1
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Flores Cortes E, Saddoris SM, Owens AK, Gibeault R, Depledge DP, Schang LM. Histone H2A variant H2A.B is enriched in transcriptionally active and replicating HSV-1 lytic chromatin. J Virol 2024; 98:e0201523. [PMID: 38451083 PMCID: PMC11019955 DOI: 10.1128/jvi.02015-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 02/19/2024] [Indexed: 03/08/2024] Open
Abstract
Herpes simplex virus 1 (HSV-1) transcription is restricted in latently infected neurons and the genomes are in mostly silenced chromatin, whereas all viral genes are transcribed in lytically infected cells, in which the genomes are dynamically chromatinized. Epigenetic regulation modulates HSV-1 transcription during lytic, latent, and reactivating infections but the precise mechanisms are not fully defined. Nucleosomes are dynamic: they slide, breathe, assemble, and disassemble. We and others have proposed that the most dynamic HSV-1 chromatin is transcriptionally competent, whereas the least dynamic is silenced. However, the mechanisms yielding the unusually dynamic viral chromatin remain unknown. Histone variants affect nucleosome dynamics. The dynamics of H2A, H2A.X, and macroH2A were enhanced in infected cells, whereas those of H2A.B were uniquely decreased. We constructed stably transduced cells expressing tagged histone H2A, H2A.B, macroH2A, or H2B, which assembles the H2A/H2B nucleosome dimers with all H2A variants. All H2A variants, as well as ectopic and endogenous H2B were assembled into HSV-1 chromatin evenly throughout the genome but canonical H2A was relatively depleted whereas H2A.B was enriched, particularly in the most dynamic viral chromatin. When viral transcription and DNA replication were restricted, H2A.B became as depleted from the viral chromatin through the entire genome as H2A. We propose that lytic HSV-1 nucleosomes are enriched in the dynamic variant H2A.B/H2B dimers to promote HSV-1 chromatin dynamics and transcriptional competency and conclude that the dynamics of HSV-1 chromatin are determined in part by the H2A variants. IMPORTANCE Herpes simplex virus 1 (HSV-1) transcription is epigenetically regulated during latent and lytic infections, and epigenetic inhibitors have been proposed as potential antiviral drugs to modulate latency and reactivation. However, the detailed epigenetic mechanisms of regulation of HSV-1 transcription have not been fully characterized and may differ from those regulating cellular transcription. Whereas lytic HSV-1 chromatin is unusually dynamic, latent silenced HSV-1 chromatin is not. The mechanisms resulting in the unique dynamics of the lytic chromatin remain unknown. Here we identify the enrichment of the highly dynamic histone 2A variant H2A in the most dynamic viral chromatin, which provides a mechanistic understanding of its unique dynamics. Future work to identify the mechanisms of enrichment in H2A.B on the viral chromatin may identify novel druggable epigenetic regulators that modulate HSV-1 latency and reactivation.
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Affiliation(s)
- Esteban Flores Cortes
- Baker Institute for Animal Health and Department of Microbiology and Immunology, Cornell University, Ithaca, New York, USA
| | - Sarah M. Saddoris
- Baker Institute for Animal Health and Department of Microbiology and Immunology, Cornell University, Ithaca, New York, USA
| | - Arryn K. Owens
- Baker Institute for Animal Health and Department of Microbiology and Immunology, Cornell University, Ithaca, New York, USA
| | - Rebecca Gibeault
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Daniel P. Depledge
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research (DZIF), partner site Hannover-Braunschweig, Hannover, Germany
- Excellence Cluster 2155 RESIST, Hannover Medical School, Hannover, Germany
| | - Luis M. Schang
- Baker Institute for Animal Health and Department of Microbiology and Immunology, Cornell University, Ithaca, New York, USA
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
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Wu Y, Sun A, Yang Q, Wang M, Tian B, Yang Q, Jia R, Chen S, Ou X, Huang J, Sun D, Zhu D, Liu M, Zhang S, Zhao XX, He Y, Wu Z, Cheng A. An alpha-herpesvirus employs host HEXIM1 to promote viral transcription. J Virol 2024; 98:e0139223. [PMID: 38363111 PMCID: PMC10949456 DOI: 10.1128/jvi.01392-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 01/29/2024] [Indexed: 02/17/2024] Open
Abstract
Although it is widely accepted that herpesviruses utilize host RNA polymerase II (RNAPII) to transcribe viral genes, the mechanism of utilization varies significantly among herpesviruses. With the exception of herpes simplex virus 1 (HSV-1) in alpha-herpesviruses, the mechanism by which RNAPII transcribes viral genes in the remaining alpha-herpesviruses has not been reported. In this study, we investigated the transcriptional mechanism of an avian alpha-herpesvirus, Anatid herpesvirus 1 (AnHV-1). We discovered for the first time that hexamethylene-bis-acetamide-inducing protein 1 (HEXIM1), a major inhibitor of positive elongation factor B (P-TEFb), was significantly upregulated during AnHV-1 infection, and its expression was dynamically regulated throughout the progression of the disease. However, the expression level of HEXIM1 remained stable before and after HSV-1 infection. Excessive HEXIM1 assists AnHV-1 in progeny virus production, gene expression, and RNA polymerase II recruitment by promoting the formation of more inactive P-TEFb and the loss of RNAPII S2 phosphorylation. Conversely, the expression of some host survival-related genes, such as SOX8, CDK1, MYC, and ID2, was suppressed by HEXIM1 overexpression. Further investigation revealed that the C-terminus of the AnHV-1 US1 gene is responsible for the upregulation of HEXIM1 by activating its promoter but not by interacting with P-TEFb, which is the mechanism adopted by its homologs, HSV-1 ICP22. Additionally, the virus proliferation deficiency caused by US1 deletion during the early infection stage could be partially rescued by HEXIM1 overexpression, suggesting that HEXIM1 is responsible for AnHV-1 gaining transcription advantages when competing with cells. Taken together, this study revealed a novel HEXIM1-dependent AnHV-1 transcription mechanism, which has not been previously reported in herpesvirus or even DNA virus studies.IMPORTANCEHexamethylene-bis-acetamide-inducing protein 1 (HEXIM1) has been identified as an inhibitor of positive transcriptional elongation factor b associated with cancer, AIDS, myocardial hypertrophy, and inflammation. Surprisingly, no previous reports have explored the role of HEXIM1 in herpesvirus transcription. This study reveals a mechanism distinct from the currently known herpesvirus utilization of RNA polymerase II, highlighting the dependence on high HEXIM1 expression, which may be a previously unrecognized facet of the host shutoff manifested by many DNA viruses. Moreover, this discovery expands the significance of HEXIM1 in pathogen infection. It raises intriguing questions about whether other herpesviruses employ similar mechanisms to manipulate HEXIM1 and if this molecular target can be exploited to limit productive replication. Thus, this discovery not only contributes to our understanding of herpesvirus infection regulation but also holds implications for broader research on other herpesviruses, even DNA viruses.
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Affiliation(s)
- Ying Wu
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Science & Technology Department of Sichuan Province, International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
| | - Anyang Sun
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Science & Technology Department of Sichuan Province, International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
| | - Qiqi Yang
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Science & Technology Department of Sichuan Province, International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
| | - Mingshu Wang
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Science & Technology Department of Sichuan Province, International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
| | - Bin Tian
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Science & Technology Department of Sichuan Province, International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
| | - Qiao Yang
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Science & Technology Department of Sichuan Province, International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
| | - Renyong Jia
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Science & Technology Department of Sichuan Province, International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
| | - Shun Chen
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Science & Technology Department of Sichuan Province, International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
| | - Xumin Ou
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Science & Technology Department of Sichuan Province, International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
| | - Juan Huang
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Science & Technology Department of Sichuan Province, International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
| | - Di Sun
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Science & Technology Department of Sichuan Province, International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
| | - Dekang Zhu
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Science & Technology Department of Sichuan Province, International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
| | - Mafeng Liu
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Science & Technology Department of Sichuan Province, International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
| | - Shaqiu Zhang
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Science & Technology Department of Sichuan Province, International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
| | - Xin-Xin Zhao
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Science & Technology Department of Sichuan Province, International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
| | - Yu He
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Science & Technology Department of Sichuan Province, International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
| | - Zhen Wu
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Science & Technology Department of Sichuan Province, International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
| | - Anchun Cheng
- Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People’s Republic of China, Chengdu, China
- Science & Technology Department of Sichuan Province, International Joint Research Center for Animal Disease Prevention and Control of Sichuan Province, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
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Dunn LEM, Birkenheuer CH, Baines JD. A Revision of Herpes Simplex Virus Type 1 Transcription: First, Repress; Then, Express. Microorganisms 2024; 12:262. [PMID: 38399666 PMCID: PMC10892140 DOI: 10.3390/microorganisms12020262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/22/2024] [Accepted: 01/24/2024] [Indexed: 02/25/2024] Open
Abstract
The herpes virus genome bears more than 80 strong transcriptional promoters. Upon entry into the host cell nucleus, these genes are transcribed in an orderly manner, producing five immediate-early (IE) gene products, including ICP0, ICP4, and ICP22, while non-IE genes are mostly silent. The IE gene products are necessary for the transcription of temporal classes following sequentially as early, leaky late, and true late. A recent analysis using precision nuclear run-on followed by deep sequencing (PRO-seq) has revealed an important step preceding all HSV-1 transcription. Specifically, the immediate-early proteins ICP4 and ICP0 enter the cell with the incoming genome to help preclude the nascent antisense, intergenic, and sense transcription of all viral genes. VP16, which is also delivered into the nucleus upon entry, almost immediately reverses this repression on IE genes. The resulting de novo expression of ICP4 and ICP22 further repress antisense, intergenic, and early and late viral gene transcription through different mechanisms before the sequential de-repression of these gene classes later in infection. This early repression, termed transient immediate-early protein-mediated repression (TIEMR), precludes unproductive, antisense, intergenic, and late gene transcription early in infection to ensure the efficient and orderly progression of the viral cascade.
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Affiliation(s)
- Laura E M Dunn
- Baker Institute for Animal Health, Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14850, USA
| | - Claire H Birkenheuer
- Baker Institute for Animal Health, Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14850, USA
| | - Joel D Baines
- Baker Institute for Animal Health, Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14850, USA
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4
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Flores E, Saddoris SM, Owens AK, Gibeault R, Depledge DP, Schang LM. Histone H2A variant H2A.B is enriched in transcriptionally active HSV-1 lytic chromatin. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.22.573075. [PMID: 38187672 PMCID: PMC10769327 DOI: 10.1101/2023.12.22.573075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Herpes simplex virus 1 (HSV-1) transcription is restricted in latently infected neurons and the genomes are in mostly silenced chromatin, whereas all viral genes are transcribed in lytically infected cells, in which the genomes are dynamically chromatinized. Epigenetic regulation modulates HSV-1 transcription during lytic, latent, and reactivating infections, but the precise mechanisms are not fully defined. Nucleosomes are dynamic; they slide, breathe, assemble and disassemble. We and others have proposed that the most dynamic HSV-1 chromatin is transcriptionally competent whereas the least dynamic is silenced. However, the mechanisms yielding the unusually dynamic viral chromatin remain unknown. Histone variants affect nucleosome dynamics. The dynamics of H2A, H2A.X and macroH2A were enhanced in infected cells, whereas those of H2A.B uniquely decreased. We constructed stably transduced cells expressing tagged histone H2A, H2A.B, macroH2A, or H2B, which assembles the H2A/H2B nucleosome dimers with all H2A variants. All H2A variants, ectopic, and endogenous H2B, were assembled into HSV-1 chromatin evenly throughout the genome, but canonical H2A was relatively depleted from the viral chromatin whereas H2A.B was enriched in the most dynamic viral chromatin. When viral transcription was restricted, H2A.B became as depleted from the viral chromatin through the entire genome as H2A. We propose that lytic HSV-1 nucleosomes are enriched in the dynamic variant H2A.B/H2B dimers to promote HSV-1 chromatin dynamics and transcriptional competency, and conclude that the dynamics of HSV-1 chromatin are determined in part by the H2A variants. Importance HSV-1 transcription is epigenetically regulated during latent and lytic infections, and epigenetic inhibitors have been proposed as potential antiviral drugs to modulate latency and reactivation. However, the detailed mechanisms of regulation of HSV-1 transcription by epigenetics have not been fully characterized and may differ from those regulating cellular transcription. In particular, the lytic HSV-1 chromatin is unusually dynamic, whereas the latent silenced one is not, but the mechanisms resulting in the unique dynamics of the lytic chromatin remain unknown. Here we identify the enrichment on the highly dynamic histone 2A variant H2A in the most dynamic viral chromatin, which provides a mechanistic understanding for its unique dynamics. Future work to identify the mechanisms of enrichment in H2A.B on the viral chromatin may identify novel druggable epigenetic regulators that modulate HSV-1 latency and reactivation.
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5
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Lewis BA, Das SK, Jha RK, Levens D. Self-assembly of promoter DNA and RNA Pol II machinery into transcriptionally active biomolecular condensates. SCIENCE ADVANCES 2023; 9:eadi4565. [PMID: 37851801 PMCID: PMC10584347 DOI: 10.1126/sciadv.adi4565] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 09/13/2023] [Indexed: 10/20/2023]
Abstract
Transcription in the nucleus occurs in a concentrated, dense environment, and no reasonable biochemical facsimile of this milieu exists. Such a biochemical environment would be important for further understanding transcriptional regulation. We describe here the formation of dense, transcriptionally active bodies in vitro with only nuclear extracts and promoter DNA. These biomolecular condensates (BMCs) are 0.5 to 1 μm in diameter, have a macromolecular density of approximately 100 mg/ml, and are a consequence of a phase transition between promoter DNA and nuclear extract proteins. BMCs are physically associated with transcription as any disruption of one compromised the other. The BMCs contain RNA polymerase II and elongation factors, as well as factors necessary for BMC formation in vivo. We suggest that BMCs are representative of the in vivo nuclear environment and a more physiologically relevant manifestation of the preinitiation complex/elongation machinery.
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Affiliation(s)
- Brian A. Lewis
- Gene Regulation Section, LP/CCR/NCI/NIH, 9000 Rockville Pike, Bethesda, MD 20892, USA
| | - Subhendu Kumar Das
- Gene Regulation Section, LP/CCR/NCI/NIH, 9000 Rockville Pike, Bethesda, MD 20892, USA
| | - Rajiv Kumar Jha
- Gene Regulation Section, LP/CCR/NCI/NIH, 9000 Rockville Pike, Bethesda, MD 20892, USA
| | - David Levens
- Gene Regulation Section, LP/CCR/NCI/NIH, 9000 Rockville Pike, Bethesda, MD 20892, USA
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6
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Kenaston MW, Shah PS. The Archer and the Prey: The Duality of PAF1C in Antiviral Immunity. Viruses 2023; 15:v15051032. [PMID: 37243120 DOI: 10.3390/v15051032] [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: 03/29/2023] [Revised: 04/18/2023] [Accepted: 04/21/2023] [Indexed: 05/28/2023] Open
Abstract
In the ongoing arms race between virus and host, fine-tuned gene expression plays a critical role in antiviral signaling. However, viruses have evolved to disrupt this process and promote their own replication by targeting host restriction factors. Polymerase-associated factor 1 complex (PAF1C) is a key player in this relationship, recruiting other host factors to regulate transcription and modulate innate immune gene expression. Consequently, PAF1C is consistently targeted by a diverse range of viruses, either to suppress its antiviral functions or co-opt them for their own benefit. In this review, we delve into the current mechanisms through which PAF1C restricts viruses by activating interferon and inflammatory responses at the transcriptional level. We also highlight how the ubiquity of these mechanisms makes PAF1C especially vulnerable to viral hijacking and antagonism. Indeed, as often as PAF1C is revealed to be a restriction factor, viruses are found to have targeted the complex in reply.
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Affiliation(s)
- Matthew W Kenaston
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA 95616, USA
| | - Priya S Shah
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA 95616, USA
- Department of Chemical Engineering, University of California, Davis, CA 95616, USA
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Arbuckle JH, Vogel JL, Efstathiou S, Kristie TM. Deletion of the Transcriptional Coactivator HCF-1 In Vivo Impairs the Removal of Repressive Heterochromatin from Latent HSV Genomes and Suppresses the Initiation of Viral Reactivation. mBio 2023; 14:e0354222. [PMID: 36692302 PMCID: PMC9973298 DOI: 10.1128/mbio.03542-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 01/03/2023] [Indexed: 01/25/2023] Open
Abstract
Transcription of herpes simplex virus 1 (HSV-1) immediate early (IE) genes is controlled at multiple levels by the cellular transcriptional coactivator, HCF-1. HCF-1 is complexed with epigenetic factors that prevent silencing of the viral genome upon infection, transcription factors that drive initiation of IE gene expression, and transcription elongation factors required to circumvent RNAPII pausing at IE genes and promote productive IE mRNA synthesis. Significantly, the coactivator is also implicated in the control of viral reactivation from latency in sensory neurons based on studies that demonstrate that HCF-1-associated epigenetic and transcriptional elongation complexes are critical to initiate IE expression and viral reactivation. Here, an HCF-1 conditional knockout mouse model (HCF-1cKO) was derived to probe the role and significance of HCF-1 in the regulation of HSV-1 latency/reactivation in vivo. Upon deletion of HCF-1 in sensory neurons, there is a striking reduction in the number of latently infected neurons that initiate viral reactivation. Importantly, this correlated with a defect in the removal of repressive chromatin associated with latent viral genomes. These data demonstrate that HCF-1 is a critical regulatory factor that governs the initiation of HSV reactivation, in part, by promoting the transition of latent viral genomes from a repressed heterochromatic state. IMPORTANCE Herpes simplex virus is responsible for a substantial worldwide disease burden. An initial infection leads to the establishment of a lifelong persistent infection in sensory neurons. Periodic reactivation can result in recurrent oral and genital lesions to more significant ocular disease. Despite the significance of this pathogen, many of the regulatory factors and molecular mechanisms that govern the viral latency-reactivation cycles have yet to be elucidated. Initiation of both lytic infection and reactivation are dependent on the expression of the viral immediate early genes. In vivo deletion of a central component of the IE regulatory paradigm, the cellular transcriptional coactivator HCF-1, reduces the epigenetic transition of latent viral genomes, thus suppressing HSV reactivation. These observations define HCF-1 as a critical regulator that controls the initiation of HSV reactivation from latency in vivo and contribute to understanding of the molecular mechanisms that govern viral reactivation.
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Affiliation(s)
- Jesse H. Arbuckle
- Laboratory of Viral Diseases, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Jodi L. Vogel
- Laboratory of Viral Diseases, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Stacey Efstathiou
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Thomas M. Kristie
- Laboratory of Viral Diseases, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
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8
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Zhen X, Xu X, Shao X, Tian H, Xu J, Zhu B, Zuo Y, Zhang L, Yu Y. Risk factors of herpes simplex virus reactivation after surgery for primary trigeminal neuralgia. J Neurovirol 2022; 28:367-373. [PMID: 35334082 DOI: 10.1007/s13365-022-01064-5] [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: 11/16/2021] [Revised: 01/20/2022] [Accepted: 02/10/2022] [Indexed: 11/30/2022]
Abstract
The objective of this study is to investigate the risk factors of oral or facial herpes simplex virus (HSV-1) infection after primary trigeminal neuralgia (PTN). The clinical data of 33 PTN patients admitted by the same surgeon in the neurosurgery were retrospectively analyzed. Among the 33 patients, 26 patients underwent microvascular decompression (MVD), 6 patients who have not been found the clear offending vessels during the operation underwent partial sensory rhizotomy (PSR), and only one underwent adhesive band separation. Thirteen patients with postoperative oral and facial HSV-1 infection were selected as the herpes group, and the remaining 20 patients without postoperative oral and facial HSV-1 infection were selected as the non-herpes group. The differences between the two groups were compared by statistical analysis of factors such as gender, age, operation mode, operation time, and serum HSV-1 antibody titer value before surgery. Compared with the non-herpes group, there were no statistically significant differences in sex ratio (P = 0.930), age composition (P = 0.261), or disease profile (P = 0.226). Twenty-six patients underwent MVD operation, eight of whom were infected, and the difference between the two groups was statistically significant (P = 0.029). The operation time of the herpes group was 10-30 min, which was significantly longer than that of the non-herpes group. The difference in operation time between the two groups was statistically significant (P = 0.023). Serum HSV-1-IgM was negative (< 0.9 COI) in all patients before surgery, but the positive rate of HSV-1-IgG (≥ 1.1 COI) was 97%, and the titer was greater than four times in 97% (32/33) of patients. The titer of IgG antibody in the herpes group was significantly lower than that in the non-herpes group, and the difference between the two groups was statistically significant (P = 0.017). The serum HSV-1-IgG in most of the PTN patients was positive. Latent HSV-1 in the trigeminal ganglion may be reactivate after PTN surgery to produce ipsilateral oral and facial herpes infection. The infection of HSV-1 reactivation after PTN surgery was positively correlated with the operation time but negatively correlated with the titer of HSV-1-IgG antibody before PTN surgery. The incidence of HSV-1 infection after PTN operation is related to different surgical procedures.
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Affiliation(s)
- Xueke Zhen
- Department of Neurosurgery, China-Japan Friendship Hospital, No. 2 East Cherry Street, Chaoyang District, Beijing, 100029, China
| | - Xiaoli Xu
- Department of Neurosurgery, China-Japan Friendship Hospital, No. 2 East Cherry Street, Chaoyang District, Beijing, 100029, China
| | - Xu Shao
- Department of Neurosurgery, China-Japan Friendship Hospital, No. 2 East Cherry Street, Chaoyang District, Beijing, 100029, China
| | - Hong Tian
- Department of Neurosurgery, China-Japan Friendship Hospital, No. 2 East Cherry Street, Chaoyang District, Beijing, 100029, China
| | - Jun Xu
- Department of Neurosurgery, China-Japan Friendship Hospital, No. 2 East Cherry Street, Chaoyang District, Beijing, 100029, China
| | - Bin Zhu
- Department of Neurosurgery, China-Japan Friendship Hospital, No. 2 East Cherry Street, Chaoyang District, Beijing, 100029, China
| | - Ying Zuo
- Department of Neurosurgery, China-Japan Friendship Hospital, No. 2 East Cherry Street, Chaoyang District, Beijing, 100029, China
| | - Li Zhang
- Department of Neurosurgery, China-Japan Friendship Hospital, No. 2 East Cherry Street, Chaoyang District, Beijing, 100029, China
| | - Yanbing Yu
- Department of Neurosurgery, China-Japan Friendship Hospital, No. 2 East Cherry Street, Chaoyang District, Beijing, 100029, China.
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9
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Schang LM, Hu M, Cortes EF, Sun K. Chromatin-mediated epigenetic regulation of HSV-1 transcription as a potential target in antiviral therapy. Antiviral Res 2021; 192:105103. [PMID: 34082058 PMCID: PMC8277756 DOI: 10.1016/j.antiviral.2021.105103] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 05/21/2021] [Accepted: 05/26/2021] [Indexed: 12/13/2022]
Abstract
The ability to establish, and reactivate from, latent infections is central to the biology and pathogenesis of HSV-1. It also poses a strong challenge to antiviral therapy, as latent HSV-1 genomes do not replicate or express any protein to be targeted. Although the processes regulating the establishment and maintenance of, and reactivation from, latency are not fully elucidated, the current general consensus is that epigenetics play a major role. A unifying model postulates that whereas HSV-1 avoids or counteracts chromatin silencing in lytic infections, it becomes silenced during latency, silencing which is somewhat disrupted during reactivation. Many years of work by different groups using a variety of approaches have also shown that the lytic HSV-1 chromatin is distinct and has unique biophysical properties not shared with most cellular chromatin. Nonetheless, the lytic and latent viral chromatins are typically enriched in post translational modifications or histone variants characteristic of active or repressed transcription, respectively. Moreover, a variety of small molecule epigenetic modulators inhibit viral replication and reactivation from latency. Despite these successes in culture and animal models, it is not obvious how epigenetic modulation would be used in antiviral therapy if the same epigenetic mechanisms governed viral and cellular gene expression. Recent work has highlighted several important differences between the viral and cellular chromatins, which appear to be of consequence to their respective epigenetic regulations. In this review, we will discuss the distinctiveness of the viral chromatin, and explore whether it is regulated by mechanisms unique enough to be exploited in antiviral therapy.
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Affiliation(s)
- Luis M Schang
- Department of Microbiology and Immunology and Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University. 235 Hungerford Hill Road, Ithaca, NY, 14850, USA.
| | - MiYao Hu
- Department of Microbiology and Immunology and Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University. 235 Hungerford Hill Road, Ithaca, NY, 14850, USA; Departments of Biochemistry and Medical Microbiology and Immunology, University of Alberta. 470 MSB, Edmonton, AB, T6G 2H7, Canada.
| | - Esteban Flores Cortes
- Department of Microbiology and Immunology and Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University. 235 Hungerford Hill Road, Ithaca, NY, 14850, USA.
| | - Kairui Sun
- Department of Microbiology and Immunology and Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University. 235 Hungerford Hill Road, Ithaca, NY, 14850, USA.
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10
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Mandal R, Becker S, Strebhardt K. Targeting CDK9 for Anti-Cancer Therapeutics. Cancers (Basel) 2021; 13:2181. [PMID: 34062779 PMCID: PMC8124690 DOI: 10.3390/cancers13092181] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/28/2021] [Accepted: 04/29/2021] [Indexed: 12/23/2022] Open
Abstract
Cyclin Dependent Kinase 9 (CDK9) is one of the most important transcription regulatory members of the CDK family. In conjunction with its main cyclin partner-Cyclin T1, it forms the Positive Transcription Elongation Factor b (P-TEFb) whose primary function in eukaryotic cells is to mediate the positive transcription elongation of nascent mRNA strands, by phosphorylating the S2 residues of the YSPTSPS tandem repeats at the C-terminus domain (CTD) of RNA Polymerase II (RNAP II). To aid in this process, P-TEFb also simultaneously phosphorylates and inactivates a number of negative transcription regulators like 5,6-dichloro-1-β-D-ribofuranosylbenzimidazole (DRB) Sensitivity-Inducing Factor (DSIF) and Negative Elongation Factor (NELF). Significantly enhanced activity of CDK9 is observed in multiple cancer types, which is universally associated with significantly shortened Overall Survival (OS) of the patients. In these cancer types, CDK9 regulates a plethora of cellular functions including proliferation, survival, cell cycle regulation, DNA damage repair and metastasis. Due to the extremely critical role of CDK9 in cancer cells, inhibiting its functions has been the subject of intense research, resulting the development of multiple, increasingly specific small-molecule inhibitors, some of which are presently in clinical trials. The search for newer generation CDK9 inhibitors with higher specificity and lower potential toxicities and suitable combination therapies continues. In fact, the Phase I clinical trials of the latest, highly specific CDK9 inhibitor BAY1251152, against different solid tumors have shown good anti-tumor and on-target activities and pharmacokinetics, combined with manageable safety profile while the phase I and II clinical trials of another inhibitor AT-7519 have been undertaken or are undergoing. To enhance the effectiveness and target diversity and reduce potential drug-resistance, the future of CDK9 inhibition would likely involve combining CDK9 inhibitors with inhibitors like those against BRD4, SEC, MYC, MCL-1 and HSP90.
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Affiliation(s)
- Ranadip Mandal
- Department of Gynecology and Obstetrics, Johann Wolfgang Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (R.M.); (S.B.)
| | - Sven Becker
- Department of Gynecology and Obstetrics, Johann Wolfgang Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (R.M.); (S.B.)
| | - Klaus Strebhardt
- Department of Gynecology and Obstetrics, Johann Wolfgang Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (R.M.); (S.B.)
- German Cancer Consortium (DKTK), 69120 Heidelberg, Germany
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11
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Groves IJ, Jackson SE, Poole EL, Nachshon A, Rozman B, Schwartz M, Prinjha RK, Tough DF, Sinclair JH, Wills MR. Bromodomain proteins regulate human cytomegalovirus latency and reactivation allowing epigenetic therapeutic intervention. Proc Natl Acad Sci U S A 2021; 118:e2023025118. [PMID: 33619107 PMCID: PMC7936348 DOI: 10.1073/pnas.2023025118] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Reactivation of human cytomegalovirus (HCMV) from latency is a major health consideration for recipients of stem-cell and solid organ transplantations. With over 200,000 transplants taking place globally per annum, virus reactivation can occur in more than 50% of cases leading to loss of grafts as well as serious morbidity and even mortality. Here, we present the most extensive screening to date of epigenetic inhibitors on HCMV latently infected cells and find that histone deacetylase inhibitors (HDACis) and bromodomain inhibitors are broadly effective at inducing virus immediate early gene expression. However, while HDACis, such as myeloid-selective CHR-4487, lead to production of infectious virions, inhibitors of bromodomain (BRD) and extraterminal proteins (I-BETs), including GSK726, restrict full reactivation. Mechanistically, we show that BET proteins (BRDs) are pivotally connected to regulation of HCMV latency and reactivation. Through BRD4 interaction, the transcriptional activator complex P-TEFb (CDK9/CycT1) is sequestered by repressive complexes during HCMV latency. Consequently, I-BETs allow release of P-TEFb and subsequent recruitment to promoters via the superelongation complex (SEC), inducing transcription of HCMV lytic genes encoding immunogenic antigens from otherwise latently infected cells. Surprisingly, this occurs without inducing many viral immunoevasins and, importantly, while also restricting viral DNA replication and full HCMV reactivation. Therefore, this pattern of HCMV transcriptional dysregulation allows effective cytotoxic immune targeting and killing of latently infected cells, thus reducing the latent virus genome load. This approach could be safely used to pre-emptively purge the virus latent reservoir prior to transplantation, thereby reducing HCMV reactivation-related morbidity and mortality.
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MESH Headings
- Azepines/pharmacology
- Bacterial Proteins/genetics
- Bacterial Proteins/metabolism
- Benzodiazepines/pharmacology
- Cell Cycle Proteins/antagonists & inhibitors
- Cell Cycle Proteins/genetics
- Cell Cycle Proteins/immunology
- Cyclin T/genetics
- Cyclin T/immunology
- Cyclin-Dependent Kinase 9/genetics
- Cyclin-Dependent Kinase 9/immunology
- Cytomegalovirus/drug effects
- Cytomegalovirus/genetics
- Cytomegalovirus/immunology
- Cytomegalovirus Infections/genetics
- Cytomegalovirus Infections/immunology
- Cytomegalovirus Infections/pathology
- DNA Replication/drug effects
- DNA, Viral/antagonists & inhibitors
- DNA, Viral/genetics
- DNA, Viral/immunology
- Epigenesis, Genetic
- Genes, Immediate-Early
- Genes, Reporter
- Histone Deacetylase Inhibitors/pharmacology
- Histone Deacetylases/genetics
- Histone Deacetylases/immunology
- Host-Pathogen Interactions
- Humans
- Luminescent Proteins/genetics
- Luminescent Proteins/metabolism
- Models, Biological
- Positive Transcriptional Elongation Factor B/genetics
- Positive Transcriptional Elongation Factor B/immunology
- Primary Cell Culture
- Promoter Regions, Genetic
- T-Lymphocytes, Cytotoxic/drug effects
- T-Lymphocytes, Cytotoxic/immunology
- T-Lymphocytes, Cytotoxic/virology
- THP-1 Cells
- Thalidomide/analogs & derivatives
- Thalidomide/pharmacology
- Transcription Factors/antagonists & inhibitors
- Transcription Factors/genetics
- Transcription Factors/immunology
- Transcription, Genetic
- Virus Activation/drug effects
- Virus Latency/drug effects
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Affiliation(s)
- Ian J Groves
- Cambridge Institute of Therapeutic Immunology and Infectious Disease, Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, CB2 0QQ, United Kingdom;
| | - Sarah E Jackson
- Cambridge Institute of Therapeutic Immunology and Infectious Disease, Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, CB2 0QQ, United Kingdom
| | - Emma L Poole
- Cambridge Institute of Therapeutic Immunology and Infectious Disease, Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, CB2 0QQ, United Kingdom
| | - Aharon Nachshon
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Batsheva Rozman
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Michal Schwartz
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Rab K Prinjha
- Adaptive Immunity Research Unit, GlaxoSmithKline Medicines Research Centre, Stevenage, SG1 2NY, United Kingdom
| | - David F Tough
- Adaptive Immunity Research Unit, GlaxoSmithKline Medicines Research Centre, Stevenage, SG1 2NY, United Kingdom
| | - John H Sinclair
- Cambridge Institute of Therapeutic Immunology and Infectious Disease, Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, CB2 0QQ, United Kingdom
| | - Mark R Wills
- Cambridge Institute of Therapeutic Immunology and Infectious Disease, Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, CB2 0QQ, United Kingdom;
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