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Bhaduri-McIntosh S, Rousseau BA. KAP1/TRIM28 - antiviral and proviral protagonist of herpesvirus biology. Trends Microbiol 2024:S0966-842X(24)00138-0. [PMID: 38871562 DOI: 10.1016/j.tim.2024.05.007] [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: 03/22/2024] [Revised: 05/19/2024] [Accepted: 05/21/2024] [Indexed: 06/15/2024]
Abstract
Dysregulation of the constitutive heterochromatin machinery (HCM) that silences pericentromeric regions and endogenous retroviral elements in the human genome has consequences for aging and cancer. By recruiting epigenetic regulators, Krüppel-associated box (KRAB)-associated protein 1 (KAP1/TRIM28/TIF1β) is integral to the function of the HCM. Epigenetically silencing DNA genomes of incoming herpesviruses to enforce latency, KAP1 and HCM also serve in an antiviral capacity. In addition to gene silencing, newer reports highlight KAP1's ability to directly activate cellular gene transcription. Here, we discuss the many facets of KAP1, including recent findings that unexpectedly connect KAP1 to the inflammasome, reveal KAP1 cleavage as a novel mode of regulation, and argue for a pro-herpesviral KAP1 function that ensures transition from transcription to replication of the herpesvirus genome.
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Affiliation(s)
- Sumita Bhaduri-McIntosh
- Division of Infectious Diseases, Department of Pediatrics, University of Florida, Gainesville, FL, USA; Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, USA.
| | - Beth A Rousseau
- Division of Infectious Diseases, Department of Pediatrics, University of Florida, Gainesville, FL, USA
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Bone B, Lichterfeld M. "Block and lock" viral integration sites in persons with drug-free control of HIV-1 infection. Curr Opin HIV AIDS 2024; 19:110-115. [PMID: 38457193 DOI: 10.1097/coh.0000000000000845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2024]
Abstract
PURPOSE OF REVIEW Elite controllers (ECs) and Posttreatment controllers (PTCs) represent a small subset of individuals who are capable of maintaining drug-free control of HIV plasma viral loads despite the persistence of a replication-competent viral reservoir. This review aims to curate recent experimental studies evaluating viral reservoirs that distinguish EC/PTC and may contribute to their ability to maintain undetectable viral loads in the absence of antiretroviral therapy. RECENT FINDINGS Recent studies on ECs have demonstrated that integration sites of intact proviruses in EC/PTC are markedly biased towards heterochromatin regions; in contrast, intact proviruses in accessible and permissive chromatin were profoundly underrepresented. Of note, no such biases were noted when CD4 + T cells from EC were infected directly ex vivo, suggesting that the viral reservoir profile in EC is not related to altered integration site preferences during acute infection, but instead represents the result of immune-mediated selection mechanisms that can eliminate proviruses in transcriptionally-active euchromatin regions while promoting preferential persistence of intact proviruses in nonpermissive genome regions. Proviral transcription in such "blocked and locked" regions may be restricted through epigenetic mechanisms, protecting them from immune-recognition but presumably limiting their ability to drive viral rebound. While the exact immune mechanisms driving this selection process remain undefined, recent single-cell analytic approaches support the hypothesis that HIV reservoir cells are subject to immune selection pressure by host factors. SUMMARY A "blocked and locked" viral reservoir profile may constitute a structural virological correlate of a functional cure of HIV-1 infection. Further research into the immunological mechanism promoting HIV-1 reservoir selection and evolution in EC/PTC is warranted and could inform foreseeable cure strategies.
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Affiliation(s)
- Benjamin Bone
- Infectious Disease Division, Brigham Women's Hospital, Boston
- The Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, USA
| | - Mathias Lichterfeld
- Infectious Disease Division, Brigham Women's Hospital, Boston
- The Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, USA
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Mbonye U, Karn J. The cell biology of HIV-1 latency and rebound. Retrovirology 2024; 21:6. [PMID: 38580979 PMCID: PMC10996279 DOI: 10.1186/s12977-024-00639-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2024] Open
Abstract
Transcriptionally latent forms of replication-competent proviruses, present primarily in a small subset of memory CD4+ T cells, pose the primary barrier to a cure for HIV-1 infection because they are the source of the viral rebound that almost inevitably follows the interruption of antiretroviral therapy. Over the last 30 years, many of the factors essential for initiating HIV-1 transcription have been identified in studies performed using transformed cell lines, such as the Jurkat T-cell model. However, as highlighted in this review, several poorly understood mechanisms still need to be elucidated, including the molecular basis for promoter-proximal pausing of the transcribing complex and the detailed mechanism of the delivery of P-TEFb from 7SK snRNP. Furthermore, the central paradox of HIV-1 transcription remains unsolved: how are the initial rounds of transcription achieved in the absence of Tat? A critical limitation of the transformed cell models is that they do not recapitulate the transitions between active effector cells and quiescent memory T cells. Therefore, investigation of the molecular mechanisms of HIV-1 latency reversal and LRA efficacy in a proper physiological context requires the utilization of primary cell models. Recent mechanistic studies of HIV-1 transcription using latently infected cells recovered from donors and ex vivo cellular models of viral latency have demonstrated that the primary blocks to HIV-1 transcription in memory CD4+ T cells are restrictive epigenetic features at the proviral promoter, the cytoplasmic sequestration of key transcription initiation factors such as NFAT and NF-κB, and the vanishingly low expression of the cellular transcription elongation factor P-TEFb. One of the foremost schemes to eliminate the residual reservoir is to deliberately reactivate latent HIV-1 proviruses to enable clearance of persisting latently infected cells-the "Shock and Kill" strategy. For "Shock and Kill" to become efficient, effective, non-toxic latency-reversing agents (LRAs) must be discovered. Since multiple restrictions limit viral reactivation in primary cells, understanding the T-cell signaling mechanisms that are essential for stimulating P-TEFb biogenesis, initiation factor activation, and reversing the proviral epigenetic restrictions have become a prerequisite for the development of more effective LRAs.
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Affiliation(s)
- Uri Mbonye
- Department of Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA.
| | - Jonathan Karn
- Department of Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA.
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Roy A, Ghosh A. Epigenetic Restriction Factors (eRFs) in Virus Infection. Viruses 2024; 16:183. [PMID: 38399958 PMCID: PMC10892949 DOI: 10.3390/v16020183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Revised: 01/23/2024] [Accepted: 01/24/2024] [Indexed: 02/25/2024] Open
Abstract
The ongoing arms race between viruses and their hosts is constantly evolving. One of the ways in which cells defend themselves against invading viruses is by using restriction factors (RFs), which are cell-intrinsic antiviral mechanisms that block viral replication and transcription. Recent research has identified a specific group of RFs that belong to the cellular epigenetic machinery and are able to restrict the gene expression of certain viruses. These RFs can be referred to as epigenetic restriction factors or eRFs. In this review, eRFs have been classified into two categories. The first category includes eRFs that target viral chromatin. So far, the identified eRFs in this category include the PML-NBs, the KRAB/KAP1 complex, IFI16, and the HUSH complex. The second category includes eRFs that target viral RNA or, more specifically, the viral epitranscriptome. These epitranscriptomic eRFs have been further classified into two types: those that edit RNA bases-adenosine deaminase acting on RNA (ADAR) and pseudouridine synthases (PUS), and those that covalently modify viral RNA-the N6-methyladenosine (m6A) writers, readers, and erasers. We delve into the molecular machinery of eRFs, their role in limiting various viruses, and the mechanisms by which viruses have evolved to counteract them. We also examine the crosstalk between different eRFs, including the common effectors that connect them. Finally, we explore the potential for new discoveries in the realm of epigenetic networks that restrict viral gene expression, as well as the future research directions in this area.
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Affiliation(s)
- Arunava Roy
- Department of Molecular Medicine, University of South Florida, Tampa, FL 33612, USA;
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Wong HT, Luperchio AM, Riley S, Salamango DJ. Inhibition of ATM-directed antiviral responses by HIV-1 Vif. PLoS Pathog 2023; 19:e1011634. [PMID: 37669285 PMCID: PMC10503699 DOI: 10.1371/journal.ppat.1011634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 09/15/2023] [Accepted: 08/22/2023] [Indexed: 09/07/2023] Open
Abstract
Emerging evidence indicates that HIV-1 hijacks host DNA damage repair (DDR) pathways to facilitate multiple facets of virus replication. Canonically, HIV-1 engages proviral DDR responses through the accessory protein Vpr, which induces constitutive activation of DDR kinases ATM and ATR. However, in response to prolonged DDR signaling, ATM directly induces pro-inflammatory NF-κB signaling and activates multiple members of the TRIM family of antiviral restriction factors, several of which have been previously implicated in antagonizing retroviral and lentiviral replication. Here, we demonstrate that the HIV-1 accessory protein Vif blocks ATM-directed DNA repair processes, activation of NF-κB signaling responses, and TRIM protein phosphorylation. Vif function in ATM antagonism occurs in clinical isolates and in common HIV-1 Group M subtypes/clades circulating globally. Pharmacologic and functional studies combine to suggest that Vif blocks Vpr-directed activation of ATM but not ATR, signifying that HIV-1 utilizes discrete strategies to fine-tune DDR responses that promote virus replication while simultaneously inhibiting immune activation.
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Affiliation(s)
- Hoi Tong Wong
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, United States of America
| | - Adeline M. Luperchio
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, United States of America
| | - Sean Riley
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, United States of America
| | - Daniel J. Salamango
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, United States of America
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Saeb S, Wallet C, Rohr O, Schwartz C, Loustau T. Targeting and eradicating latent CNS reservoirs of HIV-1: original strategies and new models. Biochem Pharmacol 2023:115679. [PMID: 37399950 DOI: 10.1016/j.bcp.2023.115679] [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: 04/28/2023] [Revised: 06/28/2023] [Accepted: 06/29/2023] [Indexed: 07/05/2023]
Abstract
Nowadays, combination antiretroviral therapy (cART) is the standard treatment for all people with human immunodeficiency virus (HIV-1). Although cART is effective in treating productive infection, it does not eliminate latent reservoirs of the virus. This leads to lifelong treatment associated with the occurrence of side effects and the development of drug-resistant HIV-1. Suppression of viral latency is therefore the major hurdle to HIV-1 eradication. Multiple mechanisms exist to regulate viral gene expression and drive the transcriptional and post-transcriptional establishment of latency. Epigenetic processes are amongst the most studied mechanisms influencing both productive and latent infection states. The central nervous system (CNS) represents a key anatomical sanctuary for HIV and is the focal point of considerable research efforts. However, limited and difficult access to CNS compartments makes understanding the HIV-1 infection state in latent brain cells such as microglial cells, astrocytes, and perivascular macrophages challenging. This review examines the latest advances on epigenetic transformations involved in CNS viral latency and targeting of brain reservoirs. Evidence from clinical studies as well as in vivo and in vitro models of HIV-1 persistence in the CNS will be discussed, with a special focus on recent 3D in vitro models such as human brain organoids. Finally, the review will address therapeutic considerations for targeting latent CNS reservoirs.
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Affiliation(s)
- Sepideh Saeb
- Department of Allied Medicine, Qaen Faculty of Medical Sciences, Birjand University of Medical Sciences, Birjand, Iran; Strasbourg University, Research Unit 7292, DHPI, IUT Louis Pasteur, Schiltigheim, France
| | - Clémentine Wallet
- Strasbourg University, Research Unit 7292, DHPI, IUT Louis Pasteur, Schiltigheim, France
| | - Olivier Rohr
- Strasbourg University, Research Unit 7292, DHPI, IUT Louis Pasteur, Schiltigheim, France
| | - Christian Schwartz
- Strasbourg University, Research Unit 7292, DHPI, IUT Louis Pasteur, Schiltigheim, France
| | - Thomas Loustau
- Strasbourg University, Research Unit 7292, DHPI, IUT Louis Pasteur, Schiltigheim, France.
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Horvath RM, Dahabieh M, Malcolm T, Sadowski I. TRIM24 controls induction of latent HIV-1 by stimulating transcriptional elongation. Commun Biol 2023; 6:86. [PMID: 36690785 PMCID: PMC9870992 DOI: 10.1038/s42003-023-04484-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 01/15/2023] [Indexed: 01/24/2023] Open
Abstract
Binding of USF1/2 and TFII-I (RBF-2) at conserved sites flanking the HIV-1 LTR enhancer is essential for reactivation from latency in T cells, with TFII-I knockdown rendering the provirus insensitive to T cell signaling. We identified an interaction of TFII-I with the tripartite motif protein TRIM24, and these factors were found to be constitutively associated with the HIV-1 LTR. Similar to the effect of TFII-I depletion, loss of TRIM24 impaired reactivation of HIV-1 in response to T cell signaling. TRIM24 deficiency did not affect recruitment of RNA Pol II to the LTR promoter, but inhibited transcriptional elongation, an effect that was associated with decreased RNA Pol II CTD S2 phosphorylation and impaired recruitment of CDK9. A considerable number of genomic loci are co-occupied by TRIM24/TFII-I, and we found that TRIM24 deletion caused altered T cell immune response, an effect that is facilitated by TFII-I. These results demonstrate a role of TRIM24 for regulation of transcriptional elongation from the HIV-1 promoter, through its interaction with TFII-I, and by recruitment of P-TEFb. Furthermore, these factors co-regulate a significant proportion of genes involved in T cell immune response, consistent with tight coupling of HIV-1 transcriptional activation and T cell signaling.
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Affiliation(s)
- Riley M Horvath
- Department of Biochemistry and Molecular Biology, Molecular Epigenetics Group, LSI, University of British Columbia, Vancouver, B.C., Canada
| | - Matthew Dahabieh
- Department of Biochemistry and Molecular Biology, Molecular Epigenetics Group, LSI, University of British Columbia, Vancouver, B.C., Canada
| | - Tom Malcolm
- Department of Biochemistry and Molecular Biology, Molecular Epigenetics Group, LSI, University of British Columbia, Vancouver, B.C., Canada
| | - Ivan Sadowski
- Department of Biochemistry and Molecular Biology, Molecular Epigenetics Group, LSI, University of British Columbia, Vancouver, B.C., Canada.
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Complex Relationships between HIV-1 Integrase and Its Cellular Partners. Int J Mol Sci 2022; 23:ijms232012341. [PMID: 36293197 PMCID: PMC9603942 DOI: 10.3390/ijms232012341] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 10/09/2022] [Accepted: 10/11/2022] [Indexed: 11/06/2022] Open
Abstract
RNA viruses, in pursuit of genome miniaturization, tend to employ cellular proteins to facilitate their replication. HIV-1, one of the most well-studied retroviruses, is not an exception. There is numerous evidence that the exploitation of cellular machinery relies on nucleic acid-protein and protein-protein interactions. Apart from Vpr, Vif, and Nef proteins that are known to regulate cellular functioning via interaction with cell components, another viral protein, integrase, appears to be crucial for proper virus-cell dialog at different stages of the viral life cycle. The goal of this review is to summarize and systematize existing data on known cellular partners of HIV-1 integrase and their role in the HIV-1 life cycle.
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Nakano K, Watanabe T. Tuning Rex rules HTLV-1 pathogenesis. Front Immunol 2022; 13:959962. [PMID: 36189216 PMCID: PMC9523361 DOI: 10.3389/fimmu.2022.959962] [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: 06/02/2022] [Accepted: 08/29/2022] [Indexed: 12/02/2022] Open
Abstract
HTLV-1 is an oncovirus causing ATL and other inflammatory diseases such as HAM/TSP and HU in about 5% of infected individuals. It is also known that HTLV-1-infected cells maintain a disease-free, immortalized, latent state throughout the lifetimes of about 95% of infected individuals. We believe that the stable maintenance of disease-free infected cells in the carrier is an intrinsic characteristic of HTLV-1 that has been acquired during its evolution in the human life cycle. We speculate that the pathogenesis of the virus is ruled by the orchestrated functions of viral proteins. In particular, the regulation of Rex, the conductor of viral replication rate, is expected to be closely related to the viral program in the early active viral replication followed by the stable latency in HTLV-1 infected T cells. HTLV-1 and HIV-1 belong to the family Retroviridae and share the same tropism, e.g., human CD4+ T cells. These viruses show significant similarities in the viral genomic structure and the molecular mechanism of the replication cycle. However, HTLV-1 and HIV-1 infected T cells show different phenotypes, especially in the level of virion production. We speculate that how the activity of HTLV-1 Rex and its counterpart HIV-1 Rev are regulated may be closely related to the properties of respective infected T cells. In this review, we compare various pathological aspects of HTLV-1 and HIV-1. In particular, we investigated the presence or absence of a virally encoded “regulatory valve” for HTLV-1 Rex or HIV-1 Rev to explore its importance in the regulation of viral particle production in infected T cells. Finally, wereaffirm Rex as the key conductor for viral replication and viral pathogenesis based on our recent study on the novel functional aspects of Rex. Since the activity of Rex is closely related to the viral replication rate, we hypothesize that the “regulatory valve” on the Rex activity may have been selectively evolved to achieve the “scenario” with early viral particle production and the subsequent long, stable deep latency in HTLV-1 infected cells.
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Affiliation(s)
- Kazumi Nakano
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Tokyo, Japan
- *Correspondence: Kazumi Nakano,
| | - Toshiki Watanabe
- Department of Practical Management of Medical Information, Graduate School of Medicine, St. Marianna University, Kawasaki, Japan
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da Costa LC, Bomfim LM, Dittz UVT, Velozo CDA, da Cunha RD, Tanuri A. Repression of HIV-1 reactivation mediated by CRISPR/dCas9-KRAB in lymphoid and myeloid cell models. Retrovirology 2022; 19:12. [PMID: 35733180 PMCID: PMC9215058 DOI: 10.1186/s12977-022-00600-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 06/07/2022] [Indexed: 11/28/2022] Open
Abstract
Background Despite antiretroviral treatment efficacy, it does not lead to the complete eradication of HIV infection. Consequently, reactivation of the virus from latently infected cell reservoirs is a major challenge toward cure efforts. Two strategies targeting viral latency are currently under investigation: the “shock and kill” and the “block and lock.” The “Block and Lock” methodology aims to control HIV-1 latency reactivation, promoting a functional cure. We utilized the CRISPR/dCas9-KRAB platform, which was initially developed to suppress cellular genes transcription, to block drug-induced HIV-1 reactivation in latently infected T cells and myeloid cells. Results We identified a set of five sgRNAs targeting the HIV-1 proviral genome (LTR1-LTR5), having the lowest nominated off-target activity, and transduced them into the latently infected lymphoid (J-Lat 10.6) and myeloid (U1) cell lines. One of the sgRNAs (LTR5), which binds specifically in the HIV-1 LTR NFκB binding site, was able to promote robust repression of HIV-1 reactivation in latently infected T cells stimulated with Phorbol 12-Myristate 13-Acetate (PMA) and Ingenol B (IngB), both potent protein kinase C (PKC) stimulators. Reactivation with HDAC inhibitors, such as SAHA and Panobinostat, showed the same strong inhibition of reactivation. Additionally, we observed a hundred times reduction of HIV-1 RNA expression levels in the latently infected myeloid cell line, U1 induced with IngB. Conclusion Taken together, our results show that the KRAB fused CRISPR/dCas9 system can robustly prevent the HIV-1 latency reactivation process, mediated by PMA or IngB and SAHA or Panobinostat, both in myeloid and lymphoid HIV-1 latently infected cells. In addition, we demonstrated that KRAB repressor protein is crucial to reactivation resistance phenotype, and we have identified some useful hotspots sequences in HIV-1 LTR for the design sgRNAs. Supplementary Information The online version contains supplementary material available at 10.1186/s12977-022-00600-9.
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Affiliation(s)
- Lendel Correia da Costa
- Departamento de Genética, Laboratório de Virologia Molecular, Instituto de Biologia, Universidade Federal do Rio de Janeiro (UFRJ), Av Carlos Chagas Filho 373, CCS, Bloco A, Sala 121, Ilha do Fundão, Rio de Janeiro, RJ, 21941-902, Brazil
| | - Larissa Maciel Bomfim
- Departamento de Genética, Laboratório de Virologia Molecular, Instituto de Biologia, Universidade Federal do Rio de Janeiro (UFRJ), Av Carlos Chagas Filho 373, CCS, Bloco A, Sala 121, Ilha do Fundão, Rio de Janeiro, RJ, 21941-902, Brazil
| | - Uilla Victoria Torres Dittz
- Departamento de Genética, Laboratório de Virologia Molecular, Instituto de Biologia, Universidade Federal do Rio de Janeiro (UFRJ), Av Carlos Chagas Filho 373, CCS, Bloco A, Sala 121, Ilha do Fundão, Rio de Janeiro, RJ, 21941-902, Brazil
| | - Camila de Almeida Velozo
- Departamento de Genética, Laboratório de Virologia Molecular, Instituto de Biologia, Universidade Federal do Rio de Janeiro (UFRJ), Av Carlos Chagas Filho 373, CCS, Bloco A, Sala 121, Ilha do Fundão, Rio de Janeiro, RJ, 21941-902, Brazil
| | - Rodrigo Delvecchio da Cunha
- Departamento de Genética, Laboratório de Virologia Molecular, Instituto de Biologia, Universidade Federal do Rio de Janeiro (UFRJ), Av Carlos Chagas Filho 373, CCS, Bloco A, Sala 121, Ilha do Fundão, Rio de Janeiro, RJ, 21941-902, Brazil
| | - Amilcar Tanuri
- Departamento de Genética, Laboratório de Virologia Molecular, Instituto de Biologia, Universidade Federal do Rio de Janeiro (UFRJ), Av Carlos Chagas Filho 373, CCS, Bloco A, Sala 121, Ilha do Fundão, Rio de Janeiro, RJ, 21941-902, Brazil.
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Verdikt R, Bendoumou M, Bouchat S, Nestola L, Pasternak AO, Darcis G, Avettand-Fenoel V, Vanhulle C, Aït-Ammar A, Santangelo M, Plant E, Douce VL, Delacourt N, Cicilionytė A, Necsoi C, Corazza F, Passaes CPB, Schwartz C, Bizet M, Fuks F, Sáez-Cirión A, Rouzioux C, De Wit S, Berkhout B, Gautier V, Rohr O, Van Lint C. Novel role of UHRF1 in the epigenetic repression of the latent HIV-1. EBioMedicine 2022; 79:103985. [PMID: 35429693 PMCID: PMC9038550 DOI: 10.1016/j.ebiom.2022.103985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 03/11/2022] [Accepted: 03/21/2022] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND The multiplicity, heterogeneity, and dynamic nature of human immunodeficiency virus type-1 (HIV-1) latency mechanisms are reflected in the current lack of functional cure for HIV-1. Accordingly, all classes of latency-reversing agents (LRAs) have been reported to present variable ex vivo potencies. Here, we investigated the molecular mechanisms underlying the potency variability of one LRA: the DNA methylation inhibitor 5-aza-2'-deoxycytidine (5-AzadC). METHODS We employed epigenetic interrogation methods (electrophoretic mobility shift assays, chromatin immunoprecipitation, Infinium array) in complementary HIV-1 infection models (latently-infected T-cell line models, primary CD4+ T-cell models and ex vivo cultures of PBMCs from HIV+ individuals). Extracellular staining of cell surface receptors and intracellular metabolic activity were measured in drug-treated cells. HIV-1 expression in reactivation studies was explored by combining the measures of capsid p24Gag protein, green fluorescence protein signal, intracellular and extracellular viral RNA and viral DNA. FINDINGS We uncovered specific demethylation CpG signatures induced by 5-AzadC in the HIV-1 promoter. By analyzing the binding modalities to these CpG, we revealed the recruitment of the epigenetic integrator Ubiquitin-like with PHD and RING finger domain 1 (UHRF1) to the HIV-1 promoter. We showed that UHRF1 redundantly binds to the HIV-1 promoter with different binding modalities where DNA methylation was either non-essential, essential or enhancing UHRF1 binding. We further demonstrated the role of UHRF1 in the epigenetic repression of the latent viral promoter by a concerted control of DNA and histone methylations. INTERPRETATION A better understanding of the molecular mechanisms of HIV-1 latency allows for the development of innovative antiviral strategies. As a proof-of-concept, we showed that pharmacological inhibition of UHRF1 in ex vivo HIV+ patient cell cultures resulted in potent viral reactivation from latency. Together, we identify UHRF1 as a novel actor in HIV-1 epigenetic silencing and highlight that it constitutes a new molecular target for HIV-1 cure strategies. FUNDING Funding was provided by the Belgian National Fund for Scientific Research (F.R.S.-FNRS, Belgium), the « Fondation Roi Baudouin », the NEAT (European AIDS Treatment Network) program, the Internationale Brachet Stiftung, ViiV Healthcare, the Télévie, the Walloon Region (« Fonds de Maturation »), « Les Amis des Instituts Pasteur à Bruxelles, asbl », the University of Brussels (Action de Recherche Concertée ULB grant), the Marie Skodowska Curie COFUND action, the European Union's Horizon 2020 research and innovation program under grant agreement No 691119-EU4HIVCURE-H2020-MSCA-RISE-2015, the French Agency for Research on AIDS and Viral Hepatitis (ANRS), the Sidaction and the "Alsace contre le Cancer" Foundation. This work is supported by 1UM1AI164562-01, co-funded by National Heart, Lung and Blood Institute, National Institute of Diabetes and Digestive and Kidney Diseases, National Institute of Neurological Disorders and Stroke, National Institute on Drug Abuse and the National Institute of Allergy and Infectious Diseases.
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Affiliation(s)
- Roxane Verdikt
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Gosselies 6041, Belgium
| | - Maryam Bendoumou
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Gosselies 6041, Belgium
| | - Sophie Bouchat
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Gosselies 6041, Belgium
| | - Lorena Nestola
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Gosselies 6041, Belgium
| | - Alexander O Pasternak
- Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Laboratory of Experimental Virology, Amsterdam 1105 AZ, the Netherland
| | - Gilles Darcis
- Infectious Diseases Department, Liège University Hospital, Liège 4000, Belgium
| | - Véronique Avettand-Fenoel
- AP-HP, Hôpital Necker-Enfants-Malades, Service de Microbiologie clinique, Paris 75015, France; Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris 75006, France; INSERM, U1016, Institut Cochin, Paris, 75014, France; CNRS, UMR8104, Paris 75014, France
| | - Caroline Vanhulle
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Gosselies 6041, Belgium
| | - Amina Aït-Ammar
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Gosselies 6041, Belgium
| | - Marion Santangelo
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Gosselies 6041, Belgium
| | - Estelle Plant
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Gosselies 6041, Belgium
| | - Valentin Le Douce
- Centre for Research in Infectious Diseases, University College Dublin, Dublin 4, Ireland
| | - Nadège Delacourt
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Gosselies 6041, Belgium
| | - Aurelija Cicilionytė
- Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Laboratory of Experimental Virology, Amsterdam 1105 AZ, the Netherland
| | - Coca Necsoi
- Service des Maladies Infectieuses, CHU St-Pierre, Université Libre de Bruxelles (ULB), Brussels 1000, Belgium
| | - Francis Corazza
- Laboratory of Immunology, IRISLab, CHU Brugmann, Université Libre de Bruxelles (ULB), Brussels 1020, Belgium
| | | | - Christian Schwartz
- Laboratoire DHPI EA7292, Université de Strasbourg, Schiltigheim, 67300, France; IUT Louis Pasteur, Université de Strasbourg, Schiltigheim, 67300, France
| | - Martin Bizet
- Laboratory of Cancer Epigenetics, Faculty of Medicine, ULB-Cancer Research Center (U-CRC), Université Libre de Bruxelles (ULB), Brussels 1070, Belgium
| | - François Fuks
- Laboratory of Cancer Epigenetics, Faculty of Medicine, ULB-Cancer Research Center (U-CRC), Université Libre de Bruxelles (ULB), Brussels 1070, Belgium
| | - Asier Sáez-Cirión
- Départements de Virologie et Immunologie, Institut Pasteur, Unité HIV, Inflammation et Persistance, Paris 75015, France
| | - Christine Rouzioux
- AP-HP, Hôpital Necker-Enfants-Malades, Service de Microbiologie clinique, Paris 75015, France
| | - Stéphane De Wit
- Service des Maladies Infectieuses, CHU St-Pierre, Université Libre de Bruxelles (ULB), Brussels 1000, Belgium
| | - Ben Berkhout
- Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Laboratory of Experimental Virology, Amsterdam 1105 AZ, the Netherland
| | - Virginie Gautier
- Centre for Research in Infectious Diseases, University College Dublin, Dublin 4, Ireland
| | - Olivier Rohr
- Laboratoire DHPI EA7292, Université de Strasbourg, Schiltigheim, 67300, France; IUT Louis Pasteur, Université de Strasbourg, Schiltigheim, 67300, France
| | - Carine Van Lint
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Gosselies 6041, Belgium.
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12
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Randolph K, Hyder U, D’Orso I. KAP1/TRIM28: Transcriptional Activator and/or Repressor of Viral and Cellular Programs? Front Cell Infect Microbiol 2022; 12:834636. [PMID: 35281453 PMCID: PMC8904932 DOI: 10.3389/fcimb.2022.834636] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 02/03/2022] [Indexed: 01/01/2023] Open
Abstract
Several transcriptional and epigenetic regulators have been functionally linked to the control of viral and cellular gene expression programs. One such regulator is Krüppel-associated box (KRAB)-associated protein 1 (KAP1: also named TRIM28 or TIF1β), which has been extensively studied in the past three decades. Here we offer an up-to date review of its various functions in a diversity of contexts. We first summarize the discovery of KAP1 repression of endogenous retroviruses during development. We then deliberate evidence in the literature suggesting KAP1 is both an activator and repressor of HIV-1 transcription and discuss experimental differences and limitations of previous studies. Finally, we discuss KAP1 regulation of DNA and RNA viruses, and then expand on KAP1 control of cellular responses and immune functions. While KAP1 positive and negative regulation of viral and cellular transcriptional programs is vastly documented, our mechanistic understanding remains narrow. We thus propose that precision genetic tools to reveal direct KAP1 functions in gene regulation will be required to not only illuminate new biology but also provide the foundation to translate the basic discoveries from the bench to the clinics.
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13
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Yuan P, Yan J, Wang S, Guo Y, Xi X, Han S, Yin J, Peng B, He X, Bodem J, Liu W. Trim28 acts as restriction factor of prototype foamy virus replication by modulating H3K9me3 marks and destabilizing the viral transactivator Tas. Retrovirology 2021; 18:38. [PMID: 34903241 PMCID: PMC8670036 DOI: 10.1186/s12977-021-00584-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Accepted: 11/26/2021] [Indexed: 12/17/2022] Open
Abstract
Background Prototype foamy virus (PFV) is nonpathogenic complex retroviruses that express a transcriptional transactivator Tas, which is essential for the activity of viral long terminal repeat (LTR) promoter and internal promoter (IP). Tripartite motif-containing protein 28 (Trim28) is well known as a scaffold protein normally enriched in gene promoter region to repress transcription. We sought to determine if whether Trim28 could be enriched in PFV promoter region to participate the establishment of PFV latency infection. Results In this study, we show that Trim28 restricts Tas-dependent transactivation activity of PFV promoter and negatively regulates PFV replication. Trim28 was found to be enriched in LTR instead of IP promoter regions of PFV genome and contribute to the maintenance of histone H3K9me3 marks on the LTR promoter. Furthermore, Trim28 interacts with Tas and colocalizes with Tas in the nucleus. Besides, we found that Trim28, an E3 ubiquitin ligase, binds directly to and promotes Tas for ubiquitination and degradation. And the RBCC domain of Trim28 is required for the ubiquitination and degradation of Tas. Conclusions Collectively, our findings not only identify a host factor Trim28 negatively inhibits PFV replication by acting as transcriptional restriction factor enriched in viral LTR promoter through modulating H3K9me3 mark here, but also reveal that Trim28 mediated ubiquitin proteasome degradation of Tas as a mechanism underlying Trim28 restricts Tas-dependent transcription activity of PFV promoter and PFV replication. These findings provide new insights into the process of PFV latency establishment. Graphical Abstract ![]()
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Affiliation(s)
- Peipei Yuan
- Department of Immunology, School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, 442000, China.,Hubei Province Key Laboratory of Allergy and Immunology, School of Basic Medical Sciences, Wuhan University, No. 185, Donghu Road, Wuchang District, Wuhan, 430071, China.,Hubei Key Laboratory of Embryonic Stem Cell Research, Hubei University of Medicine, Shiyan, 442000, Hubei, China
| | - Jun Yan
- Hubei Province Key Laboratory of Allergy and Immunology, School of Basic Medical Sciences, Wuhan University, No. 185, Donghu Road, Wuchang District, Wuhan, 430071, China.,Hubei Provincial Key Laboratory of Developmentally Originated Disease, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Shuang Wang
- Hubei Province Key Laboratory of Allergy and Immunology, School of Basic Medical Sciences, Wuhan University, No. 185, Donghu Road, Wuchang District, Wuhan, 430071, China.,Hubei Provincial Key Laboratory of Developmentally Originated Disease, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Yang Guo
- Department of Immunology, School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, 442000, China.,Hubei Key Laboratory of Embryonic Stem Cell Research, Hubei University of Medicine, Shiyan, 442000, Hubei, China
| | - Xueyan Xi
- Department of Immunology, School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, 442000, China.,Hubei Key Laboratory of Embryonic Stem Cell Research, Hubei University of Medicine, Shiyan, 442000, Hubei, China
| | - Song Han
- Hubei Province Key Laboratory of Allergy and Immunology, School of Basic Medical Sciences, Wuhan University, No. 185, Donghu Road, Wuchang District, Wuhan, 430071, China.,Hubei Provincial Key Laboratory of Developmentally Originated Disease, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Jun Yin
- Hubei Province Key Laboratory of Allergy and Immunology, School of Basic Medical Sciences, Wuhan University, No. 185, Donghu Road, Wuchang District, Wuhan, 430071, China.,Hubei Provincial Key Laboratory of Developmentally Originated Disease, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Biwen Peng
- Hubei Province Key Laboratory of Allergy and Immunology, School of Basic Medical Sciences, Wuhan University, No. 185, Donghu Road, Wuchang District, Wuhan, 430071, China.,Hubei Provincial Key Laboratory of Developmentally Originated Disease, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Xiaohua He
- Hubei Province Key Laboratory of Allergy and Immunology, School of Basic Medical Sciences, Wuhan University, No. 185, Donghu Road, Wuchang District, Wuhan, 430071, China.,Hubei Provincial Key Laboratory of Developmentally Originated Disease, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Jochen Bodem
- Institut für Virologie und Immunbiologie, Julius-Maximilians-Universität Würzburg, 97078, Würzburg, Germany
| | - Wanhong Liu
- Hubei Province Key Laboratory of Allergy and Immunology, School of Basic Medical Sciences, Wuhan University, No. 185, Donghu Road, Wuchang District, Wuhan, 430071, China. .,Hubei Provincial Key Laboratory of Developmentally Originated Disease, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China.
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14
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Chen CJ, Chiu ML, Hung CH, Liang WM, Ho MW, Lin TH, Liu X, Tsang H, Liao CC, Huang SM, Wu YF, Wu YC, Li TM, Tsai FJ, Lin YJ. Effect of Xanthium Strumarium on HIV-1 5'-LTR Transcriptional Activity and Viral Reactivation in Latently Infected Cells. Front Pharmacol 2021; 12:720821. [PMID: 34421615 PMCID: PMC8378250 DOI: 10.3389/fphar.2021.720821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Accepted: 07/26/2021] [Indexed: 11/13/2022] Open
Abstract
Chinese herbal medicines (CHMs) are widely used in Asian countries. They show multiple pharmacological activities, including antiviral activities. The 5'-long terminal repeat (LTR) region of HIV-1, required for viral transcription, is a potential drug target for HIV-1 reactivation and intrinsic cell death induction of infected or latently infected cells. Modulation of HIV-1 reactivation requires interactions between host cell proteins and viral 5'-LTR elements. By evaluation of two CHMs- Xanthium strumarium and Pueraria montana, we found that 1) X. strumarium reactivated HIV-1 latently infected cells in J-Lat 8.4, J-Lat 9.2, U1, and ACH-2 cells in vitro; 2) 27 nuclear regulatory proteins were associated with HIV-1 5'-LTR using deoxyribonucleic acid affinity pull-down and LC-MS/MS analyses; and 3) among them, silencing of XRCC6 reactivated HIV-1 5'-LTR transcriptional activity. We found that X. strumarium inhibits the 5'-LTR associated XRCC6 nuclear regulatory proteins, increases its viral 5'-LTR promoter transcriptional activity, and reactivates HIV-1 latently infected cells in vitro. These findings may contribute to understanding the 5'-LTR activity and the host cell nuclear regulatory protein machinery for reactivating HIV-1 and for future investigations to eradicate and cure HIV-1 infection.
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Affiliation(s)
- Chao-Jung Chen
- Genetic Center, Proteomics Core Laboratory, Department of Medical Research, China Medical University Hospital, Taichung, Taiwan.,Graduate Institute of Integrated Medicine, China Medical University, Taichung, Taiwan
| | - Mu-Lin Chiu
- School of Chinese Medicine, China Medical University, Taichung, Taiwan
| | - Chien-Hui Hung
- Graduate Institute of Clinical Medical Sciences, Chang-Gung University, Taoyuan, Taiwan.,Division of Infectious Diseases, Chang Gung Memorial Hospital Chiayi Branch, Chiayi, Taiwan
| | - Wen-Miin Liang
- Department of Health Services Administration, China Medical University, Taichung, Taiwan
| | - Mao-Wang Ho
- Section of Infectious Diseases, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan.,Department of Internal Medicine, School of Medicine, China Medical University, Taichung, Taiwan
| | - Ting-Hsu Lin
- Genetic Center, Proteomics Core Laboratory, Department of Medical Research, China Medical University Hospital, Taichung, Taiwan
| | - Xiang Liu
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Hsinyi Tsang
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Chiu-Chu Liao
- Genetic Center, Proteomics Core Laboratory, Department of Medical Research, China Medical University Hospital, Taichung, Taiwan
| | - Shao-Mei Huang
- Genetic Center, Proteomics Core Laboratory, Department of Medical Research, China Medical University Hospital, Taichung, Taiwan
| | - Yi-Fang Wu
- Genetic Center, Proteomics Core Laboratory, Department of Medical Research, China Medical University Hospital, Taichung, Taiwan
| | - Yang-Chang Wu
- Graduate Institute of Integrated Medicine, China Medical University, Taichung, Taiwan.,Chinese Medicine Research and Development Center, China Medical University Hospital, Taichung, Taiwan.,Department of Biotechnology and Bioinformatics, Asia University, Taichung, Taiwan
| | - Te-Mao Li
- School of Chinese Medicine, China Medical University, Taichung, Taiwan
| | - Fuu-Jen Tsai
- Genetic Center, Proteomics Core Laboratory, Department of Medical Research, China Medical University Hospital, Taichung, Taiwan.,School of Chinese Medicine, China Medical University, Taichung, Taiwan.,Department of Biotechnology and Bioinformatics, Asia University, Taichung, Taiwan
| | - Ying-Ju Lin
- Genetic Center, Proteomics Core Laboratory, Department of Medical Research, China Medical University Hospital, Taichung, Taiwan.,School of Chinese Medicine, China Medical University, Taichung, Taiwan
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15
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Imbert F, Langford D. Viruses, SUMO, and immunity: the interplay between viruses and the host SUMOylation system. J Neurovirol 2021; 27:531-541. [PMID: 34342851 PMCID: PMC8330205 DOI: 10.1007/s13365-021-00995-9] [Citation(s) in RCA: 10] [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: 03/01/2021] [Revised: 06/19/2021] [Accepted: 06/29/2021] [Indexed: 12/14/2022]
Abstract
The conjugation of small ubiquitin-like modifier (SUMO) proteins to substrates is a well-described post-translational modification that regulates protein activity, subcellular localization, and protein-protein interactions for a variety of downstream cellular activities. Several studies describe SUMOylation as an essential post-translational modification for successful viral infection across a broad range of viruses, including RNA and DNA viruses, both enveloped and un-enveloped. These viruses include but are not limited to herpes viruses, human immunodeficiency virus-1, and coronaviruses. In addition to the SUMOylation of viral proteins during infection, evidence shows that viruses manipulate the SUMO pathway for host protein SUMOylation. SUMOylation of host and viral proteins greatly impacts host innate immunity through viral manipulation of the host SUMOylation machinery to promote viral replication and pathogenesis. Other post-translational modifications like phosphorylation can also modulate SUMO function. For example, phosphorylation of COUP-TF interacting protein 2 (CTIP2) leads to its SUMOylation and subsequent proteasomal degradation. The SUMOylation of CTIP2 and subsequent degradation prevents CTIP2-mediated recruitment of a multi-enzymatic complex to the HIV-1 promoter that usually prevents the transcription of integrated viral DNA. Thus, the "SUMO switch" could have implications for CTIP2-mediated transcriptional repression of HIV-1 in latency and viral persistence. In this review, we describe the consequences of SUMO in innate immunity and then focus on the various ways that viral pathogens have evolved to hijack the conserved SUMO machinery. Increased understanding of the many roles of SUMOylation in viral infections can lead to novel insight into the regulation of viral pathogenesis with the potential to uncover new targets for antiviral therapies.
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Affiliation(s)
- Fergan Imbert
- Department of Neuroscience, Lewis Katz School of Medicine, Temple University, PA, 19140, Philadelphia, USA
| | - Dianne Langford
- Department of Neuroscience, Lewis Katz School of Medicine, Temple University, PA, 19140, Philadelphia, USA.
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16
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Salahong T, Schwartz C, Sungthong R. Are BET Inhibitors yet Promising Latency-Reversing Agents for HIV-1 Reactivation in AIDS Therapy? Viruses 2021; 13:v13061026. [PMID: 34072421 PMCID: PMC8228869 DOI: 10.3390/v13061026] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 05/24/2021] [Accepted: 05/26/2021] [Indexed: 12/26/2022] Open
Abstract
AIDS first emerged decades ago; however, its cure, i.e., eliminating all virus sources, is still unachievable. A critical burden of AIDS therapy is the evasive nature of HIV-1 in face of host immune responses, the so-called "latency." Recently, a promising approach, the "Shock and Kill" strategy, was proposed to eliminate latently HIV-1-infected cell reservoirs. The "Shock and Kill" concept involves two crucial steps: HIV-1 reactivation from its latency stage using a latency-reversing agent (LRA) followed by host immune responses to destroy HIV-1-infected cells in combination with reinforced antiretroviral therapy to kill the progeny virus. Hence, a key challenge is to search for optimal LRAs. Looking at epigenetics of HIV-1 infection, researchers proved that some bromodomains and extra-terminal motif protein inhibitors (BETis) are able to reactivate HIV-1 from latency. However, to date, only a few BETis have shown HIV-1-reactivating functions, and none of them have yet been approved for clinical trial. In this review, we aim to demonstrate the epigenetic roles of BETis in HIV-1 infection and HIV-1-related immune responses. Possible future applications of BETis and their HIV-1-reactivating properties are summarized and discussed.
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Affiliation(s)
- Thanarat Salahong
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand;
| | - Christian Schwartz
- Research Unit 7292, DHPI, IUT Louis Pasteur, University of Strasbourg, 67300 Schiltigheim, France
- Correspondence: (C.S.); (R.S.)
| | - Rungroch Sungthong
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow G61 1QH, UK
- Laboratory of Hydrology and Geochemistry of Strasbourg, University of Strasbourg, UMR 7517 CNRS/EOST, 67084 Strasbourg CEDEX, France
- Correspondence: (C.S.); (R.S.)
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17
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Epigenetic Mechanisms of HIV-1 Persistence. Vaccines (Basel) 2021; 9:vaccines9050514. [PMID: 34067608 PMCID: PMC8156729 DOI: 10.3390/vaccines9050514] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 05/01/2021] [Accepted: 05/11/2021] [Indexed: 12/14/2022] Open
Abstract
Eradicating HIV-1 in infected individuals will not be possible without addressing the persistence of the virus in its multiple reservoirs. In this context, the molecular characterization of HIV-1 persistence is key for the development of rationalized therapeutic interventions. HIV-1 gene expression relies on the redundant and cooperative recruitment of cellular epigenetic machineries to cis-regulatory proviral regions. Furthermore, the complex repertoire of HIV-1 repression mechanisms varies depending on the nature of the viral reservoir, although, so far, few studies have addressed the specific regulatory mechanisms of HIV-1 persistence in other reservoirs than the well-studied latently infected CD4+ T cells. Here, we present an exhaustive and updated picture of the heterochromatinization of the HIV-1 promoter in its different reservoirs. We highlight the complexity, heterogeneity and dynamics of the epigenetic mechanisms of HIV-1 persistence, while discussing the importance of further understanding HIV-1 gene regulation for the rational design of novel HIV-1 cure strategies.
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18
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Sidwell T, Rothenberg EV. Epigenetic Dynamics in the Function of T-Lineage Regulatory Factor Bcl11b. Front Immunol 2021; 12:669498. [PMID: 33936112 PMCID: PMC8079813 DOI: 10.3389/fimmu.2021.669498] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 03/23/2021] [Indexed: 11/18/2022] Open
Abstract
The transcription factor Bcl11b is critically required to support the development of diverse cell types, including T lymphocytes, type 2 innate lymphoid cells, neurons, craniofacial mesenchyme and keratinocytes. Although in T cell development its onset of expression is tightly linked to T-lymphoid lineage commitment, the Bcl11b protein in fact regulates substantially different sets of genes in different lymphocyte populations, playing strongly context-dependent roles. Somewhat unusually for lineage-defining transcription factors with site-specific DNA binding activity, much of the reported chromatin binding of Bcl11b appears to be indirect, or guided in large part by interactions with other transcription factors. We describe evidence suggesting that a further way in which Bcl11b exerts such distinct stage-dependent functions is by nucleating changes in regional suites of epigenetic modifications through recruitment of multiple families of chromatin-modifying enzyme complexes. Herein we explore what is - and what remains to be - understood of the roles of Bcl11b, its cofactors, and how it modifies the epigenetic state of the cell to enforce its diverse set of context-specific transcriptional and developmental programs.
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Affiliation(s)
- Tom Sidwell
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA, United States
| | - Ellen V Rothenberg
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA, United States
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