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Trejo-Villegas OA, Heijink IH, Ávila-Moreno F. Preclinical evidence in the assembly of mammalian SWI/SNF complexes: Epigenetic insights and clinical perspectives in human lung disease therapy. Mol Ther 2024; 32:2470-2488. [PMID: 38910326 DOI: 10.1016/j.ymthe.2024.06.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 04/18/2024] [Accepted: 06/20/2024] [Indexed: 06/25/2024] Open
Abstract
The SWI/SNF complex, also known as the BRG1/BRM-associated factor (BAF) complex, represents a critical regulator of chromatin remodeling mechanisms in mammals. It is alternatively referred to as mSWI/SNF and has been suggested to be imbalanced in human disease compared with human health. Three types of BAF assemblies associated with it have been described, including (1) canonical BAF (cBAF), (2) polybromo-associated BAF (PBAF), and (3) non-canonical BAF (ncBAF) complexes. Each of these BAF assemblies plays a role, either functional or dysfunctional, in governing gene expression patterns, cellular processes, epigenetic mechanisms, and biological processes. Recent evidence increasingly links the dysregulation of mSWI/SNF complexes to various human non-malignant lung chronic disorders and lung malignant diseases. This review aims to provide a comprehensive general state-of-the-art and a profound examination of the current understanding of mSWI/SNF assembly processes, as well as the structural and functional organization of mSWI/SNF complexes and their subunits. In addition, it explores their intricate functional connections with potentially dysregulated transcription factors, placing particular emphasis on molecular and cellular pathogenic processes in lung diseases. These processes are reflected in human epigenome aberrations that impact clinical and therapeutic levels, suggesting novel perspectives on the diagnosis and molecular therapies for human respiratory diseases.
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Affiliation(s)
- Octavio A Trejo-Villegas
- Lung Diseases and Functional Epigenomics Laboratory (LUDIFE), Biomedicine Research Unit (UBIMED), Facultad de Estudios Superiores-Iztacala (FES-Iztacala), Universidad Nacional Autónoma de México (UNAM), Avenida de los Barrios #1, Colonia Los Reyes Iztacala, Tlalnepantla de Baz, 54090, Estado de México, México
| | - Irene H Heijink
- Departments of Pathology & Medical Biology and Pulmonology, GRIAC Research Institute, University Medical Center Groningen, University of Groningen, 9713 Groningen, the Netherlands
| | - Federico Ávila-Moreno
- Lung Diseases and Functional Epigenomics Laboratory (LUDIFE), Biomedicine Research Unit (UBIMED), Facultad de Estudios Superiores-Iztacala (FES-Iztacala), Universidad Nacional Autónoma de México (UNAM), Avenida de los Barrios #1, Colonia Los Reyes Iztacala, Tlalnepantla de Baz, 54090, Estado de México, México; Research Unit, Instituto Nacional de Enfermedades Respiratorias (INER), Ismael Cosío Villegas, 14080, Ciudad de México, México; Research Tower, Subdirección de Investigación Básica, Instituto Nacional de Cancerología (INCan), 14080, Ciudad de México, México.
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2
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Chou TC, Maggirwar NS, Marsden MD. HIV Persistence, Latency, and Cure Approaches: Where Are We Now? Viruses 2024; 16:1163. [PMID: 39066325 PMCID: PMC11281696 DOI: 10.3390/v16071163] [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: 06/25/2024] [Revised: 07/13/2024] [Accepted: 07/17/2024] [Indexed: 07/28/2024] Open
Abstract
The latent reservoir remains a major roadblock to curing human immunodeficiency virus (HIV) infection. Currently available antiretroviral therapy (ART) can suppress active HIV replication, reduce viral loads to undetectable levels, and halt disease progression. However, antiretroviral drugs are unable to target cells that are latently infected with HIV, which can seed viral rebound if ART is stopped. Consequently, a major focus of the field is to study the latent viral reservoir and develop safe and effective methods to eliminate it. Here, we provide an overview of the major mechanisms governing the establishment and maintenance of HIV latency, the key challenges posed by latent reservoirs, small animal models utilized to study HIV latency, and contemporary cure approaches. We also discuss ongoing efforts to apply these approaches in combination, with the goal of achieving a safe, effective, and scalable cure for HIV that can be extended to the tens of millions of people with HIV worldwide.
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Affiliation(s)
- Tessa C. Chou
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California, Irvine, CA 92617, USA; (T.C.C.); (N.S.M.)
| | - Nishad S. Maggirwar
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California, Irvine, CA 92617, USA; (T.C.C.); (N.S.M.)
| | - Matthew D. Marsden
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California, Irvine, CA 92617, USA; (T.C.C.); (N.S.M.)
- Department of Medicine, Division of Infectious Disease, School of Medicine, University of California, Irvine, CA 92617, USA
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3
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D'Orso I. The HIV-1 Transcriptional Program: From Initiation to Elongation Control. J Mol Biol 2024:168690. [PMID: 38936695 DOI: 10.1016/j.jmb.2024.168690] [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: 04/01/2024] [Revised: 06/20/2024] [Accepted: 06/21/2024] [Indexed: 06/29/2024]
Abstract
A large body of work in the last four decades has revealed the key pillars of HIV-1 transcription control at the initiation and elongation steps. Here, I provide a recount of this collective knowledge starting with the genomic elements (DNA and nascent TAR RNA stem-loop) and transcription factors (cellular and the viral transactivator Tat), and later transitioning to the assembly and regulation of transcription initiation and elongation complexes, and the role of chromatin structure. Compelling evidence support a core HIV-1 transcriptional program regulated by the sequential and concerted action of cellular transcription factors and Tat to promote initiation and sustain elongation, highlighting the efficiency of a small virus to take over its host to produce the high levels of transcription required for viral replication. I summarize new advances including the use of CRISPR-Cas9, genetic tools for acute factor depletion, and imaging to study transcriptional dynamics, bursting and the progression through the multiple phases of the transcriptional cycle. Finally, I describe current challenges to future major advances and discuss areas that deserve more attention to both bolster our basic knowledge of the core HIV-1 transcriptional program and open up new therapeutic opportunities.
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Affiliation(s)
- Iván D'Orso
- Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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4
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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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5
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Rausch JW, Parvez S, Pathak S, Capoferri AA, Kearney MF. HIV Expression in Infected T Cell Clones. Viruses 2024; 16:108. [PMID: 38257808 PMCID: PMC10820123 DOI: 10.3390/v16010108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 01/04/2024] [Accepted: 01/06/2024] [Indexed: 01/24/2024] Open
Abstract
The principal barrier to an HIV-1 cure is the persistence of infected cells harboring replication-competent proviruses despite antiretroviral therapy (ART). HIV-1 transcriptional suppression, referred to as viral latency, is foremost among persistence determinants, as it allows infected cells to evade the cytopathic effects of virion production and killing by cytotoxic T lymphocytes (CTL) and other immune factors. HIV-1 persistence is also governed by cellular proliferation, an innate and essential capacity of CD4+ T cells that both sustains cell populations over time and enables a robust directed response to immunological threats. However, when HIV-1 infects CD4+ T cells, this capacity for proliferation can enable surreptitious HIV-1 propagation without the deleterious effects of viral gene expression in latently infected cells. Over time on ART, the HIV-1 reservoir is shaped by both persistence determinants, with selective forces most often favoring clonally expanded infected cell populations harboring transcriptionally quiescent proviruses. Moreover, if HIV latency is incomplete or sporadically reversed in clonal infected cell populations that are replenished faster than they are depleted, such populations could both persist indefinitely and contribute to low-level persistent viremia during ART and viremic rebound if treatment is withdrawn. In this review, select genetic, epigenetic, cellular, and immunological determinants of viral transcriptional suppression and clonal expansion of HIV-1 reservoir T cells, interdependencies among these determinants, and implications for HIV-1 persistence will be presented and discussed.
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Affiliation(s)
- Jason W. Rausch
- HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA; (S.P.); (S.P.); (A.A.C.); (M.F.K.)
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6
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Peterson JJ, Lewis CA, Burgos SD, Manickam A, Xu Y, Rowley AA, Clutton G, Richardson B, Zou F, Simon JM, Margolis DM, Goonetilleke N, Browne EP. A histone deacetylase network regulates epigenetic reprogramming and viral silencing in HIV-infected cells. Cell Chem Biol 2023; 30:1617-1633.e9. [PMID: 38134881 PMCID: PMC10754471 DOI: 10.1016/j.chembiol.2023.11.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 08/23/2023] [Accepted: 11/15/2023] [Indexed: 12/24/2023]
Abstract
A long-lived latent reservoir of HIV-1-infected CD4 T cells persists with antiretroviral therapy and prevents cure. We report that the emergence of latently infected primary CD4 T cells requires the activity of histone deacetylase enzymes HDAC1/2 and HDAC3. Data from targeted HDAC molecules, an HDAC3-directed PROTAC, and CRISPR-Cas9 knockout experiments converge on a model where either HDAC1/2 or HDAC3 targeting can prevent latency, whereas all three enzymes must be targeted to achieve latency reversal. Furthermore, HDACi treatment targets features of memory T cells that are linked to proviral latency and persistence. Latency prevention is associated with increased H3K9ac at the proviral LTR promoter region and decreased H3K9me3, suggesting that this epigenetic switch is a key proviral silencing mechanism that depends on HDAC activity. These findings support further mechanistic work on latency initiation and eventual clinical studies of HDAC inhibitors to interfere with latency initiation.
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Affiliation(s)
- Jackson J Peterson
- Department of Microbiology and Immunology, University of North Carolina (UNC) School of Medicine, Chapel Hill, NC 27514, USA; University of North Carolina HIV Cure Center, Institute of Global Health and Infectious Diseases, Chapel Hill, NC 27514, USA
| | - Catherine A Lewis
- Department of Microbiology and Immunology, University of North Carolina (UNC) School of Medicine, Chapel Hill, NC 27514, USA; University of North Carolina HIV Cure Center, Institute of Global Health and Infectious Diseases, Chapel Hill, NC 27514, USA
| | - Samuel D Burgos
- Department of Microbiology and Immunology, University of North Carolina (UNC) School of Medicine, Chapel Hill, NC 27514, USA; University of North Carolina HIV Cure Center, Institute of Global Health and Infectious Diseases, Chapel Hill, NC 27514, USA
| | - Ashokkumar Manickam
- University of North Carolina HIV Cure Center, Institute of Global Health and Infectious Diseases, Chapel Hill, NC 27514, USA
| | - Yinyan Xu
- Department of Microbiology and Immunology, University of North Carolina (UNC) School of Medicine, Chapel Hill, NC 27514, USA; University of North Carolina HIV Cure Center, Institute of Global Health and Infectious Diseases, Chapel Hill, NC 27514, USA
| | - Allison A Rowley
- University of North Carolina HIV Cure Center, Institute of Global Health and Infectious Diseases, Chapel Hill, NC 27514, USA
| | - Genevieve Clutton
- Department of Microbiology and Immunology, University of North Carolina (UNC) School of Medicine, Chapel Hill, NC 27514, USA; University of North Carolina HIV Cure Center, Institute of Global Health and Infectious Diseases, Chapel Hill, NC 27514, USA
| | - Brian Richardson
- Department of Biostatistics, UNC Gillings School of Global Public Health, Chapel Hill, NC 27514, USA
| | - Fei Zou
- Department of Biostatistics, UNC Gillings School of Global Public Health, Chapel Hill, NC 27514, USA
| | - Jeremy M Simon
- Department of Genetics, UNC School of Medicine, Chapel Hill, NC 27514, USA; UNC Neuroscience Center, UNC School of Medicine, Chapel Hill, NC 27514, USA; Department of Data Science, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - David M Margolis
- Department of Microbiology and Immunology, University of North Carolina (UNC) School of Medicine, Chapel Hill, NC 27514, USA; University of North Carolina HIV Cure Center, Institute of Global Health and Infectious Diseases, Chapel Hill, NC 27514, USA; Department of Medicine, UNC School of Medicine, Chapel Hill, NC 27514, USA; Department of Epidemiology, UNC Gillings School of Global Public Health, Chapel Hill, NC 27514, USA
| | - Nilu Goonetilleke
- Department of Microbiology and Immunology, University of North Carolina (UNC) School of Medicine, Chapel Hill, NC 27514, USA; University of North Carolina HIV Cure Center, Institute of Global Health and Infectious Diseases, Chapel Hill, NC 27514, USA
| | - Edward P Browne
- Department of Microbiology and Immunology, University of North Carolina (UNC) School of Medicine, Chapel Hill, NC 27514, USA; University of North Carolina HIV Cure Center, Institute of Global Health and Infectious Diseases, Chapel Hill, NC 27514, USA.
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7
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Lê-Bury G, Chen Y, Rhen JM, Grenier JK, Singhal A, Russell DG, Boliar S. HIV-1 active and latent infections induce disparate chromatin reorganization and transcriptional regulation of mRNAs and lncRNAs in SupT1 cells. mBio 2023; 14:e0261923. [PMID: 38038477 PMCID: PMC10746154 DOI: 10.1128/mbio.02619-23] [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: 10/02/2023] [Accepted: 10/20/2023] [Indexed: 12/02/2023] Open
Abstract
IMPORTANCE HIV-1 infection of T-lymphocytes depends on co-opting cellular transcriptional and translational machineries for viral replication. This requires significant changes in the cellular microenvironment. We have characterized and compared the changes in cellular chromatin structures as well as gene expression landscapes in T cells that are either actively or latently infected with HIV-1. Our results reveal that chromatin accessibility and expression of both protein-coding mRNAs and non-coding lncRNAs are uniquely regulated in HIV-1-infected T cells, depending on whether the virus is actively transcribing or remains in a transcriptionally silent, latent state. HIV-1 latent infection elicits more robust changes in the cellular chromatin organization than active viral infection. Our analysis also identifies the effects of such epigenomic changes on the cellular gene expression and subsequent biological pathways. This study comprehensively characterizes the cellular epigenomic and transcriptomic states that support active and latent HIV-1 infection in an in vitro model of SupT1 cells.
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Affiliation(s)
- Gabrielle Lê-Bury
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Yao Chen
- A*STAR Infectious Diseases Laboratories, Agency for Science, Technology and Research, Singapore, Singapore
| | - Jordan M. Rhen
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Jennifer K. Grenier
- Transcription Regulation and Expression Facility, Cornell University, Ithaca, New York, USA
| | - Amit Singhal
- A*STAR Infectious Diseases Laboratories, Agency for Science, Technology and Research, Singapore, Singapore
| | - David G. Russell
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Saikat Boliar
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
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8
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Duggan NN, Dragic T, Chanda SK, Pache L. Breaking the Silence: Regulation of HIV Transcription and Latency on the Road to a Cure. Viruses 2023; 15:2435. [PMID: 38140676 PMCID: PMC10747579 DOI: 10.3390/v15122435] [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: 11/21/2023] [Revised: 12/12/2023] [Accepted: 12/13/2023] [Indexed: 12/24/2023] Open
Abstract
Antiretroviral therapy (ART) has brought the HIV/AIDS epidemic under control, but a curative strategy for viral eradication is still needed. The cessation of ART results in rapid viral rebound from latently infected CD4+ T cells, showing that control of viral replication alone does not fully restore immune function, nor does it eradicate viral reservoirs. With a better understanding of factors and mechanisms that promote viral latency, current approaches are primarily focused on the permanent silencing of latently infected cells ("block and lock") or reactivating HIV-1 gene expression in latently infected cells, in combination with immune restoration strategies to eliminate HIV infected cells from the host ("shock and kill"). In this review, we provide a summary of the current, most promising approaches for HIV-1 cure strategies, including an analysis of both latency-promoting agents (LPA) and latency-reversing agents (LRA) that have shown promise in vitro, ex vivo, and in human clinical trials to reduce the HIV-1 reservoir.
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Affiliation(s)
- Natasha N. Duggan
- Department of Immunology and Microbiology, Scripps Research, La Jolla, CA 92037, USA
| | - Tatjana Dragic
- Department of Immunology and Microbiology, Scripps Research, La Jolla, CA 92037, USA
| | - Sumit K. Chanda
- Department of Immunology and Microbiology, Scripps Research, La Jolla, CA 92037, USA
| | - Lars Pache
- NCI Designated Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
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9
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Ramachandran J, Chen W, Lex RK, Windsor KE, Lee H, Wang T, Zhou W, Ji H, Vokes SA. The BAF chromatin complex component SMARCC1 does not mediate GLI transcriptional repression of Hedgehog target genes in limb buds. Dev Biol 2023; 504:128-136. [PMID: 37805104 DOI: 10.1016/j.ydbio.2023.10.001] [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: 08/16/2023] [Revised: 10/02/2023] [Accepted: 10/04/2023] [Indexed: 10/09/2023]
Abstract
Transcriptional responses to the Hedgehog (HH) signaling pathway are primarily modulated by GLI repression in the mouse limb. Previous studies suggested a role for the BAF chromatin remodeling complex in mediating GLI repression. Consistent with this possibility, the core BAF complex protein SMARCC1 is present at most active limb enhancers including the majority of GLI enhancers. However, in contrast to GLI repression which reduces chromatin accessibility, SMARCC1 maintains chromatin accessibility at most enhancers, including those bound by GLI. Moreover, SMARCC1 binding at GLI-regulated enhancers occurs independently of GLI3. Consistent with previous studies, some individual GLI target genes are mis-regulated in Smarcc1 conditional knockouts, though most GLI target genes are unaffected. Moreover, SMARCC1 is not necessary for mediating constitutive GLI repression in HH mutant limb buds. We conclude that SMARCC1 does not mediate GLI3 repression, which we propose utilizes alternative chromatin remodeling complexes.
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Affiliation(s)
- Janani Ramachandran
- Department of Molecular Biosciences, University of Texas at Austin, 100 E 24th Street, Stop A5000, Austin, TX, 78712, USA
| | - Wanlu Chen
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD, 21205, USA
| | - Rachel K Lex
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Kathryn E Windsor
- Department of Molecular Biosciences, University of Texas at Austin, 100 E 24th Street, Stop A5000, Austin, TX, 78712, USA
| | - Hyunji Lee
- Department of Molecular Biosciences, University of Texas at Austin, 100 E 24th Street, Stop A5000, Austin, TX, 78712, USA
| | - Tingchang Wang
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD, 21205, USA
| | - Weiqiang Zhou
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD, 21205, USA
| | - Hongkai Ji
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD, 21205, USA
| | - Steven A Vokes
- Department of Molecular Biosciences, University of Texas at Austin, 100 E 24th Street, Stop A5000, Austin, TX, 78712, USA.
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10
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Lyons DE, Kumar P, Roan NR, Defechereux PA, Feschotte C, Lange UC, Murthy N, Sameshima P, Verdin E, Ake JA, Parsons MS, Nath A, Gianella S, Smith DM, Kallas EG, Villa TJ, Strange R, Mwesigwa B, Furler O’Brien RL, Nixon DF, Ndhlovu LC, Valente ST, Ott M. HIV-1 Remission: Accelerating the Path to Permanent HIV-1 Silencing. Viruses 2023; 15:2171. [PMID: 38005849 PMCID: PMC10674359 DOI: 10.3390/v15112171] [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: 09/30/2023] [Revised: 10/26/2023] [Accepted: 10/26/2023] [Indexed: 11/26/2023] Open
Abstract
Despite remarkable progress, a cure for HIV-1 infection remains elusive. Rebound competent latent and transcriptionally active reservoir cells persevere despite antiretroviral therapy and rekindle infection due to inefficient proviral silencing. We propose a novel "block-lock-stop" approach, entailing long term durable silencing of viral expression towards an irreversible transcriptionally inactive latent provirus to achieve long term antiretroviral free control of the virus. A graded transformation of remnant HIV-1 in PLWH from persistent into silent to permanently defective proviruses is proposed, emulating and accelerating the natural path that human endogenous retroviruses (HERVs) take over millions of years. This hypothesis was based on research into delineating the mechanisms of HIV-1 latency, lessons from latency reversing agents and advances of Tat inhibitors, as well as expertise in the biology of HERVs. Insights from elite controllers and the availability of advanced genome engineering technologies for the direct excision of remnant virus set the stage for a rapid path to an HIV-1 cure.
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Affiliation(s)
- Danielle E. Lyons
- Gladstone Institute of Virology, Gladstone Institutes, San Francisco, CA 94158, USA
| | - Priti Kumar
- Department of Internal Medicine, Section of Infectious Diseases, Yale University School of Medicine, New Haven, CT 06510, USA;
| | - Nadia R. Roan
- Gladstone Institute of Virology, Gladstone Institutes, San Francisco, CA 94158, USA
- Department of Urology, University of California San Francisco, San Francisco, CA 94158, USA
| | - Patricia A. Defechereux
- Department of Medicine, University of California San Francisco, San Francisco, CA 94158, USA
| | - Cedric Feschotte
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | | | - Niren Murthy
- Department of Bioengineering, University of California, Berkeley, CA 94720, USA;
- Innovative Genomics Institute, Berkeley, CA 94720, USA
| | - Pauline Sameshima
- Faculty of Education, Lakehead University, Thunder Bay, ON P7B 5E1, Canada;
| | - Eric Verdin
- Department of Medicine, University of California San Francisco, San Francisco, CA 94158, USA
- Buck Institute for Research on Aging, Novato, CA 94945, USA
| | - Julie A. Ake
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA (M.S.P.)
| | - Matthew S. Parsons
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA (M.S.P.)
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD 20817, USA
- Armed Forces Research Institute of Medical Sciences, Bangkok 10400, Thailand
| | - Avindra Nath
- Section of Infections of the Nervous System, National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, MD 20824, USA;
| | - Sara Gianella
- Division of Infectious Diseases, Department of Medicine, University of California San Diego, San Diego, CA 92093, USA
| | - Davey M. Smith
- Division of Infectious Diseases, Department of Medicine, University of California San Diego, San Diego, CA 92093, USA
| | - Esper G. Kallas
- Department of Infectious and Parasitic Diseases, University of Sao Paulo, São Paulo 04023-900, Brazil
| | - Thomas J. Villa
- HOPE Martin Delaney Collaboratory for HIV Cure Research Community Engagement Ambassador, Washinton, DC 20004, USA (R.S.)
- National HIV & Aging Advocacy Network, Washington, DC 20004, USA
| | - Richard Strange
- HOPE Martin Delaney Collaboratory for HIV Cure Research Community Engagement Ambassador, Washinton, DC 20004, USA (R.S.)
| | - Betty Mwesigwa
- Research Department, Makerere University Walter Reed Project, Kampala P.O Box 7062, Uganda
| | - Robert L. Furler O’Brien
- Division of Infectious Diseases, Department of Medicine, Weill Cornell Medicine, New York, NY 10021, USA
| | - Douglas F. Nixon
- Division of Infectious Diseases, Department of Medicine, Weill Cornell Medicine, New York, NY 10021, USA
| | - Lishomwa C. Ndhlovu
- Division of Infectious Diseases, Department of Medicine, Weill Cornell Medicine, New York, NY 10021, USA
| | - Susana T. Valente
- Department of Immunology and Microbiology, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation and Technology, Jupiter, FL 33458, USA
| | - Melanie Ott
- Gladstone Institute of Virology, Gladstone Institutes, San Francisco, CA 94158, USA
- Department of Medicine, University of California San Francisco, San Francisco, CA 94158, USA
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11
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Li Z, Deeks SG, Ott M, Greene WC. Comprehensive synergy mapping links a BAF- and NSL-containing "supercomplex" to the transcriptional silencing of HIV-1. Cell Rep 2023; 42:113055. [PMID: 37682714 PMCID: PMC10591912 DOI: 10.1016/j.celrep.2023.113055] [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: 12/09/2022] [Revised: 05/26/2023] [Accepted: 08/16/2023] [Indexed: 09/10/2023] Open
Abstract
Host repressors mediate HIV latency, but how they interactively silence the virus remains unclear. Here, we develop "reiterative enrichment and authentication of CRISPRi targets for synergies (REACTS)" to probe the genome for synergies between HIV transcription repressors. Using eight known host repressors as queries, we identify 32 synergies involving eleven repressors, including BCL7C, KANSL2, and SIRT2. Overexpression of these three proteins reduces HIV reactivation in Jurkat T cells and in CD4 T cells from people living with HIV on antiretroviral therapy (ART). We show that the BCL7C-containing BAF complex and the KANSL2-containing NSL complex form a "supercomplex" that increases inhibitory histone acetylation of the HIV long-terminal repeat (LTR) and its occupancy by the short variant of the acetyl-lysine reader Brd4. Collectively, we provide a validated platform for defining gene synergies genome wide, and the BAF-NSL "supercomplex" represents a potential target for overcoming HIV rebound after ART cessation.
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Affiliation(s)
- Zichong Li
- Gladstone Institute of Virology, San Francisco, CA 94158, USA.
| | - Steven G Deeks
- University of California, San Francisco, San Francisco, CA 94143, USA
| | - Melanie Ott
- Gladstone Institute of Virology, San Francisco, CA 94158, USA; University of California, San Francisco, San Francisco, CA 94143, USA
| | - Warner C Greene
- Gladstone Institute of Virology, San Francisco, CA 94158, USA; University of California, San Francisco, San Francisco, CA 94143, USA.
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12
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Damour A, Slaninova V, Radulescu O, Bertrand E, Basyuk E. Transcriptional Stochasticity as a Key Aspect of HIV-1 Latency. Viruses 2023; 15:1969. [PMID: 37766375 PMCID: PMC10535884 DOI: 10.3390/v15091969] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 09/16/2023] [Accepted: 09/18/2023] [Indexed: 09/29/2023] Open
Abstract
This review summarizes current advances in the role of transcriptional stochasticity in HIV-1 latency, which were possible in a large part due to the development of single-cell approaches. HIV-1 transcription proceeds in bursts of RNA production, which stem from the stochastic switching of the viral promoter between ON and OFF states. This switching is caused by random binding dynamics of transcription factors and nucleosomes to the viral promoter and occurs at several time scales from minutes to hours. Transcriptional bursts are mainly controlled by the core transcription factors TBP, SP1 and NF-κb, the chromatin status of the viral promoter and RNA polymerase II pausing. In particular, spontaneous variability in the promoter chromatin creates heterogeneity in the response to activators such as TNF-α, which is then amplified by the Tat feedback loop to generate high and low viral transcriptional states. This phenomenon is likely at the basis of the partial and stochastic response of latent T cells from HIV-1 patients to latency-reversing agents, which is a barrier for the development of shock-and-kill strategies of viral eradication. A detailed understanding of the transcriptional stochasticity of HIV-1 and the possibility to precisely model this phenomenon will be important assets to develop more effective therapeutic strategies.
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Affiliation(s)
- Alexia Damour
- MFP UMR 5234 CNRS, Université de Bordeaux, 33076 Bordeaux, France;
| | - Vera Slaninova
- IGH UMR 9002 CNRS, Université de Montpellier, 34094 Montpellier, France;
| | - Ovidiu Radulescu
- LPHI, UMR 5294 CNRS, University of Montpellier, 34095 Montpellier, France;
| | - Edouard Bertrand
- IGH UMR 9002 CNRS, Université de Montpellier, 34094 Montpellier, France;
| | - Eugenia Basyuk
- MFP UMR 5234 CNRS, Université de Bordeaux, 33076 Bordeaux, France;
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13
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Ramachandran J, Chen W, Lex RK, Windsor KE, Lee H, Wang T, Zhou W, Ji H, Vokes SA. The BAF chromatin complex component SMARCC1 does not mediate GLI transcriptional repression of Hedgehog target genes in limb buds. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.03.527038. [PMID: 36798239 PMCID: PMC9934545 DOI: 10.1101/2023.02.03.527038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Transcriptional responses to the Hedgehog (HH) signaling pathway are primarily modulated by GLI repression in the mouse limb. Previous studies suggested a role for the BAF chromatin remodeling complex in mediating GLI repression. Consistent with this possibility, the core BAF complex protein SMARCC1 is present at most active limb enhancers including the majority of GLI enhancers. However, in contrast to GLI repression which reduces chromatin accessibility, SMARCC1 maintains chromatin accessibility at most enhancers, including those bound by GLI. Moreover, SMARCC1 binding at GLI-regulated enhancers occurs independently of GLI3. Consistent with previous studies, some individual GLI target genes are mis-regulated in Smarcc1 conditional knockouts, though most GLI target genes are unaffected. Moreover, SMARCC1 is not necessary for mediating constitutive GLI repression in HH mutant limb buds. We conclude that SMARCC1 does not mediate GLI3 repression, which we propose utilizes alternative chromatin remodeling complexes.
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Affiliation(s)
- Janani Ramachandran
- Department of Molecular Biosciences, University of Texas at Austin, 100 E 24th Street Stop A5000, Austin, TX 78712 USA
| | - Wanlu Chen
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205, USA
| | - Rachel K. Lex
- Department of Molecular Biosciences, University of Texas at Austin, 100 E 24th Street Stop A5000, Austin, TX 78712 USA
| | - Kathryn E. Windsor
- Department of Molecular Biosciences, University of Texas at Austin, 100 E 24th Street Stop A5000, Austin, TX 78712 USA
| | - Hyunji Lee
- Department of Molecular Biosciences, University of Texas at Austin, 100 E 24th Street Stop A5000, Austin, TX 78712 USA
| | - Tingchang Wang
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205, USA
| | - Weiqiang Zhou
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205, USA
| | - Hongkai Ji
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205, USA
| | - Steven A. Vokes
- Department of Molecular Biosciences, University of Texas at Austin, 100 E 24th Street Stop A5000, Austin, TX 78712 USA
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14
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Lista MJ, Jousset AC, Cheng M, Saint-André V, Perrot E, Rodrigues M, Di Primo C, Gadelle D, Toccafondi E, Segeral E, Berlioz-Torrent C, Emiliani S, Mergny JL, Lavigne M. DNA topoisomerase 1 represses HIV-1 promoter activity through its interaction with a guanine quadruplex present in the LTR sequence. Retrovirology 2023; 20:10. [PMID: 37254203 DOI: 10.1186/s12977-023-00625-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 05/20/2023] [Indexed: 06/01/2023] Open
Abstract
BACKGROUND Once integrated in the genome of infected cells, HIV-1 provirus is transcribed by the cellular transcription machinery. This process is regulated by both viral and cellular factors, which are necessary for an efficient viral replication as well as for the setting up of viral latency, leading to a repressed transcription of the integrated provirus. RESULTS In this study, we examined the role of two parameters in HIV-1 LTR promoter activity. We identified DNA topoisomerase1 (TOP1) to be a potent repressor of this promoter and linked this repression to its catalytic domain. Additionally, we confirmed the folding of a Guanine quadruplex (G4) structure in the HIV-1 promoter and its repressive effect. We demonstrated a direct interaction between TOP1 and this G4 structure, providing evidence of a functional relationship between the two repressive elements. Mutations abolishing G4 folding affected TOP1/G4 interaction and hindered G4-dependent inhibition of TOP1 catalytic activity in vitro. As a result, HIV-1 promoter activity was reactivated in a native chromatin environment. Lastly, we noticed an enrichment of predicted G4 sequences in the promoter of TOP1-repressed cellular genes. CONCLUSIONS Our results demonstrate the formation of a TOP1/G4 complex on the HIV-1 LTR promoter and its repressive effect on the promoter activity. They reveal the existence of a new mechanism of TOP1/G4-dependent transcriptional repression conserved between viral and human genes. This mechanism contrasts with the known property of TOP1 as global transcriptional activator and offers new perspectives for anti-cancer and anti-viral strategies.
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Affiliation(s)
- María José Lista
- Université Paris Cité, Institut Cochin, INSERM, CNRS, F-75014, Paris, France
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, UK
| | - Anne-Caroline Jousset
- Université Paris Cité, Institut Cochin, INSERM, CNRS, F-75014, Paris, France
- Université de Strasbourg, CNRS UPR 9002, Architecture et réactivité de l'ARN, 67000, Strasbourg, France
| | - Mingpan Cheng
- CNRS UMR 5320, INSERM U1212, ARNA, Univ. Bordeaux, IECB, 33000, Bordeaux, France
- School of Engineering, China Pharmaceutical University, Nanjing, 211198, China
| | - Violaine Saint-André
- Institut Pasteur, Bioinformatics and Biostatistics Hub, Université Paris Cité, 75015, Paris, France
| | - Elouan Perrot
- Institut Pasteur, Departement of Virology, Université Paris Cité, 75015, Paris, France
| | - Melissa Rodrigues
- Institut Pasteur, Departement of Virology, Université Paris Cité, 75015, Paris, France
| | - Carmelo Di Primo
- CNRS UMR 5320, INSERM U1212, ARNA, Univ. Bordeaux, IECB, 33000, Bordeaux, France
| | - Danielle Gadelle
- Institut de Biologie Integrative de la Cellule, CNRS, Université Paris-Saclay, 91198, Gif Sur Yvette, Cedex, France
| | - Elenia Toccafondi
- Université Paris Cité, Institut Cochin, INSERM, CNRS, F-75014, Paris, France
- Université de Strasbourg, CNRS UPR 9002, Architecture et réactivité de l'ARN, 67000, Strasbourg, France
| | - Emmanuel Segeral
- Université Paris Cité, Institut Cochin, INSERM, CNRS, F-75014, Paris, France
| | | | - Stéphane Emiliani
- Université Paris Cité, Institut Cochin, INSERM, CNRS, F-75014, Paris, France
| | - Jean-Louis Mergny
- CNRS UMR 5320, INSERM U1212, ARNA, Univ. Bordeaux, IECB, 33000, Bordeaux, France
- Laboratoire d'Optique et Biosciences, Ecole Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, 91120, Palaiseau, France
| | - Marc Lavigne
- Université Paris Cité, Institut Cochin, INSERM, CNRS, F-75014, Paris, France.
- Institut Pasteur, Departement of Virology, Université Paris Cité, 75015, Paris, France.
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15
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Boehm D, Lam V, Schnolzer M, Ott M. The lysine methyltransferase SMYD5 amplifies HIV-1 transcription and is post-transcriptionally upregulated by Tat and USP11. Cell Rep 2023; 42:112234. [PMID: 36897778 PMCID: PMC10124996 DOI: 10.1016/j.celrep.2023.112234] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 09/22/2022] [Accepted: 02/22/2023] [Indexed: 03/11/2023] Open
Abstract
A successful HIV-1 cure strategy may require enhancing HIV-1 latency to silence HIV-1 transcription. Modulators of gene expression show promise as latency-promoting agents in vitro and in vivo. Here, we identify Su(var)3-9, enhancer-of-zeste, and trithorax (SET) and myeloid, Nervy, and DEAF-1 (MYND) domain-containing protein 5 (SMYD5) as a host factor required for HIV-1 transcription. SMYD5 is expressed in CD4+ T cells and activates the HIV-1 promoter with or without the viral Tat protein, while knockdown of SMYD5 decreases HIV-1 transcription in cell lines and primary T cells. SMYD5 associates in vivo with the HIV-1 promoter and binds the HIV trans-activation response (TAR) element RNA and Tat. Tat is methylated by SMYD5 in vitro, and in cells expressing Tat, SMYD5 protein levels are increased. The latter requires expression of the Tat cofactor and ubiquitin-specific peptidase 11 (USP11). We propose that SMYD5 is a host activator of HIV-1 transcription stabilized by Tat and USP11 and, together with USP11, a possible target for latency-promoting therapy.
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Affiliation(s)
- Daniela Boehm
- Gladstone Institute of Virology, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Victor Lam
- Tetrad Graduate Program, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Martina Schnolzer
- Functional Proteome Analysis, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Melanie Ott
- Gladstone Institute of Virology, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA.
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16
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Prins HAB, Crespo R, Lungu C, Rao S, Li L, Overmars RJ, Papageorgiou G, Mueller YM, Stoszko M, Hossain T, Kan TW, Rijnders BJA, Bax HI, van Gorp ECM, Nouwen JL, de Vries-Sluijs TEMS, Schurink CAM, de Mendonça Melo M, van Nood E, Colbers A, Burger D, Palstra RJ, van Kampen JJA, van de Vijver DAMC, Mesplède T, Katsikis PD, Gruters RA, Koch BCP, Verbon A, Mahmoudi T, Rokx C. The BAF complex inhibitor pyrimethamine reverses HIV-1 latency in people with HIV-1 on antiretroviral therapy. SCIENCE ADVANCES 2023; 9:eade6675. [PMID: 36921041 PMCID: PMC10017042 DOI: 10.1126/sciadv.ade6675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 02/09/2023] [Indexed: 06/18/2023]
Abstract
Reactivation of the latent HIV-1 reservoir is a first step toward triggering reservoir decay. Here, we investigated the impact of the BAF complex inhibitor pyrimethamine on the reservoir of people living with HIV-1 (PLWH). Twenty-eight PLWH on suppressive antiretroviral therapy were randomized (1:1:1:1 ratio) to receive pyrimethamine, valproic acid, both, or no intervention for 14 days. The primary end point was change in cell-associated unspliced (CA US) HIV-1 RNA at days 0 and 14. We observed a rapid, modest, and significant increase in (CA US) HIV-1 RNA in response to pyrimethamine exposure, which persisted throughout treatment and follow-up. Valproic acid treatment alone did not increase (CA US) HIV-1 RNA or augment the effect of pyrimethamine. Pyrimethamine treatment did not result in a reduction in the size of the inducible reservoir. These data demonstrate that the licensed drug pyrimethamine can be repurposed as a BAF complex inhibitor to reverse HIV-1 latency in vivo in PLWH, substantiating its potential advancement in clinical studies.
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Affiliation(s)
- Henrieke A. B. Prins
- Department of Internal Medicine, Section Infectious Diseases, Erasmus University Medical Center, Rotterdam, Netherlands
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Raquel Crespo
- Department of Biochemistry, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Cynthia Lungu
- Department of Biochemistry, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Shringar Rao
- Department of Biochemistry, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Letao Li
- Department of Pharmacy, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Ronald J. Overmars
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, Netherlands
| | | | - Yvonne M. Mueller
- Department of Immunology, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Mateusz Stoszko
- Department of Biochemistry, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Tanvir Hossain
- Department of Biochemistry, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Tsung Wai Kan
- Department of Biochemistry, Erasmus University Medical Center, Rotterdam, Netherlands
- Department of Pathology, Erasmus University Medical Center, Rotterdam, Netherlands
- Department of Urology, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Bart J. A. Rijnders
- Department of Internal Medicine, Section Infectious Diseases, Erasmus University Medical Center, Rotterdam, Netherlands
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Hannelore I. Bax
- Department of Internal Medicine, Section Infectious Diseases, Erasmus University Medical Center, Rotterdam, Netherlands
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Eric C. M. van Gorp
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Jan L. Nouwen
- Department of Internal Medicine, Section Infectious Diseases, Erasmus University Medical Center, Rotterdam, Netherlands
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Theodora E. M. S. de Vries-Sluijs
- Department of Internal Medicine, Section Infectious Diseases, Erasmus University Medical Center, Rotterdam, Netherlands
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Carolina A. M. Schurink
- Department of Internal Medicine, Section Infectious Diseases, Erasmus University Medical Center, Rotterdam, Netherlands
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Mariana de Mendonça Melo
- Department of Internal Medicine, Section Infectious Diseases, Erasmus University Medical Center, Rotterdam, Netherlands
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Els van Nood
- Department of Internal Medicine, Section Infectious Diseases, Erasmus University Medical Center, Rotterdam, Netherlands
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Angela Colbers
- Department of Pharmacy, Radboud Institute for Health Sciences, Radboud University Medical Center Nijmegen, Nijmegen, Netherlands
| | - David Burger
- Department of Pharmacy, Radboud Institute for Health Sciences, Radboud University Medical Center Nijmegen, Nijmegen, Netherlands
| | - Robert-Jan Palstra
- Department of Biochemistry, Erasmus University Medical Center, Rotterdam, Netherlands
- Department of Pathology, Erasmus University Medical Center, Rotterdam, Netherlands
- Department of Urology, Erasmus University Medical Center, Rotterdam, Netherlands
| | | | | | - Thibault Mesplède
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Peter D. Katsikis
- Department of Immunology, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Rob A. Gruters
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Birgit C. P. Koch
- Department of Pharmacy, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Annelies Verbon
- Department of Internal Medicine, Section Infectious Diseases, Erasmus University Medical Center, Rotterdam, Netherlands
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, Netherlands
- Department of Internal Medicine, University Medical Center, Utrecht, Netherlands
| | - Tokameh Mahmoudi
- Department of Biochemistry, Erasmus University Medical Center, Rotterdam, Netherlands
- Department of Pathology, Erasmus University Medical Center, Rotterdam, Netherlands
- Department of Urology, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Casper Rokx
- Department of Internal Medicine, Section Infectious Diseases, Erasmus University Medical Center, Rotterdam, Netherlands
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, Netherlands
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17
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Wu VH, Nordin JML, Nguyen S, Joy J, Mampe F, Del Rio Estrada PM, Torres-Ruiz F, González-Navarro M, Luna-Villalobos YA, Ávila-Ríos S, Reyes-Terán G, Tebas P, Montaner LJ, Bar KJ, Vella LA, Betts MR. Profound phenotypic and epigenetic heterogeneity of the HIV-1-infected CD4 + T cell reservoir. Nat Immunol 2023; 24:359-370. [PMID: 36536105 PMCID: PMC9892009 DOI: 10.1038/s41590-022-01371-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 10/24/2022] [Indexed: 12/24/2022]
Abstract
Understanding the complexity of the long-lived HIV reservoir during antiretroviral therapy (ART) remains a considerable impediment in research towards a cure for HIV. To address this, we developed a single-cell strategy to precisely define the unperturbed peripheral blood HIV-infected memory CD4+ T cell reservoir from ART-treated people living with HIV (ART-PLWH) via the presence of integrated accessible proviral DNA in concert with epigenetic and cell surface protein profiling. We identified profound reservoir heterogeneity within and between ART-PLWH, characterized by new and known surface markers within total and individual memory CD4+ T cell subsets. We further uncovered new epigenetic profiles and transcription factor motifs enriched in HIV-infected cells that suggest infected cells with accessible provirus, irrespective of reservoir distribution, are poised for reactivation during ART treatment. Together, our findings reveal the extensive inter- and intrapersonal cellular heterogeneity of the HIV reservoir, and establish an initial multiomic atlas to develop targeted reservoir elimination strategies.
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Affiliation(s)
- Vincent H Wu
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Center for AIDS Research, University of Pennsylvania, Philadelphia, PA, USA
| | - Jayme M L Nordin
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Center for AIDS Research, University of Pennsylvania, Philadelphia, PA, USA
| | - Son Nguyen
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Institute for Medical Engineering and Science, Department of Chemistry, and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Jaimy Joy
- Center for AIDS Research, University of Pennsylvania, Philadelphia, PA, USA
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Felicity Mampe
- Center for AIDS Research, University of Pennsylvania, Philadelphia, PA, USA
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Perla M Del Rio Estrada
- Centro de Investigación en Enfermedades Infecciosas, Instituto Nacional de Enfermedades Respiratorias, Mexico City, Mexico
| | - Fernanda Torres-Ruiz
- Centro de Investigación en Enfermedades Infecciosas, Instituto Nacional de Enfermedades Respiratorias, Mexico City, Mexico
| | - Mauricio González-Navarro
- Centro de Investigación en Enfermedades Infecciosas, Instituto Nacional de Enfermedades Respiratorias, Mexico City, Mexico
| | - Yara Andrea Luna-Villalobos
- Centro de Investigación en Enfermedades Infecciosas, Instituto Nacional de Enfermedades Respiratorias, Mexico City, Mexico
| | - Santiago Ávila-Ríos
- Centro de Investigación en Enfermedades Infecciosas, Instituto Nacional de Enfermedades Respiratorias, Mexico City, Mexico
| | - Gustavo Reyes-Terán
- Institutos Nacionales de Salud y Hospitales de Alta Especialidad, Secretaría de Salud de México, Mexico City, Mexico
| | - Pablo Tebas
- Center for AIDS Research, University of Pennsylvania, Philadelphia, PA, USA
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Luis J Montaner
- Center for AIDS Research, University of Pennsylvania, Philadelphia, PA, USA
- The Wistar Institute, Philadelphia, PA, USA
| | - Katharine J Bar
- Center for AIDS Research, University of Pennsylvania, Philadelphia, PA, USA
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Laura A Vella
- Center for AIDS Research, University of Pennsylvania, Philadelphia, PA, USA.
- Division of Infectious Diseases, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
| | - Michael R Betts
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
- Center for AIDS Research, University of Pennsylvania, Philadelphia, PA, USA.
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18
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Epigenetic Regulation of HIV-1 Sense and Antisense Transcription in Response to Latency-Reversing Agents. Noncoding RNA 2023; 9:ncrna9010005. [PMID: 36649034 PMCID: PMC9844351 DOI: 10.3390/ncrna9010005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 12/29/2022] [Accepted: 01/05/2023] [Indexed: 01/12/2023] Open
Abstract
Nucleosomes positioned on the HIV-1 5' long terminal repeat (LTR) regulate sense transcription as well as the establishment and maintenance of latency. A negative-sense promoter (NSP) in the 3' LTR expresses antisense transcripts with coding and non-coding activities. Previous studies identified cis-acting elements that modulate NSP activity. Here, we used the two chronically infected T cell lines, ACH-2 and J1.1, to investigate epigenetic regulation of NSP activity. We found that histones H3 and H4 are present on the 3' LTR in both cell lines. Following treatment with histone deacetylase inhibitors (HDACi), the levels of H3K27Ac increased and histone occupancy declined. HDACi treatment also led to increased levels of RNA polymerase II (RNPII) at NSP, and antisense transcription was induced with similar kinetics and to a similar extent as 5' LTR-driven sense transcription. We also detected H3K9me2 and H3K27me3 on NSP, along with the enzymes responsible for these epigenetic marks, namely G9a and EZH2, respectively. Treatment with their respective inhibitors had little or no effect on RNPII occupancy at the two LTRs, but it induced both sense and antisense transcription. Moreover, the increased expression of antisense transcripts in response to treatment with a panel of eleven latency-reversing agents closely paralleled and was often greater than the effect on sense transcripts. Thus, HIV-1 sense and antisense RNA expression are both regulated via acetylation and methylation of lysine 9 and 27 on histone H3. Since HIV-1 antisense transcripts act as non-coding RNAs promoting epigenetic silencing of the 5' LTR, our results suggest that the limited efficacy of latency-reversing agents in the context of 'shock and kill' cure strategies may be due to concurrent induction of antisense transcripts thwarting their effect on sense transcription.
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19
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Hsieh E, Janssens DH, Paddison PJ, Browne EP, Henikoff S, OhAinle M, Emerman M. A modular CRISPR screen identifies individual and combination pathways contributing to HIV-1 latency. PLoS Pathog 2023; 19:e1011101. [PMID: 36706161 PMCID: PMC9907829 DOI: 10.1371/journal.ppat.1011101] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 02/08/2023] [Accepted: 01/05/2023] [Indexed: 01/28/2023] Open
Abstract
Transcriptional silencing of latent HIV-1 proviruses entails complex and overlapping mechanisms that pose a major barrier to in vivo elimination of HIV-1. We developed a new latency CRISPR screening strategy, called Latency HIV-CRISPR which uses the packaging of guideRNA-encoding lentiviral vector genomes into the supernatant of budding virions as a direct readout of factors involved in the maintenance of HIV-1 latency. We developed a custom guideRNA library targeting epigenetic regulatory genes and paired the screen with and without a latency reversal agent-AZD5582, an activator of the non-canonical NFκB pathway-to examine a combination of mechanisms controlling HIV-1 latency. A component of the Nucleosome Acetyltransferase of H4 histone acetylation (NuA4 HAT) complex, ING3, acts in concert with AZD5582 to activate proviruses in J-Lat cell lines and in a primary CD4+ T cell model of HIV-1 latency. We found that the knockout of ING3 reduces acetylation of the H4 histone tail and BRD4 occupancy on the HIV-1 LTR. However, the combination of ING3 knockout accompanied with the activation of the non-canonical NFκB pathway via AZD5582 resulted in a dramatic increase in initiation and elongation of RNA Polymerase II on the HIV-1 provirus in a manner that is nearly unique among all cellular promoters.
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Affiliation(s)
- Emily Hsieh
- Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, Washington, United States of America
| | - Derek H. Janssens
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, Washington, United States of America
| | - Patrick J. Paddison
- Division of Human Biology, Fred Hutchinson Cancer Center, Seattle, Washington, United States of America
| | - Edward P. Browne
- Division of Infectious Diseases, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Steve Henikoff
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, Washington, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
| | - Molly OhAinle
- Division of Human Biology, Fred Hutchinson Cancer Center, Seattle, Washington, United States of America
| | - Michael Emerman
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, Washington, United States of America
- Division of Human Biology, Fred Hutchinson Cancer Center, Seattle, Washington, United States of America
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20
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Reske JJ, Wilson MR, Armistead B, Harkins S, Perez C, Hrit J, Adams M, Rothbart SB, Missmer SA, Fazleabas AT, Chandler RL. ARID1A-dependent maintenance of H3.3 is required for repressive CHD4-ZMYND8 chromatin interactions at super-enhancers. BMC Biol 2022; 20:209. [PMID: 36153585 PMCID: PMC9509632 DOI: 10.1186/s12915-022-01407-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 09/12/2022] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND SWI/SNF (BAF) chromatin remodeling complexes regulate lineage-specific enhancer activity by promoting accessibility for diverse DNA-binding factors and chromatin regulators. Additionally, they are known to modulate the function of the epigenome through regulation of histone post-translational modifications and nucleosome composition, although the way SWI/SNF complexes govern the epigenome remains poorly understood. Here, we investigate the function of ARID1A, a subunit of certain mammalian SWI/SNF chromatin remodeling complexes associated with malignancies and benign diseases originating from the uterine endometrium. RESULTS Through genome-wide analysis of human endometriotic epithelial cells, we show that more than half of ARID1A binding sites are marked by the variant histone H3.3, including active regulatory elements such as super-enhancers. ARID1A knockdown leads to H3.3 depletion and gain of canonical H3.1/3.2 at ARID1A-bound active regulatory elements, and a concomitant redistribution of H3.3 toward genic elements. ARID1A interactions with the repressive chromatin remodeler CHD4 (NuRD) are associated with H3.3, and ARID1A is required for CHD4 recruitment to H3.3. ZMYND8 interacts with CHD4 to suppress a subset of ARID1A, CHD4, and ZMYND8 co-bound, H3.3+ H4K16ac+ super-enhancers near genes governing extracellular matrix, motility, adhesion, and epithelial-to-mesenchymal transition. Moreover, these gene expression alterations are observed in human endometriomas. CONCLUSIONS These studies demonstrate that ARID1A-containing BAF complexes are required for maintenance of the histone variant H3.3 at active regulatory elements, such as super-enhancers, and this function is required for the physiologically relevant activities of alternative chromatin remodelers.
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Affiliation(s)
- Jake J. Reske
- grid.17088.360000 0001 2150 1785Department of Obstetrics, Gynecology and Reproductive Biology, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503 USA
| | - Mike R. Wilson
- grid.17088.360000 0001 2150 1785Department of Obstetrics, Gynecology and Reproductive Biology, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503 USA
| | - Brooke Armistead
- grid.17088.360000 0001 2150 1785Department of Obstetrics, Gynecology and Reproductive Biology, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503 USA
| | - Shannon Harkins
- grid.17088.360000 0001 2150 1785Department of Obstetrics, Gynecology and Reproductive Biology, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503 USA
| | - Cristina Perez
- grid.17088.360000 0001 2150 1785Department of Obstetrics, Gynecology and Reproductive Biology, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503 USA
| | - Joel Hrit
- grid.251017.00000 0004 0406 2057Department of Epigenetics, Van Andel Research Institute, Grand Rapids, MI 49503 USA
| | - Marie Adams
- grid.251017.00000 0004 0406 2057Genomics Core Facility, Van Andel Research Institute, Grand Rapids, MI 49503 USA
| | - Scott B. Rothbart
- grid.251017.00000 0004 0406 2057Department of Epigenetics, Van Andel Research Institute, Grand Rapids, MI 49503 USA
| | - Stacey A. Missmer
- grid.17088.360000 0001 2150 1785Department of Obstetrics, Gynecology and Reproductive Biology, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503 USA ,grid.416230.20000 0004 0406 3236Department of Women’s Health, Spectrum Health System, Grand Rapids, MI 49341 USA
| | - Asgerally T. Fazleabas
- grid.17088.360000 0001 2150 1785Department of Obstetrics, Gynecology and Reproductive Biology, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503 USA ,grid.416230.20000 0004 0406 3236Department of Women’s Health, Spectrum Health System, Grand Rapids, MI 49341 USA
| | - Ronald L. Chandler
- grid.17088.360000 0001 2150 1785Department of Obstetrics, Gynecology and Reproductive Biology, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503 USA ,grid.251017.00000 0004 0406 2057Department of Epigenetics, Van Andel Research Institute, Grand Rapids, MI 49503 USA ,grid.416230.20000 0004 0406 3236Department of Women’s Health, Spectrum Health System, Grand Rapids, MI 49341 USA
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21
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Mediouni S, Lyu S, Schader SM, Valente ST. Forging a Functional Cure for HIV: Transcription Regulators and Inhibitors. Viruses 2022; 14:1980. [PMID: 36146786 PMCID: PMC9502519 DOI: 10.3390/v14091980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 08/28/2022] [Accepted: 09/01/2022] [Indexed: 11/16/2022] Open
Abstract
Current antiretroviral therapy (ART) increases the survival of HIV-infected individuals, yet it is not curative. The major barrier to finding a definitive cure for HIV is our inability to identify and eliminate long-lived cells containing the dormant provirus, termed viral reservoir. When ART is interrupted, the viral reservoir ensures heterogenous and stochastic HIV viral gene expression, which can reseed infection back to pre-ART levels. While strategies to permanently eradicate the virus have not yet provided significant success, recent work has focused on the management of this residual viral reservoir to effectively limit comorbidities associated with the ongoing viral transcription still observed during suppressive ART, as well as limit the need for daily ART. Our group has been at the forefront of exploring the viability of the block-and-lock remission approach, focused on the long-lasting epigenetic block of viral transcription such that without daily ART, there is no risk of viral rebound, transmission, or progression to AIDS. Numerous studies have reported inhibitors of both viral and host factors required for HIV transcriptional activation. Here, we highlight and review some of the latest HIV transcriptional inhibitor discoveries that may be leveraged for the clinical exploration of block-and-lock and revolutionize the way we treat HIV infections.
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Affiliation(s)
- Sonia Mediouni
- Department of Immunology and Microbiology, UF Scripps Biomedical Research, 130 Scripps Way, 3C1, Jupiter, FL 33458, USA
| | - Shuang Lyu
- Department of Immunology and Microbiology, UF Scripps Biomedical Research, 130 Scripps Way, 3C1, Jupiter, FL 33458, USA
| | - Susan M. Schader
- Department of Infectious Disease Research, Drug Development Division, Southern Research, 431 Aviation Way, Frederick, MD 21701, USA
| | - Susana T. Valente
- Department of Immunology and Microbiology, UF Scripps Biomedical Research, 130 Scripps Way, 3C1, Jupiter, FL 33458, USA
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22
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Zhang Q, Wang S, Li W, Yau E, Hui H, Singh PK, Achuthan V, Young Karris MA, Engelman AN, Rana T. Genome-wide CRISPR/Cas9 transcriptional activation screen identifies a histone acetyltransferase inhibitor complex as a regulator of HIV-1 integration. Nucleic Acids Res 2022; 50:6687-6701. [PMID: 35713529 PMCID: PMC9262610 DOI: 10.1093/nar/gkac464] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 04/28/2022] [Accepted: 06/14/2022] [Indexed: 12/24/2022] Open
Abstract
The retrovirus human immunodeficiency virus-1 (HIV-1) is the causative agent of AIDS. Although treatment of HIV/AIDS with antiretroviral therapy provides suppression of viremia, latent reservoirs of integrated proviruses preclude cure by current antiviral treatments. Understanding the mechanisms of host-viral interactions may elucidate new treatment strategies. Here, we performed a CRISPR/Cas9 transcriptional activation screen using a high-complexity, genome-wide sgRNA library to identify cellular factors that inhibit HIV-1 infection of human CD4+ T cells. MT4 cells were transduced with a CRISPR/Cas9 sgRNA library and infected with nef-deficient HIV-1NL4-3 expressing ganciclovir-sensitive thymidine kinase, thus enabling selection of HIV-1-resistant cells for analysis of enriched sgRNAs. After validation of screen hits, multiple host factors essential for HIV-1 infection were identified, including SET (SET nuclear proto-oncogene) and ANP32A (acidic nuclear phosphoprotein 32A, PP32A), which together form a histone acetylase inhibitor complex. Using multiple human cell lines and peripheral blood mononuclear cells (PBMCs) from healthy donors and HIV-1-infected individuals, we demonstrate that SET depletion increased HIV-1 infectivity by augmenting DNA integration without significantly changing sites of integration. Conversely, SET overexpression decreased HIV-1 integration and infectivity. SET protein expression was significantly reduced in PBMCs from HIV-1-infected individuals and was downregulated by HIV-1 infection of healthy donor cells in vitro. Notably, HIV-1-induced downregulation of SET could be alleviated by inhibition of the protease granzyme A. Altogether, we have identified cellular inhibitors of HIV-1 infection on a genome-wide scale, which affords new insight into host-virus interactions and may provide new strategies for HIV-1 treatment.
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Affiliation(s)
| | | | - Wanyu Li
- Division of Genetics, Department of Pediatrics, Program in Immunology, Institute for Genomic Medicine, UCSD Center for AIDS Research, University of California San Diego, 9500 Gilman Drive MC 0762, La Jolla, CA 92093, USA
| | - Edwin Yau
- Division of Genetics, Department of Pediatrics, Program in Immunology, Institute for Genomic Medicine, UCSD Center for AIDS Research, University of California San Diego, 9500 Gilman Drive MC 0762, La Jolla, CA 92093, USA
| | - Hui Hui
- Division of Genetics, Department of Pediatrics, Program in Immunology, Institute for Genomic Medicine, UCSD Center for AIDS Research, University of California San Diego, 9500 Gilman Drive MC 0762, La Jolla, CA 92093, USA
| | - Parmit Kumar Singh
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02215, USA,Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Vasudevan Achuthan
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02215, USA,Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Maile Ann Young Karris
- Division of Infectious Diseases, Department of Medicine, UCSD Center for AIDS Research, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Alan N Engelman
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02215, USA,Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Tariq M Rana
- To whom correspondence should be addressed. Tel: +1 858 246 1100; Fax: +1 858 246 1600;
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23
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Ne E, Crespo R, Izquierdo-Lara R, Rao S, Koçer S, Górska A, van Staveren T, Kan TW, van de Vijver D, Dekkers D, Rokx C, Moulos P, Hatzis P, Palstra RJ, Demmers J, Mahmoudi T. Catchet-MS identifies IKZF1-targeting thalidomide analogues as novel HIV-1 latency reversal agents. Nucleic Acids Res 2022; 50:5577-5598. [PMID: 35640596 PMCID: PMC9177988 DOI: 10.1093/nar/gkac407] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 04/11/2022] [Accepted: 05/24/2022] [Indexed: 12/27/2022] Open
Abstract
A major pharmacological strategy toward HIV cure aims to reverse latency in infected cells as a first step leading to their elimination. While the unbiased identification of molecular targets physically associated with the latent HIV-1 provirus would be highly valuable to unravel the molecular determinants of HIV-1 transcriptional repression and latency reversal, due to technical limitations, this has been challenging. Here we use a dCas9 targeted chromatin and histone enrichment strategy coupled to mass spectrometry (Catchet-MS) to probe the differential protein composition of the latent and activated HIV-1 5′LTR. Catchet-MS identified known and novel latent 5′LTR-associated host factors. Among these, IKZF1 is a novel HIV-1 transcriptional repressor, required for Polycomb Repressive Complex 2 recruitment to the LTR. We find the clinically advanced thalidomide analogue iberdomide, and the FDA approved analogues lenalidomide and pomalidomide, to be novel LRAs. We demonstrate that, by targeting IKZF1 for degradation, these compounds reverse HIV-1 latency in CD4+ T-cells isolated from virally suppressed people living with HIV-1 and that they are able to synergize with other known LRAs.
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Affiliation(s)
- Enrico Ne
- Department of Biochemistry, Erasmus University Medical Center, Ee622 PO Box 2040, 3000CA Rotterdam, The Netherlands
| | - Raquel Crespo
- Department of Biochemistry, Erasmus University Medical Center, Ee622 PO Box 2040, 3000CA Rotterdam, The Netherlands
| | - Ray Izquierdo-Lara
- Department of Biochemistry, Erasmus University Medical Center, Ee622 PO Box 2040, 3000CA Rotterdam, The Netherlands
| | - Shringar Rao
- Department of Biochemistry, Erasmus University Medical Center, Ee622 PO Box 2040, 3000CA Rotterdam, The Netherlands
| | - Selin Koçer
- Department of Biochemistry, Erasmus University Medical Center, Ee622 PO Box 2040, 3000CA Rotterdam, The Netherlands
| | - Alicja Górska
- Department of Biochemistry, Erasmus University Medical Center, Ee622 PO Box 2040, 3000CA Rotterdam, The Netherlands
| | - Thomas van Staveren
- Department of Biochemistry, Erasmus University Medical Center, Ee622 PO Box 2040, 3000CA Rotterdam, The Netherlands
| | - Tsung Wai Kan
- Department of Biochemistry, Erasmus University Medical Center, Ee622 PO Box 2040, 3000CA Rotterdam, The Netherlands.,Department of Pathology, Erasmus University Medical Center, The Netherlands.,Department of Urology, Erasmus University Medical Center, The Netherlands
| | - David van de Vijver
- Department of Viroscience, Erasmus University Medical Center, The Netherlands
| | - Dick Dekkers
- Proteomics Center, Erasmus University Medical Center, Ee679a PO Box 2040, 3000CA Rotterdam, The Netherlands
| | - Casper Rokx
- Department of Internal Medicine, Section of Infectious Diseases, Erasmus University Medical Center, Rg-530, PO Box 2040, 3000CA Rotterdam, The Netherlands
| | - Panagiotis Moulos
- Institute for Fundamental Biomedical Research, Biomedical Sciences Research Center "Alexander Fleming", 16672, Vari, Greece
| | - Pantelis Hatzis
- Institute for Fundamental Biomedical Research, Biomedical Sciences Research Center "Alexander Fleming", 16672, Vari, Greece
| | - Robert-Jan Palstra
- Department of Biochemistry, Erasmus University Medical Center, Ee622 PO Box 2040, 3000CA Rotterdam, The Netherlands.,Department of Pathology, Erasmus University Medical Center, The Netherlands.,Department of Urology, Erasmus University Medical Center, The Netherlands
| | - Jeroen Demmers
- Proteomics Center, Erasmus University Medical Center, Ee679a PO Box 2040, 3000CA Rotterdam, The Netherlands
| | - Tokameh Mahmoudi
- Department of Biochemistry, Erasmus University Medical Center, Ee622 PO Box 2040, 3000CA Rotterdam, The Netherlands.,Department of Pathology, Erasmus University Medical Center, The Netherlands.,Department of Urology, Erasmus University Medical Center, The Netherlands
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24
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Huang R, Liu M, Gong G, Wu P, Bai M, Qin H, Wang G, Liao H, Wang X, Li Y, Wu H, Wang X, Yang C, Schubert D, Zhang S. BLISTER promotes seed maturation and fatty acid biosynthesis by interacting with WRINKLED1 to regulate chromatin dynamics in Arabidopsis. THE PLANT CELL 2022; 34:2242-2265. [PMID: 35262735 PMCID: PMC9134064 DOI: 10.1093/plcell/koac083] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 03/01/2022] [Indexed: 05/09/2023]
Abstract
WRINKLED1 (WRI1) is an important transcription factor that regulates seed oil biosynthesis. However, how WRI1 regulates gene expression during this process remains poorly understood. Here, we found that BLISTER (BLI) is expressed in maturing Arabidopsis thaliana seeds and acts as an interacting partner of WRI1. bli mutant seeds showed delayed maturation, a wrinkled seed phenotype, and reduced oil content, similar to the phenotypes of wri1. In contrast, BLI overexpression resulted in enlarged seeds and increased oil content. Gene expression and genetic analyses revealed that BLI plays a role in promoting the expression of WRI1 targets involved in fatty acid biosynthesis and regulates seed maturation together with WRI1. BLI is recruited by WRI1 to the AW boxes in the promoters of fatty acid biosynthesis genes. BLI shows a mutually exclusive interaction with the Polycomb-group protein CURLY LEAF (CLF) or the chromatin remodeling factor SWITCH/SUCROSE NONFERMENTING 3B (SWI3B), which facilitates gene expression by modifying nucleosomal occupancy and histone modifications. Together, these data suggest that BLI promotes the expression of fatty acid biosynthesis genes by interacting with WRI1 to regulate chromatin dynamics, leading to increased fatty acid production. These findings provide insights into the roles of the WRI1-BLI-CLF-SWI3B module in mediating seed maturation and gene expression.
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Affiliation(s)
| | | | - Guanping Gong
- Guangdong Key Laboratory of Biotechnology for Plant Development, College of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Pingzhi Wu
- Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization, Ministry of Agriculture, Institution of Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China
| | - Mei Bai
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou 510642, China
| | - Hongting Qin
- Guangdong Key Laboratory of Biotechnology for Plant Development, College of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Guohe Wang
- Guangdong Key Laboratory of Biotechnology for Plant Development, College of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Huimei Liao
- Guangdong Key Laboratory of Biotechnology for Plant Development, College of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Xiaoxiu Wang
- Guangdong Key Laboratory of Biotechnology for Plant Development, College of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Yanqun Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou 510642, China
| | - Hong Wu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou 510642, China
| | - Xiaojing Wang
- Guangdong Key Laboratory of Biotechnology for Plant Development, College of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Chengwei Yang
- Guangdong Key Laboratory of Biotechnology for Plant Development, College of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Daniel Schubert
- Institute for Biology, Freie Universität Berlin, Berlin 14195, Germany
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25
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Abstract
Human immunodeficiency virus (HIV)-infected macrophages are long-lived cells that sustain persistent virus expression, which is both a barrier to viral eradication and contributor to neurological complications in patients despite antiretroviral therapy (ART). To better understand the regulation of HIV-1 in macrophages, we compared HIV-infected primary human monocyte-derived macrophages (MDM) to acutely infected primary CD4 T cells and Jurkat cells latently infected with HIV (JLAT 8.4). HIV genomes in MDM were actively transcribed despite enrichment with heterochromatin-associated H3K9me3 across the complete HIV genome in combination with elevated activation marks of H3K9ac and H3K27ac at the long terminal repeat (LTR). Macrophage patterns contrasted with JLAT cells, which showed conventional bivalent H3K4me3/H3K27me3, and acutely infected CD4 T cells, which showed an intermediate epigenotype. 5'-Methylcytosine (5mC) was enriched across the HIV genome in latently infected JLAT cells, while 5'-hydroxymethylcytosine (5hmC) was enriched in CD4 cells and MDMs. HIV infection induced multinucleation of MDMs along with DNA damage-associated p53 phosphorylation, as well as loss of TET2 and the nuclear redistribution of 5-hydoxymethylation. Taken together, our findings suggest that HIV induces a unique macrophage nuclear and transcriptional profile, and viral genomes are maintained in a noncanonical bivalent epigenetic state. IMPORTANCE Macrophages serve as a reservoir for long-term persistence and chronic production of HIV. We found an atypical epigenetic control of HIV in macrophages marked by heterochromatic H3K9me3 despite active viral transcription. HIV infection induced changes in macrophage nuclear morphology and epigenetic regulatory factors. These findings may identify new mechanisms to control chronic HIV expression in infected macrophages.
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26
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Mori L, Valente ST. Cure and Long-Term Remission Strategies. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2022; 2407:391-428. [PMID: 34985678 DOI: 10.1007/978-1-0716-1871-4_26] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The majority of virally suppressed individuals will experience rapid viral rebound upon antiretroviral therapy (ART) interruption, providing a strong rationale for the development of cure strategies. Moreover, despite ART virological control, HIV infection is still associated with chronic immune activation, inflammation, comorbidities, and accelerated aging. These effects are believed to be due, in part, to low-grade persistent transcription and trickling production of viral proteins from the pool of latent proviruses constituting the viral reservoir. In recent years there has been an increasing interest in developing what has been termed a functional cure for HIV. This approach entails the long-term, durable control of viral expression in the absence of therapy, preventing disease progression and transmission, despite the presence of detectable integrated proviruses. One such strategy, the block-and-lock approach for a functional cure, proposes the epigenetic silencing of proviral expression, locking the virus in a profound latent state, from which reactivation is very unlikely. The proof-of-concept for this approach was demonstrated with the use of a specific small molecule targeting HIV transcription. Here we review the principles behind the block-and-lock approach and some of the additional strategies proposed to silence HIV expression.
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Affiliation(s)
- Luisa Mori
- Department of Immunology and Microbiology, The Scripps Research Institute, Jupiter, FL, USA
| | - Susana T Valente
- Department of Immunology and Microbiology, The Scripps Research Institute, Jupiter, FL, USA.
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27
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Lentiviral Nef Proteins Differentially Govern the Establishment of Viral Latency. J Virol 2022; 96:e0220621. [PMID: 35266804 DOI: 10.1128/jvi.02206-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Despite the clinical importance of latent human immunodeficiency virus type 1 (HIV-1) infection, our understanding of the biomolecular processes involved in HIV-1 latency control is still limited. This study was designed to address whether interactions between viral proteins, specifically HIV Nef, and the host cell could affect latency establishment. The study was driven by three reported observations. First, early reports suggested that human immunodeficiency virus type 2 (HIV-2) infection in patients produces a lower viral RNA/DNA ratio than HIV-1 infection, potentially indicating an increased propensity of HIV-2 to produce latent infection. Second, Nef, an early viral gene product, has been shown to alter the activation state of infected cells in a lentiviral lineage-dependent manner. Third, it has been demonstrated that the ability of HIV-1 to establish latent infection is a function of the activation state of the host cell at the time of infection. Based on these observations, we reasoned that HIV-2 Nef may have the ability to promote latency establishment. We demonstrate that HIV-1 latency establishment in T cell lines and primary T cells is indeed differentially modulated by Nef proteins. In the context of an HIV-1 backbone, HIV-1 Nef promoted active HIV-1 infection, while HIV-2 Nef strongly promoted latency establishment. Given that Nef represents the only difference in these HIV-1 vectors and is known to interact with numerous cellular factors, these data add support to the idea that latency establishment is a host cell-virus interaction phenomenon, but they also suggest that the HIV-1 lineage may have evolved mechanisms to counteract host cell suppression. IMPORTANCE Therapeutic attempts to eliminate the latent HIV-1 reservoir have failed, at least in part due to our incomplete biomolecular understanding of how latent HIV-1 infection is established and maintained. We here address the fundamental question of whether all lentiviruses actually possess a similar capacity to establish latent infections or whether there are differences between the lentiviral lineages driving differential latency establishment that could be exploited to develop improved latency reversal agents. Research investigating the viral RNA/DNA ratio in HIV-1 and HIV-2 patients could suggest that HIV-2 indeed has a much higher propensity to establish latent infections, a trait that we found, at least in part, to be attributable to the HIV-2 Nef protein. Reported Nef-mediated effects on host cell activation thus also affect latency establishment, and HIV-1 vectors that carry different lentiviral nef genes should become key tools to develop a better understanding of the biomolecular basis of HIV-1 latency establishment.
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28
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Abstract
The development of therapies to eliminate the latent HIV-1 reservoir is hampered by our incomplete understanding of the biomolecular mechanism governing HIV-1 latency. To further complicate matters, recent single cell RNA-seq studies reported extensive heterogeneity between latently HIV-1-infected primary T cells, implying that latent HIV-1 infection can persist in greatly differing host cell environments. We here show that transcriptomic heterogeneity is also found between latently infected T cell lines, which allowed us to study the underlying mechanisms of intercell heterogeneity at high signal resolution. Latently infected T cells exhibited a de-differentiated phenotype, characterized by the loss of T cell-specific markers and gene regulation profiles reminiscent of hematopoietic stem cells (HSC). These changes had functional consequences. As reported for stem cells, latently HIV-1 infected T cells efficiently forced lentiviral superinfections into a latent state and favored glycolysis. As a result, metabolic reprogramming or cell re-differentiation destabilized latent infection. Guided by these findings, data-mining of single cell RNA-seq data of latently HIV-1 infected primary T cells from patients revealed the presence of similar dedifferentiation motifs. >20% of the highly detectable genes that were differentially regulated in latently infected cells were associated with hematopoietic lineage development (e.g. HUWE1, IRF4, PRDM1, BATF3, TOX, ID2, IKZF3, CDK6) or were hematopoietic markers (SRGN; hematopoietic proteoglycan core protein). The data add to evidence that the biomolecular phenotype of latently HIV-1 infected cells differs from normal T cells and strategies to address their differential phenotype need to be considered in the design of therapeutic cure interventions. IMPORTANCE HIV-1 persists in a latent reservoir in memory CD4 T cells for the lifetime of a patient. Understanding the biomolecular mechanisms used by the host cells to suppress viral expression will provide essential insights required to develop curative therapeutic interventions. Unfortunately, our current understanding of these control mechanisms is still limited. By studying gene expression profiles, we demonstrated that latently HIV-1-infected T cells have a de-differentiated T cell phenotype. Software-based data integration allowed for the identification of drug targets that would re-differentiate viral host cells and, in extension, destabilize latent HIV-1 infection events. The importance of the presented data lies within the clear demonstration that HIV-1 latency is a host cell phenomenon. As such, therapeutic strategies must first restore proper host cell functionality to accomplish efficient HIV-1 reactivation.
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Abstract
To identify novel host factors as putative targets to reverse HIV-1 latency, we performed an insertional mutagenesis genetic screen in a latent HIV-1 infected pseudohaploid KBM7 cell line (Hap-Lat). Following mutagenesis, insertions were mapped to the genome, and bioinformatic analysis resulted in the identification of 69 candidate host genes involved in maintaining HIV-1 latency. A select set of candidate genes was functionally validated using short hairpin RNA (shRNA)-mediated depletion in latent HIV-1 infected J-Lat A2 and 11.1 T cell lines. We confirmed ADK, CHD9, CMSS1, EVI2B, EXOSC8, FAM19A, GRIK5, IRF2BP2, NF1, and USP15 as novel host factors involved in the maintenance of HIV-1 latency. Chromatin immunoprecipitation assays indicated that CHD9, a chromodomain helicase DNA-binding protein, maintains HIV-1 latency via direct association with the HIV-1 5′ long terminal repeat (LTR), and its depletion results in increased histone acetylation at the HIV-1 promoter, concomitant with HIV-1 latency reversal. FDA-approved inhibitors 5-iodotubercidin, trametinib, and topiramate, targeting ADK, NF1, and GRIK5, respectively, were characterized for their latency reversal potential. While 5-iodotubercidin exhibited significant cytotoxicity in both J-Lat and primary CD4+ T cells, trametinib reversed latency in J-Lat cells but not in latent HIV-1 infected primary CD4+ T cells. Importantly, topiramate reversed latency in cell line models, in latently infected primary CD4+ T cells, and crucially in CD4+ T cells from three people living with HIV-1 (PLWH) under suppressive antiretroviral therapy, without inducing T cell activation or significant toxicity. Thus, using an adaptation of a haploid forward genetic screen, we identified novel and druggable host factors contributing to HIV-1 latency.
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Pal VK, Agrawal R, Rakshit S, Shekar P, Murthy DTN, Vyakarnam A, Singh A. Hydrogen sulfide blocks HIV rebound by maintaining mitochondrial bioenergetics and redox homeostasis. eLife 2021; 10:68487. [PMID: 34792020 PMCID: PMC8660018 DOI: 10.7554/elife.68487] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 11/17/2021] [Indexed: 01/12/2023] Open
Abstract
A fundamental challenge in human immunodeficiency virus (HIV) eradication is to understand how the virus establishes latency, maintains stable cellular reservoirs, and promotes rebound upon interruption of antiretroviral therapy (ART). Here, we discovered an unexpected role of the ubiquitous gasotransmitter hydrogen sulfide (H2S) in HIV latency and reactivation. We show that reactivation of HIV is associated with downregulation of the key H2S producing enzyme cystathionine-γ-lyase (CTH) and reduction in endogenous H2S. Genetic silencing of CTH disrupts redox homeostasis, impairs mitochondrial function, and remodels the transcriptome of latent cells to trigger HIV reactivation. Chemical complementation of CTH activity using a slow-releasing H2S donor, GYY4137, suppressed HIV reactivation and diminished virus replication. Mechanistically, GYY4137 blocked HIV reactivation by inducing the Keap1-Nrf2 pathway, inhibiting NF-κB, and recruiting the epigenetic silencer, YY1, to the HIV promoter. In latently infected CD4+ T cells from ART-suppressed human subjects, GYY4137 in combination with ART prevented viral rebound and improved mitochondrial bioenergetics. Moreover, prolonged exposure to GYY4137 exhibited no adverse influence on proviral content or CD4+ T cell subsets, indicating that diminished viral rebound is due to a loss of transcription rather than a selective loss of infected cells. In summary, this work provides mechanistic insight into H2S-mediated suppression of viral rebound and suggests exploration of H2S donors to maintain HIV in a latent form.
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Affiliation(s)
- Virender Kumar Pal
- Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Ragini Agrawal
- Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | | | - Pooja Shekar
- BMCRI, Bangalore Medical College and Research Institute, Bangalore, India
| | | | | | - Amit Singh
- Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
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Campbell GR, Spector SA. Induction of Autophagy to Achieve a Human Immunodeficiency Virus Type 1 Cure. Cells 2021; 10:cells10071798. [PMID: 34359967 PMCID: PMC8307643 DOI: 10.3390/cells10071798] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 07/13/2021] [Accepted: 07/13/2021] [Indexed: 02/06/2023] Open
Abstract
Effective antiretroviral therapy has led to significant human immunodeficiency virus type 1 (HIV-1) suppression and improvement in immune function. However, the persistence of integrated proviral DNA in latently infected reservoir cells, which drive viral rebound post-interruption of antiretroviral therapy, remains the major roadblock to a cure. Therefore, the targeted elimination or permanent silencing of this latently infected reservoir is a major focus of HIV-1 research. The most studied approach in the development of a cure is the activation of HIV-1 expression to expose latently infected cells for immune clearance while inducing HIV-1 cytotoxicity—the “kick and kill” approach. However, the complex and highly heterogeneous nature of the latent reservoir, combined with the failure of clinical trials to reduce the reservoir size casts doubt on the feasibility of this approach. This concern that total elimination of HIV-1 from the body may not be possible has led to increased emphasis on a “functional cure” where the virus remains but is unable to reactivate which presents the challenge of permanently silencing transcription of HIV-1 for prolonged drug-free remission—a “block and lock” approach. In this review, we discuss the interaction of HIV-1 and autophagy, and the exploitation of autophagy to kill selectively HIV-1 latently infected cells as part of a cure strategy. The cure strategy proposed has the advantage of significantly decreasing the size of the HIV-1 reservoir that can contribute to a functional cure and when optimised has the potential to eradicate completely HIV-1.
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Affiliation(s)
- Grant R. Campbell
- Division of Infectious Diseases, Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA;
- Correspondence: ; Tel.: +1-858-534-7477
| | - Stephen A. Spector
- Division of Infectious Diseases, Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA;
- Rady Children’s Hospital, San Diego, CA 92123, USA
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Debyser Z, Bruggemans A, Van Belle S, Janssens J, Christ F. LEDGINs, Inhibitors of the Interaction Between HIV-1 Integrase and LEDGF/p75, Are Potent Antivirals with a Potential to Cure HIV Infection. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1322:97-114. [PMID: 34258738 DOI: 10.1007/978-981-16-0267-2_4] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
A permanent cure remains the greatest challenge in the field of HIV research. In order to reach this goal, a profound understanding of the molecular mechanisms controlling HIV integration and transcription is needed. Here we provide an overview of recent advances in the field. Lens epithelium-derived growth factor p75 (LEDGF/p75), a transcriptional coactivator, tethers and targets the HIV integrase into transcriptionally active regions of the chromatin through an interaction with the epigenetic mark H3K36me2/3. This finding prompted us to propose a "block-and-lock" strategy to retarget HIV integration into deep latency. A decade ago, we pioneered protein-protein interaction inhibitors for HIV and discovered LEDGINs. LEDGINs are small molecule inhibitors of the interaction between the integrase binding domain (IBD) of LEDGF/p75 and HIV integrase. They modify integration site selection and therefore might be molecules with a "block-and-lock" mechanism of action. Here we will describe how LEDGINs may become part in the future functional cure strategies.
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Affiliation(s)
- Zeger Debyser
- Molecular Virology and Gene Therapy, Department of Pharmacological and Pharmaceutical Sciences, KU Leuven, Leuven, Belgium.
| | - Anne Bruggemans
- Molecular Virology and Gene Therapy, Department of Pharmacological and Pharmaceutical Sciences, KU Leuven, Leuven, Belgium
| | - Siska Van Belle
- Molecular Virology and Gene Therapy, Department of Pharmacological and Pharmaceutical Sciences, KU Leuven, Leuven, Belgium
| | - Julie Janssens
- Molecular Virology and Gene Therapy, Department of Pharmacological and Pharmaceutical Sciences, KU Leuven, Leuven, Belgium
| | - Frauke Christ
- Molecular Virology and Gene Therapy, Department of Pharmacological and Pharmaceutical Sciences, KU Leuven, Leuven, Belgium
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Abstract
Pancreatic cancer is a genetic disease, and the recurrent genetic alterations characteristic of pancreatic cancer indicate the cellular processes that are targeted for malignant transformation. In addition to somatic alterations in the most common driver genes (KRAS, CDKN2A, TP53 and SMAD4), large-scale studies have revealed major roles for genetic alterations of the SWI/SNF and COMPASS complexes, copy number alterations in GATA6 and MYC that partially define phenotypes of pancreatic cancer, and the role(s) of polyploidy and chromothripsis as factors contributing to pancreatic cancer biology and progression. Germline variants that increase the risk of pancreatic cancer continue to be discovered along with a greater appreciation of the features of pancreatic cancers with mismatch repair deficiencies and homologous recombination deficiencies that confer sensitivity to therapeutic targeting. Wild-type KRAS pancreatic cancers, some of which are driven by alternative oncogenic events affecting NRG1 or NTRK1 - for which targeted therapies exist - further underscore that pancreatic cancer is formally entering the era of precision medicine. Given the vast developments within this field, here we review the wide-ranging and most current information related to pancreatic cancer genomics with the goal of integrating this information into a unifying description of the life history of pancreatic cancer.
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Kato H, Shimizu M, Urano T. Chemical map-based prediction of nucleosome positioning using the Bioconductor package nuCpos. BMC Bioinformatics 2021; 22:322. [PMID: 34120589 PMCID: PMC8201924 DOI: 10.1186/s12859-021-04240-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 06/06/2021] [Indexed: 11/10/2022] Open
Abstract
Background Assessing the nucleosome-forming potential of specific DNA sequences is important for understanding complex chromatin organization. Methods for predicting nucleosome positioning include bioinformatics and biophysical approaches. An advantage of bioinformatics methods, which are based on in vivo nucleosome maps, is the use of natural sequences that may contain previously unknown elements involved in nucleosome positioning in vivo. The accuracy of such prediction attempts reflects the genomic coordinate resolution of the nucleosome maps applied. Nucleosome maps are constructed using micrococcal nuclease digestion followed by high-throughput sequencing (MNase-seq). However, as MNase has a strong preference for A/T-rich sequences, MNase-seq may not be appropriate for this purpose. In addition to MNase-seq-based maps, base pair-resolution chemical maps of in vivo nucleosomes from three different species (budding and fission yeasts, and mice) are currently available. However, these chemical maps have yet to be integrated into publicly available computational methods. Results We developed a Bioconductor package (named nuCpos) to demonstrate the superiority of chemical maps in predicting nucleosome positioning. The accuracy of chemical map-based prediction in rotational settings was higher than that of the previously developed MNase-seq-based approach. With our method, predicted nucleosome occupancy reasonably matched in vivo observations and was not affected by A/T nucleotide frequency. Effects of genetic alterations on nucleosome positioning that had been observed in living yeast cells could also be predicted. nuCpos calculates individual histone binding affinity (HBA) scores for given 147-bp sequences to examine their suitability for nucleosome formation. We also established local HBA as a new parameter to predict nucleosome formation, which was calculated for 13 overlapping nucleosomal DNA subsequences. HBA and local HBA scores for various sequences agreed well with previous in vitro and in vivo studies. Furthermore, our results suggest that nucleosomal subsegments that are disfavored in different rotational settings contribute to the defined positioning of nucleosomes. Conclusions Our results demonstrate that chemical map-based statistical models are beneficial for studying nucleosomal DNA features. Studies employing nuCpos software can enhance understanding of chromatin regulation and the interpretation of genetic alterations and facilitate the design of artificial sequences. Supplementary Information The online version contains supplementary material available at 10.1186/s12859-021-04240-2.
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Affiliation(s)
- Hiroaki Kato
- Department of Biochemistry, Shimane University School of Medicine, 89-1 Enya-cho, Izumo, Shimane, 693-8501, Japan.
| | - Mitsuhiro Shimizu
- Department of Chemistry, Graduate School of Science and Engineering, Program in Chemistry and Life Science, School of Science and Engineering, Meisei University, 2-1-1 Hodokubo, Hino, Tokyo, 191-8506, Japan
| | - Takeshi Urano
- Department of Biochemistry, Shimane University School of Medicine, 89-1 Enya-cho, Izumo, Shimane, 693-8501, Japan
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Blanco A, Mahajan T, Coronado RA, Ma K, Demma DR, Dar RD. Synergistic Chromatin-Modifying Treatments Reactivate Latent HIV and Decrease Migration of Multiple Host-Cell Types. Viruses 2021; 13:v13061097. [PMID: 34201394 PMCID: PMC8228244 DOI: 10.3390/v13061097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/29/2021] [Accepted: 06/02/2021] [Indexed: 11/29/2022] Open
Abstract
Upon infection of its host cell, human immunodeficiency virus (HIV) establishes a quiescent and non-productive state capable of spontaneous reactivation. Diverse cell types harboring the provirus form a latent reservoir, constituting a major obstacle to curing HIV. Here, we investigate the effects of latency reversal agents (LRAs) in an HIV-infected THP-1 monocyte cell line in vitro. We demonstrate that leading drug treatments synergize activation of the HIV long terminal repeat (LTR) promoter. We establish a latency model in THP-1 monocytes using a replication incompetent HIV reporter vector with functional Tat, and show that chromatin modifiers synergize with a potent transcriptional activator to enhance HIV reactivation, similar to T-cells. Furthermore, leading reactivation cocktails are shown to differentially affect latency reactivation and surface expression of chemokine receptor type 4 (CXCR4), leading to altered host cell migration. This study investigates the effect of chromatin-modifying LRA treatments on HIV latent reactivation and cell migration in monocytes. As previously reported in T-cells, epigenetic mechanisms in monocytes contribute to controlling the relationship between latent reactivation and cell migration. Ultimately, advanced “Shock and Kill” therapy needs to successfully target and account for all host cell types represented in a complex and composite latency milieu.
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Affiliation(s)
- Alexandra Blanco
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; (A.B.); (T.M.); (R.A.C.); (K.M.); (D.R.D.)
| | - Tarun Mahajan
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; (A.B.); (T.M.); (R.A.C.); (K.M.); (D.R.D.)
| | - Robert A. Coronado
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; (A.B.); (T.M.); (R.A.C.); (K.M.); (D.R.D.)
| | - Kelly Ma
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; (A.B.); (T.M.); (R.A.C.); (K.M.); (D.R.D.)
| | - Dominic R. Demma
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; (A.B.); (T.M.); (R.A.C.); (K.M.); (D.R.D.)
| | - Roy D. Dar
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; (A.B.); (T.M.); (R.A.C.); (K.M.); (D.R.D.)
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Correspondence: ; Tel.: +1-(217)-265-0708
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Launching a multidisciplinary European collaboration towards a cure for HIV: The EU2Cure Consortium. J Virus Erad 2021; 7:100045. [PMID: 34141442 PMCID: PMC8184646 DOI: 10.1016/j.jve.2021.100045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 05/11/2021] [Accepted: 05/11/2021] [Indexed: 11/23/2022] Open
Abstract
We felt the urgency to launch the EU2Cure Consortium to support research and find a cure for the human immunodeficiency virus (HIV) infection through intensified collaboration within Europe. This consortium is open to stakeholders on cure in Europe from academia and the community to connect. The aim of this consortium is to intensify the research collaboration amongst European HIV cure groups and the community and facilitate interactions with other academic and community cure consortia, private parties, and policy makers. Our main aim is to create a European research agenda, data sharing, and development of best practice for clinical and translational science to achieve breakthroughs with clinically feasible HIV cure strategies. This consortium should also enable setting up collaborative studies accessible to a broader group of people living with HIV. Besides reservoir studies, we have identified three overlapping scientific interests in the consortium that provide a starting point for further research within a European network: developing “shock and kill” cure strategies, defining HIV cure biomarkers, and connecting cure cohorts. This strategy should aid stakeholders to sustain progress in HIV cure research regardless of coincidental global health or political crises.
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Epigenetic Mechanisms of HIV-1 Persistence. Vaccines (Basel) 2021; 9:vaccines9050514. [PMID: 34067608 PMCID: PMC8156729 DOI: 10.3390/vaccines9050514] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 05/01/2021] [Accepted: 05/11/2021] [Indexed: 12/14/2022] Open
Abstract
Eradicating HIV-1 in infected individuals will not be possible without addressing the persistence of the virus in its multiple reservoirs. In this context, the molecular characterization of HIV-1 persistence is key for the development of rationalized therapeutic interventions. HIV-1 gene expression relies on the redundant and cooperative recruitment of cellular epigenetic machineries to cis-regulatory proviral regions. Furthermore, the complex repertoire of HIV-1 repression mechanisms varies depending on the nature of the viral reservoir, although, so far, few studies have addressed the specific regulatory mechanisms of HIV-1 persistence in other reservoirs than the well-studied latently infected CD4+ T cells. Here, we present an exhaustive and updated picture of the heterochromatinization of the HIV-1 promoter in its different reservoirs. We highlight the complexity, heterogeneity and dynamics of the epigenetic mechanisms of HIV-1 persistence, while discussing the importance of further understanding HIV-1 gene regulation for the rational design of novel HIV-1 cure strategies.
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Ma L, Chen S, Wang Z, Guo S, Zhao J, Yi D, Li Q, Liu Z, Guo F, Li X, Jia P, Ding J, Liang C, Cen S. The CREB Regulated Transcription Coactivator 2 Suppresses HIV-1 Transcription by Preventing RNA Pol II from Binding to HIV-1 LTR. Virol Sin 2021; 36:796-809. [PMID: 33723808 DOI: 10.1007/s12250-021-00363-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 12/09/2020] [Indexed: 10/21/2022] Open
Abstract
The CREB-regulated transcriptional co-activators (CRTCs), including CRTC1, CRTC2 and CRTC3, enhance transcription of CREB-targeted genes. In addition to regulating host gene expression in response to cAMP, CRTCs also increase the infection of several viruses. While human immunodeficiency virus type 1 (HIV-1) long terminal repeat (LTR) promoter harbors a cAMP response element and activation of the cAMP pathway promotes HIV-1 transcription, it remains unknown whether CRTCs have any effect on HIV-1 transcription and HIV-1 infection. Here, we reported that CRTC2 expression was induced by HIV-1 infection, but CRTC2 suppressed HIV-1 infection and diminished viral RNA expression. Mechanistic studies revealed that CRTC2 inhibited transcription from HIV-1 LTR and diminished RNA Pol II occupancy at the LTR independent of its association with CREB. Importantly, CRTC2 inhibits the activation of latent HIV-1. Together, these data suggest that in response to HIV-1 infection, cells increase the expression of CRTC2 which inhibits HIV-1 gene expression and may play a role in driving HIV-1 into latency.
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Affiliation(s)
- Ling Ma
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical School, Beijing, 100050, China
| | - Shumin Chen
- Department of Blood Transfusion, The Affiliated Hospital of Qingdao University, Qingdao 266000, China
| | - Zhen Wang
- Lady Davis Institute, Jewish General Hospital, McGill University, Montreal, QC, H3T 1E2, Canada
| | - Saisai Guo
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical School, Beijing, 100050, China
| | - Jianyuan Zhao
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical School, Beijing, 100050, China
| | - Dongrong Yi
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical School, Beijing, 100050, China
| | - Quanjie Li
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical School, Beijing, 100050, China
| | - Zhenlong Liu
- Lady Davis Institute, Jewish General Hospital, McGill University, Montreal, QC, H3T 1E2, Canada
| | - Fei Guo
- Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical School, Beijing, 100176, China
| | - Xiaoyu Li
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical School, Beijing, 100050, China
| | - Pingping Jia
- Beijing Shijitan Hospital, Capital Medical University, Beijing, 100038, China
| | - Jiwei Ding
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical School, Beijing, 100050, China. .,CAMS Key Laboratory of Antiviral Drug Research, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100050, China.
| | - Chen Liang
- Lady Davis Institute, Jewish General Hospital, McGill University, Montreal, QC, H3T 1E2, Canada
| | - Shan Cen
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical School, Beijing, 100050, China. .,CAMS Key Laboratory of Antiviral Drug Research, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100050, China. .,Beijing Friendship Hospital, Capital Medical University, Beijing, 100029, China.
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Jefferys SR, Burgos SD, Peterson JJ, Selitsky SR, Turner AMW, James LI, Tsai YH, Coffey AR, Margolis DM, Parker J, Browne EP. Epigenomic characterization of latent HIV infection identifies latency regulating transcription factors. PLoS Pathog 2021; 17:e1009346. [PMID: 33635929 PMCID: PMC7946360 DOI: 10.1371/journal.ppat.1009346] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 03/10/2021] [Accepted: 01/29/2021] [Indexed: 12/12/2022] Open
Abstract
Transcriptional silencing of HIV in CD4 T cells generates a reservoir of latently infected cells that can reseed infection after interruption of therapy. As such, these cells represent the principal barrier to curing HIV infection, but little is known about their characteristics. To further our understanding of the molecular mechanisms of latency, we characterized a primary cell model of HIV latency in which infected cells adopt heterogeneous transcriptional fates. In this model, we observed that latency is a stable, heritable state that is transmitted through cell division. Using Assay of Transposon-Accessible Chromatin sequencing (ATACseq) we found that latently infected cells exhibit greatly reduced proviral accessibility, indicating the presence of chromatin-based structural barriers to viral gene expression. By quantifying the activity of host cell transcription factors, we observe elevated activity of Forkhead and Kruppel-like factor transcription factors (TFs), and reduced activity of AP-1, RUNX and GATA TFs in latently infected cells. Interestingly, latency reversing agents with different mechanisms of action caused distinct patterns of chromatin reopening across the provirus. We observe that binding sites for the chromatin insulator CTCF are highly enriched in the differentially open chromatin of infected CD4 T cells. Furthermore, depletion of CTCF inhibited HIV latency, identifying this factor as playing a key role in the initiation or enforcement of latency. These data indicate that HIV latency develops preferentially in cells with a distinct pattern of TF activity that promotes a closed proviral structure and inhibits viral gene expression. Furthermore, these findings identify CTCF as a novel regulator of HIV latency. HIV is able to persist during antiviral therapy by entering a state of viral latency, in which viral gene expression is greatly reduced. These latently infected cells can re-seed infection if therapy is interrupted, and thus represent a major obstacle to an HIV cure. Identifying the mechanisms that lead to this state will help to identify strategies to block or eliminate HIV latency, leading to a cure for infection. By observing HIV gene expression in infected CD4 T cells, we isolated cells in which HIV has entered latency and identified characteristics that distinguish them from cells with active viral replication. We found that latently infected cells have elevated activity of specific transcription factors including Forkhead TFs and Kruppel-like factors. We also identify CTCF, a protein responsible for mediating insulation of genome domains from each other, as being required for the establishment of HIV latency. Developing agents to target these factors may lead to new strategies to eliminate the HIV reservoir.
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Affiliation(s)
- Stuart R. Jefferys
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Samuel D. Burgos
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Jackson J. Peterson
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Sara R. Selitsky
- Lineberger Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Anne-Marie W. Turner
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Lindsey I. James
- Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Yi-Hsuan Tsai
- Lineberger Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Alisha R. Coffey
- Lineberger Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - David M. Margolis
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Joel Parker
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Edward P. Browne
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- * E-mail:
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40
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Li C, Mori L, Valente ST. The Block-and-Lock Strategy for Human Immunodeficiency Virus Cure: Lessons Learned from Didehydro-Cortistatin A. J Infect Dis 2021; 223:46-53. [PMID: 33586776 DOI: 10.1093/infdis/jiaa681] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Antiretroviral therapy effectively controls human immunodeficiency virus (HIV) infection. However, a reservoir of latently infected cells persists under suppressive therapy, constituting a major barrier to an HIV cure. The block-and-lock approach to a functional cure aims at the transcriptional and epigenetic silencing of proviruses, blocking viral reactivation in the absence of therapy, preventing disease progression and transmission, despite the presence of detectable integrated proviruses. This approach has been put forward for exploration based on the activity of didehydro-cortistatin A, an inhibitor of the HIV transcriptional activator Tat. Here we review the mechanisms by which didehydro-cortistatin A inhibition of Tat's feedback loop transcriptional amplification results in epigenetic silencing of the HIV promoter, and we discuss the benefits and limitations of the block-and-lock approach for an HIV cure.
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Affiliation(s)
- Chuan Li
- Department of Immunology and Microbiology, The Scripps Research Institute, Jupiter, Florida, USA
| | - Luisa Mori
- Department of Immunology and Microbiology, The Scripps Research Institute, Jupiter, Florida, USA
| | - Susana T Valente
- Department of Immunology and Microbiology, The Scripps Research Institute, Jupiter, Florida, USA
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41
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Boliar S, Russell DG. Lnc(ing)RNAs to the "shock and kill" strategy for HIV-1 cure. MOLECULAR THERAPY-NUCLEIC ACIDS 2021; 23:1272-1280. [PMID: 33717648 PMCID: PMC7907223 DOI: 10.1016/j.omtn.2021.02.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The advent of antiretroviral therapy almost 25 years ago has transformed HIV-1 infection into a manageable chronic condition, albeit still incurable. The inability of the treatment regimen to eliminate latently infected cells that harbor the virus in an epigenetically silent state poses a major hurdle. Current cure approaches are focused on a "shock and kill" strategy that uses latency-reversing agents to chemically reverse the proviral quiescence in latently infected cells, followed by immune-mediated clearance of reactivated cells. To date, hundreds of compounds have been investigated for viral reactivation, yet none has resulted in a functional cure. The insufficiency of these latency-reversing agents (LRAs) alone indicates a critical need for additional, alternate approaches such as genetic manipulation. Long non-coding RNAs (lncRNAs) are an emerging class of regulatory RNAs with functional roles in many cellular processes, including epigenetic modulation. A number of lncRNAs have already been implicated to play important roles in HIV-1 latency and, as such, pharmacological modulation of lncRNAs constitutes a rational alternative approach in HIV-1 cure research. In this review, we discuss the current state of knowledge of the role of lncRNAs in HIV-1 infection and explore the scope for a lncRNA-mediated genetic approach within the shock and kill strategy of HIV-1 cure.
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Affiliation(s)
- Saikat Boliar
- Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
- Corresponding author: Saikat Boliar, Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.
| | - David G. Russell
- Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
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Alamer E, Zhong C, Hajnik R, Soong L, Hu H. Modulation of BRD4 in HIV epigenetic regulation: implications for finding an HIV cure. Retrovirology 2021; 18:3. [PMID: 33413475 PMCID: PMC7792063 DOI: 10.1186/s12977-020-00547-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 11/30/2020] [Accepted: 12/23/2020] [Indexed: 12/16/2022] Open
Abstract
Following reverse transcription, HIV viral DNA is integrated into host cell genomes and establishes a stable latent infection, which has posed a major obstacle for obtaining a cure for HIV. HIV proviral transcription is regulated in cellular reservoirs by complex host epigenetic and transcriptional machineries. The Bromodomain (BD) and Extra-Terminal Domain (ET) protein, BRD4, is an important epigenetic reader that interacts with acetyl-histones and a variety of chromatin and transcriptional regulators to control gene expression, including HIV. Modulation of BRD4 by a pan BET inhibitor (JQ1) has been shown to activate HIV transcription. Recent studies by my group and others indicate that the function of BRD4 is versatile and its effects on HIV transcription may depend on the partner proteins or pathways engaged by BRD4. Our studies have reported a novel class of small-molecule modulators that are distinct from JQ1 but induce HIV transcriptional suppression through BRD4. Herein, we reviewed recent research on the modulation of BRD4 in HIV epigenetic regulation and discussed their potential implications for finding an HIV cure.
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Affiliation(s)
- Edrous Alamer
- Department of Microbiology and Immunology, University of Texas Medical Branch (UTMB), MRB 4.142A, 301 University Blvd, Galveston, TX, 77555, USA.,Department of Medical Laboratories Technology, College of Applied Medical Sciences, Jazan University, Jazan, Saudi Arabia.,Medical Research Center, Jazan University, Jazan, 45142, Saudi Arabia
| | - Chaojie Zhong
- Department of Microbiology and Immunology, University of Texas Medical Branch (UTMB), MRB 4.142A, 301 University Blvd, Galveston, TX, 77555, USA
| | - Renee Hajnik
- Department of Microbiology and Immunology, University of Texas Medical Branch (UTMB), MRB 4.142A, 301 University Blvd, Galveston, TX, 77555, USA
| | - Lynn Soong
- Department of Microbiology and Immunology, University of Texas Medical Branch (UTMB), MRB 4.142A, 301 University Blvd, Galveston, TX, 77555, USA.,Institute for Human Infections and Immunity, Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Haitao Hu
- Department of Microbiology and Immunology, University of Texas Medical Branch (UTMB), MRB 4.142A, 301 University Blvd, Galveston, TX, 77555, USA. .,Institute for Human Infections and Immunity, Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, Galveston, TX, 77555, USA.
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Balance between Retroviral Latency and Transcription: Based on HIV Model. Pathogens 2020; 10:pathogens10010016. [PMID: 33383617 PMCID: PMC7824405 DOI: 10.3390/pathogens10010016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 12/23/2020] [Accepted: 12/24/2020] [Indexed: 01/04/2023] Open
Abstract
The representative of the Lentivirus genus is the human immunodeficiency virus type 1 (HIV-1), the causative agent of acquired immunodeficiency syndrome (AIDS). To date, there is no cure for AIDS because of the existence of the HIV-1 reservoir. HIV-1 infection can persist for decades despite effective antiretroviral therapy (ART), due to the persistence of infectious latent viruses in long-lived resting memory CD4+ T cells, macrophages, monocytes, microglial cells, and other cell types. However, the biology of HIV-1 latency remains incompletely understood. Retroviral long terminal repeat region (LTR) plays an indispensable role in controlling viral gene expression. Regulation of the transcription initiation plays a crucial role in establishing and maintaining a retrovirus latency. Whether and how retroviruses establish latency and reactivate remains unclear. In this article, we describe what is known about the regulation of LTR-driven transcription in HIV-1, that is, the cis-elements present in the LTR, the role of LTR transcription factor binding sites in LTR-driven transcription, the role of HIV-1-encoded transactivator protein, hormonal effects on virus transcription, impact of LTR variability on transcription, and epigenetic control of retrovirus LTR. Finally, we focus on a novel clustered regularly interspaced short palindromic repeats-associated protein 9 (CRISPR/dCas9)-based strategy for HIV-1 reservoir purging.
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44
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Moranguinho I, Valente ST. Block-And-Lock: New Horizons for a Cure for HIV-1. Viruses 2020; 12:v12121443. [PMID: 33334019 PMCID: PMC7765451 DOI: 10.3390/v12121443] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 12/01/2020] [Accepted: 12/08/2020] [Indexed: 12/12/2022] Open
Abstract
HIV-1/AIDS remains a global public health problem. The world health organization (WHO) reported at the end of 2019 that 38 million people were living with HIV-1 worldwide, of which only 67% were accessing antiretroviral therapy (ART). Despite great success in the clinical management of HIV-1 infection, ART does not eliminate the virus from the host genome. Instead, HIV-1 remains latent as a viral reservoir in any tissue containing resting memory CD4+ T cells. The elimination of these residual proviruses that can reseed full-blown infection upon treatment interruption remains the major barrier towards curing HIV-1. Novel approaches have recently been developed to excise or disrupt the virus from the host cells (e.g., gene editing with the CRISPR-Cas system) to permanently shut off transcription of the virus (block-and-lock and RNA interference strategies), or to reactivate the virus from cell reservoirs so that it can be eliminated by the immune system or cytopathic effects (shock-and-kill strategy). Here, we will review each of these approaches, with the major focus placed on the block-and-lock strategy.
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45
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Depicting HIV-1 Transcriptional Mechanisms: A Summary of What We Know. Viruses 2020; 12:v12121385. [PMID: 33287435 PMCID: PMC7761857 DOI: 10.3390/v12121385] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 11/26/2020] [Accepted: 12/01/2020] [Indexed: 12/19/2022] Open
Abstract
Despite the introduction of combinatory antiretroviral therapy (cART), HIV-1 infection cannot be cured and is still one of the major health issues worldwide. Indeed, as soon as cART is interrupted, a rapid rebound of viremia is observed. The establishment of viral latency and the persistence of the virus in cellular reservoirs constitute the main barrier to HIV eradication. For this reason, new therapeutic approaches have emerged to purge or restrain the HIV-1 reservoirs in order to cure infected patients. However, the viral latency is a multifactorial process that depends on various cellular mechanisms. Since these new therapies mainly target viral transcription, their development requires a detailed and precise understanding of the regulatory mechanism underlying HIV-1 transcription. In this review, we discuss the complex molecular transcriptional network regulating HIV-1 gene expression by focusing on the involvement of host cell factors that could be used as potential drug targets to design new therapeutic strategies and, to a larger extent, to reach an HIV-1 functional cure.
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46
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Mammalian SWI/SNF Chromatin Remodeling Complexes: Emerging Mechanisms and Therapeutic Strategies. Trends Genet 2020; 36:936-950. [PMID: 32873422 DOI: 10.1016/j.tig.2020.07.011] [Citation(s) in RCA: 180] [Impact Index Per Article: 45.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 07/22/2020] [Accepted: 07/24/2020] [Indexed: 02/06/2023]
Abstract
Small molecule-based targeting of chromatin regulatory factors has emerged as a promising therapeutic strategy in recent years. The development and ongoing clinical evaluation of novel agents targeting a range of chromatin regulatory processes, including DNA or histone modifiers, histone readers, and chromatin regulatory protein complexes, has inspired the field to identify and act upon the full compendium of therapeutic opportunities. Emerging studies highlight the frequent involvement of altered mammalian Switch/Sucrose-Nonfermentable (mSWI/SNF) chromatin-remodeling complexes (also called BAF complexes) in both human cancer and neurological disorders, suggesting new mechanisms and accompanying routes toward therapeutic intervention. Here, we review current approaches for direct targeting of mSWI/SNF complex structure and function and discuss settings in which aberrant mSWI/SNF biology is implicated in oncology and other diseases.
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47
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Stoszko M, Al-Hatmi AMS, Skriba A, Roling M, Ne E, Crespo R, Mueller YM, Najafzadeh MJ, Kang J, Ptackova R, LeMasters E, Biswas P, Bertoldi A, Kan TW, de Crignis E, Sulc M, Lebbink JH, Rokx C, Verbon A, van Ijcken W, Katsikis PD, Palstra RJ, Havlicek V, de Hoog S, Mahmoudi T. Gliotoxin, identified from a screen of fungal metabolites, disrupts 7SK snRNP, releases P-TEFb, and reverses HIV-1 latency. SCIENCE ADVANCES 2020; 6:eaba6617. [PMID: 32851167 PMCID: PMC7423394 DOI: 10.1126/sciadv.aba6617] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 07/01/2020] [Indexed: 05/16/2023]
Abstract
A leading pharmacological strategy toward HIV cure requires "shock" or activation of HIV gene expression in latently infected cells with latency reversal agents (LRAs) followed by their subsequent clearance. In a screen for novel LRAs, we used fungal secondary metabolites as a source of bioactive molecules. Using orthogonal mass spectrometry (MS) coupled to latency reversal bioassays, we identified gliotoxin (GTX) as a novel LRA. GTX significantly induced HIV-1 gene expression in latent ex vivo infected primary cells and in CD4+ T cells from all aviremic HIV-1+ participants. RNA sequencing identified 7SK RNA, the scaffold of the positive transcription elongation factor b (P-TEFb) inhibitory 7SK small nuclear ribonucleoprotein (snRNP) complex, to be significantly reduced upon GTX treatment of CD4+ T cells. GTX directly disrupted 7SK snRNP by targeting La-related protein 7 (LARP7), releasing active P-TEFb, which phosphorylated RNA polymerase II (Pol II) C-terminal domain (CTD), inducing HIV transcription.
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Affiliation(s)
- Mateusz Stoszko
- Department of Biochemistry, Erasmus MC University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, Netherlands
| | - Abdullah M. S. Al-Hatmi
- Westerdijk Fungal Biodiversity Institute, Utrecht, Netherlands
- Center of Expertise in Mycology of Radboud UMC/CWZ, Nijmegen, Netherlands
- Ministry of Health, Directorate General of Health Services, Ibri, Oman
| | - Anton Skriba
- Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, CZ 14220 Prague 4, Czech Republic
| | - Michael Roling
- Department of Biochemistry, Erasmus MC University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, Netherlands
| | - Enrico Ne
- Department of Biochemistry, Erasmus MC University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, Netherlands
| | - Raquel Crespo
- Department of Biochemistry, Erasmus MC University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, Netherlands
| | - Yvonne M. Mueller
- Department of Immunology, Erasmus MC University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, Netherlands
| | - Mohammad Javad Najafzadeh
- Westerdijk Fungal Biodiversity Institute, Utrecht, Netherlands
- Department of Parasitology and Mycology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Joyce Kang
- Key Laboratory of Environmental Pollution Monitoring/Disease Control, Ministry of Education and Guizhou Talent Base of Microbes and Human Health, School of Basic Medicine, Guizhou Medical University, Guiyang 550025, P. R. China
| | - Renata Ptackova
- Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, CZ 14220 Prague 4, Czech Republic
| | - Elizabeth LeMasters
- Department of Biochemistry, Erasmus MC University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, Netherlands
| | - Pritha Biswas
- Department of Biochemistry, Erasmus MC University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, Netherlands
| | - Alessia Bertoldi
- Department of Biochemistry, Erasmus MC University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, Netherlands
- Microbiology Section, Department of Experimental, Diagnostic and Specialty Medicine, School of Medicine, University of Bologna, Bologna, Italy
| | - Tsung Wai Kan
- Department of Biochemistry, Erasmus MC University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, Netherlands
| | - Elisa de Crignis
- Department of Biochemistry, Erasmus MC University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, Netherlands
| | - Miroslav Sulc
- Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, CZ 14220 Prague 4, Czech Republic
| | - Joyce H.G. Lebbink
- Departments of Molecular Genetics and Radiation Oncology, Erasmus University Medical Center, PO Box 2040, 3000 CA Rotterdam, Netherlands
| | - Casper Rokx
- Department of Internal Medicine, Section of Infectious Diseases, Erasmus University Medical Center, PO Box 2040, 3000 CA, Rotterdam, Netherlands
| | - Annelies Verbon
- Department of Internal Medicine, Section of Infectious Diseases, Erasmus University Medical Center, PO Box 2040, 3000 CA, Rotterdam, Netherlands
| | - Wilfred van Ijcken
- Erasmus MC Genomics Core Facility, Department of Cell Biology, Erasmus University Medical Center, PO Box 2040, 3000 CA, Rotterdam, Netherlands
| | - Peter D. Katsikis
- Department of Immunology, Erasmus MC University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, Netherlands
| | - Robert-Jan Palstra
- Department of Biochemistry, Erasmus MC University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, Netherlands
| | - Vladimir Havlicek
- Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, CZ 14220 Prague 4, Czech Republic
| | - Sybren de Hoog
- Westerdijk Fungal Biodiversity Institute, Utrecht, Netherlands
- Center of Expertise in Mycology of Radboud UMC/CWZ, Nijmegen, Netherlands
| | - Tokameh Mahmoudi
- Department of Biochemistry, Erasmus MC University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, Netherlands
- Corresponding author.
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Turner AMW, Dronamraju R, Potjewyd F, James KS, Winecoff DK, Kirchherr JL, Archin NM, Browne EP, Strahl BD, Margolis DM, James LI. Evaluation of EED Inhibitors as a Class of PRC2-Targeted Small Molecules for HIV Latency Reversal. ACS Infect Dis 2020; 6:1719-1733. [PMID: 32347704 PMCID: PMC7359025 DOI: 10.1021/acsinfecdis.9b00514] [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] [Indexed: 01/03/2023]
Abstract
![]()
A hallmark of human
immunodeficiency type-1 (HIV) infection is
the integration of the viral genome into host chromatin, resulting
in a latent reservoir that persists despite antiviral therapy or immune
response. Thus, key priorities toward eradication of HIV infection
are to understand the mechanisms that allow HIV latency and to develop
latency reversal agents (LRAs) that can facilitate the clearance of
latently infected cells. The repressive H3K27me3 histone mark, catalyzed
by the PRC2 complex, plays a pivotal role in transcriptional repression
at the viral promoter in both cell line and primary CD4+ T cell models
of latency. EZH2 inhibitors which block H3K27 methylation have been
shown to act as LRAs, suggesting other PRC2 components could also
be potential targets for latency reversal. EED, a core component of
PRC2, ensures the propagation of H3K27me3 by allosterically activating
EZH2 methyltransferase activity. Therefore, we sought to investigate
if inhibition of EED would also reverse latency. Inhibitors of EED,
EED226 and A-395, demonstrated latency reversal activity as single
agents, and this activity was further enhanced when used in combination
with other known LRAs. Loss of H3K27me3 following EED inhibition significantly
increased the levels of H3K27 acetylation globally and at the HIV
LTR. These results further confirm that PRC2 mediated repression plays
a significant role in the maintenance of HIV latency and suggest that
EED may serve as a promising new target for LRA development.
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Affiliation(s)
- Anne-Marie W. Turner
- UNC HIV Cure Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
- Department of Medicine, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Raghuvar Dronamraju
- Department of Biochemistry & Biophysics, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Frances Potjewyd
- Center for Integrative Chemical Biology and Drug Discovery, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Katherine S. James
- UNC HIV Cure Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Daniel K. Winecoff
- UNC HIV Cure Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Jennifer L. Kirchherr
- UNC HIV Cure Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Nancie M. Archin
- UNC HIV Cure Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
- Department of Medicine, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Edward P. Browne
- UNC HIV Cure Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
- Department of Medicine, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Brian D. Strahl
- Department of Biochemistry & Biophysics, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - David M. Margolis
- UNC HIV Cure Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
- Department of Medicine, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
- Department of Epidemiology, University of North Carolina at Chapel Hill School of Public Health, Chapel Hill, North Carolina 27599, United States
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Lindsey I. James
- UNC HIV Cure Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
- Center for Integrative Chemical Biology and Drug Discovery, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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Chory EJ, Kirkland JG, Chang CY, D'Andrea VD, Gourisankar S, Dykhuizen EC, Crabtree GR. Chemical Inhibitors of a Selective SWI/SNF Function Synergize with ATR Inhibition in Cancer Cell Killing. ACS Chem Biol 2020; 15:1685-1696. [PMID: 32369697 PMCID: PMC8273930 DOI: 10.1021/acschembio.0c00312] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
SWI/SNF (BAF) complexes are a diverse family of ATP-dependent chromatin remodelers produced by combinatorial assembly that are mutated in and thought to contribute to 20% of human cancers and a large number of neurologic diseases. The gene-activating functions of BAF complexes are essential for viability of many cell types, limiting the development of small molecule inhibitors. To circumvent the potential toxicity of SWI/SNF inhibition, we identified small molecules that inhibit the specific repressive function of these complexes but are relatively nontoxic and importantly synergize with ATR inhibitors in killing cancer cells. Our studies suggest an avenue for therapeutic enhancement of ATR/ATM inhibition and provide evidence for chemical synthetic lethality of BAF complexes as a therapeutic strategy in cancer.
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Affiliation(s)
- Emma J Chory
- Department of Chemical Engineering, Stanford University, Stanford, California 94305, United States
- Departments of Developmental Biology and Pathology, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Jacob G Kirkland
- Departments of Developmental Biology and Pathology, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Chiung-Ying Chang
- Departments of Developmental Biology and Pathology, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Vincent D D'Andrea
- Departments of Developmental Biology and Pathology, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Sai Gourisankar
- Department of Chemical Engineering, Stanford University, Stanford, California 94305, United States
- Departments of Developmental Biology and Pathology, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Emily C Dykhuizen
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana 47907, United States
| | - Gerald R Crabtree
- Departments of Developmental Biology and Pathology, Stanford University School of Medicine, Stanford, California 94305, United States
- Howard Hughes Medical Institute, Chevy Chase, Maryland 20815, United States
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50
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Epigenetic Suppression of HIV in Myeloid Cells by the BRD4-Selective Small Molecule Modulator ZL0580. J Virol 2020; 94:JVI.01880-19. [PMID: 32188727 DOI: 10.1128/jvi.01880-19] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 03/08/2020] [Indexed: 01/06/2023] Open
Abstract
Brain-resident microglia and myeloid cells (perivascular macrophages) are important HIV reservoirs in vivo, especially in the central nervous system (CNS). Despite antiretroviral therapy (ART), low-level persistent HIV replication in these reservoirs remains detectable, which contributes to neuroinflammation and neurological disorders in HIV-infected patients. New approaches complementary to ART to repress residual HIV replication in CNS reservoirs are needed. Our group has recently identified a BRD4-selective small molecule modulator (ZL0580) that induces the epigenetic suppression of HIV. Here, we examined the effects of this compound on HIV in human myeloid cells. We found that ZL0580 induces potent and durable suppression of both induced and basal HIV transcription in microglial cells (HC69) and monocytic cell lines (U1 and OM10.1). Pretreatment of microglia with ZL0580 renders them more refractory to latent HIV reactivation, indicating an epigenetic reprogramming effect of ZL0580 on HIV long terminal repeat (LTR) in microglia. We also demonstrate that ZL0580 induces repressive effect on HIV in human primary monocyte-derived macrophages (MDMs) by promoting HIV suppression during ART treatment. Mechanistically, ZL0580 inhibits Tat transactivation in microglia by disrupting binding of Tat to CDK9, a process key to HIV transcription elongation. High-resolution micrococcal nuclease mapping showed that ZL0580 induces a repressive chromatin structure at the HIV LTR. Taken together, our data suggest that ZL0580 represents a potential approach that could be used in combination with ART to suppress residual HIV replication and/or latent HIV reactivation in CNS reservoirs, thereby reducing HIV-associated neuroinflammation.IMPORTANCE Brain-resident microglia and perivascular macrophages are important HIV reservoirs in the CNS. Persistent viral replication and latent HIV reactivation in the CNS, even under ART, are believed to occur, causing neuroinflammation and neurological disorders in HIV-infected patients. It is critical to identify new approaches that can control residual HIV replication and/or latent HIV reactivation in these reservoirs. We here report that the BRD4-selective small molecule modulator, ZL0580, induces potent and durable suppression of HIV in human microglial and monocytic cell lines. Using an in vitro HIV-infected, ART-treated MDM model, we show that ZL0580 also induces suppressive effect on HIV in human primary macrophages. The significance of our research is that it suggests a potential new approach that has utility in combination with ART to suppress residual HIV replication and/or HIV reactivation in CNS reservoirs, thereby reducing neuroinflammation and neurological disorders in HIV-infected individuals.
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