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Thompson LJP, Genovese J, Hong Z, Singh MV, Singh VB. HIV-Associated Neurocognitive Disorder: A Look into Cellular and Molecular Pathology. Int J Mol Sci 2024; 25:4697. [PMID: 38731913 PMCID: PMC11083163 DOI: 10.3390/ijms25094697] [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: 03/25/2024] [Revised: 04/21/2024] [Accepted: 04/23/2024] [Indexed: 05/13/2024] Open
Abstract
Despite combined antiretroviral therapy (cART) limiting HIV replication to undetectable levels in the blood, people living with HIV continue to experience HIV-associated neurocognitive disorder (HAND). HAND is associated with neurocognitive impairment, including motor impairment, and memory loss. HIV has been detected in the brain within 8 days of estimated exposure and the mechanisms for this early entry are being actively studied. Once having entered into the central nervous system (CNS), HIV degrades the blood-brain barrier through the production of its gp120 and Tat proteins. These proteins are directly toxic to endothelial cells and neurons, and propagate inflammatory cytokines by the activation of immune cells and dysregulation of tight junction proteins. The BBB breakdown is associated with the progression of neurocognitive disease. One of the main hurdles for treatment for HAND is the latent pool of cells, which are insensitive to cART and prolong inflammation by harboring the provirus in long-lived cells that can reactivate, causing damage. Multiple strategies are being studied to combat the latent pool and HAND; however, clinically, these approaches have been insufficient and require further revisions. The goal of this paper is to aggregate the known mechanisms and challenges associated with HAND.
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Affiliation(s)
| | - Jessica Genovese
- Department of Life Sciences, Albany College of Pharmacy and Health Sciences, Albany, NY 12208, USA
| | - Zhenzi Hong
- Department of Life Sciences, Albany College of Pharmacy and Health Sciences, Albany, NY 12208, USA
| | - Meera Vir Singh
- Department of Neurology, University of Rochester, Rochester, NY 14642, USA
| | - Vir Bahadur Singh
- Department of Life Sciences, Albany College of Pharmacy and Health Sciences, Albany, NY 12208, USA
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2
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Izquierdo-Pujol J, Puertas MC, Martinez-Picado J, Morón-López S. Targeting Viral Transcription for HIV Cure Strategies. Microorganisms 2024; 12:752. [PMID: 38674696 PMCID: PMC11052381 DOI: 10.3390/microorganisms12040752] [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: 03/21/2024] [Revised: 04/05/2024] [Accepted: 04/05/2024] [Indexed: 04/28/2024] Open
Abstract
Combination antiretroviral therapy (ART) suppresses viral replication to undetectable levels, reduces mortality and morbidity, and improves the quality of life of people living with HIV (PWH). However, ART cannot cure HIV infection because it is unable to eliminate latently infected cells. HIV latency may be regulated by different HIV transcription mechanisms, such as blocks to initiation, elongation, and post-transcriptional processes. Several latency-reversing (LRA) and -promoting agents (LPA) have been investigated in clinical trials aiming to eliminate or reduce the HIV reservoir. However, none of these trials has shown a conclusive impact on the HIV reservoir. Here, we review the cellular and viral factors that regulate HIV-1 transcription, the potential pharmacological targets and genetic and epigenetic editing techniques that have been or might be evaluated to disrupt HIV-1 latency, the role of miRNA in post-transcriptional regulation of HIV-1, and the differences between the mechanisms regulating HIV-1 and HIV-2 expression.
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Affiliation(s)
- Jon Izquierdo-Pujol
- IrsiCaixa, 08916 Badalona, Spain; (J.I.-P.); (M.C.P.); (J.M.-P.)
- Germans Trias i Pujol Research Institute (IGTP), 08916 Badalona, Spain
| | - Maria C. Puertas
- IrsiCaixa, 08916 Badalona, Spain; (J.I.-P.); (M.C.P.); (J.M.-P.)
- Germans Trias i Pujol Research Institute (IGTP), 08916 Badalona, Spain
- CIBERINFEC, 28029 Madrid, Spain
| | - Javier Martinez-Picado
- IrsiCaixa, 08916 Badalona, Spain; (J.I.-P.); (M.C.P.); (J.M.-P.)
- Germans Trias i Pujol Research Institute (IGTP), 08916 Badalona, Spain
- CIBERINFEC, 28029 Madrid, Spain
- Department of Infectious Diseases and Immunity, School of Medicine, University of Vic-Central University of Catalonia (UVic-UCC), 08500 Vic, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), 08010 Barcelona, Spain
| | - Sara Morón-López
- IrsiCaixa, 08916 Badalona, Spain; (J.I.-P.); (M.C.P.); (J.M.-P.)
- Germans Trias i Pujol Research Institute (IGTP), 08916 Badalona, Spain
- CIBERINFEC, 28029 Madrid, Spain
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3
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Ait Said M, Bejjani F, Abdouni A, Ségéral E, Emiliani S. Premature transcription termination complex proteins PCF11 and WDR82 silence HIV-1 expression in latently infected cells. Proc Natl Acad Sci U S A 2023; 120:e2313356120. [PMID: 38015843 PMCID: PMC10710072 DOI: 10.1073/pnas.2313356120] [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: 08/03/2023] [Accepted: 10/30/2023] [Indexed: 11/30/2023] Open
Abstract
Postintegration transcriptional silencing of HIV-1 leads to the establishment of a pool of latently infected cells. In these cells, mechanisms controlling RNA Polymerase II (RNAPII) pausing and premature transcription termination (PTT) remain to be explored. Here, we found that the cleavage and polyadenylation (CPA) factor PCF11 represses HIV-1 expression independently of the other subunits of the CPA complex or the polyadenylation signal located at the 5' LTR. We show that PCF11 interacts with the RNAPII-binding protein WDR82. Knock-down of PCF11 or WDR82 reactivated HIV-1 expression in latently infected cells. To silence HIV-1 transcription, PCF11 and WDR82 are specifically recruited at the promoter-proximal region of the provirus in an interdependent manner. Codepletion of PCF11 and WDR82 indicated that they act on the same pathway to repress HIV expression. These findings reveal PCF11/WDR82 as a PTT complex silencing HIV-1 expression in latently infected cells.
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Affiliation(s)
- Melissa Ait Said
- Université Paris Cité, Institut Cochin, INSERM, CNRS, ParisF-75014, France
| | - Fabienne Bejjani
- Université Paris Cité, Institut Cochin, INSERM, CNRS, ParisF-75014, France
| | - Ahmed Abdouni
- Université Paris Cité, Institut Cochin, INSERM, CNRS, ParisF-75014, France
| | - Emmanuel Ségéral
- Université Paris Cité, Institut Cochin, INSERM, CNRS, ParisF-75014, France
| | - Stéphane Emiliani
- Université Paris Cité, Institut Cochin, INSERM, CNRS, ParisF-75014, France
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4
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Pan H, Cheng X, Rodríguez PFG, Zhang X, Chung I, Jin VX, Li W, Hu Y, Li R. An essential signaling function of cytoplasmic NELFB is independent of RNA polymerase II pausing. J Biol Chem 2023; 299:105259. [PMID: 37717699 PMCID: PMC10591015 DOI: 10.1016/j.jbc.2023.105259] [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: 08/10/2023] [Revised: 08/24/2023] [Accepted: 08/30/2023] [Indexed: 09/19/2023] Open
Abstract
The four-subunit negative elongation factor (NELF) complex mediates RNA polymerase II (Pol II) pausing at promoter-proximal regions. Ablation of individual NELF subunits destabilizes the NELF complex and causes cell lethality, leading to the prevailing concept that NELF-mediated Pol II pausing is essential for cell proliferation. Using separation-of-function mutations, we show here that NELFB function in cell proliferation can be uncoupled from that in Pol II pausing. NELFB mutants sequestered in the cytoplasm and deprived of NELF nuclear function still support cell proliferation and part of the NELFB-dependent transcriptome. Mechanistically, cytoplasmic NELFB physically and functionally interacts with prosurvival signaling kinases, most notably phosphatidylinositol-3-kinase/AKT. Ectopic expression of membrane-tethered phosphatidylinositol-3-kinase/AKT partially bypasses the role of NELFB in cell proliferation, but not Pol II occupancy. Together, these data expand the current understanding of the physiological impact of Pol II pausing and underscore the multiplicity of the biological functions of individual NELF subunits.
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Affiliation(s)
- Haihui Pan
- Department of Biochemistry & Molecular Medicine, School of Medicine & Health Sciences, The George Washington University, Washington, District of Columbia, USA.
| | - Xiaolong Cheng
- Department of Genomics & Precision Medicine, School of Medicine & Health Sciences, The George Washington University, Washington, District of Columbia, USA; Center for Genetic Medicine Research, Children's National Hospital, Washington, District of Columbia, USA
| | - Pedro Felipe Gardeazábal Rodríguez
- Department of Anatomy & Cell Biology, School of Medicine & Health Sciences, The George Washington University, Washington, District of Columbia, USA
| | - Xiaowen Zhang
- Department of Biochemistry & Molecular Medicine, School of Medicine & Health Sciences, The George Washington University, Washington, District of Columbia, USA
| | - Inhee Chung
- Department of Anatomy & Cell Biology, School of Medicine & Health Sciences, The George Washington University, Washington, District of Columbia, USA
| | - Victor X Jin
- Institute of Health Equity and Cancer Center, The Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Wei Li
- Department of Genomics & Precision Medicine, School of Medicine & Health Sciences, The George Washington University, Washington, District of Columbia, USA; Center for Genetic Medicine Research, Children's National Hospital, Washington, District of Columbia, USA
| | - Yanfen Hu
- Department of Anatomy & Cell Biology, School of Medicine & Health Sciences, The George Washington University, Washington, District of Columbia, USA
| | - Rong Li
- Department of Biochemistry & Molecular Medicine, School of Medicine & Health Sciences, The George Washington University, Washington, District of Columbia, USA.
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5
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Whelan M, Pelchat M. Role of RNA Polymerase II Promoter-Proximal Pausing in Viral Transcription. Viruses 2022; 14:v14092029. [PMID: 36146833 PMCID: PMC9503719 DOI: 10.3390/v14092029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 09/09/2022] [Accepted: 09/11/2022] [Indexed: 11/16/2022] Open
Abstract
The promoter-proximal pause induced by the binding of the DRB sensitivity-inducing factor (DSIF) and the negative elongation factor (NELF) to RNAP II is a key step in the regulation of metazoan gene expression. It helps maintain a permissive chromatin landscape and ensures a quick transcriptional response from stimulus-responsive pathways such as the innate immune response. It is also involved in the biology of several RNA viruses such as the human immunodeficiency virus (HIV), the influenza A virus (IAV) and the hepatitis delta virus (HDV). HIV uses the pause as one of its mechanisms to enter and maintain latency, leading to the creation of viral reservoirs resistant to antiretrovirals. IAV, on the other hand, uses the pause to acquire the capped primers necessary to initiate viral transcription through cap-snatching. Finally, the HDV RNA genome is transcribed directly by RNAP II and requires the small hepatitis delta antigen to displace NELF from the polymerase and overcome the transcriptional block caused by RNAP II promoter-proximal pausing. In this review, we will discuss the RNAP II promoter-proximal pause and the roles it plays in the life cycle of RNA viruses such as HIV, IAV and HDV.
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6
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Pedersen SF, Collora JA, Kim RN, Yang K, Razmi A, Catalano AA, Yeh YHJ, Mounzer K, Tebas P, Montaner LJ, Ho YC. Inhibition of a Chromatin and Transcription Modulator, SLTM, Increases HIV-1 Reactivation Identified by a CRISPR Inhibition Screen. J Virol 2022; 96:e0057722. [PMID: 35730977 PMCID: PMC9278143 DOI: 10.1128/jvi.00577-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 05/27/2022] [Indexed: 12/24/2022] Open
Abstract
Despite effective antiretroviral therapy, HIV-1 persistence in latent reservoirs remains a major obstacle to a cure. We postulate that HIV-1 silencing factors suppress HIV-1 reactivation and that inhibition of these factors will increase HIV-1 reactivation. To identify HIV-1 silencing factors, we conducted a genome-wide CRISPR inhibition (CRISPRi) screen using four CRISPRi-ready, HIV-1-d6-GFP-infected Jurkat T cell clones with distinct integration sites. We sorted cells with increased green fluorescent protein (GFP) expression and captured single guide RNAs (sgRNAs) via targeted deep sequencing. We identified 18 HIV-1 silencing factors that were significantly enriched in HIV-1-d6-GFPhigh cells. Among them, SLTM (scaffold attachment factor B-like transcription modulator) is an epigenetic and transcriptional modulator having both DNA and RNA binding capacities not previously known to affect HIV-1 transcription. Knocking down SLTM by CRISPRi significantly increased HIV-1-d6-GFP expression (by 1.9- to 4.2-fold) in three HIV-1-d6-GFP-Jurkat T cell clones. Furthermore, SLTM knockdown increased the chromatin accessibility of HIV-1 and the gene in which HIV-1 is integrated but not the housekeeping gene POLR2A. To test whether SLTM inhibition can reactivate HIV-1 and further induce cell death of HIV-1-infected cells ex vivo, we established a small interfering RNA (siRNA) knockdown method that reduced SLTM expression in CD4+ T cells from 10 antiretroviral therapy (ART)-treated, virally suppressed, HIV-1-infected individuals ex vivo. Using limiting dilution culture, we found that SLTM knockdown significantly reduced the frequency of HIV-1-infected cells harboring inducible HIV-1 by 62.2% (0.56/106 versus 1.48/106 CD4+ T cells [P = 0.029]). Overall, our study indicates that SLTM inhibition reactivates HIV-1 in vitro and induces cell death of HIV-1-infected cells ex vivo. Our study identified SLTM as a novel therapeutic target. IMPORTANCE HIV-1-infected cells, which can survive drug treatment and immune cell killing, prevent an HIV-1 cure. Immune recognition of infected cells requires HIV-1 protein expression; however, HIV-1 protein expression is limited in infected cells after long-term therapy. The ways in which the HIV-1 provirus is blocked from producing protein are unknown. We identified a new host protein that regulates HIV-1 gene expression. We also provided a new method of studying HIV-1-host factor interactions in cells from infected individuals. These improvements may enable future strategies to reactivate HIV-1 in infected individuals so that infected cells can be killed by immune cells, drug treatment, or the virus itself.
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Affiliation(s)
- Savannah F. Pedersen
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Jack A. Collora
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Rachel N. Kim
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Kerui Yang
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Anya Razmi
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Allison A. Catalano
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Yang-Hui Jimmy Yeh
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Karam Mounzer
- Philadelphia FIGHT Community Health Centers, Philadelphia, Pennsylvania, USA
| | - Pablo Tebas
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | - Ya-Chi Ho
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
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7
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A functional map of HIV-host interactions in primary human T cells. Nat Commun 2022; 13:1752. [PMID: 35365639 PMCID: PMC8976027 DOI: 10.1038/s41467-022-29346-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 03/08/2022] [Indexed: 02/07/2023] Open
Abstract
Human Immunodeficiency Virus (HIV) relies on host molecular machinery for replication. Systematic attempts to genetically or biochemically define these host factors have yielded hundreds of candidates, but few have been functionally validated in primary cells. Here, we target 426 genes previously implicated in the HIV lifecycle through protein interaction studies for CRISPR-Cas9-mediated knock-out in primary human CD4+ T cells in order to systematically assess their functional roles in HIV replication. We achieve efficient knockout (>50% of alleles) in 364 of the targeted genes and identify 86 candidate host factors that alter HIV infection. 47 of these factors validate by multiplex gene editing in independent donors, including 23 factors with restrictive activity. Both gene editing efficiencies and HIV-1 phenotypes are highly concordant among independent donors. Importantly, over half of these factors have not been previously described to play a functional role in HIV replication, providing numerous novel avenues for understanding HIV biology. These data further suggest that host-pathogen protein-protein interaction datasets offer an enriched source of candidates for functional host factor discovery and provide an improved understanding of the mechanics of HIV replication in primary T cells.
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8
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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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9
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Abstract
Viral infection is intrinsically linked to the capacity of the virus to generate progeny. Many DNA and some RNA viruses need to access the nuclear machinery and therefore transverse the nuclear envelope barrier through the nuclear pore complex. Viral genomes then become chromatinized either in their episomal form or upon integration into the host genome. Interactions with host DNA, transcription factors or nuclear bodies mediate their replication. Often interfering with nuclear functions, viruses use nuclear architecture to ensure persistent infections. Discovering these multiple modes of replication and persistence served in unraveling many important nuclear processes, such as nuclear trafficking, transcription, and splicing. Here, by using examples of DNA and RNA viral families, we portray the nucleus with the virus inside.
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Affiliation(s)
- Bojana Lucic
- Department of Infectious Diseases, Integrative Virology, Heidelberg University Hospital and German Center for Infection Research, Im Neuenheimer Feld 344, 69120 Heidelberg, Germany
| | - Ines J de Castro
- Department of Infectious Diseases, Integrative Virology, Heidelberg University Hospital and German Center for Infection Research, Im Neuenheimer Feld 344, 69120 Heidelberg, Germany
| | - Marina Lusic
- Department of Infectious Diseases, Integrative Virology, Heidelberg University Hospital and German Center for Infection Research, Im Neuenheimer Feld 344, 69120 Heidelberg, Germany
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10
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Wu Y, Yang Q, Wang M, Chen S, Jia R, Yang Q, Zhu D, Liu M, Zhao X, Zhang S, Huang J, Ou X, Mao S, Gao Q, Sun D, Tian B, Cheng A. Multifaceted Roles of ICP22/ORF63 Proteins in the Life Cycle of Human Herpesviruses. Front Microbiol 2021; 12:668461. [PMID: 34163446 PMCID: PMC8215345 DOI: 10.3389/fmicb.2021.668461] [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: 02/16/2021] [Accepted: 05/05/2021] [Indexed: 01/03/2023] Open
Abstract
Herpesviruses are extremely successful parasites that have evolved over millions of years to develop a variety of mechanisms to coexist with their hosts and to maintain host-to-host transmission and lifelong infection by regulating their life cycles. The life cycle of herpesviruses consists of two phases: lytic infection and latent infection. During lytic infection, active replication and the production of numerous progeny virions occur. Subsequent suppression of the host immune response leads to a lifetime latent infection of the host. During latent infection, the viral genome remains in an inactive state in the host cell to avoid host immune surveillance, but the virus can be reactivated and reenter the lytic cycle. The balance between these two phases of the herpesvirus life cycle is controlled by broad interactions among numerous viral and cellular factors. ICP22/ORF63 proteins are among these factors and are involved in transcription, nuclear budding, latency establishment, and reactivation. In this review, we summarized the various roles and complex mechanisms by which ICP22/ORF63 proteins regulate the life cycle of human herpesviruses and the complex relationships among host and viral factors. Elucidating the role and mechanism of ICP22/ORF63 in virus-host interactions will deepen our understanding of the viral life cycle. In addition, it will also help us to understand the pathogenesis of herpesvirus infections and provide new strategies for combating these infections.
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Affiliation(s)
- Ying Wu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
| | - Qiqi Yang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
| | - Mingshu Wang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
| | - Shun Chen
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
| | - Renyong Jia
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
| | - Qiao Yang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
| | - Dekang Zhu
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
| | - Mafeng Liu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
| | - Xinxin Zhao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
| | - Shaqiu Zhang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
| | - Juan Huang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
| | - Xumin Ou
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
| | - Sai Mao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
| | - Qun Gao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
| | - Di Sun
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
| | - Bin Tian
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
| | - Anchun Cheng
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
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11
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Ledet RJ, Ruff SE, Wang Y, Nayak S, Schneider JA, Ueberheide B, Logan SK, Garabedian MJ. Identification of PIM1 substrates reveals a role for NDRG1 phosphorylation in prostate cancer cellular migration and invasion. Commun Biol 2021; 4:36. [PMID: 33398037 PMCID: PMC7782530 DOI: 10.1038/s42003-020-01528-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 11/25/2020] [Indexed: 12/17/2022] Open
Abstract
PIM1 is a serine/threonine kinase that promotes and maintains prostate tumorigenesis. While PIM1 protein levels are elevated in prostate cancer relative to local disease, the mechanisms by which PIM1 contributes to oncogenesis have not been fully elucidated. Here, we performed a direct, unbiased chemical genetic screen to identify PIM1 substrates in prostate cancer cells. The PIM1 substrates we identified were involved in a variety of oncogenic processes, and included N-Myc Downstream-Regulated Gene 1 (NDRG1), which has reported roles in suppressing cancer cell invasion and metastasis. NDRG1 is phosphorylated by PIM1 at serine 330 (pS330), and the level of NDRG1 pS330 is associated higher grade prostate tumors. We have shown that PIM1 phosphorylation of NDRG1 at S330 reduced its stability, nuclear localization, and interaction with AR, resulting in enhanced cell migration and invasion.
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Affiliation(s)
- Russell J Ledet
- Departments of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA
- Department of Urology, New York University School of Medicine, New York, NY, 10016, USA
- Department of Microbiology, New York University School of Medicine, New York, NY, 10016, USA
| | - Sophie E Ruff
- Departments of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA
- Department of Urology, New York University School of Medicine, New York, NY, 10016, USA
- Department of Microbiology, New York University School of Medicine, New York, NY, 10016, USA
| | - Yu Wang
- Departments of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA
- Department of Urology, New York University School of Medicine, New York, NY, 10016, USA
| | - Shruti Nayak
- Proteomics Laboratory, New York University School of Medicine, New York, NY, 10016, USA
| | - Jeffrey A Schneider
- Departments of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA
- Department of Urology, New York University School of Medicine, New York, NY, 10016, USA
- Department of Microbiology, New York University School of Medicine, New York, NY, 10016, USA
| | - Beatrix Ueberheide
- Departments of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA
- Proteomics Laboratory, New York University School of Medicine, New York, NY, 10016, USA
| | - Susan K Logan
- Departments of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA.
- Department of Urology, New York University School of Medicine, New York, NY, 10016, USA.
| | - Michael J Garabedian
- Department of Urology, New York University School of Medicine, New York, NY, 10016, USA.
- Department of Microbiology, New York University School of Medicine, New York, NY, 10016, USA.
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12
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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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13
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Chaiben CL, Batista TBD, Penteado CAS, Barbosa MCM, Ventura TMO, Dionizio A, Rosa EAR, Buzalaf MAR, Azevedo-Alanis LR. Salivary proteome analysis of crack cocaine dependents. Arch Oral Biol 2020; 121:104952. [PMID: 33186792 DOI: 10.1016/j.archoralbio.2020.104952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 10/13/2020] [Accepted: 10/15/2020] [Indexed: 11/24/2022]
Abstract
OBJECTIVE Salivary proteomic analysis may help to understand physiopathological changes in crack cocaine dependents. This study aimed to compare the salivary protein profile between crack cocaine dependents and non-drug users. DESIGN Nine heavy smokers and alcohol consumers men admitted to rehab due to crack cocaine abuse and nine non-drug users age-matched men were evaluated. Unstimulated whole saliva was collected. Proteomic analysis was performed by mass spectrometer. Data were processed using ProteinLynx GlobalServer software. Results were obtained by searching the Homo sapiens database from the UniProt catalog. The search tool IBI-IMIM was used to identify proteins candidates for biomarkers. RESULTS The mean age of crack cocaine and control groups was 36.89 ± 7.78 and 35.78 ± 6.68 years, respectively. 458 salivary proteins were identified in both groups; 305 proteins in the crack cocaine group. Among the 68 proteins presented in both groups, 29 were down-regulated (i.e. "Statherin" and "Transforming growth factor-beta-induced protein ig-h3" were down-regulated at least 10-fold) and 27 up-regulated (i.e. "Negative elongation factor" was up-regulated 19-fold) in the crack cocaine group compared to controls. 90 out of the 458 proteins found in the proteomic analysis were identified as candidates for biomarkers of diseases. Among these, 65 (72.22 %) were detected in the crack cocaine group. CONCLUSION Crack cocaine dependents with chronic alcohol and tobacco use have a higher number of proteins in saliva compared to non-drug users. 22.3 % of salivary proteins present in crack cocaine dependents were present in controls; 3.9 % of them were expressed in similar quantity.
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Affiliation(s)
- Cassiano Lima Chaiben
- Graduate Program in Dentistry, School of Life Sciences, Pontifícia Universidade Católica do Paraná, Rua Imaculada Conceição 1155, Curitiba, PR, Postal Code: 80215-901, Brazil.
| | - Thiago Beltrami Dias Batista
- Graduate Program in Dentistry, School of Life Sciences, Pontifícia Universidade Católica do Paraná, Rua Imaculada Conceição 1155, Curitiba, PR, Postal Code: 80215-901, Brazil.
| | - Carlos Antonio Schäffer Penteado
- Graduate Program in Dentistry, School of Life Sciences, Pontifícia Universidade Católica do Paraná, Rua Imaculada Conceição 1155, Curitiba, PR, Postal Code: 80215-901, Brazil.
| | - Maria Carolina Maciel Barbosa
- School of Life Sciences, Pontifícia Universidade Católica do Paraná, Rua Imaculada Conceição 1155, Curitiba, PR, Postal Code: 80215-901, Brazil.
| | - Talita Mendes Oliveira Ventura
- Bauru School of Dentistry, University of São Paulo, Alameda Doutor Octávio Pinheiro Brisolla, 9-75, Bauru, SP Postal Code: 17012-901, Brazil.
| | - Aline Dionizio
- Bauru School of Dentistry, University of São Paulo, Alameda Doutor Octávio Pinheiro Brisolla, 9-75, Bauru, SP Postal Code: 17012-901, Brazil.
| | - Edvaldo Antonio Ribeiro Rosa
- Graduate Program in Dentistry, School of Life Sciences, Pontifícia Universidade Católica do Paraná, Rua Imaculada Conceição 1155, Curitiba, PR, Postal Code: 80215-901, Brazil.
| | - Marília Afonso Rabelo Buzalaf
- Bauru School of Dentistry, University of São Paulo, Alameda Doutor Octávio Pinheiro Brisolla, 9-75, Bauru, SP Postal Code: 17012-901, Brazil.
| | - Luciana Reis Azevedo-Alanis
- Graduate Program in Dentistry, School of Life Sciences, Pontifícia Universidade Católica do Paraná, Rua Imaculada Conceição 1155, Curitiba, PR, Postal Code: 80215-901, Brazil.
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14
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PIWIL4 Maintains HIV-1 Latency by Enforcing Epigenetically Suppressive Modifications on the 5' Long Terminal Repeat. J Virol 2020; 94:JVI.01923-19. [PMID: 32161174 DOI: 10.1128/jvi.01923-19] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 02/21/2020] [Indexed: 02/07/2023] Open
Abstract
Although substantial progress has been made in depicting the molecular pathogenesis of human immunodeficiency virus type 1 (HIV-1) infection, the comprehensive mechanism of HIV-1 latency and the most promising therapeutic strategies to effectively reactivate the HIV-1 latent reservoir to achieve a functional cure for AIDS remain to be systematically illuminated. Here, we demonstrated that piwi (P element-induced Wimpy)-like RNA-mediated gene silencing 4 (PIWIL4) played an important role in suppressing HIV-1 transcription and contributed to the latency state in HIV-1-infected cells through its recruitment of various suppressive factors, including heterochromatin protein 1α/β/γ, SETDB1, and HDAC4. The knockdown of PIWIL4 enhanced HIV-1 transcription and reversed HIV-1 latency in both HIV-1 latently infected Jurkat T cells and primary CD4+ T lymphocytes and resting CD4+ T lymphocytes from HIV-1-infected individuals on suppressive combined antiretroviral therapy (cART). Furthermore, in the absence of PIWIL4, HIV-1 latently infected Jurkat T cells were more sensitive to reactivation with vorinostat (suberoylanilide hydroxamic acid, or SAHA), JQ1, or prostratin. These findings indicated that PIWIL4 promotes HIV-1 latency by imposing repressive marks at the HIV-1 5' long terminal repeat. Thus, the manipulation of PIWIL4 could be a novel strategy for developing promising latency-reversing agents (LRAs).IMPORTANCE HIV-1 latency is systematically modulated by host factors and viral proteins. During this process, the suppression of HIV-1 transcription plays an essential role in promoting HIV-1 latency. In this study, we found that PIWIL4 repressed HIV-1 promoter activity and maintained HIV-1 latency. In particular, we report that PIWIL4 can regulate gene expression through its association with the suppressive activity of HDAC4. Therefore, we have identified a new function for PIWIL4: it is not only a suppressor of endogenous retrotransposons but also plays an important role in inhibiting transcription and leading to latent infection of HIV-1, a well-known exogenous retrovirus. Our results also indicate a novel therapeutic target to reactivate the HIV-1 latent reservoir.
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15
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Gao R, Bao J, Yan H, Xie L, Qin W, Ning H, Huang S, Cheng J, Zhi R, Li Z, Tucker B, Chen Y, Zhang K, Wu X, Liu Z, Gao X, Hu D. Competition between PAF1 and MLL1/COMPASS confers the opposing function of LEDGF/p75 in HIV latency and proviral reactivation. SCIENCE ADVANCES 2020; 6:eaaz8411. [PMID: 32426500 PMCID: PMC7220354 DOI: 10.1126/sciadv.aaz8411] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 03/02/2020] [Indexed: 05/19/2023]
Abstract
Transcriptional status determines the HIV replicative state in infected patients. However, the transcriptional mechanisms for proviral replication control remain unclear. In this study, we show that, apart from its function in HIV integration, LEDGF/p75 differentially regulates HIV transcription in latency and proviral reactivation. During latency, LEDGF/p75 suppresses proviral transcription via promoter-proximal pausing of RNA polymerase II (Pol II) by recruiting PAF1 complex to the provirus. Following latency reversal, MLL1 complex competitively displaces PAF1 from the provirus through casein kinase II (CKII)-dependent association with LEDGF/p75. Depleting or pharmacologically inhibiting CKII prevents PAF1 dissociation and abrogates the recruitment of both MLL1 and Super Elongation Complex (SEC) to the provirus, thereby impairing transcriptional reactivation for latency reversal. These findings, therefore, provide a mechanistic understanding of how LEDGF/p75 coordinates its distinct regulatory functions at different stages of the post-integrated HIV life cycles. Targeting these mechanisms may have a therapeutic potential to eradicate HIV infection.
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Affiliation(s)
- Ru Gao
- State Key Laboratory of Experimental Hematology, Tianjin Key Laboratory of Medical Epigenetics, Tianjin Key Laboratory of Cellular Homeostasis and Human Diseases, Department of Cell Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Jiaqian Bao
- State Key Laboratory of Experimental Hematology, Tianjin Key Laboratory of Medical Epigenetics, Tianjin Key Laboratory of Cellular Homeostasis and Human Diseases, Department of Cell Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Han Yan
- State Key Laboratory of Experimental Hematology, Tianjin Key Laboratory of Medical Epigenetics, Tianjin Key Laboratory of Cellular Homeostasis and Human Diseases, Department of Cell Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Liya Xie
- State Key Laboratory of Experimental Hematology, Tianjin Key Laboratory of Medical Epigenetics, Tianjin Key Laboratory of Cellular Homeostasis and Human Diseases, Department of Cell Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Wanchang Qin
- State Key Laboratory of Experimental Hematology, Tianjin Key Laboratory of Medical Epigenetics, Tianjin Key Laboratory of Cellular Homeostasis and Human Diseases, Department of Cell Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Hanhan Ning
- State Key Laboratory of Experimental Hematology, Tianjin Key Laboratory of Medical Epigenetics, Tianjin Key Laboratory of Cellular Homeostasis and Human Diseases, Department of Cell Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Shuqi Huang
- State Key Laboratory of Experimental Hematology, Tianjin Key Laboratory of Medical Epigenetics, Tianjin Key Laboratory of Cellular Homeostasis and Human Diseases, Department of Cell Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Jun Cheng
- State Key Laboratory of Experimental Hematology, Tianjin Key Laboratory of Medical Epigenetics, Tianjin Key Laboratory of Cellular Homeostasis and Human Diseases, Department of Cell Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Renyong Zhi
- Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, Cancer Institute and Hospital of Tianjin Medical University, Tianjin 300060, China
| | - Zexing Li
- Department of Cell Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Bronwyn Tucker
- School of Medical English and Health Communication, Tianjin Medical University, Tianjin 300070, China
| | - Yupeng Chen
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Kai Zhang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Xudong Wu
- Department of Cell Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Zhe Liu
- Department of Immunology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Xin Gao
- State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300020, China
- Corresponding author. (D.H.); (X.G.)
| | - Deqing Hu
- State Key Laboratory of Experimental Hematology, Tianjin Key Laboratory of Medical Epigenetics, Tianjin Key Laboratory of Cellular Homeostasis and Human Diseases, Department of Cell Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
- Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, Cancer Institute and Hospital of Tianjin Medical University, Tianjin 300060, China
- Corresponding author. (D.H.); (X.G.)
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16
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Exploring histone loading on HIV DNA reveals a dynamic nucleosome positioning between unintegrated and integrated viral genome. Proc Natl Acad Sci U S A 2020; 117:6822-6830. [PMID: 32161134 PMCID: PMC7104181 DOI: 10.1073/pnas.1913754117] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The biology of HIV DNA, from its synthesis to its integration into the host genome, remains poorly understood. Here we show that in the nucleus, histones are rapidly loaded on newly synthesized unintegrated HIV DNA. Interestingly, the chromatin architecture around the HIV long terminal repeat (LTR) is different in unintegrated and integrated HIV DNA. Specifically, a nucleosome present only on the DNase hypersensitive site of unintegrated HIV DNA contributes to the transcriptional silencing of unintegrated HIV DNA by preventing RNAPII recruitment. The aim of the present study was to understand the biology of unintegrated HIV-1 DNA and reveal the mechanisms involved in its transcriptional silencing. We found that histones are loaded on HIV-1 DNA after its nuclear import and before its integration in the host genome. Nucleosome positioning analysis along the unintegrated and integrated viral genomes revealed major differences in nucleosome density and position. Indeed, in addition to the well-known nucleosomes Nuc0, Nuc1, and Nuc2 loaded on integrated HIV-1 DNA, we also found NucDHS, a nucleosome that covers the DNase hypersensitive site, in unintegrated viral DNA. In addition, unintegrated viral DNA-associated Nuc0 and Nuc2 were positioned slightly more to the 5′ end relative to their position in integrated DNA. The presence of NucDHS in the proximal region of the long terminal repeat (LTR) promoter was associated with the absence of RNAPII and of the active histone marks H3K4me3 and H3ac at the LTR. Conversely, analysis of integrated HIV-1 DNA showed a loss of NucDHS, loading of RNAPII, and enrichment in active histone marks within the LTR. We propose that unintegrated HIV-1 DNA adopts a repressive chromatin structure that competes with the transcription machinery, leading to its silencing.
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17
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DeMarino C, Cowen M, Pleet ML, Pinto DO, Khatkar P, Erickson J, Docken SS, Russell N, Reichmuth B, Phan T, Kuang Y, Anderson DM, Emelianenko M, Kashanchi F. Differences in Transcriptional Dynamics Between T-cells and Macrophages as Determined by a Three-State Mathematical Model. Sci Rep 2020; 10:2227. [PMID: 32042107 PMCID: PMC7010665 DOI: 10.1038/s41598-020-59008-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 01/17/2020] [Indexed: 12/18/2022] Open
Abstract
HIV-1 viral transcription persists in patients despite antiretroviral treatment, potentially due to intermittent HIV-1 LTR activation. While several mathematical models have been explored in the context of LTR-protein interactions, in this work for the first time HIV-1 LTR model featuring repressed, intermediate, and activated LTR states is integrated with generation of long (env) and short (TAR) RNAs and proteins (Tat, Pr55, and p24) in T-cells and macrophages using both cell lines and infected primary cells. This type of extended modeling framework allows us to compare and contrast behavior of these two cell types. We demonstrate that they exhibit unique LTR dynamics, which ultimately results in differences in the magnitude of viral products generated. One of the distinctive features of this work is that it relies on experimental data in reaction rate computations. Two RNA transcription rates from the activated promoter states are fit by comparison of experimental data to model predictions. Fitting to the data also provides estimates for the degradation/exit rates for long and short viral RNA. Our experimentally generated data is in reasonable agreement for the T-cell as well macrophage population and gives strong evidence in support of using the proposed integrated modeling paradigm. Sensitivity analysis performed using Latin hypercube sampling method confirms robustness of the model with respect to small parameter perturbations. Finally, incorporation of a transcription inhibitor (F07#13) into the governing equations demonstrates how the model can be used to assess drug efficacy. Collectively, our model indicates transcriptional differences between latently HIV-1 infected T-cells and macrophages and provides a novel platform to study various transcriptional dynamics leading to latency or activation in numerous cell types and physiological conditions.
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MESH Headings
- Anti-HIV Agents/pharmacology
- Anti-HIV Agents/therapeutic use
- Cell Line
- Drug Resistance, Viral/drug effects
- Drug Resistance, Viral/genetics
- Drug Resistance, Viral/immunology
- Gene Expression Regulation, Viral/immunology
- HIV Infections/blood
- HIV Infections/drug therapy
- HIV Infections/immunology
- HIV Long Terminal Repeat/genetics
- HIV-1/drug effects
- HIV-1/genetics
- HIV-1/immunology
- Humans
- Macrophages/immunology
- Macrophages/virology
- Models, Genetic
- Models, Immunological
- Primary Cell Culture
- RNA, Viral/genetics
- RNA, Viral/metabolism
- T-Lymphocytes/immunology
- T-Lymphocytes/virology
- Transcription, Genetic/drug effects
- Transcription, Genetic/immunology
- Virus Replication/drug effects
- Virus Replication/genetics
- Virus Replication/immunology
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Affiliation(s)
- Catherine DeMarino
- Laboratory of Molecular Virology, School of Systems Biology, George Mason University, Manassas, VA, USA
| | - Maria Cowen
- Laboratory of Molecular Virology, School of Systems Biology, George Mason University, Manassas, VA, USA
| | - Michelle L Pleet
- Laboratory of Molecular Virology, School of Systems Biology, George Mason University, Manassas, VA, USA
| | - Daniel O Pinto
- Laboratory of Molecular Virology, School of Systems Biology, George Mason University, Manassas, VA, USA
| | - Pooja Khatkar
- Laboratory of Molecular Virology, School of Systems Biology, George Mason University, Manassas, VA, USA
| | - James Erickson
- Laboratory of Molecular Virology, School of Systems Biology, George Mason University, Manassas, VA, USA
| | - Steffen S Docken
- Department of Mathematics, University of California Davis, Davis, CA, USA
| | - Nicholas Russell
- Department of Mathematical Sciences, University of Delaware, Newark, DE, USA
| | - Blake Reichmuth
- Department of Mathematical Sciences, George Mason University, Fairfax, VA, USA
| | - Tin Phan
- School of Mathematical and Statistical Sciences, Arizona State University, Tempe, AZ, USA
| | - Yang Kuang
- School of Mathematical and Statistical Sciences, Arizona State University, Tempe, AZ, USA
| | - Daniel M Anderson
- Department of Mathematical Sciences, George Mason University, Fairfax, VA, USA.
| | - Maria Emelianenko
- Department of Mathematical Sciences, George Mason University, Fairfax, VA, USA.
| | - Fatah Kashanchi
- Laboratory of Molecular Virology, School of Systems Biology, George Mason University, Manassas, VA, USA.
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18
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Xu J, Wang G, Gong W, Guo S, Li D, Zhan Q. The noncoding function of NELFA mRNA promotes the development of oesophageal squamous cell carcinoma by regulating the Rad17-RFC2-5 complex. Mol Oncol 2020; 14:611-624. [PMID: 31845510 PMCID: PMC7053240 DOI: 10.1002/1878-0261.12619] [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: 08/24/2019] [Revised: 11/27/2019] [Accepted: 12/13/2019] [Indexed: 12/11/2022] Open
Abstract
Recently, RNAs interacting with proteins have been implicated in playing an important role in the occurrence and progression of oesophageal squamous cell carcinoma (ESCC). In this study, we found that NELFA mRNA interacts with Rad17 through a novel noncoding mode in the nucleus and that the aberrant expression of USF2 contributed to the upregulation of Rad17 and NELFA. Subsequent experiments demonstrated that the deletion of NELFA mRNA significantly decreased ESCC proliferation and colony formation in vitro. Moreover, NELFA mRNA knockdown inhibited DNA damage repair and promoted apoptosis. Mechanistic studies indicated that NELFA mRNA regulated the interaction between Rad17 and RFC2‐5, which had a major impact on the phosphorylation of CHK1, CHK2 and BRCA1. NELFA mRNA expression was consistently elevated in ESCC patients and closely related to decreased overall survival. Taken together, our results confirmed the critical role of the noncoding function of NELFA mRNA in ESCC tumorigenesis and indicated that NELFA mRNA can be regarded as a therapeutic target and an independent prognostic indicator in ESCC patients.
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Affiliation(s)
- Jiancheng Xu
- State Key Laboratory of Molecular Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Guangchao Wang
- State Key Laboratory of Molecular Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Wei Gong
- State Key Laboratory of Molecular Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Shichao Guo
- State Key Laboratory of Molecular Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Dan Li
- State Key Laboratory of Molecular Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Qimin Zhan
- State Key Laboratory of Molecular Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Laboratory of Molecular Oncology, Peking University Cancer Hospital and Institute, Beijing, China
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19
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Chinnapaiyan S, Dutta RK, Nair M, Chand HS, Rahman I, Unwalla HJ. TGF-β1 increases viral burden and promotes HIV-1 latency in primary differentiated human bronchial epithelial cells. Sci Rep 2019; 9:12552. [PMID: 31467373 PMCID: PMC6715689 DOI: 10.1038/s41598-019-49056-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 08/15/2019] [Indexed: 12/28/2022] Open
Abstract
Combination antiretroviral therapy (cART) has increased the life expectancy of HIV patients. However, the incidence of non-AIDS associated lung comorbidities, such as COPD and asthma, and that of opportunistic lung infections have become more common among this population. HIV proteins secreted by the anatomical HIV reservoirs can have both autocrine and paracrine effects contributing to the HIV-associated comorbidities. HIV has been recovered from cell-free bronchoalveolar lavage fluid, alveolar macrophages, and intrapulmonary lymphocytes. We have recently shown that ex-vivo cultured primary bronchial epithelial cells and the bronchial brushings from human subjects express canonical HIV receptors CD4, CCR5 and CXCR4 and can be infected with HIV. Together these studies suggest that the lung tissue can serve as an important reservoir for HIV. In this report, we show that TGF-β1 promotes HIV latency by upregulating a transcriptional repressor BLIMP-1. Furthermore, we identify miR-9-5p as an important intermediate in TGF-β-mediated BLIMP-1 upregulation and consequent HIV latency. The transcriptionally suppressed HIV can be reactivated by common latency reactivating agents. Together our data suggest that in patients with chronic airway diseases, TGF-β can elevate the HIV viral reservoir load that could further exacerbate the HIV associated lung comorbidities.
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Affiliation(s)
- S Chinnapaiyan
- Department of Immunology and Nano-Medicine, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, 33199, USA
| | - R K Dutta
- Department of Immunology and Nano-Medicine, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, 33199, USA
| | - M Nair
- Department of Immunology and Nano-Medicine, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, 33199, USA
| | - H S Chand
- Department of Immunology and Nano-Medicine, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, 33199, USA
| | - I Rahman
- University of Rochester Medical Center, School of Medicine and Dentistry, Rochester, NY, 14642, USA
| | - H J Unwalla
- Department of Immunology and Nano-Medicine, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, 33199, USA.
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20
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Krasnopolsky S, Marom L, Victor RA, Kuzmina A, Schwartz JC, Fujinaga K, Taube R. Fused in sarcoma silences HIV gene transcription and maintains viral latency through suppressing AFF4 gene activation. Retrovirology 2019; 16:16. [PMID: 31238957 PMCID: PMC6593535 DOI: 10.1186/s12977-019-0478-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 06/11/2019] [Indexed: 12/12/2022] Open
Abstract
Background The human immunodeficiency virus (HIV) cell reservoir is currently a main obstacle towards complete eradication of the virus. This infected pool is refractory to anti-viral therapy and harbors integrated proviruses that are transcriptionally repressed but replication competent. As transcription silencing is key for establishing the HIV reservoir, significant efforts have been made to understand the mechanism that regulate HIV gene transcription, and the role of the elongation machinery in promoting this step. However, while the role of the super elongation complex (SEC) in enhancing transcription activation of HIV is well established, the function of SEC in modulating viral latency is less defined and its cell partners are yet to be identified. Results In this study we identify fused in sarcoma (FUS) as a partner of AFF4 in cells. FUS inhibits the activation of HIV transcription by AFF4 and ELL2, and silences overall HIV gene transcription. Concordantly, depletion of FUS elevates the occupancy of AFF4 and Cdk9 on the viral promoter and activates HIV gene transcription. Live cell imaging demonstrates that FUS co-localizes with AFF4 within nuclear punctuated condensates, which are disrupted upon treating cells with aliphatic alcohol. In HIV infected cells, knockout of FUS delays the gradual entry of HIV into latency, and similarly promotes viral activation in a T cell latency model that is treated with JQ1. Finally, effects of FUS on HIV gene transcription are also exhibited genome wide, where FUS mainly occupies gene promoters at transcription starting sites, while its knockdown leads to an increase in AFF4 and Cdk9 occupancy on gene promoters of FUS affected genes. Conclusions Towards eliminating the HIV infected reservoir, understanding the mechanisms by which the virus persists in the face of therapy is important. Our observations show that FUS regulates both HIV and global gene transcription and modulates viral latency, thus can potentially serve as a target for future therapy that sets to reactivate HIV from its latent state. Electronic supplementary material The online version of this article (10.1186/s12977-019-0478-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Simona Krasnopolsky
- The Shraga Segal Department of Microbiology Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, 84105, Beer Sheva, Israel
| | - Lital Marom
- The Shraga Segal Department of Microbiology Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, 84105, Beer Sheva, Israel
| | - Rachel A Victor
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, USA
| | - Alona Kuzmina
- The Shraga Segal Department of Microbiology Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, 84105, Beer Sheva, Israel
| | - Jacob C Schwartz
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, USA
| | - Koh Fujinaga
- Department of Medicine, University of California, San Francisco, CA, USA
| | - Ran Taube
- The Shraga Segal Department of Microbiology Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, 84105, Beer Sheva, Israel.
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Gagne M, Michaels D, Schiralli Lester GM, Gummuluru S, Wong WW, Henderson AJ. Strength of T cell signaling regulates HIV-1 replication and establishment of latency. PLoS Pathog 2019; 15:e1007802. [PMID: 31116788 PMCID: PMC6548398 DOI: 10.1371/journal.ppat.1007802] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 06/04/2019] [Accepted: 04/30/2019] [Indexed: 01/27/2023] Open
Abstract
A major barrier to curing HIV-1 is the long-lived latent reservoir that supports re-emergence of HIV-1 upon treatment interruption. Targeting this reservoir will require mechanistic insights into the establishment and maintenance of HIV-1 latency. Whether T cell signaling at the time of HIV-1 infection influences productive replication or latency is not fully understood. We used a panel of chimeric antigen receptors (CARs) with different ligand binding affinities to induce a range of signaling strengths to model differential T cell receptor signaling at the time of HIV-1 infection. Stimulation of T cell lines or primary CD4+ T cells expressing chimeric antigen receptors supported HIV-1 infection regardless of affinity for ligand; however, only signaling by the highest affinity receptor facilitated HIV-1 expression. Activation of chimeric antigen receptors that had intermediate and low binding affinities did not support provirus transcription, suggesting that a minimal signal is required for optimal HIV-1 expression. In addition, strong signaling at the time of infection produced a latent population that was readily inducible, whereas latent cells generated in response to weaker signals were not easily reversed. Chromatin immunoprecipitation showed HIV-1 transcription was limited by transcriptional elongation and that robust signaling decreased the presence of negative elongation factor, a pausing factor, by more than 80%. These studies demonstrate that T cell signaling influences HIV-1 infection and the establishment of different subsets of latently infected cells, which may have implications for targeting the HIV-1 reservoir. Activation of CD4+ T cells facilitates HIV-1 infection; however, whether there are minimal signals required for the establishment of infection, replication, and latency has not been explored. To determine how T cell signaling influences HIV-1 infection and the generation of latently infected cells, we used chimeric antigen receptors to create a tunable model. Stronger signals result in robust HIV-1 expression and an inducible latent population. Minimal signals predispose cells towards latent infections that are refractory to reversal. We discovered that repression of HIV-1 transcription immediately after infection is due to RNA polymerase II pausing and inefficient transcription elongation. These studies demonstrate that signaling events influence the course of HIV-1 infection and have implications for cure strategies. They also provide a mechanistic explanation for why a significant portion of the HIV-1 latent reservoir is not responsive to latency reversing agents which function by modifying chromatin.
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Affiliation(s)
- Matthew Gagne
- Department of Microbiology, Boston University School of Medicine, Boston, MA, United States of America
| | - Daniel Michaels
- Department of Microbiology, Boston University School of Medicine, Boston, MA, United States of America
- Department of Medicine, Section of Infectious Diseases, Boston University Medical Center, Boston, MA, United States of America
| | - Gillian M. Schiralli Lester
- Department of Pediatrics, Neonatology, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY, United States of America
| | - Suryaram Gummuluru
- Department of Microbiology, Boston University School of Medicine, Boston, MA, United States of America
| | - Wilson W. Wong
- Department of Biomedical Engineering, Boston University, Boston, MA, United States of America
- Biological Design Center, Boston University, Boston, MA, United States of America
| | - Andrew J. Henderson
- Department of Microbiology, Boston University School of Medicine, Boston, MA, United States of America
- Department of Medicine, Section of Infectious Diseases, Boston University Medical Center, Boston, MA, United States of America
- * E-mail:
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22
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Abstract
Current primary cell models for HIV latency correlate poorly with the reactivation behavior of patient cells. We have developed a new model, called QUECEL, which generates a large and homogenous population of latently infected CD4+ memory cells. By purifying HIV-infected cells and inducing cell quiescence with a defined cocktail of cytokines, we have eliminated the largest problems with previous primary cell models of HIV latency: variable infection levels, ill-defined polarization states, and inefficient shutdown of cellular transcription. Latency reversal in the QUECEL model by a wide range of agents correlates strongly with RNA induction in patient samples. This scalable and highly reproducible model of HIV latency will permit detailed analysis of cellular mechanisms controlling HIV latency and reactivation. The latent HIV reservoir is generated following HIV infection of activated effector CD4 T cells, which then transition to a memory phenotype. Here, we describe an ex vivo method, called QUECEL (quiescent effector cell latency), that mimics this process efficiently and allows production of large numbers of latently infected CD4+ T cells. Naïve CD4+ T cells were polarized into the four major T cell subsets (Th1, Th2, Th17, and Treg) and subsequently infected with a single-round reporter virus which expressed GFP/CD8a. The infected cells were purified and coerced into quiescence using a defined cocktail of cytokines, including tumor growth factor beta, interleukin-10 (IL-10), and IL-8, producing a homogeneous population of latently infected cells. Flow cytometry and transcriptome sequencing (RNA-Seq) demonstrated that the cells maintained the correct polarization phenotypes and had withdrawn from the cell cycle. Key pathways and gene sets enriched during transition from quiescence to reactivation include E2F targets, G2M checkpoint, estrogen response late gene expression, and c-myc targets. Reactivation of HIV by latency-reversing agents (LRAs) closely mimics RNA induction profiles seen in cells from well-suppressed HIV patient samples using the envelope detection of in vitro transcription sequencing (EDITS) assay. Since homogeneous populations of latently infected cells can be recovered, the QUECEL model has an excellent signal-to-noise ratio and has been extremely consistent and reproducible in numerous experiments performed during the last 4 years. The ease, efficiency, and accuracy of the mimicking of physiological conditions make the QUECEL model a robust and reproducible tool to study the molecular mechanisms underlying HIV latency.
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23
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Cardamone MD, Tanasa B, Cederquist CT, Huang J, Mahdaviani K, Li W, Rosenfeld MG, Liesa M, Perissi V. Mitochondrial Retrograde Signaling in Mammals Is Mediated by the Transcriptional Cofactor GPS2 via Direct Mitochondria-to-Nucleus Translocation. Mol Cell 2019; 69:757-772.e7. [PMID: 29499132 DOI: 10.1016/j.molcel.2018.01.037] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 12/15/2017] [Accepted: 01/29/2018] [Indexed: 12/24/2022]
Abstract
As most of the mitochondrial proteome is encoded in the nucleus, mitochondrial functions critically depend on nuclear gene expression and bidirectional mito-nuclear communication. However, mitochondria-to-nucleus communication pathways in mammals are incompletely understood. Here, we identify G-Protein Pathway Suppressor 2 (GPS2) as a mediator of mitochondrial retrograde signaling and a transcriptional activator of nuclear-encoded mitochondrial genes. GPS2-regulated translocation from mitochondria to nucleus is essential for the transcriptional activation of a nuclear stress response to mitochondrial depolarization and for supporting basal mitochondrial biogenesis in differentiating adipocytes and brown adipose tissue (BAT) from mice. In the nucleus, GPS2 recruitment to target gene promoters regulates histone H3K9 demethylation and RNA POL2 activation through inhibition of Ubc13-mediated ubiquitination. These findings, together, reveal an additional layer of regulation of mitochondrial gene transcription, uncover a direct mitochondria-nuclear communication pathway, and indicate that GPS2 retrograde signaling is a key component of the mitochondrial stress response in mammals.
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Affiliation(s)
- Maria Dafne Cardamone
- Biochemistry Department, Boston University School of Medicine, Boston, MA 02118, USA
| | - Bogdan Tanasa
- Howard Hughes Medical Institute, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Carly T Cederquist
- Biochemistry Department, Boston University School of Medicine, Boston, MA 02118, USA
| | - Jiawen Huang
- Biochemistry Department, Boston University School of Medicine, Boston, MA 02118, USA
| | - Kiana Mahdaviani
- Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA
| | - Wenbo Li
- Howard Hughes Medical Institute, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Michael G Rosenfeld
- Howard Hughes Medical Institute, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Marc Liesa
- Department of Medicine, Division of Endocrinology and Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Valentina Perissi
- Biochemistry Department, Boston University School of Medicine, Boston, MA 02118, USA.
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24
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Agosto LM, Henderson AJ. CD4 + T Cell Subsets and Pathways to HIV Latency. AIDS Res Hum Retroviruses 2018; 34:780-789. [PMID: 29869531 DOI: 10.1089/aid.2018.0105] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Latent infection of CD4+ T cells is the main barrier to eradicating HIV-1 infection from infected patients. The cellular and molecular mechanisms involved in the establishment and maintenance of latent infection are directly linked to the transcriptional program of the different CD4+ T cell subsets targeted by the virus. In this review, we provide an overview of how T cell activation, T cell differentiation into functional subsets, and the mode of initial viral infection influence HIV proviral transcription and entry into latency.
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Affiliation(s)
- Luis M. Agosto
- Section of Infectious Diseases, Department of Medicine, Boston University Medical Center, Boston, Massachusetts
| | - Andrew J. Henderson
- Section of Infectious Diseases, Department of Medicine, Boston University Medical Center, Boston, Massachusetts
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25
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RNA Polymerase II Transcription Attenuation at the Yeast DNA Repair Gene, DEF1, Involves Sen1-Dependent and Polyadenylation Site-Dependent Termination. G3-GENES GENOMES GENETICS 2018; 8:2043-2058. [PMID: 29686108 PMCID: PMC5982831 DOI: 10.1534/g3.118.200072] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Termination of RNA Polymerase II (Pol II) activity serves a vital cellular role by separating ubiquitous transcription units and influencing RNA fate and function. In the yeast Saccharomyces cerevisiae, Pol II termination is carried out by cleavage and polyadenylation factor (CPF-CF) and Nrd1-Nab3-Sen1 (NNS) complexes, which operate primarily at mRNA and non-coding RNA genes, respectively. Premature Pol II termination (attenuation) contributes to gene regulation, but there is limited knowledge of its prevalence and biological significance. In particular, it is unclear how much crosstalk occurs between CPF-CF and NNS complexes and how Pol II attenuation is modulated during stress adaptation. In this study, we have identified an attenuator in the DEF1 DNA repair gene, which includes a portion of the 5′-untranslated region (UTR) and upstream open reading frame (ORF). Using a plasmid-based reporter gene system, we conducted a genetic screen of 14 termination mutants and their ability to confer Pol II read-through defects. The DEF1 attenuator behaved as a hybrid terminator, relying heavily on CPF-CF and Sen1 but without Nrd1 and Nab3 involvement. Our genetic selection identified 22 cis-acting point mutations that clustered into four regions, including a polyadenylation site efficiency element that genetically interacts with its cognate binding-protein Hrp1. Outside of the reporter gene context, a DEF1 attenuator mutant increased mRNA and protein expression, exacerbating the toxicity of a constitutively active Def1 protein. Overall, our data support a biologically significant role for transcription attenuation in regulating DEF1 expression, which can be modulated during the DNA damage response.
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26
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Contreras X, Salifou K, Sanchez G, Helsmoortel M, Beyne E, Bluy L, Pelletier S, Rousset E, Rouquier S, Kiernan R. Nuclear RNA surveillance complexes silence HIV-1 transcription. PLoS Pathog 2018; 14:e1006950. [PMID: 29554134 PMCID: PMC5875879 DOI: 10.1371/journal.ppat.1006950] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 03/29/2018] [Accepted: 02/26/2018] [Indexed: 12/11/2022] Open
Abstract
Expression from the HIV-1 LTR can be repressed in a small population of cells, which contributes to the latent reservoir. The factors mediating this repression have not been clearly elucidated. We have identified a network of nuclear RNA surveillance factors that act as effectors of HIV-1 silencing. RRP6, MTR4, ZCCHC8 and ZFC3H1 physically associate with the HIV-1 TAR region and repress transcriptional output and recruitment of RNAPII to the LTR. Knock-down of these factors in J-Lat cells increased the number of GFP-positive cells, with a concomitant increase in histone marks associated with transcriptional activation. Loss of these factors increased HIV-1 expression from infected PBMCs and led to reactivation of HIV-1 from latently infected PBMCs. These findings identify a network of novel transcriptional repressors that control HIV-1 expression and which could open new avenues for therapeutic intervention. Following integration into the host genome, HIV-1 expression is silenced in a small population of cells, largely via epigenetic mechanisms that repress LTR-mediated transcription. This repression creates a reservoir of cells that prevent an effective cure. It is unclear how and why integrated HIV-1 becomes transcriptionally silenced. Here, we identify a network of nuclear RNA surveillance factors that repress HIV transcription and whose loss increases virus expression in latently infected J-Lat and PBMCs. These findings advance the understanding of transcriptional repression of HIV-1.
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Affiliation(s)
- Xavier Contreras
- Institut de Génétique Humaine, CNRS-University of Montpellier UMR9002, Gene Regulation Laboratory, 141 rue de la cardonille, Montpellier, France
- * E-mail: (XC); (RK)
| | - Kader Salifou
- Institut de Génétique Humaine, CNRS-University of Montpellier UMR9002, Gene Regulation Laboratory, 141 rue de la cardonille, Montpellier, France
| | - Gabriel Sanchez
- Institut de Génétique Humaine, CNRS-University of Montpellier UMR9002, Gene Regulation Laboratory, 141 rue de la cardonille, Montpellier, France
| | - Marion Helsmoortel
- Institut de Génétique Humaine, CNRS-University of Montpellier UMR9002, Gene Regulation Laboratory, 141 rue de la cardonille, Montpellier, France
| | - Emmanuelle Beyne
- Institut de Génétique Humaine, CNRS-University of Montpellier UMR9002, Gene Regulation Laboratory, 141 rue de la cardonille, Montpellier, France
| | - Lisa Bluy
- Institut de Génétique Humaine, CNRS-University of Montpellier UMR9002, Gene Regulation Laboratory, 141 rue de la cardonille, Montpellier, France
| | - Stéphane Pelletier
- Institut de Génétique Humaine, CNRS-University of Montpellier UMR9002, Gene Regulation Laboratory, 141 rue de la cardonille, Montpellier, France
| | - Emilie Rousset
- Institut de Génétique Humaine, CNRS-University of Montpellier UMR9002, Gene Regulation Laboratory, 141 rue de la cardonille, Montpellier, France
| | - Sylvie Rouquier
- Institut de Génétique Humaine, CNRS-University of Montpellier UMR9002, Gene Regulation Laboratory, 141 rue de la cardonille, Montpellier, France
| | - Rosemary Kiernan
- Institut de Génétique Humaine, CNRS-University of Montpellier UMR9002, Gene Regulation Laboratory, 141 rue de la cardonille, Montpellier, France
- * E-mail: (XC); (RK)
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27
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Multiple Inhibitory Factors Act in the Late Phase of HIV-1 Replication: a Systematic Review of the Literature. Microbiol Mol Biol Rev 2018; 82:82/1/e00051-17. [PMID: 29321222 DOI: 10.1128/mmbr.00051-17] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The use of lentiviral vectors for therapeutic purposes has shown promising results in clinical trials. The ability to produce a clinical-grade vector at high yields remains a critical issue. One possible obstacle could be cellular factors known to inhibit human immunodeficiency virus (HIV). To date, five HIV restriction factors have been identified, although it is likely that more factors are involved in the complex HIV-cell interaction. Inhibitory factors that have an adverse effect but do not abolish virus production are much less well described. Therefore, a gap exists in the knowledge of inhibitory factors acting late in the HIV life cycle (from transcription to infection of a new cell), which are relevant to the lentiviral vector production process. The objective was to review the HIV literature to identify cellular factors previously implicated as inhibitors of the late stages of lentivirus production. A search for publications was conducted on MEDLINE via the PubMed interface, using the keyword sequence "HIV restriction factor" or "HIV restriction" or "inhibit HIV" or "repress HIV" or "restrict HIV" or "suppress HIV" or "block HIV," with a publication date up to 31 December 2016. Cited papers from the identified records were investigated, and additional database searches were performed. A total of 260 candidate inhibitory factors were identified. These factors have been identified in the literature as having a negative impact on HIV replication. This study identified hundreds of candidate inhibitory factors for which the impact of modulating their expression in lentiviral vector production could be beneficial.
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28
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Ne E, Palstra RJ, Mahmoudi T. Transcription: Insights From the HIV-1 Promoter. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2018; 335:191-243. [DOI: 10.1016/bs.ircmb.2017.07.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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29
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Harwig A, Landick R, Berkhout B. The Battle of RNA Synthesis: Virus versus Host. Viruses 2017; 9:v9100309. [PMID: 29065472 PMCID: PMC5691660 DOI: 10.3390/v9100309] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 10/19/2017] [Accepted: 10/20/2017] [Indexed: 12/13/2022] Open
Abstract
Transcription control is the foundation of gene regulation. Whereas a cell is fully equipped for this task, viruses often depend on the host to supply tools for their transcription program. Over the course of evolution and adaptation, viruses have found diverse ways to optimally exploit cellular host processes such as transcription to their own benefit. Just as cells are increasingly understood to employ nascent RNAs in transcription regulation, recent discoveries are revealing how viruses use nascent RNAs to benefit their own gene expression. In this review, we first outline the two different transcription programs used by viruses, i.e., transcription (DNA-dependent) and RNA-dependent RNA synthesis. Subsequently, we use the distinct stages (initiation, elongation, termination) to describe the latest insights into nascent RNA-mediated regulation in the context of each relevant stage.
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Affiliation(s)
- Alex Harwig
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
| | - Robert Landick
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
| | - Ben Berkhout
- Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands.
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30
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Tian J, Zhu J, Yi Y, Li C, Zhang Y, Zhao Y, Pan C, Xiang S, Li X, Li G, Newman JW, Feng X, Liu J, Han J, Wang L, Gao Y, La Frano MR, Liang A. Dose-related liver injury of Geniposide associated with the alteration in bile acid synthesis and transportation. Sci Rep 2017; 7:8938. [PMID: 28827769 PMCID: PMC5566417 DOI: 10.1038/s41598-017-09131-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 07/17/2017] [Indexed: 12/23/2022] Open
Abstract
Fructus Gardenia (FG), containing the major active constituent Geniposide, is widely used in China for medicinal purposes. Currently, clinical reports of FG toxicity have not been published, however, animal studies have shown FG or Geniposide can cause hepatotoxicity in rats. We investigated Geniposide-induced hepatic injury in male Sprague-Dawley rats after 3-day intragastric administration of 100 mg/kg or 300 mg/kg Geniposide. Changes in hepatic histomorphology, serum liver enzyme, serum and hepatic bile acid profiles, and hepatic bile acid synthesis and transportation gene expression were measured. The 300 mg/kg Geniposide caused liver injury evidenced by pathological changes and increases in serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and γ-glutamytransferase (γ-GT). While liver, but not sera, total bile acids (TBAs) were increased 75% by this dose, dominated by increases in taurine-conjugated bile acids (t-CBAs). The 300 mg/kg Geniposide also down-regulated expression of Farnesoid X receptor (FXR), small heterodimer partner (SHP) and bile salt export pump (BSEP). In conclusion, 300 mg/kg Geniposide can induce liver injury with associated changes in bile acid regulating genes, leading to an accumulation of taurine conjugates in the rat liver. Taurocholic acid (TCA), taurochenodeoxycholic acid (TCDCA) as well as tauro-α-muricholic acid (T-α-MCA) are potential markers for Geniposide-induced hepatic damage.
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Affiliation(s)
- Jingzhuo Tian
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Jingjing Zhu
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Yan Yi
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Chunying Li
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Yushi Zhang
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Yong Zhao
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Chen Pan
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Shixie Xiang
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Xiaolong Li
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Guiqin Li
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - John W Newman
- NIH West Coast Metabolomics Center, Davis, CA95616, USA
- United States Department of Agriculture, Agricultural Research Service, Western Human Nutrition Research Center, Davis, CA95616, USA
- Department of Nutrition, University of California-Davis, Davis, CA95616, USA
| | - Xiaoyi Feng
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Jing Liu
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Jiayin Han
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Lianmei Wang
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Yue Gao
- Beijing Institute of Radiation Medicine, Beijing, China
| | - Michael R La Frano
- NIH West Coast Metabolomics Center, Davis, CA95616, USA
- Department of Food Science and Nutrition, California Polytechnic State University, San Luis Obispo, CA, USA
| | - Aihua Liang
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China.
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31
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Graci JD, Michaels D, Chen G, Schiralli Lester GM, Nodder S, Weetall M, Karp GM, Gu Z, Colacino JM, Henderson AJ. Identification of benzazole compounds that induce HIV-1 transcription. PLoS One 2017; 12:e0179100. [PMID: 28658263 PMCID: PMC5489165 DOI: 10.1371/journal.pone.0179100] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 05/24/2017] [Indexed: 02/07/2023] Open
Abstract
Despite advances in antiretroviral therapy, HIV-1 infection remains incurable in patients and continues to present a significant public health burden worldwide. While a number of factors contribute to persistent HIV-1 infection in patients, the presence of a stable, long-lived reservoir of latent provirus represents a significant hurdle in realizing an effective cure. One potential strategy to eliminate HIV-1 reservoirs in patients is reactivation of latent provirus with latency reversing agents in combination with antiretroviral therapy, a strategy termed "shock and kill". This strategy has shown limited clinical effectiveness thus far, potentially due to limitations of the few therapeutics currently available. We have identified a novel class of benzazole compounds effective at inducing HIV-1 expression in several cellular models. These compounds do not act via histone deacetylase inhibition or T cell activation, and show specificity in activating HIV-1 in vitro. Initial exploration of structure-activity relationships and pharmaceutical properties indicates that these compounds represent a potential scaffold for development of more potent HIV-1 latency reversing agents.
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Affiliation(s)
- Jason D. Graci
- PTC Therapeutics, Inc., South Plainfield, New Jersey, United States of America
| | - Daniel Michaels
- Department of Medicine and Microbiology, Section of Infectious Diseases, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Guangming Chen
- PTC Therapeutics, Inc., South Plainfield, New Jersey, United States of America
| | - Gillian M. Schiralli Lester
- Department of Pediatrics, Neonatology, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, New York, United States of America
| | - Sarah Nodder
- Department of Medicine and Microbiology, Section of Infectious Diseases, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Marla Weetall
- PTC Therapeutics, Inc., South Plainfield, New Jersey, United States of America
| | - Gary M. Karp
- PTC Therapeutics, Inc., South Plainfield, New Jersey, United States of America
| | - Zhengxian Gu
- PTC Therapeutics, Inc., South Plainfield, New Jersey, United States of America
| | - Joseph M. Colacino
- PTC Therapeutics, Inc., South Plainfield, New Jersey, United States of America
| | - Andrew J. Henderson
- Department of Medicine and Microbiology, Section of Infectious Diseases, Boston University School of Medicine, Boston, Massachusetts, United States of America
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32
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Kuzmina A, Krasnopolsky S, Taube R. Super elongation complex promotes early HIV transcription and its function is modulated by P-TEFb. Transcription 2017; 8:133-149. [PMID: 28340332 DOI: 10.1080/21541264.2017.1295831] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Early work on the control of transcription of the human immunodeficiency virus (HIV) laid the foundation for our current knowledge of how RNA Polymerase II is released from promoter-proximal pausing sites and transcription elongation is enhanced. The viral Tat activator recruits Positive Transcription Elongation Factor b (P-TEFb) and Super Elongation Complex (SEC) that jointly drive transcription elongation. While substantial progress in understanding the role of SEC in HIV gene transcription elongation has been obtained, defining of the mechanisms that govern SEC functions is still limited, and the role of SEC in controlling HIV transcription in the absence of Tat is less clear. Here we revisit the contribution of SEC in early steps of HIV gene transcription. In the absence of Tat, the AF4/FMR2 Family member 4 (AFF4) of SEC efficiently activates HIV transcription, while gene activation by its homolog AFF1 is substantially lower. Differential recruitment to the HIV promoter and association with Human Polymerase-Associated Factor complex (PAFc) play key role in this functional distinction between AFF4 and AFF1. Moreover, while depletion of cyclin T1 expression has subtle effects on HIV gene transcription in the absence of Tat, knockout (KO) of AFF1, AFF4, or both proteins slightly repress this early step of viral transcription. Upon Tat expression, HIV transcription reaches optimal levels despite KO of AFF1 or AFF4 expression. However, double AFF1/AFF4 KO completely diminishes Tat trans-activation. Significantly, our results show that P-TEFb phosphorylates AFF4 and modulates SEC assembly, AFF1/4 dimerization and recruitment to the viral promoter. We conclude that SEC promotes both early steps of HIV transcription in the absence of Tat, as well as elongation of transcription, when Tat is expressed. Significantly, SEC functions are modulated by P-TEFb.
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Affiliation(s)
- Alona Kuzmina
- a The Shraga Segal Department of Microbiology Immunology and Genetics Faculty of Health Sciences , Ben-Gurion University of the Negev , Israel
| | - Simona Krasnopolsky
- a The Shraga Segal Department of Microbiology Immunology and Genetics Faculty of Health Sciences , Ben-Gurion University of the Negev , Israel
| | - Ran Taube
- a The Shraga Segal Department of Microbiology Immunology and Genetics Faculty of Health Sciences , Ben-Gurion University of the Negev , Israel
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Assays for precise quantification of total (including short) and elongated HIV-1 transcripts. J Virol Methods 2016; 242:1-8. [PMID: 28034670 DOI: 10.1016/j.jviromet.2016.12.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 12/21/2016] [Accepted: 12/23/2016] [Indexed: 11/24/2022]
Abstract
Despite intensive study, it is unclear which mechanisms are responsible for latent HIV infection in vivo. One potential mechanism is inhibition of HIV transcriptional elongation, which results in short abortive transcripts containing the trans-activation response (TAR) region. Because the relative levels of total (including short) and processive transcripts provide measures of HIV transcriptional initiation and elongation, there is a compelling need for techniques that accurately measure both. Nonetheless, prior assays for total transcripts have been semi-quantitative and have seen limited application to patient samples. This manuscript reports the validation of quantitative reverse transcription (RT) droplet digital PCR assays for measurement of total (TAR) and processive (R-U5/gag) HIV transcripts. Traditional RT priming strategies can efficiently detect the TAR region on long HIV transcripts but detect <4% of true short transcripts. The TAR assay presented here utilizes an initial polyadenylation step, which provides an accessible RT priming site and detects short and long transcripts with approximately equal efficiency (70%). By applying these assays to blood samples from 8 ART-treated HIV+ individuals, total HIV transcripts were detected at levels >10-fold higher than elongated transcripts, implying a substantial block to transcriptional elongation in vivo. This approach may be applied to other difficult-to-prime RNA targets.
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The Multifaceted Contributions of Chromatin to HIV-1 Integration, Transcription, and Latency. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 328:197-252. [PMID: 28069134 DOI: 10.1016/bs.ircmb.2016.08.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The capacity of the human immunodeficiency virus (HIV-1) to establish latent infections constitutes a major barrier to the development of a cure for HIV-1. In latent infection, replication competent HIV-1 provirus is integrated within the host genome but remains silent, masking the infected cells from the activity of the host immune response. Despite the progress in elucidating the molecular players that regulate HIV-1 gene expression, the mechanisms driving the establishment and maintenance of latency are still not fully understood. Transcription from the HIV-1 genome occurs in the context of chromatin and is subjected to the same regulatory mechanisms that drive cellular gene expression. Much like in eukaryotic genes, the nucleosomal landscape of the HIV-1 promoter and its position within genomic chromatin are determinants of its transcriptional activity. Understanding the multilayered chromatin-mediated mechanisms that underpin HIV-1 integration and expression is of utmost importance for the development of therapeutic strategies aimed at reducing the pool of latently infected cells. In this review, we discuss the impact of chromatin structure on viral integration, transcriptional regulation and latency, and the host factors that influence HIV-1 replication by regulating chromatin organization. Finally, we describe therapeutic strategies under development to target the chromatin-HIV-1 interplay.
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Vos SM, Pöllmann D, Caizzi L, Hofmann KB, Rombaut P, Zimniak T, Herzog F, Cramer P. Architecture and RNA binding of the human negative elongation factor. eLife 2016; 5. [PMID: 27282391 PMCID: PMC4940160 DOI: 10.7554/elife.14981] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 06/09/2016] [Indexed: 11/30/2022] Open
Abstract
Transcription regulation in metazoans often involves promoter-proximal pausing of RNA polymerase (Pol) II, which requires the 4-subunit negative elongation factor (NELF). Here we discern the functional architecture of human NELF through X-ray crystallography, protein crosslinking, biochemical assays, and RNA crosslinking in cells. We identify a NELF core subcomplex formed by conserved regions in subunits NELF-A and NELF-C, and resolve its crystal structure. The NELF-AC subcomplex binds single-stranded nucleic acids in vitro, and NELF-C associates with RNA in vivo. A positively charged face of NELF-AC is involved in RNA binding, whereas the opposite face of the NELF-AC subcomplex binds NELF-B. NELF-B is predicted to form a HEAT repeat fold, also binds RNA in vivo, and anchors the subunit NELF-E, which is confirmed to bind RNA in vivo. These results reveal the three-dimensional architecture and three RNA-binding faces of NELF. DOI:http://dx.doi.org/10.7554/eLife.14981.001
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Affiliation(s)
- Seychelle M Vos
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - David Pöllmann
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Gene Center Munich, Ludwig-Maximilians-Universität München, Munich, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Livia Caizzi
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Katharina B Hofmann
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Pascaline Rombaut
- Gene Center Munich, Ludwig-Maximilians-Universität München, Munich, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Tomasz Zimniak
- Gene Center Munich, Ludwig-Maximilians-Universität München, Munich, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Franz Herzog
- Gene Center Munich, Ludwig-Maximilians-Universität München, Munich, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Patrick Cramer
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
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36
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Zhang J, Landick R. A Two-Way Street: Regulatory Interplay between RNA Polymerase and Nascent RNA Structure. Trends Biochem Sci 2016; 41:293-310. [PMID: 26822487 DOI: 10.1016/j.tibs.2015.12.009] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 12/21/2015] [Accepted: 12/22/2015] [Indexed: 02/06/2023]
Abstract
The vectorial (5'-to-3' at varying velocity) synthesis of RNA by cellular RNA polymerases (RNAPs) creates a rugged kinetic landscape, demarcated by frequent, sometimes long-lived, pauses. In addition to myriad gene-regulatory roles, these pauses temporally and spatially program the co-transcriptional, hierarchical folding of biologically active RNAs. Conversely, these RNA structures, which form inside or near the RNA exit channel, interact with the polymerase and adjacent protein factors to influence RNA synthesis by modulating pausing, termination, antitermination, and slippage. Here, we review the evolutionary origin, mechanistic underpinnings, and regulatory consequences of this interplay between RNAP and nascent RNA structure. We categorize and rationalize the extensive linkage between the transcriptional machinery and its product, and provide a framework for future studies.
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Affiliation(s)
- Jinwei Zhang
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA.
| | - Robert Landick
- Departments of Biochemistry and Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA.
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37
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Burton ZF. The Old and New Testaments of gene regulation. Evolution of multi-subunit RNA polymerases and co-evolution of eukaryote complexity with the RNAP II CTD. Transcription 2015; 5:e28674. [PMID: 25764332 PMCID: PMC4215175 DOI: 10.4161/trns.28674] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
I relate a story of genesis told from the point of view of multi-subunit RNA polymerases (RNAPs) including an Old Testament (core RNAP motifs in all cellular life) and a New Testament (the RNAP II heptad repeat carboxy terminal domain (CTD) and CTD interactome in eukarya). The Old Testament: at their active site, one class of eukaryotic interfering RNAP and ubiquitous multi-subunit RNAPs each have two-double psi β barrel (DPBB) motifs (a distinct pattern for compact 6-β sheet barrels). Between β sheets 2 and 3 of the β subunit type DPBB of all multi-subunit RNAPs is a sandwich barrel hybrid motif (SBHM) that interacts with conserved initiation and elongation factors required to utilize a DNA template. Analysis of RNAP core protein motifs, therefore, indicates that RNAP evolution can be traced from the RNA-protein world to LUCA (the last universal common ancestor) branching to LECA (the last eukaryotic common ancestor) and to the present day, spanning about 4 billion years. The New Testament: in the eukaryotic lineage, I posit that splitting RNAP functions into RNAPs I, II and III and innovations developed around the CTD heptad repeat of RNAP II and the extensive CTD interactome helps to describe how greater structural, cell cycle, epigenetic and signaling complexity co-evolved in eukaryotes relative to eubacteria and archaea.
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Affiliation(s)
- Zachary F Burton
- a Department of Biochemistry and Molecular Biology; Michigan State University; East Lansing, MI USA
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38
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Impact of Chromatin on HIV Replication. Genes (Basel) 2015; 6:957-76. [PMID: 26437430 PMCID: PMC4690024 DOI: 10.3390/genes6040957] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 09/14/2015] [Accepted: 09/22/2015] [Indexed: 12/22/2022] Open
Abstract
Chromatin influences Human Immunodeficiency Virus (HIV) integration and replication. This review highlights critical host factors that influence chromatin structure and organization and that also impact HIV integration, transcriptional regulation and latency. Furthermore, recent attempts to target chromatin associated factors to reduce the HIV proviral load are discussed.
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39
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Bose D, Gagnon J, Chebloune Y. Comparative Analysis of Tat-Dependent and Tat-Deficient Natural Lentiviruses. Vet Sci 2015; 2:293-348. [PMID: 29061947 PMCID: PMC5644649 DOI: 10.3390/vetsci2040293] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 08/24/2015] [Accepted: 08/24/2015] [Indexed: 01/10/2023] Open
Abstract
The emergence of human immunodeficiency virus (HIV) causing acquired immunodeficiency syndrome (AIDS) in infected humans has resulted in a global pandemic that has killed millions. HIV-1 and HIV-2 belong to the lentivirus genus of the Retroviridae family. This genus also includes viruses that infect other vertebrate animals, among them caprine arthritis-encephalitis virus (CAEV) and Maedi-Visna virus (MVV), the prototypes of a heterogeneous group of viruses known as small ruminant lentiviruses (SRLVs), affecting both goat and sheep worldwide. Despite their long host-SRLV natural history, SRLVs were never found to be responsible for immunodeficiency in contrast to primate lentiviruses. SRLVs only replicate productively in monocytes/macrophages in infected animals but not in CD4+ T cells. The focus of this review is to examine and compare the biological and pathological properties of SRLVs as prototypic Tat-independent lentiviruses with HIV-1 as prototypic Tat-dependent lentiviruses. Results from this analysis will help to improve the understanding of why and how these two prototypic lentiviruses evolved in opposite directions in term of virulence and pathogenicity. Results may also help develop new strategies based on the attenuation of SRLVs to control the highly pathogenic HIV-1 in humans.
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Affiliation(s)
- Deepanwita Bose
- Pathogénèse et Vaccination Lentivirales, PAVAL Lab., Université Joseph Fourier Grenoble 1, Bat. NanoBio2, 570 rue de la Chimie, BP 53, 38041, Grenoble Cedex 9, France.
| | - Jean Gagnon
- Pathogénèse et Vaccination Lentivirales, PAVAL Lab., Université Joseph Fourier Grenoble 1, Bat. NanoBio2, 570 rue de la Chimie, BP 53, 38041, Grenoble Cedex 9, France.
| | - Yahia Chebloune
- Pathogénèse et Vaccination Lentivirales, PAVAL Lab., Université Joseph Fourier Grenoble 1, Bat. NanoBio2, 570 rue de la Chimie, BP 53, 38041, Grenoble Cedex 9, France.
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40
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Scheidegger A, Nechaev S. RNA polymerase II pausing as a context-dependent reader of the genome. Biochem Cell Biol 2015; 94:82-92. [PMID: 26555214 DOI: 10.1139/bcb-2015-0045] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The RNA polymerase II (Pol II) transcribes all mRNA genes in eukaryotes and is among the most highly regulated enzymes in the cell. The classic model of mRNA gene regulation involves recruitment of the RNA polymerase to gene promoters in response to environmental signals. Higher eukaryotes have an additional ability to generate multiple cell types. This extra level of regulation enables each cell to interpret the same genome by committing to one of the many possible transcription programs and executing it in a precise and robust manner. Whereas multiple mechanisms are implicated in cell type-specific transcriptional regulation, how one genome can give rise to distinct transcriptional programs and what mechanisms activate and maintain the appropriate program in each cell remains unclear. This review focuses on the process of promoter-proximal Pol II pausing during early transcription elongation as a key step in context-dependent interpretation of the metazoan genome. We highlight aspects of promoter-proximal Pol II pausing, including its interplay with epigenetic mechanisms, that may enable cell type-specific regulation, and emphasize some of the pertinent questions that remain unanswered and open for investigation.
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Affiliation(s)
- Adam Scheidegger
- Department of Basic Sciences, University of North Dakota School of Medicine, Grand Forks, ND 58201, USA.,Department of Basic Sciences, University of North Dakota School of Medicine, Grand Forks, ND 58201, USA
| | - Sergei Nechaev
- Department of Basic Sciences, University of North Dakota School of Medicine, Grand Forks, ND 58201, USA.,Department of Basic Sciences, University of North Dakota School of Medicine, Grand Forks, ND 58201, USA
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41
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Kaczmarek Michaels K, Wolschendorf F, Schiralli Lester GM, Natarajan M, Kutsch O, Henderson AJ. RNAP II processivity is a limiting step for HIV-1 transcription independent of orientation to and activity of endogenous neighboring promoters. Virology 2015; 486:7-14. [PMID: 26379089 DOI: 10.1016/j.virol.2015.08.027] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 08/09/2015] [Accepted: 08/25/2015] [Indexed: 11/29/2022]
Abstract
Since HIV-1 has a propensity to integrate into actively expressed genes, transcriptional interference from neighboring host promoters has been proposed to contribute to the establishment and maintenance HIV-1 latency. To gain insights into how endogenous promoters influence HIV-1 transcription we utilized a set of inducible T cell lines and characterized whether there were correlations between expression of endogenous genes, provirus and long terminal repeat architecture. We show that neighboring promoters are active but have minimal impact on HIV-1 transcription, in particular, expression of the endogenous gene did not prevent expression of HIV-1 following induction of latent provirus. We also demonstrate that releasing paused RNAP II by diminishing negative elongation factor (NELF) is sufficient to reactivate transcriptionally repressed HIV-1 provirus regardless of the integration site and orientation of the provirus suggesting that NELF-mediated RNAP II pausing is a common mechanism of maintaining HIV-1 latency.
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Affiliation(s)
- Katarzyna Kaczmarek Michaels
- Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA; Graduate Program in Molecular and Translational Medicine, Boston University School of Medicine, Boston, MA 02118, USA
| | - Frank Wolschendorf
- Department of Medicine, Division of Infectious Diseases, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Gillian M Schiralli Lester
- University of Rochester Medical Center, Department of Pediatrics, Division of Neonatology, Rochester, NY 14642, USA
| | - Malini Natarajan
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Olaf Kutsch
- Department of Medicine, Division of Infectious Diseases, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Andrew J Henderson
- Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA; Graduate Program in Molecular and Translational Medicine, Boston University School of Medicine, Boston, MA 02118, USA.
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42
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Shang HT, Ding JW, Yu SY, Wu T, Zhang QL, Liang FJ. Progress and challenges in the use of latent HIV-1 reactivating agents. Acta Pharmacol Sin 2015; 36:908-16. [PMID: 26027656 DOI: 10.1038/aps.2015.22] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 02/27/2015] [Indexed: 12/30/2022] Open
Abstract
Highly active antiretroviral therapy (HAART) can effectively suppress the replication of human immunodeficiency virus-1 (HIV-1) and block disease progression. However, chronic HIV-1 infection remains incurable due to the persistence of a viral reservoir, including the transcriptionally silent provirus in CD4(+) memory T cells and the sanctuary sites that are inaccessible to drugs. Reactivation and the subsequent elimination of latent virus through virus-specific cytotoxic effects or host immune responses are critical strategies for combating the disease. Indeed, a number of latency reactivating reagents have been identified through mechanism-directed approaches and large-scale screening, including: (1) histone deacetylase inhibitors (HDACi); (2) cytokines and chemokines; (3) DNA methyltransferase inhibitors (DNMTI); (4) histone methyltransferase inhibitors (HMTI); (5) protein kinase C (PKC) activators; (6) P-TEFb activators; and (7) unclassified agents, such as disulfram. They have proved to be efficacious in latent cell line models and CD4(+) T lymphocytes from HIV-1-infected patients. This review comprehensively summarizes the recent progress and relative challenges in this field.
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43
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Budhiraja S, Liu H, Couturier J, Malovannaya A, Qin J, Lewis DE, Rice AP. Mining the human complexome database identifies RBM14 as an XPO1-associated protein involved in HIV-1 Rev function. J Virol 2015; 89:3557-67. [PMID: 25589658 PMCID: PMC4403413 DOI: 10.1128/jvi.03232-14] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 01/06/2015] [Indexed: 12/24/2022] Open
Abstract
UNLABELLED By recruiting the host protein XPO1 (CRM1), the HIV-1 Rev protein mediates the nuclear export of incompletely spliced viral transcripts. We mined data from the recently described human nuclear complexome to identify a host protein, RBM14, which associates with XPO1 and Rev and is involved in Rev function. Using a Rev-dependent p24 reporter plasmid, we found that RBM14 depletion decreased Rev activity and Rev-mediated enhancement of the cytoplasmic levels of unspliced viral transcripts. RBM14 depletion also reduced p24 expression during viral infection, indicating that RBM14 is limiting for Rev function. RBM14 has previously been shown to localize to nuclear paraspeckles, a structure implicated in retaining unspliced HIV-1 transcripts for either Rev-mediated nuclear export or degradation. We found that depletion of NEAT1 RNA, a long noncoding RNA required for paraspeckle integrity, abolished the ability of overexpressed RBM14 to enhance Rev function, indicating the dependence of RBM14 function on paraspeckle integrity. Our study extends the known host cell interactome of Rev and XPO1 and further substantiates a critical role for paraspeckles in the mechanism of action of Rev. Our study also validates the nuclear complexome as a database from which viral cofactors can be mined. IMPORTANCE This study mined a database of nuclear protein complexes to identify a cellular protein named RBM14 that is associated with XPO1 (CRM1), a nuclear protein that binds to the HIV-1 Rev protein and mediates nuclear export of incompletely spliced viral RNAs. Functional assays demonstrated that RBM14, a protein found in paraspeckle structures in the nucleus, is involved in HIV-1 Rev function. This study validates the nuclear complexome database as a reference that can be mined to identify viral cofactors.
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Affiliation(s)
- Sona Budhiraja
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA
| | - Hongbing Liu
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA
| | - Jacob Couturier
- Department of Internal Medicine, University of Texas Health Sciences Center, Houston, Texas, USA
| | - Anna Malovannaya
- Department of Biochemistry, Baylor College of Medicine, Houston, Texas, USA
| | - Jun Qin
- Department of Biochemistry, Baylor College of Medicine, Houston, Texas, USA
| | - Dorothy E Lewis
- Department of Internal Medicine, University of Texas Health Sciences Center, Houston, Texas, USA
| | - Andrew P Rice
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA
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Kaczmarek Michaels K, Natarajan M, Euler Z, Alter G, Viglianti G, Henderson AJ. Blimp-1, an intrinsic factor that represses HIV-1 proviral transcription in memory CD4+ T cells. THE JOURNAL OF IMMUNOLOGY 2015; 194:3267-74. [PMID: 25710909 DOI: 10.4049/jimmunol.1402581] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
CD4(+) T cell subsets differentially support HIV-1 replication. For example, quiescent CD4(+) memory T cells are susceptible to HIV-1 infection but do not support robust HIV-1 transcription and have been implicated as the primary reservoir of latent HIV-1. T cell transcription factors that regulate maturation potentially limit HIV-1 transcription and mediate the establishment and maintenance of HIV-1 latency. We report that B lymphocyte-induced maturation protein-1 (Blimp-1), a critical regulator of B and T cell differentiation, is highly expressed in memory CD4(+) T cells compared with naive CD4(+) T cells and represses basal and Tat-mediated HIV-1 transcription. Blimp-1 binds an IFN-stimulated response element within HIV-1 provirus, and it is displaced following T cell activation. Reduction of Blimp-1 in infected primary T cells including CD4(+) memory T cells increases RNA polymerase II processivity, histone acetylation, and baseline HIV-1 transcription. Therefore, the transcriptional repressor, Blimp-1, is an intrinsic factor that predisposes CD4(+) memory T cells to latent HIV-1 infection.
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Affiliation(s)
- Katarzyna Kaczmarek Michaels
- Section of Infectious Diseases, Department of Medicine, Boston University School of Medicine, Boston, MA 02118; Graduate Program in Molecular and Translational Medicine, Boston University School of Medicine, Boston, MA 02118
| | | | - Zelda Euler
- Ragon Institute of MGH, MIT and Harvard University, Boston, MA 02139; and
| | - Galit Alter
- Ragon Institute of MGH, MIT and Harvard University, Boston, MA 02139; and
| | - Gregory Viglianti
- Department of Microbiology, Boston University School of Medicine, Boston, MA 02118
| | - Andrew J Henderson
- Section of Infectious Diseases, Department of Medicine, Boston University School of Medicine, Boston, MA 02118; Graduate Program in Molecular and Translational Medicine, Boston University School of Medicine, Boston, MA 02118; Department of Microbiology, Boston University School of Medicine, Boston, MA 02118
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De Crignis E, Mahmoudi T. HIV eradication: combinatorial approaches to activate latent viruses. Viruses 2014; 6:4581-608. [PMID: 25421889 PMCID: PMC4246239 DOI: 10.3390/v6114581] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 11/01/2014] [Accepted: 11/13/2014] [Indexed: 12/11/2022] Open
Abstract
The concept of eradication of the Human Immune Deficiency Virus (HIV) from infected patients has gained much attention in the last few years. While combination Anti-Retroviral Therapy (c-ART) has been extremely effective in suppressing viral replication, it is not curative. This is due to the presence of a reservoir of latent HIV infected cells, which persist in the presence of c-ART. Recently, pharmaceutical approaches have focused on the development of molecules able to induce HIV-1 replication from latently infected cells in order to render them susceptible to viral cytopathic effects and host immune responses. Alternative pathways and transcription complexes function to regulate the activity of the HIV promoter and might serve as molecular targets for compounds to activate latent HIV. A combined therapy coupling various depressors and activators will likely be the most effective in promoting HIV replication while avoiding pleiotropic effects at the cellular level. Moreover, in light of differences among HIV subtypes and variability in integration sites, the combination of multiple agents targeting multiple pathways will increase likelihood of therapeutic effectiveness and prevent mutational escape. This review provides an overview of the mechanisms that can be targeted to induce HIV activation focusing on potential combinatorial approaches.
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Affiliation(s)
- Elisa De Crignis
- Department of Biochemistry, Erasmus University Medical Center, Rotterdam 3015 CN, The Netherlands.
| | - Tokameh Mahmoudi
- Department of Biochemistry, Erasmus University Medical Center, Rotterdam 3015 CN, The Netherlands.
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46
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Das B, Dobrowolski C, Shahir AM, Feng Z, Yu X, Sha J, Bissada NF, Weinberg A, Karn J, Ye F. Short chain fatty acids potently induce latent HIV-1 in T-cells by activating P-TEFb and multiple histone modifications. Virology 2014; 474:65-81. [PMID: 25463605 DOI: 10.1016/j.virol.2014.10.033] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 10/25/2014] [Accepted: 10/27/2014] [Indexed: 12/14/2022]
Abstract
HIV patients with severe periodontitis have high levels of residual virus in their saliva and plasma despite effective therapy (HAART). Multiple short chain fatty acids (SCFAs) from periodontal pathogens reactivate HIV-1 in both Jurkat and primary T-cell models of latency. SCFAs not only activate positive transcription elongation factor b (P-TEFb), which is an essential cellular cofactor for Tat, but can also reverse chromatin blocks by inducing histone modifications. SCFAs simultaneously increase histone acetylation by inhibiting class-1/2 histone deacetylases (HDACs) and decrease repressive histone tri-methylation at the proviral LTR by downregulating expression of the class-3 HDAC sirtuin-1 (SIRT1), and the histone methyltransferases enhancer of Zeste homolog 2 (EZH2) and suppressor of variegation 3-9 homolog 1 (SUV39H1). Our findings provide a mechanistic link between periodontal disease and enhanced HIV-1 replication, and suggest that treatment of periodontal disease, or blocking the activities of SCFAs, will have a therapeutic benefit for HIV patients.
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Affiliation(s)
- Biswajit Das
- Department of Molecular Biology and Microbiology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, United States
| | - Curtis Dobrowolski
- Department of Molecular Biology and Microbiology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, United States
| | - Abdel-Malek Shahir
- Department of Periodontics, School of Dental Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH, United States
| | - Zhimin Feng
- Department of Biological Sciences, School of Dental Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, United States
| | - Xiaolan Yu
- Department of Biological Sciences, School of Dental Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, United States
| | - Jinfeng Sha
- Department of Biological Sciences, School of Dental Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, United States
| | - Nabil F Bissada
- Department of Periodontics, School of Dental Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH, United States
| | - Aaron Weinberg
- Department of Biological Sciences, School of Dental Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, United States
| | - Jonathan Karn
- Department of Molecular Biology and Microbiology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, United States.
| | - Fengchun Ye
- Department of Biological Sciences, School of Dental Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, United States.
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Negative elongation factor is required for the maintenance of proviral latency but does not induce promoter-proximal pausing of RNA polymerase II on the HIV long terminal repeat. Mol Cell Biol 2014; 34:1911-28. [PMID: 24636995 DOI: 10.1128/mcb.01013-13] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The role of the negative elongation factor (NELF) in maintaining HIV latency was investigated following small hairpin RNA (shRNA) knockdown of the NELF-E subunit, a condition that induced high levels of proviral transcription in latently infected Jurkat T cells. Chromatin immunoprecipitation (ChIP) assays showed that latent proviruses accumulate RNA polymerase II (RNAP II) on the 5' long terminal repeat (LTR) but not on the 3' LTR. NELF colocalizes with RNAP II, and its level increases following proviral induction. RNAP II pause sites on the HIV provirus were mapped to high resolution by ChIP with high-throughput sequencing (ChIP-Seq). Like cellular promoters, RNAP II accumulates at around position +30, but HIV also shows additional pausing at +90, which is immediately downstream of a transactivation response (TAR) element and other distal sites on the HIV LTR. Following NELF-E knockdown or tumor necrosis factor alpha (TNF-α) stimulation, promoter-proximal RNAP II levels increase up to 3-fold, and there is a dramatic increase in RNAP II levels within the HIV genome. These data support a kinetic model for proviral transcription based on continuous replacement of paused RNAP II during both latency and productive transcription. In contrast to most cellular genes, HIV is highly activated by the combined effects of NELF-E depletion and activation of initiation by TNF-α, suggesting that opportunities exist to selectively activate latent HIV proviruses.
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Haverland NA, Fox HS, Ciborowski P. Quantitative proteomics by SWATH-MS reveals altered expression of nucleic acid binding and regulatory proteins in HIV-1-infected macrophages. J Proteome Res 2014; 13:2109-19. [PMID: 24564501 PMCID: PMC3993959 DOI: 10.1021/pr4012602] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Human immunodeficiency virus type 1 (HIV-1) infection remains a worldwide epidemic, and innovative therapies to combat the virus are needed. Developing a host-oriented antiviral strategy capable of targeting the biomolecules that are directly or indirectly required for viral replication may provide advantages over traditional virus-centric approaches. We used quantitative proteomics by SWATH-MS in conjunction with bioinformatic analyses to identify host proteins, with an emphasis on nucleic acid binding and regulatory proteins, which could serve as candidates in the development of host-oriented antiretroviral strategies. Using SWATH-MS, we identified and quantified the expression of 3608 proteins in uninfected and HIV-1-infected monocyte-derived macrophages. Of these 3608 proteins, 420 were significantly altered upon HIV-1 infection. Bioinformatic analyses revealed functional enrichment for RNA binding and processing as well as transcription regulation. Our findings highlight a novel subset of proteins and processes that are involved in the host response to HIV-1 infection. In addition, we provide an original and transparent methodology for the analysis of label-free quantitative proteomics data generated by SWATH-MS that can be readily adapted to other biological systems.
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Affiliation(s)
- Nicole A Haverland
- Department of Pharmacology and Experimental Neuroscience University of Nebraska Medical Center , Durham Research Center I, 985800 Nebraska Medical Center Omaha, Nebraska 68198-5800, United States
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Mbonye U, Karn J. Transcriptional control of HIV latency: cellular signaling pathways, epigenetics, happenstance and the hope for a cure. Virology 2014; 454-455:328-39. [PMID: 24565118 DOI: 10.1016/j.virol.2014.02.008] [Citation(s) in RCA: 178] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Revised: 01/23/2014] [Accepted: 02/07/2014] [Indexed: 02/06/2023]
Abstract
Replication-competent latent HIV-1 proviruses that persist in the genomes of a very small subset of resting memory T cells in infected individuals under life-long antiretroviral therapy present a major barrier towards viral eradication. Multiple molecular mechanisms are required to repress the viral trans-activating factor Tat and disrupt the regulatory Tat feedback circuit leading to the establishment of the latent viral reservoir. In particular, latency is due to a combination of transcriptional silencing of proviruses via host epigenetic mechanisms and restrictions on the expression of P-TEFb, an essential co-factor for Tat. Induction of latent proviruses in the presence of antiretroviral therapy is expected to enable clearance of latently infected cells by viral cytopathic effects and host antiviral immune responses. An in-depth comprehensive understanding of the molecular control of HIV-1 transcription should inform the development of optimal combinatorial reactivation strategies that are intended to purge the latent viral reservoir.
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Affiliation(s)
- Uri Mbonye
- Department of Molecular Biology and Microbiology, Case Western Reserve University, School of Medicine, Cleveland, OH 44106, United States
| | - Jonathan Karn
- Department of Molecular Biology and Microbiology, Case Western Reserve University, School of Medicine, Cleveland, OH 44106, United States.
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