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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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Abdalla AL, Guajardo-Contreras G, Mouland AJ. A Canadian Survey of Research on HIV-1 Latency-Where Are We Now and Where Are We Heading? Viruses 2024; 16:229. [PMID: 38400005 PMCID: PMC10891605 DOI: 10.3390/v16020229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 01/26/2024] [Accepted: 01/30/2024] [Indexed: 02/25/2024] Open
Abstract
Worldwide, almost 40 million people are currently living with HIV-1. The implementation of cART inhibits HIV-1 replication and reduces viremia but fails to eliminate HIV-1 from latently infected cells. These cells are considered viral reservoirs from which HIV-1 rebounds if cART is interrupted. Several efforts have been made to identify these cells and their niches. There has been little success in diminishing the pool of latently infected cells, underscoring the urgency to continue efforts to fully understand how HIV-1 establishes and maintains a latent state. Reactivating HIV-1 expression in these cells using latency-reversing agents (LRAs) has been successful, but only in vitro. This review aims to provide a broad view of HIV-1 latency, highlighting Canadian contributions toward these aims. We will summarize the research efforts conducted in Canadian labs to understand the establishment of latently infected cells and how this informs curative strategies, by reviewing how HIV latency is established, which cells are latently infected, what methodologies have been developed to characterize them, how new compounds are discovered and evaluated as potential LRAs, and what clinical trials aim to reverse latency in people living with HIV (PLWH).
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Affiliation(s)
- Ana Luiza Abdalla
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montreal, QC H3T 1E2, Canada; (A.L.A.); (G.G.-C.)
- Department of Microbiology and Immunology, McGill University, Montreal, QC H3A 2B4, Canada
| | - Gabriel Guajardo-Contreras
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montreal, QC H3T 1E2, Canada; (A.L.A.); (G.G.-C.)
- Department of Medicine, McGill University, Montreal, QC H4A 3J1, Canada
| | - Andrew J. Mouland
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montreal, QC H3T 1E2, Canada; (A.L.A.); (G.G.-C.)
- Department of Microbiology and Immunology, McGill University, Montreal, QC H3A 2B4, Canada
- Department of Medicine, McGill University, Montreal, QC H4A 3J1, Canada
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Zhou Z, Jiang Y, Zhong X, Yang J, Yang G. Characteristics and mechanisms of latency-reversing agents in the activation of the human immunodeficiency virus 1 reservoir. Arch Virol 2023; 168:301. [PMID: 38019293 DOI: 10.1007/s00705-023-05931-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 10/23/2023] [Indexed: 11/30/2023]
Abstract
The "Shock and Kill" method is being considered as a potential treatment for eradicating HIV-1 and achieving a functional cure for acquired immunodeficiency syndrome (AIDS). This approach involves using latency-reversing agents (LRAs) to activate human immunodeficiency virus (HIV-1) transcription in latent cells, followed by treatment with antiviral drugs to kill these cells. Although LRAs have shown promise in HIV-1 patient research, their widespread clinical use is hindered by side effects and limitations. In this review, we categorize and explain the mechanisms of these agonists in activating HIV-1 in vivo and discuss their advantages and disadvantages. In the future, combining different HIV-1 LRAs may overcome their respective shortcomings and facilitate a functional cure for HIV-1.
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Affiliation(s)
- Zhujiao Zhou
- Department of Clinical Medicine, School of Medicine, Hangzhou City University, Hangzhou, China
- College of Pharmacy, Zhejiang University of Technology, Hangzhou, 310013, China
| | - Yashuang Jiang
- Department of Clinical Medicine, School of Medicine, Hangzhou City University, Hangzhou, China
| | - Xinyu Zhong
- Department of Clinical Medicine, School of Medicine, Hangzhou City University, Hangzhou, China
- College of Pharmacy, Zhejiang University of Technology, Hangzhou, 310013, China
| | - Jingyi Yang
- Department of Clinical Medicine, School of Medicine, Hangzhou City University, Hangzhou, China
| | - Geng Yang
- Department of Clinical Medicine, School of Medicine, Hangzhou City University, Hangzhou, China.
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province, School of Medicine, Hangzhou City University, Hangzhou, 310013, China.
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Horvath RM, Brumme ZL, Sadowski I. CDK8 inhibitors antagonize HIV-1 reactivation and promote provirus latency in T cells. J Virol 2023; 97:e0092323. [PMID: 37671866 PMCID: PMC10537590 DOI: 10.1128/jvi.00923-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 07/15/2023] [Indexed: 09/07/2023] Open
Abstract
Latent HIV-1 provirus represents the barrier toward a cure for infection and is dependent upon the host RNA Polymerase (Pol) II machinery for reemergence. Here, we find that inhibitors of the RNA Pol II mediator kinases CDK8/19, Senexin A and BRD6989, inhibit induction of HIV-1 expression in response to latency-reversing agents and T cell signaling agonists. These inhibitors were found to impair recruitment of RNA Pol II to the HIV-1 LTR. Furthermore, HIV-1 expression in response to several latency reversal agents was impaired upon disruption of CDK8 by shRNA or gene knockout. However, the effects of CDK8 depletion did not entirely mimic CDK8/19 kinase inhibition suggesting that the mediator kinases are not functionally redundant. Additionally, treatment of CD4+ peripheral blood mononuclear cells isolated from people living with HIV-1 and who are receiving antiretroviral therapy with Senexin A inhibited induction of viral replication in response to T cell stimulation by PMA and ionomycin. These observations indicate that the mediator kinases, CDK8 and CDK19, play a significant role for regulation of HIV-1 transcription and that small molecule inhibitors of these enzymes may contribute to therapies designed to promote deep latency involving the durable suppression of provirus expression. IMPORTANCE A cure for HIV-1 infection will require novel therapies that can force elimination of cells that contain copies of the virus genome inserted into the cell chromosome, but which is shut off, or silenced. These are known as latently-infected cells, which represent the main reason why current treatment for HIV/AIDS cannot cure the infection because the virus in these cells is unaffected by current drugs. Our results indicate that chemical inhibitors of Cdk8 also inhibit the expression of latent HIV provirus. Cdk8 is an important enzyme that regulates the expression of genes in response to signals to which cells need to respond and which is produced by a gene that is frequently mutated in cancers. Our observations indicate that Cdk8 inhibitors may be employed in novel therapies to prevent expression from latent provirus, which might eventually enable infected individuals to cease treatment with antiretroviral drugs.
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Affiliation(s)
- Riley M. Horvath
- Department of Biochemistry and Molecular Biology, Molecular Epigenetics Group, LSI, University of British Columbia, Vancouver, British Columbia, Canada
| | - Zabrina L. Brumme
- Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
- British Columbia Centre for Excellence in HIV/AIDS, Vancouver, British Columbia, Canada
| | - Ivan Sadowski
- Department of Biochemistry and Molecular Biology, Molecular Epigenetics Group, LSI, University of British Columbia, Vancouver, British Columbia, Canada
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5
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Horvath RM, Sadowski I. Upstream Stimulatory Factors Regulate HIV-1 Latency and Are Required for Robust T Cell Activation. Viruses 2023; 15:1470. [PMID: 37515158 PMCID: PMC10384547 DOI: 10.3390/v15071470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 06/25/2023] [Accepted: 06/26/2023] [Indexed: 07/30/2023] Open
Abstract
HIV-1 provirus expression is controlled by signaling pathways that are responsive to T cell receptor engagement, including those involving Ras and downstream protein kinases. The induction of transcription from the HIV-1 LTR in response to Ras signaling requires binding of the Ras-responsive element binding factor (RBF-2) to conserved cis elements flanking the enhancer region, designated RBE3 and RBE1. RBF-2 is composed minimally of the USF1, USF2, and TFII-I transcription factors. We recently determined that TFII-I regulates transcriptional elongation from the LTR through recruitment of the co-activator TRIM24. However, the function of USF1 and USF2 for this effect are uncharacterized. Here, we find that genetic deletion of USF2 but not USF1 in T cells inhibits HIV-1 expression. The loss of USF2 caused a reduction in expression of the USF1 protein, an effect that was not associated with decreased USF1 mRNA abundance. USF1 and USF2 were previously shown to exist predominately as heterodimers and to cooperatively regulate target genes. To examine cooperativity between these factors, we performed RNA-seq analysis of T cell lines bearing knockouts of the genes encoding these factors. In untreated cells, we found limited evidence of coordinated global gene regulation between USF1 and USF2. In contrast, we observed a high degree of genome-wide cooperative regulation of RNA expression between these factors in cells stimulated with the combination of PMA and ionomycin. In particular, we found that the deletion of USF1 or USF2 restricted T cell activation response. These observations indicate that USF2, but not USF1, is crucial for HIV-1 expression, while the combined function of these factors is required for a robust T cell inflammatory response.
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Affiliation(s)
- Riley M Horvath
- Molecular Epigenetics Group, Department of Biochemistry and Molecular Biology, LSI, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Ivan Sadowski
- Molecular Epigenetics Group, Department of Biochemistry and Molecular Biology, LSI, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
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Horvath RM, Dahabieh M, Malcolm T, Sadowski I. TRIM24 controls induction of latent HIV-1 by stimulating transcriptional elongation. Commun Biol 2023; 6:86. [PMID: 36690785 PMCID: PMC9870992 DOI: 10.1038/s42003-023-04484-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 01/15/2023] [Indexed: 01/24/2023] Open
Abstract
Binding of USF1/2 and TFII-I (RBF-2) at conserved sites flanking the HIV-1 LTR enhancer is essential for reactivation from latency in T cells, with TFII-I knockdown rendering the provirus insensitive to T cell signaling. We identified an interaction of TFII-I with the tripartite motif protein TRIM24, and these factors were found to be constitutively associated with the HIV-1 LTR. Similar to the effect of TFII-I depletion, loss of TRIM24 impaired reactivation of HIV-1 in response to T cell signaling. TRIM24 deficiency did not affect recruitment of RNA Pol II to the LTR promoter, but inhibited transcriptional elongation, an effect that was associated with decreased RNA Pol II CTD S2 phosphorylation and impaired recruitment of CDK9. A considerable number of genomic loci are co-occupied by TRIM24/TFII-I, and we found that TRIM24 deletion caused altered T cell immune response, an effect that is facilitated by TFII-I. These results demonstrate a role of TRIM24 for regulation of transcriptional elongation from the HIV-1 promoter, through its interaction with TFII-I, and by recruitment of P-TEFb. Furthermore, these factors co-regulate a significant proportion of genes involved in T cell immune response, consistent with tight coupling of HIV-1 transcriptional activation and T cell signaling.
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Affiliation(s)
- Riley M Horvath
- Department of Biochemistry and Molecular Biology, Molecular Epigenetics Group, LSI, University of British Columbia, Vancouver, B.C., Canada
| | - Matthew Dahabieh
- Department of Biochemistry and Molecular Biology, Molecular Epigenetics Group, LSI, University of British Columbia, Vancouver, B.C., Canada
| | - Tom Malcolm
- Department of Biochemistry and Molecular Biology, Molecular Epigenetics Group, LSI, University of British Columbia, Vancouver, B.C., Canada
| | - Ivan Sadowski
- Department of Biochemistry and Molecular Biology, Molecular Epigenetics Group, LSI, University of British Columbia, Vancouver, B.C., Canada.
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Medicinal Chemistry of Anti-HIV-1 Latency Chemotherapeutics: Biotargets, Binding Modes and Structure-Activity Relationship Investigation. MOLECULES (BASEL, SWITZERLAND) 2022; 28:molecules28010003. [PMID: 36615199 PMCID: PMC9822059 DOI: 10.3390/molecules28010003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/12/2022] [Accepted: 12/15/2022] [Indexed: 12/24/2022]
Abstract
The existence of latent viral reservoirs (LVRs), also called latent cells, has long been an acknowledged stubborn hurdle for effective treatment of HIV-1/AIDS. This stable and heterogeneous reservoir, which mainly exists in resting memory CD4+ T cells, is not only resistant to highly active antiretroviral therapy (HAART) but cannot be detected by the immune system, leading to rapid drug resistance and viral rebound once antiviral treatment is interrupted. Accordingly, various functional cure strategies have been proposed to combat this barrier, among which one of the widely accepted and utilized protocols is the so-called 'shock-and-kill' regimen. The protocol begins with latency-reversing agents (LRAs), either alone or in combination, to reactivate the latent HIV-1 proviruses, then eliminates them by viral cytopathic mechanisms (e.g., currently available antiviral drugs) or by the immune killing function of the immune system (e.g., NK and CD8+ T cells). In this review, we focuse on the currently explored small molecular LRAs, with emphasis on their mechanism-directed drug targets, binding modes and structure-relationship activity (SAR) profiles, aiming to provide safer and more effective remedies for treating HIV-1 infection.
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8
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Chen J, Zhou T, Zhang Y, Luo S, Chen H, Chen D, Li C, Li W. The reservoir of latent HIV. Front Cell Infect Microbiol 2022; 12:945956. [PMID: 35967854 PMCID: PMC9368196 DOI: 10.3389/fcimb.2022.945956] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 06/30/2022] [Indexed: 11/13/2022] Open
Abstract
The persistence of latent reservoir of the human immunodeficiency virus (HIV) is currently the major challenge in curing HIV infection. After HIV infects the human body, the latent HIV is unable to be recognized by the body’s immune system. Currently, the widely adopted antiretroviral therapy (ART) is also unble to eliminate it, thus hindering the progress of HIV treatment. This review discusses the existence of latent HIV vault for HIV treatment, its formation and factors affecting its formation, cell, and tissue localization, methods for detection and removing latent reservoir, to provide a comprehensive understanding of latent HIV vault, in order to assist in the future research and play a potential role in achieving HIV treatment.
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Affiliation(s)
- Jing Chen
- Beijing Institute of Hepatology, Beijing Youan Hospital, Capital Medical University, Beijing, China
| | - Tong Zhou
- Xiangya School of Medicine, Central South University, Changsha, China
| | - Yuan Zhang
- Beijing Youan Hospital, Capital Medical University, Beijing, China
| | - Shumin Luo
- Beijing Institute of Hepatology, Beijing Youan Hospital, Capital Medical University, Beijing, China
| | - Huan Chen
- Beijing Youan Hospital, Capital Medical University, Beijing, China
| | - Dexi Chen
- Beijing Institute of Hepatology, Beijing Youan Hospital, Capital Medical University, Beijing, China
| | - Chuanyun Li
- Beijing Youan Hospital, Capital Medical University, Beijing, China
- *Correspondence: Chuanyun Li, ; Weihua Li,
| | - Weihua Li
- Beijing Institute of Hepatology, Beijing Youan Hospital, Capital Medical University, Beijing, China
- *Correspondence: Chuanyun Li, ; Weihua Li,
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Abstract
Combinatory antiretroviral therapy (cART) reduces human immunodeficiency virus type 1 (HIV-1) replication but is not curative because cART interruption almost invariably leads to a rapid rebound of viremia due to the persistence of stable HIV-1-infected cellular reservoirs. These reservoirs are mainly composed of CD4+ T cells harboring replication-competent latent proviruses. A broadly explored approach to reduce the HIV-1 reservoir size, the shock and kill strategy, consists of reactivating HIV-1 gene expression from the latently infected cellular reservoirs (the shock), followed by killing of the virus-producing infected cells (the kill). Based on improved understanding of the multiple molecular mechanisms controlling HIV-1 latency, distinct classes of latency reversing agents (LRAs) have been studied for their efficiency to reactivate viral gene expression in in vitro and ex vivo cell models. Here, we provide an up-to-date review of these different mechanistic classes of LRAs and discuss optimizations of the shock strategy by combining several LRAs simultaneously or sequentially.
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Affiliation(s)
- Anthony Rodari
- Service of Molecular Virology, Department of Molecular Biology, Université Libre de Bruxelles (ULB), 6041 Gosselies, Belgium;
| | - Gilles Darcis
- Infectious Diseases Department, Liège University Hospital, 4000 Liège, Belgium
| | - Carine M Van Lint
- Service of Molecular Virology, Department of Molecular Biology, Université Libre de Bruxelles (ULB), 6041 Gosselies, Belgium;
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Potential Utility of Natural Killer Cells for Eliminating Cells Harboring Reactivated Latent HIV-1 Following the Removal of CD8 + T Cell-Mediated Pro-Latency Effect(s). Viruses 2021; 13:v13081451. [PMID: 34452317 PMCID: PMC8402732 DOI: 10.3390/v13081451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 07/14/2021] [Accepted: 07/15/2021] [Indexed: 11/17/2022] Open
Abstract
An impediment to curing HIV-1 infection is the persistence of latently infected cells in ART-treated people living with HIV (PLWH). A key strategy for curing HIV-1 infection is to activate transcription and translation of latent virus using latency reversing agents (LRAs) and eliminate cells harboring reactivated virus via viral cytopathic effect or immune clearance. In this review, we provide an overview of available LRAs and their use in clinical trials. Furthermore, we describe recent data suggesting that CD8+ T cells promote HIV-1 latency in the context of ART, even in the presence of LRAs, which might at least partially explain the clinical inefficiency of previous “shock and kill” trials. Here, we propose a novel cure strategy called “unlock, shock, disarm, and kill”. The general premise of this strategy is to shut down the pro-latency function(s) of CD8+ T cells, use LRAs to reverse HIV-1 latency, counteract anti-apoptotic molecules, and engage natural killer (NK) cells to mediate the killing of cells harboring reactivated latent HIV-1.
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Fujinaga K, Cary DC. Experimental Systems for Measuring HIV Latency and Reactivation. Viruses 2020; 12:v12111279. [PMID: 33182414 PMCID: PMC7696534 DOI: 10.3390/v12111279] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 11/02/2020] [Accepted: 11/05/2020] [Indexed: 02/07/2023] Open
Abstract
The final obstacle to achieving a cure to HIV/AIDS is the presence of latent HIV reservoirs scattered throughout the body. Although antiretroviral therapy maintains plasma viral loads below the levels of detection, upon cessation of therapy, the latent reservoir immediately produces infectious progeny viruses. This results in elevated plasma viremia, which leads to clinical progression to AIDS. Thus, if a HIV cure is ever to become a reality, it will be necessary to target and eliminate the latent reservoir. To this end, tremendous effort has been dedicated to locate the viral reservoir, understand the mechanisms contributing to latency, find optimal methods to reactivate HIV, and specifically kill latently infected cells. Although we have not yet identified a therapeutic approach to completely eliminate HIV from patients, these efforts have provided many technological breakthroughs in understanding the underlying mechanisms that regulate HIV latency and reactivation in vitro. In this review, we summarize and compare experimental systems which are frequently used to study HIV latency. While none of these models are a perfect proxy for the complex systems at work in HIV+ patients, each aim to replicate HIV latency in vitro.
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Affiliation(s)
- Koh Fujinaga
- Division of Rheumatology, Department of Medicine, School of Medicine, University of California, San Francisco, CA 94143-0703, USA
- Correspondence: ; Tel.: +1-415-502-1908
| | - Daniele C. Cary
- Department of Medicine, Microbiology, and Immunology, School of Medicine, University of California, San Francisco, CA 94143-0703, USA;
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Sahay B, Mergia A. The Potential Contribution of Caveolin 1 to HIV Latent Infection. Pathogens 2020; 9:pathogens9110896. [PMID: 33121153 PMCID: PMC7692328 DOI: 10.3390/pathogens9110896] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 10/22/2020] [Accepted: 10/23/2020] [Indexed: 12/25/2022] Open
Abstract
Combinatorial antiretroviral therapy (cART) suppresses HIV replication to undetectable levels and has been effective in prolonging the lives of HIV infected individuals. However, cART is not capable of eradicating HIV from infected individuals mainly due to HIV’s persistence in small reservoirs of latently infected resting cells. Latent infection occurs when the HIV-1 provirus becomes transcriptionally inactive and several mechanisms that contribute to the silencing of HIV transcription have been described. Despite these advances, latent infection remains a major hurdle to cure HIV infected individuals. Therefore, there is a need for more understanding of novel mechanisms that are associated with latent infection to purge HIV from infected individuals thoroughly. Caveolin 1(Cav-1) is a multifaceted functional protein expressed in many cell types. The expression of Cav-1 in lymphocytes has been controversial. Recent evidence, however, convincingly established the expression of Cav-1 in lymphocytes. In lieu of this finding, the current review examines the potential role of Cav-1 in HIV latent infection and provides a perspective that helps uncover new insights to understand HIV latent infection.
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Affiliation(s)
| | - Ayalew Mergia
- Correspondence: ; Tel.: +352-294-4139; Fax: +352-392-9704
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X-Linked RNA-Binding Motif Protein Modulates HIV-1 Infection of CD4 + T Cells by Maintaining the Trimethylation of Histone H3 Lysine 9 at the Downstream Region of the 5' Long Terminal Repeat of HIV Proviral DNA. mBio 2020; 11:mBio.03424-19. [PMID: 32317327 PMCID: PMC7175097 DOI: 10.1128/mbio.03424-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
HIV-1 latency featuring silence of transcription from HIV-1 proviral DNA represents a major obstacle for HIV-1 eradication. Reversible repression of HIV-1 5′-LTR-mediated transcription represents the main mechanism for HIV-1 to maintain latency. The 5′-LTR-driven HIV gene transcription can be modulated by multiple host factors and mechanisms. The hnRNPs are known to regulate gene expression. A member of the hnRNP family, RBMX, has been identified in this study as a novel HIV-1 restriction factor that modulates HIV-1 5′-LTR-driven transcription of viral genome in CD4+ T cells and maintains viral latency. These findings provide a new understanding of how host factors modulate HIV-1 infection and latency and suggest a potential new target for the development of HIV-1 therapies. Reversible repression of HIV-1 5′ long terminal repeat (5′-LTR)-mediated transcription represents the main mechanism for HIV-1 to maintain latency. Identification of host factors that modulate LTR activity and viral latency may help develop new antiretroviral therapies. The heterogeneous nuclear ribonucleoproteins (hnRNPs) are known to regulate gene expression and possess multiple physiological functions. hnRNP family members have recently been identified as the sensors for viral nucleic acids to induce antiviral responses, highlighting the crucial roles of hnRNPs in regulating viral infection. A member of the hnRNP family, X-linked RNA-binding motif protein (RBMX), has been identified in this study as a novel HIV-1 restriction factor that modulates HIV-1 5′-LTR-driven transcription of viral genome in CD4+ T cells. Mechanistically, RBMX binds to HIV-1 proviral DNA at the LTR downstream region and maintains the repressive trimethylation of histone H3 lysine 9 (H3K9me3), leading to a blockage of the recruitment of the positive transcription factor phosphorylated RNA polymerase II (RNA pol II) and consequential impediment of transcription elongation. This RBMX-mediated modulation of HIV-1 transcription maintains viral latency by inhibiting viral reactivation from an integrated proviral DNA. Our findings provide a new understanding of how host factors modulate HIV-1 infection and latency and suggest a potential new target for the development of HIV-1 therapies.
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14
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Samer S, Arif MS, Giron LB, Zukurov JPL, Hunter J, Santillo BT, Namiyama G, Galinskas J, Komninakis SV, Oshiro TM, Sucupira MC, Janini LM, Diaz RS. Nicotinamide activates latent HIV-1 ex vivo in ART suppressed individuals, revealing higher potency than the association of two methyltransferase inhibitors, chaetocin and BIX01294. Braz J Infect Dis 2020; 24:150-159. [PMID: 32105620 PMCID: PMC9392037 DOI: 10.1016/j.bjid.2020.01.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 12/27/2019] [Accepted: 01/31/2020] [Indexed: 12/31/2022] Open
Abstract
Background Latent HIV-1 is a major hurdle in obtaining HIV-1 sustained virological remission (SVR). Here we explored histone deacetylation inhibition property of nicotinamide (NAM; n = 17) for the first time in comparison to a combination of methyltransferase inhibitors (MTIs; Chaetocin and BIX01294; n = 25) to reactivate latent HIV ex vivo in CD8-depleted PBMCs from antiretroviral treated aviremic individuals. Results NAM reactivated HIV-1 from 13/17 (76.4%) samples compared to 20/25 (80.0%) using MTIs with mean viral load (VLs) of 4.32 and 3.22 log10 RNA copies/mL, respectively (p = 0.004). Mean purging time after NAM and MTIs stimulation was 5.1 and 6.75 days, respectively (p = 0.73). Viral purging in autologous cultures exhibited blunted HIV recovery with fluctuating VLs followed by a complete viral extinction when expanded in allogenic system. Electron microscopy from five supernatants revealed anomalous viral particles, with lack of complete viral genomes when characterized by ultradeep sequencing through metagenomics approach (n = 4). Conclusion NAM alone was more potent HIV-1 activator than combination of MTIs, with potential of clinical use.
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Affiliation(s)
- Sadia Samer
- Yerkes National Primate Research Center, Emory University, Atlanta, Georgia
| | - Muhammad Shoaib Arif
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, USA.
| | | | - Jean Paulo Lopes Zukurov
- Department of Microbiology, Immunology and Parasitology, Federal University of São Paulo, São Paulo, SP, Brazil
| | - James Hunter
- Department of Medicine, Federal University of Sao Paulo, São Paulo, SP, Brazil
| | | | - Gislene Namiyama
- Department of Electron Microscopy, Institute of Adolfo Lutz, São Paulo, SP, Brazil
| | - Juliana Galinskas
- Department of Medicine, Federal University of Sao Paulo, São Paulo, SP, Brazil
| | | | | | | | - Luiz Mario Janini
- Department of Microbiology, Immunology and Parasitology, Federal University of São Paulo, São Paulo, SP, Brazil
| | - Ricardo Sobhie Diaz
- Department of Medicine, Federal University of Sao Paulo, São Paulo, SP, Brazil.
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15
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Kruize Z, Kootstra NA. The Role of Macrophages in HIV-1 Persistence and Pathogenesis. Front Microbiol 2019; 10:2828. [PMID: 31866988 PMCID: PMC6906147 DOI: 10.3389/fmicb.2019.02828] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 11/21/2019] [Indexed: 12/12/2022] Open
Abstract
Current antiretroviral therapy (ART) effectively suppresses Human Immunodeficiency Virus type 1 (HIV-1) in infected individuals. However, even long term ART does not eradicate HIV-1 infected cells and the virus persists in cellular reservoirs. Beside memory CD4+ T cells, cells of the myeloid lineage, especially macrophages, are believed to be an important sanctuary for HIV-1. Monocytes and macrophages are key players in the innate immune response to pathogens and are recruited to sites of infection and inflammation. Due to their long life span and ability to reside in virtually every tissue, macrophages have been proposed to play a critical role in the establishment and persistence of the HIV-1 reservoir. Current HIV-1 cure strategies mainly focus on the concept of “shock and kill” to purge the viral reservoir. This approach aims to reactivate viral protein production in latently infected cells, which subsequently are eliminated as a consequence of viral replication, or recognized and killed by the immune system. Macrophage susceptibility to HIV-1 infection is dependent on the local microenvironment, suggesting that molecular pathways directing differentiation and polarization are involved. Current latency reversing agents (LRA) are mainly designed to reactivate the HIV-1 provirus in CD4+ T cells, while their ability to abolish viral latency in macrophages is largely unknown. Moreover, the resistance of macrophages to HIV-1 mediated kill and the presence of infected macrophages in immune privileged regions including the central nervous system (CNS), may pose a barrier to elimination of infected cells by current “shock and kill” strategies. This review focusses on the role of monocytes/macrophages in HIV-1 persistence. We will discuss mechanisms of viral latency and persistence in monocytes/macrophages. Furthermore, the role of these cells in HIV-1 tissue distribution and pathogenesis will be discussed.
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Affiliation(s)
- Zita Kruize
- Laboratory for Viral Immune Pathogenesis, Department of Experimental Immunology, Amsterdam UMC, Amsterdam Infection & Immunity Institute, University of Amsterdam, Amsterdam, Netherlands
| | - Neeltje A Kootstra
- Laboratory for Viral Immune Pathogenesis, Department of Experimental Immunology, Amsterdam UMC, Amsterdam Infection & Immunity Institute, University of Amsterdam, Amsterdam, Netherlands
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16
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Huang H, Kong W, Jean M, Fiches G, Zhou D, Hayashi T, Que J, Santoso N, Zhu J. A CRISPR/Cas9 screen identifies the histone demethylase MINA53 as a novel HIV-1 latency-promoting gene (LPG). Nucleic Acids Res 2019; 47:7333-7347. [PMID: 31165872 PMCID: PMC6698651 DOI: 10.1093/nar/gkz493] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 05/17/2019] [Accepted: 05/24/2019] [Indexed: 12/17/2022] Open
Abstract
Although combination antiretroviral therapy is potent to block active replication of HIV-1 in AIDS patients, HIV-1 persists as transcriptionally inactive proviruses in infected cells. These HIV-1 latent reservoirs remain a major obstacle for clearance of HIV-1. Investigation of host factors regulating HIV-1 latency is critical for developing novel antiretroviral reagents to eliminate HIV-1 latent reservoirs. From our recently accomplished CRISPR/Cas9 sgRNA screens, we identified that the histone demethylase, MINA53, is potentially a novel HIV-1 latency-promoting gene (LPG). We next validated MINA53’s function in maintenance of HIV-1 latency by depleting MINA53 using the alternative RNAi approach. We further identified that in vitro MINA53 preferentially demethylates the histone substrate, H3K36me3 and that in cells MINA53 depletion by RNAi also increases the local level of H3K36me3 at LTR. The effort to map the downstream effectors unraveled that H3K36me3 has the cross-talk with another epigenetic mark H4K16ac, mediated by KAT8 that recognizes the methylated H3K36 and acetylated H4K16. Removing the MINA53-mediated latency mechanisms could benefit the reversal of post-integrated latent HIV-1 proviruses for purging of reservoir cells. We further demonstrated that a pan jumonji histone demethylase inhibitor, JIB-04, inhibits MINA53-mediated demethylation of H3K36me3, and JIB-04 synergizes with other latency-reversing agents (LRAs) to reactivate latent HIV-1.
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Affiliation(s)
- Huachao Huang
- Department of Medicine, Columbia University Medical Center, New York, NY 10032, USA
| | - Weili Kong
- Department of Pathology, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Maxime Jean
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Guillaume Fiches
- Department of Pathology, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Dawei Zhou
- Department of Pathology, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Tsuyoshi Hayashi
- National Institute of Infectious Diseases, Tokyo 162-8640, Japan
| | - Jianwen Que
- Department of Medicine, Columbia University Medical Center, New York, NY 10032, USA
| | - Netty Santoso
- Department of Pathology, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Jian Zhu
- Department of Pathology, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
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17
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Sadowski I, Hashemi FB. Strategies to eradicate HIV from infected patients: elimination of latent provirus reservoirs. Cell Mol Life Sci 2019; 76:3583-3600. [PMID: 31129856 PMCID: PMC6697715 DOI: 10.1007/s00018-019-03156-8] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 04/29/2019] [Accepted: 05/20/2019] [Indexed: 02/06/2023]
Abstract
35 years since identification of HIV as the causative agent of AIDS, and 35 million deaths associated with this disease, significant effort is now directed towards the development of potential cures. Current anti-retroviral (ART) therapies for HIV/AIDS can suppress virus replication to undetectable levels, and infected individuals can live symptom free so long as treatment is maintained. However, removal of therapy allows rapid re-emergence of virus from a highly stable reservoir of latently infected cells that exist as a barrier to elimination of the infection with current ART. Prospects of a cure for HIV infection are significantly encouraged by two serendipitous cases where individuals have entered remission following stem cell transplantation from compatible HIV-resistant donors. However, development of a routine cure that could become available to millions of infected individuals will require a means of specifically purging cells harboring latent HIV, preventing replication of latent provirus, or destruction of provirus genomes by gene editing. Elimination of latently infected cells will require a means of exposing this population, which may involve identification of a natural specific biomarker or therapeutic intervention to force their exposure by reactivation of virus expression. Accordingly, the proposed "Shock and Kill" strategy involves treatment with latency-reversing agents (LRA) to induce HIV provirus expression thus exposing these cells to killing by cellular immunity or apoptosis. Current efforts to enable this strategy are directed at developing improved combinations of LRA to produce broad and robust induction of HIV provirus and enhancing the elimination of cells where replication has been reactivated by targeted immune modulation. Alternative strategies may involve preventing re-emergence virus from latently infected cells by "Lock and Block" intervention, where transcription of provirus is inhibited to prevent virus spread or disruption of the HIV provirus genome by genome editing.
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Affiliation(s)
- Ivan Sadowski
- Department of Biochemistry and Molecular Biology, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada.
| | - Farhad B Hashemi
- Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
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18
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Yang H, Li X, Yang X, Lu P, Wang Y, Jiang Z, Pan H, Zhao L, Zhu Y, Khan IU, Shen Y, Lu H, Zhang T, Jiang G, Ma Z, Wu H, Zhu H. Dual effects of the novel ingenol derivatives on the acute and latent HIV-1 infections. Antiviral Res 2019; 169:104555. [PMID: 31295520 DOI: 10.1016/j.antiviral.2019.104555] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Revised: 07/07/2019] [Accepted: 07/08/2019] [Indexed: 11/29/2022]
Abstract
The latent reservoir of HIV-1 in resting memory CD4+ T cells serves as a major barrier to curing HIV-1 infection. Reactivation of latent HIV-1 is proposed as a promising strategy for the clearance of the viral reservoirs. Because of the limitations of current latency reversal agents (LRAs), identification of new LRAs is urgently required. Here, we analyzed Euphorbia kansui extracts and obtained three ingenol derivative compounds named EK-1A, EK-5A and EK-15A. We found that ingenol derivatives can effectively reactivate latent HIV-1 at very low (nanomolar) concentrations in HIV latency model in vitro. Furthermore, ingenol derivatives exhibited synergy with other LRAs in reactivating latent HIV-1. We verified that EK-15A can promote latent HIV-1 reactivation in the ex vivo resting CD4+ T cells isolated from the peripheral blood of HIV-infected individuals on suppressive antiretroviral therapy. In addition, ingenol derivatives down-regulated the expression of cell surface HIV co-receptors CCR5 and CXCR4, therefore potentially preventing new infection of HIV-1. Our results indicated that the ingenol derivatives extracted from Euphorbia kansui have dual functions: reactivation of latent HIV-1 and inhibition of HIV-1 infection.
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Affiliation(s)
- He Yang
- State Key Laboratory of Genetic Engineering and Engineering Research Center of Gene Technology, Ministry of Education, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Xian Li
- State Key Laboratory of Genetic Engineering and Engineering Research Center of Gene Technology, Ministry of Education, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Xinyi Yang
- State Key Laboratory of Genetic Engineering and Engineering Research Center of Gene Technology, Ministry of Education, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Panpan Lu
- State Key Laboratory of Genetic Engineering and Engineering Research Center of Gene Technology, Ministry of Education, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Yanan Wang
- State Key Laboratory of Genetic Engineering and Engineering Research Center of Gene Technology, Ministry of Education, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Zhengtao Jiang
- State Key Laboratory of Genetic Engineering and Engineering Research Center of Gene Technology, Ministry of Education, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Hanyu Pan
- State Key Laboratory of Genetic Engineering and Engineering Research Center of Gene Technology, Ministry of Education, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Lin Zhao
- State Key Laboratory of Genetic Engineering and Engineering Research Center of Gene Technology, Ministry of Education, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Yuqi Zhu
- State Key Laboratory of Genetic Engineering and Engineering Research Center of Gene Technology, Ministry of Education, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Inam Ullah Khan
- State Key Laboratory of Genetic Engineering and Engineering Research Center of Gene Technology, Ministry of Education, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Yinzhong Shen
- Department of Infectious Diseases, Key Laboratory of Medical Molecular Virology of Ministry of Education/Health, Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Hongzhou Lu
- Department of Infectious Diseases, Key Laboratory of Medical Molecular Virology of Ministry of Education/Health, Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Tong Zhang
- Center for Infectious Diseases, Beijing You'an Hospital, Capital Medical University, Beijing, 100069, China
| | - Guochun Jiang
- UNC HIV Cure Center, IGHID, Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Zhongjun Ma
- Institute of Marine Biology, Ocean College, Zhejiang University, Hangzhou, 310058, China.
| | - Hao Wu
- Center for Infectious Diseases, Beijing You'an Hospital, Capital Medical University, Beijing, 100069, China.
| | - Huanzhang Zhu
- State Key Laboratory of Genetic Engineering and Engineering Research Center of Gene Technology, Ministry of Education, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, 200438, China.
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Abner E, Jordan A. HIV "shock and kill" therapy: In need of revision. Antiviral Res 2019; 166:19-34. [PMID: 30914265 DOI: 10.1016/j.antiviral.2019.03.008] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Revised: 03/08/2019] [Accepted: 03/17/2019] [Indexed: 01/05/2023]
Abstract
The implementation of antiretroviral therapy 23 years ago has rendered HIV infection clinically manageable. However, the disease remains incurable, since it establishes latent proviral reservoirs, which in turn can stochastically begin reproducing viral particles throughout the patient's lifetime. Viral latency itself depends in large part on the silencing environment of the infected host cell, which can be chemically manipulated. "Shock and kill" therapy intends to reverse proviral quiescence by inducing transcription with pharmaceuticals and allowing a combination of antiretroviral therapy, host immune clearance and HIV-cytolysis to remove latently infected cells, leading to a complete cure. Over 160 compounds functioning as latency-reversing agents (LRAs) have been identified to date, but none of the candidates has yet led to a promising functional cure. Furthermore, fundamental bioinformatic and clinical research from the past decade has highlighted the complexity and highly heterogeneous nature of the proviral reservoirs, shedding doubt on the "shock and kill" concept. Alternative therapies such as the HIV transcription-inhibiting "block and lock" strategy are therefore being considered. In this review we describe the variety of existing classes of LRAs, discuss their current drawbacks and highlight the potential for combinatorial "shocktail" therapies for potent proviral reactivation. We also suggest investigating LRAs with lesser-known mechanisms of action, and examine the feasibility of "block and lock" therapy.
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Affiliation(s)
- Erik Abner
- Molecular Biology Institute of Barcelona (IBMB-CSIC), Barcelona, Spain
| | - Albert Jordan
- Molecular Biology Institute of Barcelona (IBMB-CSIC), Barcelona, Spain.
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20
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Hashemi P, Barreto K, Bernhard W, Lomness A, Honson N, Pfeifer TA, Harrigan PR, Sadowski I. Compounds producing an effective combinatorial regimen for disruption of HIV-1 latency. EMBO Mol Med 2019; 10:160-174. [PMID: 29246970 PMCID: PMC5838563 DOI: 10.15252/emmm.201708193] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Highly active antiretroviral therapy (HAART) has improved the outlook for the HIV epidemic, but does not provide a cure. The proposed “shock‐and‐kill” strategy is directed at inducing latent HIV reservoirs, which may then be purged via boosted immune response or targeting infected cells. We describe five novel compounds that are capable of reversing HIV latency without affecting the general T‐cell activation state. The new compounds exhibit synergy for reactivation of latent provirus with other latency‐reversing agents (LRAs), in particular ingenol‐3‐angelate/PEP005. One compound, designated PH02, was efficient at reactivating viral transcription in several cell lines bearing reporter HIV‐1 at different integration sites. Furthermore, it was capable of reversing latency in resting CD4+ T lymphocytes from latently infected aviremic patient cells on HAART, while producing minimal cellular toxicity. The combination of PH02 and PEP005 produces a strong synergistic effect for reactivation, as demonstrated through a quantitative viral outgrowth assay (qVOA), on CD4+ T lymphocytes from HIV‐1‐infected individuals. We propose that the PH02/PEP005 combination may represent an effective novel treatment for abrogating persistent HIV‐1 infection.
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Affiliation(s)
- Pargol Hashemi
- Biochemistry and Molecular Biology, Molecular Epigenetics, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Kris Barreto
- Biochemistry and Molecular Biology, Molecular Epigenetics, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Wendy Bernhard
- Biochemistry and Molecular Biology, Molecular Epigenetics, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Adam Lomness
- Biochemistry and Molecular Biology, Molecular Epigenetics, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Nicolette Honson
- The Centre for Drug Research and Development, Vancouver, BC, Canada
| | - Tom A Pfeifer
- The Centre for Drug Research and Development, Vancouver, BC, Canada
| | - P Richard Harrigan
- BC Centre for Excellence in HIV/AIDS, St. Paul's Hospital, Vancouver, BC, Canada
| | - Ivan Sadowski
- Biochemistry and Molecular Biology, Molecular Epigenetics, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
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21
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Abstract
Current antiretroviral therapy (ART) effectively suppresses Human Immunodeficiency Virus type 1 (HIV-1) in infected individuals. However, even long term ART does not eradicate HIV-1 infected cells and the virus persists in cellular reservoirs. Beside memory CD4+ T cells, cells of the myeloid lineage, especially macrophages, are believed to be an important sanctuary for HIV-1. Monocytes and macrophages are key players in the innate immune response to pathogens and are recruited to sites of infection and inflammation. Due to their long life span and ability to reside in virtually every tissue, macrophages have been proposed to play a critical role in the establishment and persistence of the HIV-1 reservoir. Current HIV-1 cure strategies mainly focus on the concept of "shock and kill" to purge the viral reservoir. This approach aims to reactivate viral protein production in latently infected cells, which subsequently are eliminated as a consequence of viral replication, or recognized and killed by the immune system. Macrophage susceptibility to HIV-1 infection is dependent on the local microenvironment, suggesting that molecular pathways directing differentiation and polarization are involved. Current latency reversing agents (LRA) are mainly designed to reactivate the HIV-1 provirus in CD4+ T cells, while their ability to abolish viral latency in macrophages is largely unknown. Moreover, the resistance of macrophages to HIV-1 mediated kill and the presence of infected macrophages in immune privileged regions including the central nervous system (CNS), may pose a barrier to elimination of infected cells by current "shock and kill" strategies. This review focusses on the role of monocytes/macrophages in HIV-1 persistence. We will discuss mechanisms of viral latency and persistence in monocytes/macrophages. Furthermore, the role of these cells in HIV-1 tissue distribution and pathogenesis will be discussed.
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Affiliation(s)
- Zita Kruize
- Laboratory for Viral Immune Pathogenesis, Department of Experimental Immunology, Amsterdam UMC, Amsterdam Infection & Immunity Institute, University of Amsterdam, Amsterdam, Netherlands
| | - Neeltje A Kootstra
- Laboratory for Viral Immune Pathogenesis, Department of Experimental Immunology, Amsterdam UMC, Amsterdam Infection & Immunity Institute, University of Amsterdam, Amsterdam, Netherlands
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22
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Méndez C, Ledger S, Petoumenos K, Ahlenstiel C, Kelleher AD. RNA-induced epigenetic silencing inhibits HIV-1 reactivation from latency. Retrovirology 2018; 15:67. [PMID: 30286764 PMCID: PMC6172763 DOI: 10.1186/s12977-018-0451-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 10/01/2018] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Current antiretroviral therapy is effective in controlling HIV-1 infection. However, cessation of therapy is associated with rapid return of viremia from the viral reservoir. Eradicating the HIV-1 reservoir has proven difficult with the limited success of latency reactivation strategies and reflects the complexity of HIV-1 latency. Consequently, there is a growing need for alternate strategies. Here we explore a "block and lock" approach for enforcing latency to render the provirus unable to restart transcription despite exposure to reactivation stimuli. Reactivation of transcription from latent HIV-1 proviruses can be epigenetically blocked using promoter-targeted shRNAs to prevent productive infection. We aimed to determine if independent and combined expression of shRNAs, PromA and 143, induce a repressive epigenetic profile that is sufficiently stable to protect latently infected cells from HIV-1 reactivation when treated with a range of latency reversing agents (LRAs). RESULTS J-Lat 9.2 cells, a model of HIV-1 latency, expressing shRNAs PromA, 143, PromA/143 or controls were treated with LRAs to evaluate protection from HIV-1 reactivation as determined by levels of GFP expression. Cells expressing shRNA PromA, 143, or both, showed robust resistance to viral reactivation by: TNF, SAHA, SAHA/TNF, Bryostatin/TNF, DZNep, and Chaetocin. Given the physiological importance of TNF, HIV-1 reactivation was induced by TNF (5 ng/mL) and ChIP assays were performed to detect changes in expression of epigenetic markers within chromatin in both sorted GFP- and GFP+ cell populations, harboring latent or reactivated proviruses, respectively. Ordinary two-way ANOVA analysis used to identify interactions between shRNAs and chromatin marks associated with repressive or active chromatin in the integrated provirus revealed significant changes in the levels of H3K27me3, AGO1 and HDAC1 in the LTR, which correlated with the extent of reduced proviral reactivation. The cell line co-expressing shPromA and sh143 consistently showed the least reactivation and greatest enrichment of chromatin compaction indicators. CONCLUSION The active maintenance of epigenetic silencing by shRNAs acting on the HIV-1 LTR impedes HIV-1 reactivation from latency. Our "block and lock" approach constitutes a novel way of enforcing HIV-1 "super latency" through a closed chromatin architecture that renders the virus resistant to a range of latency reversing agents.
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Affiliation(s)
- Catalina Méndez
- Department of Immunovirology and Pathogenesis, Level 5, Wallace Wurth Building, The Kirby Institute for Infection and Immunity, UNSW Sydney, Kensington, Sydney, NSW, 2052, Australia
| | - Scott Ledger
- Department of Immunovirology and Pathogenesis, Level 5, Wallace Wurth Building, The Kirby Institute for Infection and Immunity, UNSW Sydney, Kensington, Sydney, NSW, 2052, Australia
| | - Kathy Petoumenos
- Department of Immunovirology and Pathogenesis, Level 5, Wallace Wurth Building, The Kirby Institute for Infection and Immunity, UNSW Sydney, Kensington, Sydney, NSW, 2052, Australia
| | - Chantelle Ahlenstiel
- Department of Immunovirology and Pathogenesis, Level 5, Wallace Wurth Building, The Kirby Institute for Infection and Immunity, UNSW Sydney, Kensington, Sydney, NSW, 2052, Australia.
| | - Anthony D Kelleher
- Department of Immunovirology and Pathogenesis, Level 5, Wallace Wurth Building, The Kirby Institute for Infection and Immunity, UNSW Sydney, Kensington, Sydney, NSW, 2052, Australia
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23
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Natural product-derived compounds in HIV suppression, remission, and eradication strategies. Antiviral Res 2018; 158:63-77. [PMID: 30063970 DOI: 10.1016/j.antiviral.2018.07.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Revised: 07/10/2018] [Accepted: 07/21/2018] [Indexed: 12/12/2022]
Abstract
While combination antiretroviral therapy (cART) has successfully converted HIV to a chronic but manageable infection in many parts of the world, HIV continues to persist within latent cellular reservoirs, which can become reactivated at any time to produce infectious virus. New therapies are therefore needed not only for HIV suppression but also for containing or eliminating HIV reservoirs. Compounds derived from plant, marine, and other natural products have been found to combat HIV infection and/or target HIV reservoirs, and these discoveries have substantially guided current HIV therapy-based studies. Here we summarize the role of natural product-derived compounds in current HIV suppression, remission, and cure strategies.
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24
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Cao S, Woodrow KA. Nanotechnology approaches to eradicating HIV reservoirs. Eur J Pharm Biopharm 2018; 138:48-63. [PMID: 29879528 DOI: 10.1016/j.ejpb.2018.06.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 05/29/2018] [Accepted: 06/02/2018] [Indexed: 02/06/2023]
Abstract
The advent of combination antiretroviral therapy (cART) has transformed HIV-1 infection into a controllable chronic disease, but these therapies are incapable of eradicating the virus to bring about an HIV cure. Multiple strategies have been proposed and investigated to eradicate latent viral reservoirs from various biological sanctuaries. However, due to the complexity of HIV infection and latency maintenance, a single drug is unlikely to eliminate all HIV reservoirs and novel strategies may be needed to achieve better efficacy while limiting systemic toxicity. In this review, we describe HIV latency in cellular and anatomical reservoirs, and present an overview of current strategies for HIV cure with a focus on their challenges for clinical translation. Then we provide a summary of nanotechnology solutions that have been used to address challenges in HIV cure by delivering physicochemically diverse agents for combination therapy or targeting HIV reservoir sites. We also review nanocarrier-based gene delivery and immunotherapy used in cancer treatment but may have potential applications in HIV cure.
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Affiliation(s)
- Shijie Cao
- Department of Bioengineering, University of Washington, Seattle, WA 98105, USA
| | - Kim A Woodrow
- Department of Bioengineering, University of Washington, Seattle, WA 98105, USA.
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25
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Vo MC, Nguyen-Pham TN, Lee HJ, Jung SH, Choi NR, Hoang MD, Kim HJ, Lee JJ. Chaetocin enhances dendritic cell function via the induction of heat shock protein and cancer testis antigens in myeloma cells. Oncotarget 2018; 8:46047-46056. [PMID: 28512265 PMCID: PMC5542247 DOI: 10.18632/oncotarget.17517] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 03/24/2017] [Indexed: 12/12/2022] Open
Abstract
Dendritic cells (DC)-based vaccines are considered useful in cancer immuno-therapy, and the interactions of DC and dying tumor cells are important and promising for cancer immunotherapy. We investigated whether chaetocin could be used to induce death of myeloma cells, for loading onto DCs can affect DCs function. In this study, we show that the dying myeloma cells treated with chaetocin resulted in the induction of heat shock protein (HSP) 90, which was inhibited by antioxidant N-acetyl cysteine, and showed an increase in the expression of MAGE-A3 and MAGE-C1/CT7. DCs loaded with chaetocin-treated dying myeloma cells produced low levels of IL-10 and enhanced the cross presentation of DCs. Additionally, these DCs most potently inhibited regulatory T cells, induced Th1 polarization and activated myeloma-specific cytotoxic T lymphocytes compared with DCs loaded with UVB-irradiated dying myeloma cells. These results suggest that the pretreatment of myeloma cells with chaetocin can enhance DC function through the up-regulation of HSP90 and cancer testis antigens in dying myeloma cells and can potently induce the Th1 polarization of DCs and myeloma-specific cytotoxic T lymphocytes.
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Affiliation(s)
- Manh-Cuong Vo
- Research Center for Cancer Immunotherapy, Chonnam National University Hwasun Hospital, Hwasun, Jeollanamdo, Republic of Korea
| | - Thanh-Nhan Nguyen-Pham
- Research Center for Cancer Immunotherapy, Chonnam National University Hwasun Hospital, Hwasun, Jeollanamdo, Republic of Korea.,Department of Hematology-Oncology, Chonnam National University Hwasun Hospital, Hwasun, Jeollanamdo, Republic of Korea
| | - Hyun-Ju Lee
- Research Center for Cancer Immunotherapy, Chonnam National University Hwasun Hospital, Hwasun, Jeollanamdo, Republic of Korea
| | - Sung-Hoon Jung
- Research Center for Cancer Immunotherapy, Chonnam National University Hwasun Hospital, Hwasun, Jeollanamdo, Republic of Korea.,Department of Hematology-Oncology, Chonnam National University Hwasun Hospital, Hwasun, Jeollanamdo, Republic of Korea
| | - Nu-Ri Choi
- Research Center for Cancer Immunotherapy, Chonnam National University Hwasun Hospital, Hwasun, Jeollanamdo, Republic of Korea
| | - My-Dung Hoang
- Research Center for Cancer Immunotherapy, Chonnam National University Hwasun Hospital, Hwasun, Jeollanamdo, Republic of Korea
| | - Hyeoung-Joon Kim
- Department of Hematology-Oncology, Chonnam National University Hwasun Hospital, Hwasun, Jeollanamdo, Republic of Korea
| | - Je-Jung Lee
- Research Center for Cancer Immunotherapy, Chonnam National University Hwasun Hospital, Hwasun, Jeollanamdo, Republic of Korea.,Department of Hematology-Oncology, Chonnam National University Hwasun Hospital, Hwasun, Jeollanamdo, Republic of Korea
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26
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Pan MR, Hsu MC, Luo CW, Chen LT, Shan YS, Hung WC. The histone methyltransferase G9a as a therapeutic target to override gemcitabine resistance in pancreatic cancer. Oncotarget 2018; 7:61136-61151. [PMID: 27531902 PMCID: PMC5308641 DOI: 10.18632/oncotarget.11256] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 07/27/2016] [Indexed: 01/10/2023] Open
Abstract
Gemcitabine (GEM) resistance is a critical issue for pancreatic cancer treatment. The involvement of epigenetic modification in GEM resistance is still unclear. We established a GEM-resistant subline PANC-1-R from the parental PANC-1 pancreatic cancer cells and found the elevation of various chromatin-modifying enzymes including G9a in GEM-resistant cells. Ectopic expression of G9a in PANC-1 cells increased GEM resistance while inactivation of G9a in PANC-1-R cells reduced it. Challenge of PANC-1 cells with GEM increased the expression of stemness markers including CD133, nestin and Lgr5 and promoted sphere forming activity suggesting chemotherapy enriched cancer cells with stem-like properties. Inhibition of G9a in PANC-1-R cells reduced stemness and invasiveness and sensitized the cells to GEM. We revealed interleukin-8 (IL-8) is a downstream effector of G9a to increase GEM resistance. G9a-overexpressing PANC-1-R cells exhibited autocrine IL-8/CXCR1/2 stimulation to increase GEM resistance which could be decreased by anti-IL-8 antibody and G9a inhibitor. IL-8 released by cancer cells also activated pancreatic stellate cell (PSC) to increase GEM resistance. In orthotopic animal model, GEM could not suppress tumor growth of PANC-1-R cells and eventually promoted tumor metastasis. Combination with G9a inhibitor and GEM reduced tumor growth, metastasis, IL-8 expression and PSC activation in animals. Finally, we showed that overexpression of G9a correlated with poor survival and early recurrence in pancreatic cancer patients. Collectively, our results suggest G9a is a therapeutic target to override GEM resistance in the treatment of pancreatic cancer.
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Affiliation(s)
- Mei-Ren Pan
- Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan.,Research Center for Environmental Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
| | - Ming-Chuan Hsu
- National Institute of Cancer Research, National Health Research Institutes, Tainan 704, Taiwan
| | - Chi-Wen Luo
- Department of Pathology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan
| | - Li-Tzong Chen
- National Institute of Cancer Research, National Health Research Institutes, Tainan 704, Taiwan.,Division of Hematology/Oncology, Department of Internal Medicine, National Cheng Kung University Hospital, Tainan 704, Taiwan
| | - Yan-Shen Shan
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 704, Taiwan.,Department of Surgery, National Cheng Kung University Hospital, Tainan 704, Taiwan
| | - Wen-Chun Hung
- National Institute of Cancer Research, National Health Research Institutes, Tainan 704, Taiwan.,Institute of Basic Medical Sciences, National Cheng Kung University, Tainan 704, Taiwan
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Khan S, Iqbal M, Tariq M, Baig SM, Abbas W. Epigenetic regulation of HIV-1 latency: focus on polycomb group (PcG) proteins. Clin Epigenetics 2018; 10:14. [PMID: 29441145 PMCID: PMC5800276 DOI: 10.1186/s13148-018-0441-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 01/05/2018] [Indexed: 01/10/2023] Open
Abstract
HIV-1 latency allows the virus to persist until reactivation, in a transcriptionally silent form in its cellular reservoirs despite the presence of effective cART. Such viral persistence represents a major barrier to HIV eradication since treatment interruption leads to rebound plasma viremia. Polycomb group (PcG) proteins have recently got a considerable attention in regulating HIV-1 post-integration latency as they are involved in the repression of proviral gene expression through the methylation of histones. This epigenetic regulation plays an important role in the establishment and maintenance of HIV-1 latency. In fact, PcG proteins act in complexes and modulate the epigenetic signatures of integrated HIV-1 promoter. Key role played by PcG proteins in the molecular control of HIV-1 latency has led to hypothesize that PcG proteins may represent a valuable target for future HIV-1 therapy in purging HIV-1 reservoirs. In this regard, various small molecules have been synthesized or explored to specifically block the epigenetic activity of PcG. In this review, we will highlight the possible therapeutic approaches to achieve either a functional or sterilizing cure of HIV-1 infection with special focus on histone methylation by PcG proteins together with current and novel pharmacological approaches to reactivate HIV-1 from latency that could ultimately lead towards a better clearance of viral latent reservoirs.
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Affiliation(s)
- Sheraz Khan
- Health Biotechnology Division (HBD), National Institute for Biotechnology and Genetic Engineering (NIBGE), PO Box 577, Jhang road, Faisalabad, 38000 Pakistan
- Pakistan Institute of Engineering and Applied Sciences (PIEAS), Nilore, Islamabad, Pakistan
| | - Mazhar Iqbal
- Health Biotechnology Division (HBD), National Institute for Biotechnology and Genetic Engineering (NIBGE), PO Box 577, Jhang road, Faisalabad, 38000 Pakistan
- Pakistan Institute of Engineering and Applied Sciences (PIEAS), Nilore, Islamabad, Pakistan
| | - Muhammad Tariq
- Department of Biology (Epigenetics group), SBA School of Science and Engineering, LUMS, Lahore, 54792 Pakistan
| | - Shahid M. Baig
- Health Biotechnology Division (HBD), National Institute for Biotechnology and Genetic Engineering (NIBGE), PO Box 577, Jhang road, Faisalabad, 38000 Pakistan
- Pakistan Institute of Engineering and Applied Sciences (PIEAS), Nilore, Islamabad, Pakistan
| | - Wasim Abbas
- Health Biotechnology Division (HBD), National Institute for Biotechnology and Genetic Engineering (NIBGE), PO Box 577, Jhang road, Faisalabad, 38000 Pakistan
- Pakistan Institute of Engineering and Applied Sciences (PIEAS), Nilore, Islamabad, Pakistan
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28
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Boehm D, Ott M. Host Methyltransferases and Demethylases: Potential New Epigenetic Targets for HIV Cure Strategies and Beyond. AIDS Res Hum Retroviruses 2017; 33:S8-S22. [PMID: 29140109 DOI: 10.1089/aid.2017.0180] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
A successful HIV cure strategy may require reversing HIV latency to purge hidden viral reservoirs or enhancing HIV latency to permanently silence HIV transcription. Epigenetic modifying agents show promise as antilatency therapeutics in vitro and ex vivo, but also affect other steps in the viral life cycle. In this review, we summarize what we know about cellular DNA and protein methyltransferases (PMTs) as well as demethylases involved in HIV infection. We describe the biology and function of DNA methyltransferases, and their controversial role in HIV infection. We further explain the biology of PMTs and their effects on lysine and arginine methylation of histone and nonhistone proteins. We end with a focus on protein demethylases, their unique modes of action and their emerging influence on HIV infection. An outlook on the use of methylation-modifying agents in investigational HIV cure strategies is provided.
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Affiliation(s)
- Daniela Boehm
- Gladstone Institute of Virology and Immunology, San Francisco, California
- Department of Medicine, University of California, San Francisco, California
| | - Melanie Ott
- Gladstone Institute of Virology and Immunology, San Francisco, California
- Department of Medicine, University of California, San Francisco, California
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29
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Manoto SL, Thobakgale L, Malabi R, Maphanga C, Ombinda-Lemboumba S, Mthunzi-Kufa P. Therapeutic strategies to fight HIV-1 latency: progress and challenges. Biologia (Bratisl) 2017. [DOI: 10.1515/biolog-2017-0131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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30
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Perreau M, Banga R, Pantaleo G. Targeted Immune Interventions for an HIV-1 Cure. Trends Mol Med 2017; 23:945-961. [DOI: 10.1016/j.molmed.2017.08.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 08/09/2017] [Accepted: 08/14/2017] [Indexed: 01/13/2023]
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31
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Abstract
PURPOSE OF REVIEW The 'shock and kill' strategy consists of activating HIV-1 expression to allow latently infected cells to die from viral cytopathic effects or host cytolytic immune effectors. This strategy relies on small molecules, called latency reversing agents, which activate HIV transcription. RECENT FINDINGS Several mechanisms operating at the transcriptional level are involved in the establishment and maintenance of HIV-1 latency, including the absence of crucial inducible host transcription factors, epigenetic silencing, and the sequestration of the positive transcription elongation factor B. Progresses made toward the understanding of the molecular mechanisms of HIV-1 transcriptional repression have led to the identification of latency reversing agents that activate HIV transcription, such as histone deacetylase inhibitors or protein kinase C agonists. Multiple studies have recently pointed interesting ways to optimize the shock strategy by using combinations of latency reversing agents with an appropriate time schedule. SUMMARY Combining latency reversing agents appears as one potential strategy for therapy against HIV-1 latency.
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32
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Datta PK, Kaminski R, Hu W, Pirrone V, Sullivan NT, Nonnemacher MR, Dampier W, Wigdahl B, Khalili K. HIV-1 Latency and Eradication: Past, Present and Future. Curr HIV Res 2017; 14:431-441. [PMID: 27009094 DOI: 10.2174/1570162x14666160324125536] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 12/04/2015] [Accepted: 01/16/2016] [Indexed: 02/06/2023]
Abstract
BACKGROUND It is well established that antiretroviral therapy (ART), while highly effective in controlling HIV replication, cannot eliminate virus from the body. Therefore, the majority of HIV-1-infected individuals remain at risk for developing AIDS due to persistence of infected reservoir cells serving as a source of virus re-emergence. Several reservoirs containing replication competent HIV-1 have been identified, most notably CD4+ T cells. Cells of the myeloid lineage, which are the first line of defense against pathogens and participate in HIV dissemination into sanctuary organs, also serve as cellular reservoirs of HIV-1. In latently infected resting CD4+ T cells, the integrated copies of proviral DNA remain in a dormant state, yet possess the ability to produce replication competent virus after cellular activation. Studies have demonstrated that modification of chromatin structure plays a role in establishing persistence, in part suggesting that latency is, controlled epigenetically. CONCLUSION Current efforts to eradicate HIV-1 from this cell population focus primarily on a "shock and kill" approach through cellular reactivation to trigger elimination of virus producing cells by cytolysis or host immune responses. However, studies revealed several limitations to this approach that require more investigation to assess its clinical application. Recent advances in gene editing technology prompted use of this approach for inactivating integrated proviral DNA in the genome of latently infected cells. This technology, which requires a detailed understanding of the viral genetics and robust delivery, may serve as a powerful strategy to eliminate the latent reservoir in the host leading to a sterile cure of AIDS.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Kamel Khalili
- Department of Neuroscience, Center for Neurovirology and Comprehensive NeuroAIDS Center, Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, 7th Floor, Philadelphia, PA 19140, USA.
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33
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Margolis DM, Archin NM. Proviral Latency, Persistent Human Immunodeficiency Virus Infection, and the Development of Latency Reversing Agents. J Infect Dis 2017; 215:S111-S118. [PMID: 28520964 DOI: 10.1093/infdis/jiw618] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Quiescent proviral genomes that persist during human immunodeficiency virus type 1 (HIV-1) infection despite effective antiretroviral therapy (ART) can fuel rebound viremia after ART interruption and is a central obstacle to the cure of HIV infection. The induction of quiescent provirus is the goal of a new class of potential therapeutics, latency reversing agents (LRAs). The discovery, development, and testing of HIV LRAs is a key part of current efforts to develop latency reversal and viral clearance strategies to eradicate established HIV infection. The development of LRAs is burdened by many uncertainties that make drug discovery difficult. The biology of HIV latency is complex and incompletely understood. Potential targets for LRAs are host factors, and the potential toxicities of host-directed therapies in individuals that are otherwise clinically stable may be unacceptable. Assays to measure latency reversal and assess the effectiveness of potential therapeutics are complex and incompletely validated. Despite these obstacles, novel LRAs are under development and beginning to enter combination testing with viral clearance strategies. It is hoped that the steady advances in the development of LRAs now being paired with emerging immunotherapeutics to clear persistently infected cells will soon allow measurable clinical advances toward an HIV cure.
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Affiliation(s)
- David M Margolis
- UNC HIV Cure Center.,Department of Medicine, and.,Department of Microbiology & Immunology, University of North Carolina at Chapel Hill School of Medicine ; and.,Department of Epidemiology, University of North Carolina at Chapel Hill School of Public Health
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34
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Advancements in Developing Strategies for Sterilizing and Functional HIV Cures. BIOMED RESEARCH INTERNATIONAL 2017; 2017:6096134. [PMID: 28529952 PMCID: PMC5424177 DOI: 10.1155/2017/6096134] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Accepted: 04/04/2017] [Indexed: 12/14/2022]
Abstract
Combined antiretroviral therapy (cART) has been successful in prolonging lifespan and reducing mortality of patients infected with human immunodeficiency virus (HIV). However, the eradication of latent HIV reservoirs remains a challenge for curing HIV infection (HIV cure) because of HIV latency in primary memory CD4+ T cells. Currently, two types of HIV cures are in development: a “sterilizing cure” and a “functional cure.” A sterilizing cure refers to the complete elimination of replication-competent proviruses in the body, while a functional cure refers to the long-term control of HIV replication without treatment. Based on these concepts, significant progress has been made in different areas. This review focuses on recent advancements and future prospects for HIV cures.
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35
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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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36
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The Multifaceted Contributions of Chromatin to HIV-1 Integration, Transcription, and Latency. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 328:197-252. [PMID: 28069134 DOI: 10.1016/bs.ircmb.2016.08.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The capacity of the human immunodeficiency virus (HIV-1) to establish latent infections constitutes a major barrier to the development of a cure for HIV-1. In latent infection, replication competent HIV-1 provirus is integrated within the host genome but remains silent, masking the infected cells from the activity of the host immune response. Despite the progress in elucidating the molecular players that regulate HIV-1 gene expression, the mechanisms driving the establishment and maintenance of latency are still not fully understood. Transcription from the HIV-1 genome occurs in the context of chromatin and is subjected to the same regulatory mechanisms that drive cellular gene expression. Much like in eukaryotic genes, the nucleosomal landscape of the HIV-1 promoter and its position within genomic chromatin are determinants of its transcriptional activity. Understanding the multilayered chromatin-mediated mechanisms that underpin HIV-1 integration and expression is of utmost importance for the development of therapeutic strategies aimed at reducing the pool of latently infected cells. In this review, we discuss the impact of chromatin structure on viral integration, transcriptional regulation and latency, and the host factors that influence HIV-1 replication by regulating chromatin organization. Finally, we describe therapeutic strategies under development to target the chromatin-HIV-1 interplay.
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37
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Ma YM, Liang XA, Kong Y, Jia B. Structural Diversity and Biological Activities of Indole Diketopiperazine Alkaloids from Fungi. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2016; 64:6659-6671. [PMID: 27538469 DOI: 10.1021/acs.jafc.6b01772] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Indole diketopiperazine alkaloids are secondary metabolites of microorganisms that are widely distributed in filamentous fungi, especially in the genera Aspergillus and Penicillium of the phylum Ascomycota or sac fungi. These alkaloids represent a group of natural products characterized by diversity in both chemical structures and biological activities. This review aims to summarize 166 indole diketopiperazine alkaloids from fungi published from 1944 to mid-2015. The emphasis is on diverse chemical structures within these alkaloids and their relevant biological activities. The aim is to assess which of these compounds merit further study for purposes of drug development.
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Affiliation(s)
- Yang-Min Ma
- Key Laboratory of Auxiliary Chemistry & Technology for Chemical Industry, Ministry of Education, Shaanxi University of Science & Technology , Xi'an 710021, Shaanxi, China
| | - Xi-Ai Liang
- Key Laboratory of Auxiliary Chemistry & Technology for Chemical Industry, Ministry of Education, Shaanxi University of Science & Technology , Xi'an 710021, Shaanxi, China
| | - Yang Kong
- Key Laboratory of Auxiliary Chemistry & Technology for Chemical Industry, Ministry of Education, Shaanxi University of Science & Technology , Xi'an 710021, Shaanxi, China
| | - Bin Jia
- Key Laboratory of Auxiliary Chemistry & Technology for Chemical Industry, Ministry of Education, Shaanxi University of Science & Technology , Xi'an 710021, Shaanxi, China
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38
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HIV Provirus Stably Reproduces Parental Latent and Induced Transcription Phenotypes Regardless of the Chromosomal Integration Site. J Virol 2016; 90:5302-14. [PMID: 26984732 PMCID: PMC4934743 DOI: 10.1128/jvi.02842-15] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 03/14/2016] [Indexed: 02/06/2023] Open
Abstract
Understanding the mechanisms of HIV proviral latency is essential for development of a means to eradicate infection and achieve a cure. We have previously described an in vitro latency model that reliably identifies HIV expression phenotypes of infected cells using a dual-fluorescence reporter virus. Our results have demonstrated that ∼50% of infected cells establish latency immediately upon integration of provirus, a phenomenon termed early latency, which appears to occur by mechanisms that are distinct from epigenetic silencing observed with HIV provirus that establishes productive infections. In this study, we have used a mini-dual HIV reporter virus (mdHIV) to compare the long-term stability of provirus produced as early latent or productive infections using Jurkat-Tat T cell clones. Cloned lines bearing mdHIV provirus integrated at different chromosomal locations display unique differences in responsiveness to signaling agonists and chromatin-modifying compounds, and they also produce characteristic expression patterns from the 5′ long terminal repeat (LTR) dsRed and internal EIF1α-enhanced green fluorescent protein (EIF1α-eGFP) reporters. Furthermore, reporter expression profiles of single cell sorted subcultures faithfully reproduce expression profiles identical to that of their original parental population, following prolonged growth in culture, without shifting toward expression patterns resembling that of cell subclones at the time of sorting. Comparison of population dispersion coefficient (CV) and mean fluorescence intensity (MFI) of the subcloned lines showed that both untreated and phorbol myristate acetate (PMA)-ionomycin-stimulated cultures produce expression patterns identical to those of their parental lines. These results indicate that HIV provirus expression characteristics are strongly influenced by the epigenetic landscape at the site of chromosomal integration.
IMPORTANCE There is currently considerable interest in development of therapies to eliminate latently infected cells from HIV-infected patients on antiretroviral therapy. One proposed strategy, known as “shock and kill,” would involve treatment with therapies capable of inducing expression of latent provirus, with the expectation that the latently infected cells could be killed by a host immune response or virus-induced apoptosis. In clinical trials, histone deacetylase (HDAC) inhibitors were shown to cause reactivation of latent provirus but did not produce a significant effect toward eliminating the latently infected population. Results shown here indicate that integration of HIV provirus at different chromosomal locations produces significant effects on the responsiveness of virus expression to T cell signaling agonists and chromatin-modifying compounds. Given the variety of phenotypes produced by integrated provirus, it is unlikely that any single potential shock-and-kill therapy will be effective toward purging the latently infected population.
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39
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Gray LR, Cowley D, Welsh C, Lu HK, Brew BJ, Lewin SR, Wesselingh SL, Gorry PR, Churchill MJ. CNS-specific regulatory elements in brain-derived HIV-1 strains affect responses to latency-reversing agents with implications for cure strategies. Mol Psychiatry 2016; 21:574-84. [PMID: 26303660 PMCID: PMC4804184 DOI: 10.1038/mp.2015.111] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 06/18/2015] [Accepted: 06/25/2015] [Indexed: 12/19/2022]
Abstract
Latency-reversing agents (LRAs), including histone deacetylase inhibitors (HDACi), are being investigated as a strategy to eliminate latency in HIV-infected patients on suppressive antiretroviral therapy. The effectiveness of LRAs in activating latent infection in HIV strains derived from the central nervous system (CNS) is unknown. Here we show that CNS-derived HIV-1 strains possess polymorphisms within and surrounding the Sp transcription factor motifs in the long terminal repeat (LTR). These polymorphisms result in decreased ability of the transcription factor specificity protein 1 to bind CNS-derived LTRs, reducing the transcriptional activity of CNS-derived viruses. These mutations result in CNS-derived viruses being less responsive to activation by the HDACi panobinostat and romidepsin compared with lymphoid-derived viruses from the same subjects. Our findings suggest that HIV-1 strains residing in the CNS have unique transcriptional regulatory mechanisms, which impact the regulation of latency, the consideration of which is essential for the development of HIV-1 eradication strategies.
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Affiliation(s)
- L R Gray
- Centre for Biomedical Research, Burnet Institute, Melbourne, Victoria, Australia,Department of Infectious Diseases, Monash University, Melbourne, Victoria, Australia
| | - D Cowley
- Murdoch Childrens Research Institute, Melbourne, Victoria, Australia
| | - C Welsh
- Centre for Biomedical Research, Burnet Institute, Melbourne, Victoria, Australia
| | - H K Lu
- Centre for Biomedical Research, Burnet Institute, Melbourne, Victoria, Australia,Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, Victoria, Australia
| | - B J Brew
- Departments of Neurology, Immunology and Infectious Diseases and Peter Duncan Neurosciences Unit, St Vincent's Centre for Applied Medical Research, St Vincent's Hospital, Sydney, New South Wales, Australia
| | - S R Lewin
- Centre for Biomedical Research, Burnet Institute, Melbourne, Victoria, Australia,Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, Victoria, Australia,Infectious Diseases, Alfred Hospital, Melbourne, Victoria, Australia
| | - S L Wesselingh
- Centre for Biomedical Research, Burnet Institute, Melbourne, Victoria, Australia,South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
| | - P R Gorry
- Centre for Biomedical Research, Burnet Institute, Melbourne, Victoria, Australia,Department of Infectious Diseases, Monash University, Melbourne, Victoria, Australia,School of Applied Sciences and Program in Metabolism, Exercise and Disease, Health Initiatives Research Institute, RMIT University, Melbourne, Victoria, Australia,Department of Medicine, Monash University, Melbourne, Victoria, Australia
| | - M J Churchill
- Centre for Biomedical Research, Burnet Institute, Melbourne, Victoria, Australia,Department of Medicine, Monash University, Melbourne, Victoria, Australia,Department of Microbiology, Monash University, Melbourne, Victoria, Australia,Centre for Biomedical Research, Burnet Institute, 85 Commercial Road, Melbourne, Victoria 3004, Australia. E-mail:
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40
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Zhao N, Tsuda H, Murofushi T, Imai K, Ochiai K, Yang P, Suzuki N. Chaetocin inhibits RANKL-induced osteoclast differentiation through reduction of Blimp1 in Raw264.7 cells. Life Sci 2015; 143:1-7. [PMID: 26514304 DOI: 10.1016/j.lfs.2015.10.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 10/22/2015] [Accepted: 10/23/2015] [Indexed: 10/22/2022]
Abstract
AIMS Periodontitis is one of the most common bone-destructive diseases. Osteoclast is differentiated from hematopoietic macrophage-like cells through receptor activator of NFκB ligand (RANKL)-RANK signaling system, and the reduction in osteoclast formation may result in prevention of bone-resorptive diseases. Chaetocin is a compound isolated from fungal cultures and has been reported as a potent and selective inhibitor of suppressor of variegation 3-9 homolog 1 (Suv39h1), which catalyzes histone methylation on histone H3 lysine 9 (H3K9) residues. However, the effect of chaetocin on osteoclast differentiation is uncertain. In this study, we examine the effect of chaetocin on RANKL-induced osteoclast differentiation and cell growth. MAIN METHODS Mouse macrophage-like Raw264.7 cells were treated with RANKL in the presence or absence of chaetocin, and tartrate-resistant acid phosphatase (TRAP) staining was performed. Cell growth was measured as the amount of DNA stained with SYTOX Green dye. Expression and production of osteoclast differentiation markers, anti-osteoclastogenic genes, B lymphocyte-induced maturation protein-1 (Blimp1), and cell growth suppressors were examined by qRT-PCR or/and Western blot analysis. KEY FINDINGS Here we show that chaetocin dose-dependently reduced RANKL-induced osteoclast differentiation and cell growth via Blimp1 downregulation which results in the upregulation of osteoclast differentiation inhibitors and cell growth suppressors. These effects were not derived from the chaetocin's inhibitory effect of Suv39h1. SIGNIFICANCE These results suggest that chaetocin suppresses RANKL-induced osteoclastogenesis and cell growth through blimp1 downregulation, followed by induction of anti-osteoclastogenic genes and cell growth suppressors, without inhibition of Suv39h1. Thus, chaetocin might be a drug candidate for the prevention of bone resorption in bone-destructive diseases.
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Affiliation(s)
- Ning Zhao
- Department of Biochemistry, Nihon University School of Dentistry, 1-8-13 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan; Department of Endodontics, School of Dentistry, Shandong University, 44-1 West Wen Hua Road, Jinan, Shandong Province 250012, China
| | - Hiromasa Tsuda
- Department of Biochemistry, Nihon University School of Dentistry, 1-8-13 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan; Division of Functional Morphology, Dental Research Center, Nihon University School of Dentistry, 1-8-13 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.
| | - Takahisa Murofushi
- Department of Biochemistry, Nihon University School of Dentistry, 1-8-13 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan
| | - Kenichi Imai
- Department of Oral Microbiology, Nihon University School of Dentistry, 1-8-13 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan; Division of Immunology and Pathobiology, Dental Research Center, Nihon University School of Dentistry, 1-8-13 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan
| | - Kuniyasu Ochiai
- Department of Oral Microbiology, Nihon University School of Dentistry, 1-8-13 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan; Division of Immunology and Pathobiology, Dental Research Center, Nihon University School of Dentistry, 1-8-13 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan
| | - Pishan Yang
- Department of Periodontics, School of Dentistry, Shandong University, 44-1 West Wen Hua Road, Jinan, Shandong Province 250012, China
| | - Naoto Suzuki
- Department of Biochemistry, Nihon University School of Dentistry, 1-8-13 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan; Division of Functional Morphology, Dental Research Center, Nihon University School of Dentistry, 1-8-13 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan
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Impact of Chromatin on HIV Replication. Genes (Basel) 2015; 6:957-76. [PMID: 26437430 PMCID: PMC4690024 DOI: 10.3390/genes6040957] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 09/14/2015] [Accepted: 09/22/2015] [Indexed: 12/22/2022] Open
Abstract
Chromatin influences Human Immunodeficiency Virus (HIV) integration and replication. This review highlights critical host factors that influence chromatin structure and organization and that also impact HIV integration, transcriptional regulation and latency. Furthermore, recent attempts to target chromatin associated factors to reduce the HIV proviral load are discussed.
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Kumar A, Darcis G, Van Lint C, Herbein G. Epigenetic control of HIV-1 post integration latency: implications for therapy. Clin Epigenetics 2015; 7:103. [PMID: 26405463 PMCID: PMC4581042 DOI: 10.1186/s13148-015-0137-6] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 09/17/2015] [Indexed: 12/31/2022] Open
Abstract
With the development of effective combined anti-retroviral therapy (cART), there is significant reduction in deaths associated with human immunodeficiency virus type 1 (HIV-1) infection. However, the complete cure of HIV-1 infection is difficult to achieve without the elimination of latent reservoirs which exist in the infected individuals even under cART regimen. These latent reservoirs established during early infection have long life span, include resting CD4+ T cells, macrophages, central nervous system (CNS) resident macrophage/microglia, and gut-associated lymphoid tissue/macrophages, and can actively produce virus upon interruption of the cART. Several epigenetic and non-epigenetic mechanisms have been implicated in the regulation of viral latency. Epigenetic mechanisms such as histone post translational modifications (e.g., acetylation and methylation) and DNA methylation of the proviral DNA and microRNAs are involved in the establishment of HIV-1 latency. The better understanding of epigenetic mechanisms modulating HIV-1 latency could give clues for the complete eradication of these latent reservoirs. Several latency-reversing agents (LRA) have been found effective in reactivating HIV-1 reservoirs in vitro, ex vivo, and in vivo. Some of these agents target epigenetic modifications to elicit viral expression in order to kill latently infected cells through viral cytopathic effect or host immune response. These therapeutic approaches aimed at achieving a sterilizing cure (elimination of HIV-1 from the human body). In the present review, we will discuss our current understanding of HIV-1 epigenomics and how this information can be moved from the laboratory bench to the patient’s bedside.
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Affiliation(s)
- Amit Kumar
- Department of Virology, Pathogens & Inflammation Laboratory, University of Franche-Comté and COMUE Bourgogne Franche-Comté University, UPRES EA4266, SFR FED 4234, CHRU Besançon, Hôpital Saint-Jacques, 2 place Saint-Jacques, F-25030 Besançon cedex, France
| | - Gilles Darcis
- Service of Molecular Virology, Institute of Molecular Biology and Medicine, Université Libre de Bruxelles (ULB), 12 Rue des Profs Jeener et Brachet, 6041 Gosselies, Belgium
| | - Carine Van Lint
- Service of Molecular Virology, Institute of Molecular Biology and Medicine, Université Libre de Bruxelles (ULB), 12 Rue des Profs Jeener et Brachet, 6041 Gosselies, Belgium
| | - Georges Herbein
- Department of Virology, Pathogens & Inflammation Laboratory, University of Franche-Comté and COMUE Bourgogne Franche-Comté University, UPRES EA4266, SFR FED 4234, CHRU Besançon, Hôpital Saint-Jacques, 2 place Saint-Jacques, F-25030 Besançon cedex, France
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Shang HT, Ding JW, Yu SY, Wu T, Zhang QL, Liang FJ. Progress and challenges in the use of latent HIV-1 reactivating agents. Acta Pharmacol Sin 2015; 36:908-16. [PMID: 26027656 DOI: 10.1038/aps.2015.22] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 02/27/2015] [Indexed: 12/30/2022] Open
Abstract
Highly active antiretroviral therapy (HAART) can effectively suppress the replication of human immunodeficiency virus-1 (HIV-1) and block disease progression. However, chronic HIV-1 infection remains incurable due to the persistence of a viral reservoir, including the transcriptionally silent provirus in CD4(+) memory T cells and the sanctuary sites that are inaccessible to drugs. Reactivation and the subsequent elimination of latent virus through virus-specific cytotoxic effects or host immune responses are critical strategies for combating the disease. Indeed, a number of latency reactivating reagents have been identified through mechanism-directed approaches and large-scale screening, including: (1) histone deacetylase inhibitors (HDACi); (2) cytokines and chemokines; (3) DNA methyltransferase inhibitors (DNMTI); (4) histone methyltransferase inhibitors (HMTI); (5) protein kinase C (PKC) activators; (6) P-TEFb activators; and (7) unclassified agents, such as disulfram. They have proved to be efficacious in latent cell line models and CD4(+) T lymphocytes from HIV-1-infected patients. This review comprehensively summarizes the recent progress and relative challenges in this field.
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H3K27 Demethylation at the Proviral Promoter Sensitizes Latent HIV to the Effects of Vorinostat in Ex Vivo Cultures of Resting CD4+ T Cells. J Virol 2015; 89:8392-405. [PMID: 26041287 DOI: 10.1128/jvi.00572-15] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 05/26/2015] [Indexed: 02/06/2023] Open
Abstract
UNLABELLED Histone methyltransferase inhibitors (HMTis) and histone deacetylase inhibitors (HDACis) are reported to synergistically induce the expression of latent human immunodeficiency virus type 1 (HIV-1), but studies have largely been performed with cell lines. As specific and potent HMTis directed at EZH1 (enhancer of zeste 2 Polycomb repressive complex 2 subunit 1)/EZH2 are now in human testing, we wished to rigorously test such an inhibitor in a primary resting T-cell model of HIV latency. We found that GSK343, a potent and selective EZH2/EZH1 inhibitor, reduced trimethylation of histone 3 at lysine 27 (H3K27) of the HIV provirus in resting cells. Remarkably, this epigenetic change was not associated with increased proviral expression in latently infected resting cells. However, following the reduction in H3K27 at the HIV long terminal repeat (LTR), subsequent exposure to the HDACi suberoylanilide hydroxamic acid or vorinostat (VOR) resulted in increases in HIV gag RNA and HIV p24 antigen production that were up to 2.5-fold greater than those induced by VOR alone. Therefore, in primary resting CD4(+) T cells, true mechanistic synergy in the reversal of HIV latency may be achieved by the combination of HMTis and HDACis. Although other cellular effects of EZH2 inhibition may contribute to the sensitization of the HIV LTR to subsequent exposure to VOR, and to increase viral antigen production, this synergistic effect is directly associated with H3K27 demethylation at nucleosome 1 (Nuc-1). Based upon our findings, the combination of HMTis and HDACis should be considered for testing in animal models or clinical trials. IMPORTANCE Demethylation of H3K27 mediated by the histone methyltransferase inhibitor GSK343 in primary resting T cells is slow, occurring over 96 h, but by itself does not result in a significant upregulation of cell-associated HIV RNA expression or viral antigen production. However, following H3K27 demethylation, latent viral expression within infected primary resting CD4(+) T cells is synergistically increased upon exposure to the histone deacetylase inhibitor vorinostat. Demethylation at H3K27 sensitizes the HIV promoter to the effects of an HDACi and provides a proof-of-concept for the testing of combination epigenetic approaches to disrupt latent HIV infection, a necessary step toward the eradication of HIV infection.
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Hou H, Wang JZ, Liu BG, Zhang T. Pin1 liberates the human immunodeficiency virus type-1 (HIV-1): Must we stop it? Gene 2015; 565:9-14. [PMID: 25913034 DOI: 10.1016/j.gene.2015.04.049] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2014] [Revised: 03/07/2015] [Accepted: 04/20/2015] [Indexed: 11/16/2022]
Abstract
Acquired immune deficiency syndrome (AIDS) is mainly caused by the human immunodeficiency virus type-1 (HIV-1). To our knowledge, this is the first review focusing on the vital role of Pin1 in the infection of HIV-1 and the development of AIDS. We and others have demonstrated that Pin1, the only known cis-to-trans isomerase recognizing the pThr/pSer-Pro motifs in proteins, plays striking roles in several human diseases. Interestingly, recent evidence gradually indicates that Pin1 regulates several key steps of the life cycle of HIV-1, including the uncoating of the HIV-1 core, the reverse transcription of the RNA genome of HIV-1, and the integration of the HIV-1 cDNA into human chromosomes. Whereas inhibiting Pin1 suppresses all of these key steps and attenuates the replication of HIV-1, at the same time different PIN1 gene variants are correlated with the susceptibility to HIV-1 infection. Furthermore, Pin1 potentially promotes HIV-1 infection by activating multiple oncogenes and inactivating multiple tumor suppressors, extending the life span of HIV-infected cells. These descriptions suggest Pin1 as a promising therapeutic target for the prevention of HIV-1 and highlight the possibility of blocking the development of AIDS by Pin1 inhibitors.
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Affiliation(s)
- Hai Hou
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, Shaanxi, PR China
| | - Jing-Zhang Wang
- Affiliated Hospital, College of Medicine, Hebei University of Engineering, Handan 056002, Hebei, PR China.
| | - Bao-Guo Liu
- Affiliated Hospital, College of Medicine, Hebei University of Engineering, Handan 056002, Hebei, PR China
| | - Ting Zhang
- Affiliated Hospital, College of Medicine, Hebei University of Engineering, Handan 056002, Hebei, PR China
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De Crignis E, Mahmoudi T. HIV eradication: combinatorial approaches to activate latent viruses. Viruses 2014; 6:4581-608. [PMID: 25421889 PMCID: PMC4246239 DOI: 10.3390/v6114581] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 11/01/2014] [Accepted: 11/13/2014] [Indexed: 12/11/2022] Open
Abstract
The concept of eradication of the Human Immune Deficiency Virus (HIV) from infected patients has gained much attention in the last few years. While combination Anti-Retroviral Therapy (c-ART) has been extremely effective in suppressing viral replication, it is not curative. This is due to the presence of a reservoir of latent HIV infected cells, which persist in the presence of c-ART. Recently, pharmaceutical approaches have focused on the development of molecules able to induce HIV-1 replication from latently infected cells in order to render them susceptible to viral cytopathic effects and host immune responses. Alternative pathways and transcription complexes function to regulate the activity of the HIV promoter and might serve as molecular targets for compounds to activate latent HIV. A combined therapy coupling various depressors and activators will likely be the most effective in promoting HIV replication while avoiding pleiotropic effects at the cellular level. Moreover, in light of differences among HIV subtypes and variability in integration sites, the combination of multiple agents targeting multiple pathways will increase likelihood of therapeutic effectiveness and prevent mutational escape. This review provides an overview of the mechanisms that can be targeted to induce HIV activation focusing on potential combinatorial approaches.
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Affiliation(s)
- Elisa De Crignis
- Department of Biochemistry, Erasmus University Medical Center, Rotterdam 3015 CN, The Netherlands.
| | - Tokameh Mahmoudi
- Department of Biochemistry, Erasmus University Medical Center, Rotterdam 3015 CN, The Netherlands.
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Das B, Dobrowolski C, Shahir AM, Feng Z, Yu X, Sha J, Bissada NF, Weinberg A, Karn J, Ye F. Short chain fatty acids potently induce latent HIV-1 in T-cells by activating P-TEFb and multiple histone modifications. Virology 2014; 474:65-81. [PMID: 25463605 DOI: 10.1016/j.virol.2014.10.033] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 10/25/2014] [Accepted: 10/27/2014] [Indexed: 12/14/2022]
Abstract
HIV patients with severe periodontitis have high levels of residual virus in their saliva and plasma despite effective therapy (HAART). Multiple short chain fatty acids (SCFAs) from periodontal pathogens reactivate HIV-1 in both Jurkat and primary T-cell models of latency. SCFAs not only activate positive transcription elongation factor b (P-TEFb), which is an essential cellular cofactor for Tat, but can also reverse chromatin blocks by inducing histone modifications. SCFAs simultaneously increase histone acetylation by inhibiting class-1/2 histone deacetylases (HDACs) and decrease repressive histone tri-methylation at the proviral LTR by downregulating expression of the class-3 HDAC sirtuin-1 (SIRT1), and the histone methyltransferases enhancer of Zeste homolog 2 (EZH2) and suppressor of variegation 3-9 homolog 1 (SUV39H1). Our findings provide a mechanistic link between periodontal disease and enhanced HIV-1 replication, and suggest that treatment of periodontal disease, or blocking the activities of SCFAs, will have a therapeutic benefit for HIV patients.
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Affiliation(s)
- Biswajit Das
- Department of Molecular Biology and Microbiology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, United States
| | - Curtis Dobrowolski
- Department of Molecular Biology and Microbiology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, United States
| | - Abdel-Malek Shahir
- Department of Periodontics, School of Dental Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH, United States
| | - Zhimin Feng
- Department of Biological Sciences, School of Dental Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, United States
| | - Xiaolan Yu
- Department of Biological Sciences, School of Dental Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, United States
| | - Jinfeng Sha
- Department of Biological Sciences, School of Dental Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, United States
| | - Nabil F Bissada
- Department of Periodontics, School of Dental Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH, United States
| | - Aaron Weinberg
- Department of Biological Sciences, School of Dental Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, United States
| | - Jonathan Karn
- Department of Molecular Biology and Microbiology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, United States.
| | - Fengchun Ye
- Department of Biological Sciences, School of Dental Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, United States.
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Archin NM, Sung JM, Garrido C, Soriano-Sarabia N, Margolis DM. Eradicating HIV-1 infection: seeking to clear a persistent pathogen. Nat Rev Microbiol 2014; 12:750-64. [PMID: 25402363 PMCID: PMC4383747 DOI: 10.1038/nrmicro3352] [Citation(s) in RCA: 218] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Effective antiretroviral therapy (ART) blunts viraemia, which enables HIV-1-infected individuals to control infection and live long, productive lives. However, HIV-1 infection remains incurable owing to the persistence of a viral reservoir that harbours integrated provirus within host cellular DNA. This latent infection is unaffected by ART and hidden from the immune system. Recent studies have focused on the development of therapies to disrupt latency. These efforts unmasked residual viral genomes and highlighted the need to enable the clearance of latently infected cells, perhaps via old and new strategies that improve the HIV-1-specific immune response. In this Review, we explore new approaches to eradicate established HIV-1 infection and avoid the burden of lifelong ART.
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Affiliation(s)
- Nancie M Archin
- Department of Medicine, University of North Carolina at Chapel Hill
| | - Julia Marsh Sung
- Department of Medicine, University of North Carolina at Chapel Hill
| | - Carolina Garrido
- Department of Medicine, University of North Carolina at Chapel Hill
| | | | - David M Margolis
- 1] Department of Medicine, University of North Carolina at Chapel Hill. [2] Department of Microbiology and Immunology, University of North Carolina at Chapel Hill. [3] Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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Zeng H, Liu S, Wang P, Qu X, Ji H, Wang X, Zhu X, Song Z, Yang X, Ma Z, Zhu H. Dilazep synergistically reactivates latent HIV-1 in latently infected cells. Mol Biol Rep 2014; 41:7697-704. [PMID: 25091947 DOI: 10.1007/s11033-014-3662-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 07/27/2014] [Indexed: 12/21/2022]
Abstract
The long-lived latently infected cells persist in spite of prolonged highly active anti-retroviral therapy and present a major barrier to a cure of human immunodeficiency virus type 1 (HIV-1) infection. Elimination of this reservoir requires reactivation of the latent virus. None of the current agents can safely and effectively reactivate latent HIV-1 reservoirs. Dilazep, a nucleoside transport inhibitor, is used to treat ischemic dysfunction. However, little is known about the effect of dilazep in inducing HIV expression in latently infected cells. Using the Jurkat T cell model of HIV-1 latency, we found that dilazep effectively reactivates latent HIV-1 gene expression in a dose manner. We observed that dilazep synergistically reactivated latent HIV-1 transcription with valproic acid. We also found that dilazep activates viral latency without inducing cell surface activation markers CD25 and CD69 activation. In summary, dilazep, alone or in combination with VPA, could be useful in future eradication strategies.
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Affiliation(s)
- Hanxian Zeng
- School of Life Sciences, Institute of Genetics, Fudan University, Shanghai, 200433, China
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Churchill MJ, Cowley DJ, Wesselingh SL, Gorry PR, Gray LR. HIV-1 transcriptional regulation in the central nervous system and implications for HIV cure research. J Neurovirol 2014; 21:290-300. [PMID: 25060300 DOI: 10.1007/s13365-014-0271-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2014] [Revised: 06/25/2014] [Accepted: 06/27/2014] [Indexed: 12/15/2022]
Abstract
Human immunodeficiency virus type-1 (HIV-1) invades the central nervous system (CNS) during acute infection which can result in HIV-associated neurocognitive disorders in up to 50% of patients, even in the presence of combination antiretroviral therapy (cART). Within the CNS, productive HIV-1 infection occurs in the perivascular macrophages and microglia. Astrocytes also become infected, although their infection is restricted and does not give rise to new viral particles. The major barrier to the elimination of HIV-1 is the establishment of viral reservoirs in different anatomical sites throughout the body and viral persistence during long-term treatment with cART. While the predominant viral reservoir is believed to be resting CD4(+) T cells in the blood, other anatomical compartments including the CNS, gut-associated lymphoid tissue, bone marrow, and genital tract can also harbour persistently infected cellular reservoirs of HIV-1. Viral latency is predominantly responsible for HIV-1 persistence and is most likely governed at the transcriptional level. Current clinical trials are testing transcriptional activators, in the background of cART, in an attempt to purge these viral reservoirs and reverse viral latency. These strategies aim to activate viral transcription in cells constituting the viral reservoir, so they can be recognised and cleared by the immune system, while new rounds of infection are blocked by co-administration of cART. The CNS has several unique characteristics that may result in differences in viral transcription and in the way latency is established. These include CNS-specific cell types, different transcription factors, altered immune surveillance, and reduced antiretroviral drug bioavailability. A comprehensive understanding of viral transcription and latency in the CNS is required in order to determine treatment outcomes when using transcriptional activators within the CNS.
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Affiliation(s)
- Melissa J Churchill
- Center for Biomedical Research, Burnet Institute, 85 Commercial Rd, Melbourne, 3004, Victoria, Australia,
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