functional category assessment. Integration of transcriptomic data with other biological data types is presently scarce, and the field would benefit from increased adoption of these methods in future studies. In addition, designing prospective studies that use the same methods of data acquisition and statistical analyses will facilitate a more reliable identification of latency biomarkers using different model systems and the comparison of the effects of different LRAs on host factors with a role in HIV reactivation. The results from such studies would have the potential to significantly impact the process by which candidate drugs are selected and combined for future evaluations and advancement to clinical trials.
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Abstract
The high mobility group protein A1 (HMGA1) is a master regulator of chromatin structure mediating its major gene regulatory activity by direct interactions with A/T-rich DNA sequences located in the promoter and enhancer regions of a large variety of genes. HMGA1 DNA-binding through three AT-hook motifs results in an open chromatin structure and subsequently leads to changes in gene expression. Apart from its significant expression during development, HMGA1 is over-expressed in virtually every cancer, where HMGA1 expression levels correlate with tumor malignancy. The exogenous overexpression of HMGA1 can lead to malignant cell transformation, assigning the protein a key role during cancerogenesis. Recent studies have unveiled highly specific competitive interactions of HMGA1 with cellular and viral RNAs also through an AT-hook domain of the protein, significantly impacting the HMGA1-dependent gene expression. In this review, we discuss the structure and function of HMGA1-RNA complexes during transcription and epigenomic regulation and their implications in HMGA1-related diseases.
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Shadrina OA, Knyazhanskaya ES, Korolev S, Gottikh MB. Host Proteins Ku and HMGA1 As Participants of HIV-1 Transcription. Acta Naturae 2016; 8:34-47. [PMID: 27099783 PMCID: PMC4837570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Human immunodeficiency virus type 1 is known to use the transcriptional machinery of the host cell for viral gene transcription, and the only viral protein that partakes in this process is Tat, the viral trans-activator of transcription. During acute infection, the binding of Tat to the hairpin at the beginning of the transcribed viral RNA recruits the PTEFb complex, which in turn hyperphosphorylates RNA-polymerase II and stimulates transcription elongation. Along with acute infection, HIV-1 can also lead to latent infection that is characterized by a low level of viral transcription. During the maintenance and reversal of latency, there are no detectable amounts of Tat protein in the cell and the mechanism of transcription activation in the absence of Tat protein remains unclear. The latency maintenance is also a problematic question. It seems evident that cellular proteins with a yet unknown nature or role regulate both transcriptional repression in the latent phase and its activation during transition into the lytic phase. The present review discusses the role of cellular proteins Ku and HMGA1 in the initiation of transcription elongation of the HIV-1 provirus. The review presents data regarding Ku-mediated HIV-1 transcription and its dependence on the promoter structure and the shape of viral DNA. We also describe the differential influence of the HMGA1 protein on the induced and basal transcription of HIV-1. Finally, we offer possible mechanisms for Ku and HMGA1 proteins in the proviral transcription regulation.
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Affiliation(s)
- O. A. Shadrina
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Leninskie Gory, Moscow, 119991, Russia
| | - E. S. Knyazhanskaya
- Chemistry Department, Lomonosov Moscow State University, Leninskie Gory, Moscow, 119991, Russia
| | - S.P. Korolev
- Chemistry Department, Lomonosov Moscow State University, Leninskie Gory, Moscow, 119991, Russia
| | - M. B. Gottikh
- Belozersky Institute of Physical-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory, Moscow, Russia; 119991
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Tyagi M, Weber J, Bukrinsky M, Simon GL. The effects of cocaine on HIV transcription. J Neurovirol 2015; 22:261-74. [PMID: 26572787 DOI: 10.1007/s13365-015-0398-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 10/01/2015] [Accepted: 10/21/2015] [Indexed: 11/29/2022]
Abstract
Illicit drug users are a high-risk population for infection with the human immunodeficiency virus (HIV). A strong correlation exists between prohibited drug use and an increased rate of HIV transmission. Cocaine stands out as one of the most frequently abused illicit drugs, and its use is correlated with HIV infection and disease progression. The central nervous system (CNS) is a common target for both drugs of abuse and HIV, and cocaine intake further accelerates neuronal injury in HIV patients. Although the high incidence of HIV infection in illicit drug abusers is primarily due to high-risk activities such as needle sharing and unprotected sex, several studies have demonstrated that cocaine enhances the rate of HIV gene expression and replication by activating various signal transduction pathways and downstream transcription factors. In order to generate mature HIV genomic transcript, HIV gene expression has to pass through both the initiation and elongation phases of transcription, which requires discrete transcription factors. In this review, we will provide a detailed analysis of the molecular mechanisms that regulate HIV transcription and discuss how cocaine modulates those mechanisms to upregulate HIV transcription and eventually HIV replication.
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Affiliation(s)
- Mudit Tyagi
- Division of Infectious Diseases, Department of Medicine, The George Washington University, 2300 Eye Street, N.W., Washington, DC, 20037, USA. .,Department of Microbiology, Immunology and Tropical Medicine, The George Washington University, Washington, DC, 20037, USA.
| | - Jaime Weber
- Division of Infectious Diseases, Department of Medicine, The George Washington University, 2300 Eye Street, N.W., Washington, DC, 20037, USA
| | - Michael Bukrinsky
- Department of Microbiology, Immunology and Tropical Medicine, The George Washington University, Washington, DC, 20037, USA
| | - Gary L Simon
- Division of Infectious Diseases, Department of Medicine, The George Washington University, 2300 Eye Street, N.W., Washington, DC, 20037, USA
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White CH, Johnston HE, Moesker B, Manousopoulou A, Margolis DM, Richman DD, Spina CA, Garbis SD, Woelk CH, Beliakova-Bethell N. Mixed effects of suberoylanilide hydroxamic acid (SAHA) on the host transcriptome and proteome and their implications for HIV reactivation from latency. Antiviral Res 2015; 123:78-85. [PMID: 26343910 PMCID: PMC5606336 DOI: 10.1016/j.antiviral.2015.09.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Revised: 08/22/2015] [Accepted: 09/03/2015] [Indexed: 02/06/2023]
Abstract
Suberoylanilide hydroxamic acid (SAHA) has been assessed in clinical trials as part of a "shock and kill" strategy to cure HIV-infected patients. While it was effective at inducing expression of HIV RNA ("shock"), treatment with SAHA did not result in a reduction of reservoir size ("kill"). We therefore utilized a combined analysis of effects of SAHA on the host transcriptome and proteome to dissect its mechanisms of action that may explain its limited success in "shock and kill" strategies. CD4+ T cells from HIV seronegative donors were treated with 1μM SAHA or its solvent dimethyl sulfoxide (DMSO) for 24h. Protein expression and post-translational modifications were measured with iTRAQ proteomics using ultra high-precision two-dimensional liquid chromatography-tandem mass spectrometry. Gene expression was assessed by Illumina microarrays. Using limma package in the R computing environment, we identified 185 proteins, 18 phosphorylated forms, 4 acetylated forms and 2982 genes, whose expression was modulated by SAHA. A protein interaction network integrating these 4 data types identified the HIV transcriptional repressor HMGA1 to be upregulated by SAHA at the transcript, protein and acetylated protein levels. Further functional category assessment of proteins and genes modulated by SAHA identified gene ontology terms related to NFκB signaling, protein folding and autophagy, which are all relevant to HIV reactivation. In summary, SAHA modulated numerous host cell transcripts, proteins and post-translational modifications of proteins, which would be expected to have very mixed effects on the induction of HIV-specific transcription and protein function. Proteome profiling highlighted a number of potential counter-regulatory effects of SAHA with respect to viral induction, which transcriptome profiling alone would not have identified. These observations could lead to a more informed selection and design of other HDACi with a more refined targeting profile, and prioritization of latency reversing agents of other classes to be used in combination with SAHA to achieve more potent induction of HIV expression.
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Affiliation(s)
- Cory H White
- Graduate Program in Bioinformatics and Systems Biology, University of California San Diego, La Jolla, CA 92093, USA; San Diego VA Medical Center and Veterans Medical Research Foundation, San Diego, CA 92161, USA
| | - Harvey E Johnston
- Cancer Sciences Faculty of Medicine, University of Southampton, Southampton, Hants SO16 6YD, UK; Centre for Proteomic Research, Institute for Life Sciences, University of Southampton, Highfield Campus, Southampton, UK
| | - Bastiaan Moesker
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, Hants SO16 6YD, UK
| | - Antigoni Manousopoulou
- Centre for Proteomic Research, Institute for Life Sciences, University of Southampton, Highfield Campus, Southampton, UK; Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, Hants SO16 6YD, UK
| | - David M Margolis
- Departments of Medicine, Microbiology and Immunology, Epidemiology, University of North Carolina, Chapel Hill, NC, USA
| | - Douglas D Richman
- San Diego VA Medical Center and Veterans Medical Research Foundation, San Diego, CA 92161, USA; Department of Pathology, University of California San Diego, La Jolla, CA 92093, USA; Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Celsa A Spina
- San Diego VA Medical Center and Veterans Medical Research Foundation, San Diego, CA 92161, USA; Department of Pathology, University of California San Diego, La Jolla, CA 92093, USA
| | - Spiros D Garbis
- Cancer Sciences Faculty of Medicine, University of Southampton, Southampton, Hants SO16 6YD, UK; Centre for Proteomic Research, Institute for Life Sciences, University of Southampton, Highfield Campus, Southampton, UK; Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, Hants SO16 6YD, UK.
| | - Christopher H Woelk
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, Hants SO16 6YD, UK.
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An In-Depth Comparison of Latency-Reversing Agent Combinations in Various In Vitro and Ex Vivo HIV-1 Latency Models Identified Bryostatin-1+JQ1 and Ingenol-B+JQ1 to Potently Reactivate Viral Gene Expression. PLoS Pathog 2015. [PMID: 26225566 PMCID: PMC4520688 DOI: 10.1371/journal.ppat.1005063] [Citation(s) in RCA: 210] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The persistence of latently infected cells in patients under combinatory antiretroviral therapy (cART) is a major hurdle to HIV-1 eradication. Strategies to purge these reservoirs are needed and activation of viral gene expression in latently infected cells is one promising strategy. Bromodomain and Extraterminal (BET) bromodomain inhibitors (BETi) are compounds able to reactivate latent proviruses in a positive transcription elongation factor b (P-TEFb)-dependent manner. In this study, we tested the reactivation potential of protein kinase C (PKC) agonists (prostratin, bryostatin-1 and ingenol-B), which are known to activate NF-κB signaling pathway as well as P-TEFb, used alone or in combination with P-TEFb-releasing agents (HMBA and BETi (JQ1, I-BET, I-BET151)). Using in vitro HIV-1 post-integration latency model cell lines of T-lymphoid and myeloid lineages, we demonstrated that PKC agonists and P-TEFb-releasing agents alone acted as potent latency-reversing agents (LRAs) and that their combinations led to synergistic activation of HIV-1 expression at the viral mRNA and protein levels. Mechanistically, combined treatments led to higher activations of P-TEFb and NF-κB than the corresponding individual drug treatments. Importantly, we observed in ex vivo cultures of CD8+-depleted PBMCs from 35 cART-treated HIV-1+ aviremic patients that the percentage of reactivated cultures following combinatory bryostatin-1+JQ1 treatment was identical to the percentage observed with anti-CD3+anti-CD28 antibodies positive control stimulation. Remarkably, in ex vivo cultures of resting CD4+ T cells isolated from 15 HIV-1+ cART-treated aviremic patients, the combinations bryostatin-1+JQ1 and ingenol-B+JQ1 released infectious viruses to levels similar to that obtained with the positive control stimulation. The potent effects of these two combination treatments were already detected 24 hours post-stimulation. These results constitute the first demonstration of LRA combinations exhibiting such a potent effect and represent a proof-of-concept for the co-administration of two different types of LRAs as a potential strategy to reduce the size of the latent HIV-1 reservoirs. Persistence of latently infected cells during cART is a major hurdle for HIV-1 eradication. A widely proposed strategy to purge these reservoirs involves the reactivation of latent proviruses. The low levels of active P-TEFb and the cytoplasmic sequestration of NF-κB in resting infected cells largely contribute to maintenance of HIV-1 latency. Therefore, utilization of chemical compounds that target both pathways may lead to more potent effects on HIV-1 reactivation than the effect mediated by the individual drug treatments. In this study, we showed that combined treatments of PKC agonists (prostratin, bryostatin-1 and ing-B) with compounds releasing P-TEFb (JQ1, I-BET, I-BET151 and HMBA) exhibited a synergistic increase in viral reactivation from latency. In-depth comparison of combined treatments in various in vitro cellular models of HIV-1 latency as well as in ex vivo primary cell cultures from cART-treated HIV+ aviremic patients identified bryostatin-1+JQ1 and ing-B+JQ1 to potently reactivate latent HIV-1. The potent effects of these two combinations were detected as early as 24 hours post-treatment. Importantly, bryostatin-1 was used at concentrations below the drug plasma levels achieved by doses used in children with refractory solid tumors. Our mechanistic data established a correlation between potentiated P-TEFb activation and potentiated or synergistic (depending on the HIV-1 latency cellular model used) induction of HIV-1 gene expression observed after the combined versus individual drug treatments. In conclusion, our results establish a proof-of-concept for PKC agonists combined with compounds releasing active P-TEFb as a strategy proposed for a cure or a durable remission of HIV infection.
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Tyagi M, Iordanskiy S, Ammosova T, Kumari N, Smith K, Breuer D, Ilatovskiy AV, Kont YS, Ivanov A, Üren A, Kovalskyy D, Petukhov M, Kashanchi F, Nekhai S. Reactivation of latent HIV-1 provirus via targeting protein phosphatase-1. Retrovirology 2015; 12:63. [PMID: 26178009 PMCID: PMC4504130 DOI: 10.1186/s12977-015-0190-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2014] [Accepted: 07/09/2015] [Indexed: 11/23/2022] Open
Abstract
Background HIV-1 escapes antiretroviral drugs by integrating into the host DNA and forming a latent transcriptionally silent HIV-1 provirus. This provirus presents the major hurdle in HIV-1 eradication and cure. Transcriptional activation, which is prerequisite for reactivation and the eradication of latent proviruses, is impaired in latently infected T cells due to the lack of host transcription factors, primarily NF-κB and P-TEFb (CDK9/cyclin T1). We and others previously showed that protein phosphatase-1 (PP1) regulates HIV-1 transcription by modulating CDK9 phosphorylation. Recently we have developed a panel of small molecular compounds targeting a non-catalytic site of PP1. Results Here we generated a new class of sulfonamide-containing compounds that activated HIV-1 in acute and latently infected cells. Among the tested molecules, a small molecule activator of PP1 (SMAPP1) induced both HIV-1 replication and reactivation of latent HIV-1 in chronically infected cultured and primary cells. In vitro, SMAPP1 interacted with PP1 and increased PP1 activity toward a recombinant substrate. Treatment with SMAPP1 increased phosphorylation of CDK9’s Ser90 and Thr186 residues, but not Ser175. Proteomic analysis showed upregulation of P-TEFb and PP1 related proteins, including PP1 regulatory subunit Sds22 in SMAPP1-treated T cells. Docking analysis identified a PP1 binding site for SMAPP1 located within the C-terminal binding pocket of PP1. Conclusion We identified a novel class of PP1-targeting compounds that reactivate latent HIV-1 provirus by targeting PP1, increasing CDK9 phosphorylation and enhancing HIV transcription. This compound represents a novel candidate for anti-HIV-1 therapeutics aiming at eradication of latent HIV-1 reservoirs.
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Affiliation(s)
- Mudit Tyagi
- Department of Medicine, The George Washington University, Washington, DC, 2003, USA.
| | - Sergey Iordanskiy
- National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, VA, 20110, USA.
| | - Tatyana Ammosova
- Center for Sickle Cell Disease, Howard University, 1840 7th Street, N.W. HURB1, Suite 202, Washington, DC, 20059, USA. .,Department of Medicine, Howard University, Washington, DC, 20059, USA. .,Yakut Science Center for Complex Medical Problems, Yakutsk, 677019, Russia.
| | - Namita Kumari
- Center for Sickle Cell Disease, Howard University, 1840 7th Street, N.W. HURB1, Suite 202, Washington, DC, 20059, USA.
| | - Kahli Smith
- Center for Sickle Cell Disease, Howard University, 1840 7th Street, N.W. HURB1, Suite 202, Washington, DC, 20059, USA.
| | - Denitra Breuer
- Center for Sickle Cell Disease, Howard University, 1840 7th Street, N.W. HURB1, Suite 202, Washington, DC, 20059, USA.
| | - Andrey V Ilatovskiy
- Division of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute, Gatchina, Russia. .,Instiute of Nanobiotechnologies, St. Petersburg State Polytechnical University, St. Petersburg, Russia.
| | | | - Andrey Ivanov
- Center for Sickle Cell Disease, Howard University, 1840 7th Street, N.W. HURB1, Suite 202, Washington, DC, 20059, USA.
| | - Aykut Üren
- Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC, 20057, USA.
| | - Dmytro Kovalskyy
- Department of Biochemistry and Cancer Therapy and Research Center, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, 78229, USA.
| | - Michael Petukhov
- Division of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute, Gatchina, Russia. .,Instiute of Nanobiotechnologies, St. Petersburg State Polytechnical University, St. Petersburg, Russia.
| | - Fatah Kashanchi
- National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, VA, 20110, USA.
| | - Sergei Nekhai
- Center for Sickle Cell Disease, Howard University, 1840 7th Street, N.W. HURB1, Suite 202, Washington, DC, 20059, USA. .,Department of Medicine, Howard University, Washington, DC, 20059, USA.
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Eradication of HIV-1 from the macrophage reservoir: an uncertain goal? Viruses 2015; 7:1578-98. [PMID: 25835530 PMCID: PMC4411666 DOI: 10.3390/v7041578] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Revised: 03/16/2015] [Accepted: 03/24/2015] [Indexed: 12/13/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) establishes latency in resting memory CD4+ T cells and cells of myeloid lineage. In contrast to the T cells, cells of myeloid lineage are resistant to the HIV-1 induced cytopathic effect. Cells of myeloid lineage including macrophages are present in anatomical sanctuaries making them a difficult drug target. In addition, the long life span of macrophages as compared to the CD4+ T cells make them important viral reservoirs in infected individuals especially in the late stage of viral infection where CD4+ T cells are largely depleted. In the past decade, HIV-1 persistence in resting CD4+ T cells has gained considerable attention. It is currently believed that rebound viremia following cessation of combination anti-retroviral therapy (cART) originates from this source. However, the clinical relevance of this reservoir has been questioned. It is suggested that the resting CD4+ T cells are only one source of residual viremia and other viral reservoirs such as tissue macrophages should be seriously considered. In the present review we will discuss how macrophages contribute to the development of long-lived latent reservoirs and how macrophages can be used as a therapeutic target in eradicating latent reservoir.
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Meulendyke KA, Croteau JD, Zink MC. HIV life cycle, innate immunity and autophagy in the central nervous system. Curr Opin HIV AIDS 2014; 9:565-71. [PMID: 25203639 PMCID: PMC4212891 DOI: 10.1097/coh.0000000000000106] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE OF REVIEW In this era of modern combination antiretroviral therapy (cART) HIV-associated neurocognitive disorders (HAND) continue to affect a large portion of the infected population. In this review, we highlight recent discoveries that help to define the interplay between HIV life cycle, the innate immune system and cellular autophagy in the context of the central nervous system (CNS). RECENT FINDINGS Investigators have recently elucidated themes in HAND, which place it in a unique framework. Cells of macrophage lineage and probably astrocytes play a role in disseminating virus through the CNS. Each of these cell types responds to a diverse population of constantly evolving virus existing in an inflammatory environment. This occurs though the failure of both host antiviral mechanisms, such as autophagy, and innate immunological signalling pathways to control viral replication. SUMMARY The newest findings detailed in this review help define why HIV CNS disease is a difficult target for therapeutics and create hope that these new mechanisms may be exploited to attenuate viral replication and eliminate disease.
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Affiliation(s)
- Kelly A. Meulendyke
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Joshua D. Croteau
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - M. Christine Zink
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205
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