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Kantor B, O'Donovan B, Rittiner J, Hodgson D, Lindner N, Guerrero S, Dong W, Zhang A, Chiba-Falek O. The therapeutic implications of all-in-one AAV-delivered epigenome-editing platform in neurodegenerative disorders. Nat Commun 2024; 15:7259. [PMID: 39179542 PMCID: PMC11344155 DOI: 10.1038/s41467-024-50515-6] [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: 04/09/2023] [Accepted: 07/12/2024] [Indexed: 08/26/2024] Open
Abstract
Safely and efficiently controlling gene expression is a long-standing goal of biomedical research, and CRISPR/Cas system can be harnessed to create powerful tools for epigenetic editing. Adeno-associated-viruses (AAVs) represent the delivery vehicle of choice for therapeutic platform. However, their small packaging capacity isn't suitable for large constructs including most CRISPR/dCas9-effector vectors. Thus, AAV-based CRISPR/Cas systems have been delivered via two separate viral vectors. Here we develop a compact CRISPR/dCas9-based repressor system packaged in AAV as a single optimized vector. The system comprises the small Staphylococcus aureus (Sa)dCas9 and an engineered repressor molecule, a fusion of MeCP2's transcription repression domain (TRD) and KRAB. The dSaCas9-KRAB-MeCP2(TRD) vector platform repressed robustly and sustainably the expression of multiple genes-of-interest, in vitro and in vivo, including ApoE, the strongest genetic risk factor for late onset Alzheimer's disease (LOAD). Our platform broadens the CRISPR/dCas9 toolset available for transcriptional manipulation of gene expression in research and therapeutic settings.
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Affiliation(s)
- Boris Kantor
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA.
- Viral Vector Core, Duke University School of Medicine, Durham, NC, USA.
- Center for Advanced Genomic Technologies, Duke University School of Medicine, Durham, NC, USA.
| | - Bernadette O'Donovan
- Division of Translational Brain Sciences, Department of Neurology, Duke University School of Medicine, Durham, NC, USA
- Center for Genomic and Computational Biology, Duke University School of Medicine, Durham, NC, USA
| | - Joseph Rittiner
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA
- Viral Vector Core, Duke University School of Medicine, Durham, NC, USA
- Center for Advanced Genomic Technologies, Duke University School of Medicine, Durham, NC, USA
| | - Dellila Hodgson
- Division of Translational Brain Sciences, Department of Neurology, Duke University School of Medicine, Durham, NC, USA
- Center for Genomic and Computational Biology, Duke University School of Medicine, Durham, NC, USA
| | - Nicholas Lindner
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA
- Viral Vector Core, Duke University School of Medicine, Durham, NC, USA
- Center for Advanced Genomic Technologies, Duke University School of Medicine, Durham, NC, USA
| | - Sophia Guerrero
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA
- Viral Vector Core, Duke University School of Medicine, Durham, NC, USA
- Center for Advanced Genomic Technologies, Duke University School of Medicine, Durham, NC, USA
| | - Wendy Dong
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA
- Viral Vector Core, Duke University School of Medicine, Durham, NC, USA
- Center for Advanced Genomic Technologies, Duke University School of Medicine, Durham, NC, USA
| | - Austin Zhang
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA
- Viral Vector Core, Duke University School of Medicine, Durham, NC, USA
- Center for Advanced Genomic Technologies, Duke University School of Medicine, Durham, NC, USA
| | - Ornit Chiba-Falek
- Division of Translational Brain Sciences, Department of Neurology, Duke University School of Medicine, Durham, NC, USA.
- Center for Genomic and Computational Biology, Duke University School of Medicine, Durham, NC, USA.
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2
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D'Orso I. The HIV-1 Transcriptional Program: From Initiation to Elongation Control. J Mol Biol 2024:168690. [PMID: 38936695 DOI: 10.1016/j.jmb.2024.168690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 06/20/2024] [Accepted: 06/21/2024] [Indexed: 06/29/2024]
Abstract
A large body of work in the last four decades has revealed the key pillars of HIV-1 transcription control at the initiation and elongation steps. Here, I provide a recount of this collective knowledge starting with the genomic elements (DNA and nascent TAR RNA stem-loop) and transcription factors (cellular and the viral transactivator Tat), and later transitioning to the assembly and regulation of transcription initiation and elongation complexes, and the role of chromatin structure. Compelling evidence support a core HIV-1 transcriptional program regulated by the sequential and concerted action of cellular transcription factors and Tat to promote initiation and sustain elongation, highlighting the efficiency of a small virus to take over its host to produce the high levels of transcription required for viral replication. I summarize new advances including the use of CRISPR-Cas9, genetic tools for acute factor depletion, and imaging to study transcriptional dynamics, bursting and the progression through the multiple phases of the transcriptional cycle. Finally, I describe current challenges to future major advances and discuss areas that deserve more attention to both bolster our basic knowledge of the core HIV-1 transcriptional program and open up new therapeutic opportunities.
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Affiliation(s)
- Iván D'Orso
- Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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3
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Kantor B, Odonovan B, Rittiner J, Hodgson D, Lindner N, Guerrero S, Dong W, Zhang A, Chiba-Falek O. All-in-one AAV-delivered epigenome-editing platform: proof-of-concept and therapeutic implications for neurodegenerative disorders. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.04.14.536951. [PMID: 38798630 PMCID: PMC11118458 DOI: 10.1101/2023.04.14.536951] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Safely and efficiently controlling gene expression is a long-standing goal of biomedical research, and the recently discovered bacterial CRISPR/Cas system can be harnessed to create powerful tools for epigenetic editing. Current state-of-the-art systems consist of a deactivated-Cas9 nuclease (dCas9) fused to one of several epigenetic effector motifs/domains, along with a guide RNA (gRNA) which defines the genomic target. Such systems have been used to safely and effectively silence or activate a specific gene target under a variety of circumstances. Adeno-associated vectors (AAVs) are the therapeutic platform of choice for the delivery of genetic cargo; however, their small packaging capacity is not suitable for delivery of large constructs, which includes most CRISPR/dCas9-effector systems. To circumvent this, many AAV-based CRISPR/Cas tools are delivered in two pieces, from two separate viral cassettes. However, this approach requires higher viral payloads and usually is less efficient. Here we develop a compact dCas9-based repressor system packaged within a single, optimized AAV vector. The system uses a smaller dCas9 variant derived from Staphylococcus aureus ( Sa ). A novel repressor was engineered by fusing the small transcription repression domain (TRD) from MeCP2 with the KRAB repression domain. The final d Sa Cas9-KRAB-MeCP2(TRD) construct can be efficiently packaged, along with its associated gRNA, into AAV particles. Using reporter assays, we demonstrate that the platform is capable of robustly and sustainably repressing the expression of multiple genes-of-interest, both in vitro and in vivo . Moreover, we successfully reduced the expression of ApoE, the stronger genetic risk factor for late onset Alzheimer's disease (LOAD). This new platform will broaden the CRISPR/dCas9 toolset available for transcriptional manipulation of gene expression in research and therapeutic settings.
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4
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Kilroy JM, Leal AA, Henderson AJ. Chronic HIV Transcription, Translation, and Persistent Inflammation. Viruses 2024; 16:751. [PMID: 38793632 PMCID: PMC11125830 DOI: 10.3390/v16050751] [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: 04/16/2024] [Revised: 05/02/2024] [Accepted: 05/07/2024] [Indexed: 05/26/2024] Open
Abstract
People with HIV exhibit persistent inflammation that correlates with HIV-associated comorbidities including accelerated aging, increased risk of cardiovascular disease, and neuroinflammation. Mechanisms that perpetuate chronic inflammation in people with HIV undergoing antiretroviral treatments are poorly understood. One hypothesis is that the persistent low-level expression of HIV proviruses, including RNAs generated from defective proviral genomes, drives the immune dysfunction that is responsible for chronic HIV pathogenesis. We explore factors during HIV infection that contribute to the generation of a pool of defective proviruses as well as how HIV-1 mRNA and proteins alter immune function in people living with HIV.
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Affiliation(s)
- Jonathan M. Kilroy
- Department of Virology, Immunology, Microbiology, Boston University Chobanian and Avedisian School of Medicine, Boston, MA 02118, USA; (J.M.K.); (A.A.L.)
| | - Andrew A. Leal
- Department of Virology, Immunology, Microbiology, Boston University Chobanian and Avedisian School of Medicine, Boston, MA 02118, USA; (J.M.K.); (A.A.L.)
| | - Andrew J. Henderson
- Department of Virology, Immunology, Microbiology, Boston University Chobanian and Avedisian School of Medicine, Boston, MA 02118, USA; (J.M.K.); (A.A.L.)
- Department of Medicine and Virology, Immunology, Microbiology, Boston University Chobanian and Avedisian School of Medicine, Boston, MA 02118, USA
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5
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Chen J, He Y, Zhong H, Hu F, Li Y, Zhang Y, Zhang X, Lin W, Li Q, Xu F, Chen S, Zhang H, Cai W, Li L. Transcriptome analysis of CD4+ T cells from HIV-infected individuals receiving ART with LLV revealed novel transcription factors regulating HIV-1 promoter activity. Virol Sin 2023:S1995-820X(23)00022-6. [PMID: 36907331 DOI: 10.1016/j.virs.2023.03.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 03/06/2023] [Indexed: 03/12/2023] Open
Abstract
Some HIV-infected individuals receiving ART develop low-level viremia (LLV), with a plasma viral load of 50-1000 copies/mL. Persistent low-level viremia is associated with subsequent virologic failure. The peripheral blood CD4+ T cell pool is a source of LLV. However, the intrinsic characteristics of CD4+ T cells in LLV which may contribute to low-level viremia are largely unknown. We analyzed the transcriptome profiling of peripheral blood CD4+ T cells from healthy controls (HC) and HIV-infected patients receiving ART with either virologic suppression (VS) or LLV. To identify pathways potentially responding to increasing viral loads from HC to VS and to LLV, KEGG pathways of differentially expressed genes (DEGs) were acquired by comparing VS with HC (VS-HC group) and LLV with VS (LLV-VS group). Characterization of DEGs in key overlapping pathways showed that CD4+ T cells in LLV expressed higher levels of Th1 signature transcription factors (TBX21), toll-like receptors (TLR-4, -6, -7 and -8), anti-HIV entry chemokines (CCL3 and CCL4), and anti-IL-1β factors (ILRN and IL1R2) compared to VS. Our results also indicated activation of the NF-κB and TNF signaling pathways that could promote HIV-1 transcription. Finally, we evaluated the effects of 4 and 17 transcription factors that were upregulated in the VS-HC and LLV-VS groups, respectively, on HIV-1 promoter activity. Functional studies revealed that CXXC5 significantly increased, while SOX5 markedly suppressed HIV-1 transcription. In summary, we found that CD4+ T cells in LLV displayed a distinct mRNA profiling compared to that in VS, which promoted HIV-1 replication and reactivation of viral latency and may eventually contribute to virologic failure in patients with persistent LLV. CXXC5 and SOX5 may serve as targets for the development of latency-reversing agents.
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Affiliation(s)
- Jingliang Chen
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou, 510440, China
| | - Yaozu He
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou, 510440, China
| | - Huolin Zhong
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou, 510440, China
| | - Fengyu Hu
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou, 510440, China
| | - Yonghong Li
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou, 510440, China
| | - Yeyang Zhang
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou, 510440, China
| | - Xia Zhang
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou, 510440, China
| | - Weiyin Lin
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou, 510440, China
| | - Quanmin Li
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou, 510440, China
| | - Feilong Xu
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou, 510440, China
| | - Shaozhen Chen
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou, 510440, China
| | - Hui Zhang
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China; Guangzhou Laboratory, Guangzhou International Bio-Island, Guangzhou, 510005, China.
| | - Weiping Cai
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou, 510440, China.
| | - Linghua Li
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou, 510440, China.
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6
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Ne E, Crespo R, Izquierdo-Lara R, Rao S, Koçer S, Górska A, van Staveren T, Kan TW, van de Vijver D, Dekkers D, Rokx C, Moulos P, Hatzis P, Palstra RJ, Demmers J, Mahmoudi T. Catchet-MS identifies IKZF1-targeting thalidomide analogues as novel HIV-1 latency reversal agents. Nucleic Acids Res 2022; 50:5577-5598. [PMID: 35640596 PMCID: PMC9177988 DOI: 10.1093/nar/gkac407] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 04/11/2022] [Accepted: 05/24/2022] [Indexed: 12/27/2022] Open
Abstract
A major pharmacological strategy toward HIV cure aims to reverse latency in infected cells as a first step leading to their elimination. While the unbiased identification of molecular targets physically associated with the latent HIV-1 provirus would be highly valuable to unravel the molecular determinants of HIV-1 transcriptional repression and latency reversal, due to technical limitations, this has been challenging. Here we use a dCas9 targeted chromatin and histone enrichment strategy coupled to mass spectrometry (Catchet-MS) to probe the differential protein composition of the latent and activated HIV-1 5′LTR. Catchet-MS identified known and novel latent 5′LTR-associated host factors. Among these, IKZF1 is a novel HIV-1 transcriptional repressor, required for Polycomb Repressive Complex 2 recruitment to the LTR. We find the clinically advanced thalidomide analogue iberdomide, and the FDA approved analogues lenalidomide and pomalidomide, to be novel LRAs. We demonstrate that, by targeting IKZF1 for degradation, these compounds reverse HIV-1 latency in CD4+ T-cells isolated from virally suppressed people living with HIV-1 and that they are able to synergize with other known LRAs.
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Affiliation(s)
- Enrico Ne
- Department of Biochemistry, Erasmus University Medical Center, Ee622 PO Box 2040, 3000CA Rotterdam, The Netherlands
| | - Raquel Crespo
- Department of Biochemistry, Erasmus University Medical Center, Ee622 PO Box 2040, 3000CA Rotterdam, The Netherlands
| | - Ray Izquierdo-Lara
- Department of Biochemistry, Erasmus University Medical Center, Ee622 PO Box 2040, 3000CA Rotterdam, The Netherlands
| | - Shringar Rao
- Department of Biochemistry, Erasmus University Medical Center, Ee622 PO Box 2040, 3000CA Rotterdam, The Netherlands
| | - Selin Koçer
- Department of Biochemistry, Erasmus University Medical Center, Ee622 PO Box 2040, 3000CA Rotterdam, The Netherlands
| | - Alicja Górska
- Department of Biochemistry, Erasmus University Medical Center, Ee622 PO Box 2040, 3000CA Rotterdam, The Netherlands
| | - Thomas van Staveren
- Department of Biochemistry, Erasmus University Medical Center, Ee622 PO Box 2040, 3000CA Rotterdam, The Netherlands
| | - Tsung Wai Kan
- Department of Biochemistry, Erasmus University Medical Center, Ee622 PO Box 2040, 3000CA Rotterdam, The Netherlands.,Department of Pathology, Erasmus University Medical Center, The Netherlands.,Department of Urology, Erasmus University Medical Center, The Netherlands
| | - David van de Vijver
- Department of Viroscience, Erasmus University Medical Center, The Netherlands
| | - Dick Dekkers
- Proteomics Center, Erasmus University Medical Center, Ee679a PO Box 2040, 3000CA Rotterdam, The Netherlands
| | - Casper Rokx
- Department of Internal Medicine, Section of Infectious Diseases, Erasmus University Medical Center, Rg-530, PO Box 2040, 3000CA Rotterdam, The Netherlands
| | - Panagiotis Moulos
- Institute for Fundamental Biomedical Research, Biomedical Sciences Research Center "Alexander Fleming", 16672, Vari, Greece
| | - Pantelis Hatzis
- Institute for Fundamental Biomedical Research, Biomedical Sciences Research Center "Alexander Fleming", 16672, Vari, Greece
| | - Robert-Jan Palstra
- Department of Biochemistry, Erasmus University Medical Center, Ee622 PO Box 2040, 3000CA Rotterdam, The Netherlands.,Department of Pathology, Erasmus University Medical Center, The Netherlands.,Department of Urology, Erasmus University Medical Center, The Netherlands
| | - Jeroen Demmers
- Proteomics Center, Erasmus University Medical Center, Ee679a PO Box 2040, 3000CA Rotterdam, The Netherlands
| | - Tokameh Mahmoudi
- Department of Biochemistry, Erasmus University Medical Center, Ee622 PO Box 2040, 3000CA Rotterdam, The Netherlands.,Department of Pathology, Erasmus University Medical Center, The Netherlands.,Department of Urology, Erasmus University Medical Center, The Netherlands
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7
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Papolu PK, Ramakrishnan M, Wei Q, Vinod KK, Zou LH, Yrjala K, Kalendar R, Zhou M. Long terminal repeats (LTR) and transcription factors regulate PHRE1 and PHRE2 activity in Moso bamboo under heat stress. BMC PLANT BIOLOGY 2021; 21:585. [PMID: 34886797 PMCID: PMC8656106 DOI: 10.1186/s12870-021-03339-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 11/12/2021] [Indexed: 05/28/2023]
Abstract
BACKGROUND LTR retrotransposons play a significant role in plant growth, genome evolution, and environmental stress response, but their regulatory response to heat stress remains unclear. We have investigated the activities of two LTR retrotransposons, PHRE1 and PHRE2, of moso bamboo (Phyllostachys edulis) in response to heat stress. RESULTS The differential overexpression of PHRE1 and PHRE2 with or without CaMV35s promoter showed enhanced expression under heat stress in transgenic plants. The transcriptional activity studies showed an increase in transposition activity and copy number among moso bamboo wild type and Arabidopsis transgenic plants under heat stress. Comparison of promoter activity in transgenic plants indicated that 5'LTR promoter activity was higher than CaMV35s promoter. Additionally, yeast one-hybrid (Y1H) system and in planta biomolecular fluorescence complementation (BiFC) assay revealed interactions of heat-dependent transcription factors (TFs) with 5'LTR sequence and direct interactions of TFs with pol and gag. CONCLUSIONS Our results conclude that the 5'LTR acts as a promoter and could regulate the LTR retrotransposons in moso bamboo under heat stress.
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Affiliation(s)
- Pradeep K Papolu
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, Hangzhou, 311300, Zhejiang, China
| | - Muthusamy Ramakrishnan
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, Hangzhou, 311300, Zhejiang, China
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
- Bamboo Research Institute, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
| | - Qiang Wei
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
- Bamboo Research Institute, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
| | | | - Long-Hai Zou
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, Hangzhou, 311300, Zhejiang, China
| | - Kim Yrjala
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, Hangzhou, 311300, Zhejiang, China
| | - Ruslan Kalendar
- Helsinki Institute of Life Science HiLIFE, Biocenter 3, Viikinkaari 1, FI-00014 University of Helsinki, Helsinki, Finland
| | - Mingbing Zhou
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, Hangzhou, 311300, Zhejiang, China.
- Zhejiang Provincial Collaborative Innovation Centre for Bamboo Resources and High-efficiency Utilization, Zhejiang A&F University, Hangzhou, 311300, Zhejiang, China.
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8
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Kuniholm J, Armstrong E, Bernabe B, Coote C, Berenson A, Patalano SD, Olson A, He X, Lin NH, Fuxman Bass JI, Henderson AJ. Intragenic proviral elements support transcription of defective HIV-1 proviruses. PLoS Pathog 2021; 17:e1009982. [PMID: 34962974 PMCID: PMC8746790 DOI: 10.1371/journal.ppat.1009982] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 01/10/2022] [Accepted: 12/07/2021] [Indexed: 11/18/2022] Open
Abstract
HIV-1 establishes a persistent proviral reservoir by integrating into the genome of infected host cells. Current antiretroviral treatments do not target this persistent population of proviruses which include latently infected cells that upon treatment interruption can be reactivated to contribute to HIV-1 rebound. Deep sequencing of persistent HIV proviruses has revealed that greater than 90% of integrated HIV genomes are defective and unable to produce infectious virions. We hypothesized that intragenic elements in the HIV genome support transcription of aberrant HIV-1 RNAs from defective proviruses that lack long terminal repeats (LTRs). Using an intact provirus detection assay, we observed that resting CD4+ T cells and monocyte-derived macrophages (MDMs) are biased towards generating defective HIV-1 proviruses. Multiplex reverse transcription droplet digital PCR identified env and nef transcripts which lacked 5' untranslated regions (UTR) in acutely infected CD4+ T cells and MDMs indicating transcripts are generated that do not utilize the promoter within the LTR. 5'UTR-deficient env transcripts were also identified in a cohort of people living with HIV (PLWH) on ART, suggesting that these aberrant RNAs are produced in vivo. Using 5' rapid amplification of cDNA ends (RACE), we mapped the start site of these transcripts within the Env gene. This region bound several cellular transcription factors and functioned as a transcriptional regulatory element that could support transcription and translation of downstream HIV-1 RNAs. These studies provide mechanistic insights into how defective HIV-1 proviruses are persistently expressed to potentially drive inflammation in PLWH.
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Affiliation(s)
- Jeffrey Kuniholm
- Boston University School of Medicine, Department of Microbiology, Boston, Massachusetts, United States of America
| | - Elise Armstrong
- Boston University School of Medicine, Department of Medicine, Section of Infectious Diseases; Boston, Massachusetts, United States of America
| | - Brandy Bernabe
- Boston University School of Medicine Graduate Medical Sciences, Boston, Massachusetts, United States of America
| | - Carolyn Coote
- Boston University School of Medicine, Department of Medicine, Section of Infectious Diseases; Boston, Massachusetts, United States of America
| | - Anna Berenson
- Boston University, Department of Biology, Boston, Massachusetts, United States of America
| | - Samantha D. Patalano
- Boston University, Department of Biology, Boston, Massachusetts, United States of America
| | - Alex Olson
- Boston University School of Medicine, Department of Medicine, Section of Infectious Diseases; Boston, Massachusetts, United States of America
| | - Xianbao He
- Boston University School of Medicine, Department of Medicine, Section of Infectious Diseases; Boston, Massachusetts, United States of America
| | - Nina H. Lin
- Boston University School of Medicine, Department of Medicine, Section of Infectious Diseases; Boston, Massachusetts, United States of America
| | - Juan I. Fuxman Bass
- Boston University, Department of Biology, Boston, Massachusetts, United States of America
| | - Andrew J. Henderson
- Boston University School of Medicine, Department of Microbiology, Boston, Massachusetts, United States of America
- Boston University School of Medicine, Department of Medicine, Section of Infectious Diseases; Boston, Massachusetts, United States of America
- Boston University School of Medicine Graduate Medical Sciences, Boston, Massachusetts, United States of America
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9
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Depicting HIV-1 Transcriptional Mechanisms: A Summary of What We Know. Viruses 2020; 12:v12121385. [PMID: 33287435 PMCID: PMC7761857 DOI: 10.3390/v12121385] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 11/26/2020] [Accepted: 12/01/2020] [Indexed: 12/19/2022] Open
Abstract
Despite the introduction of combinatory antiretroviral therapy (cART), HIV-1 infection cannot be cured and is still one of the major health issues worldwide. Indeed, as soon as cART is interrupted, a rapid rebound of viremia is observed. The establishment of viral latency and the persistence of the virus in cellular reservoirs constitute the main barrier to HIV eradication. For this reason, new therapeutic approaches have emerged to purge or restrain the HIV-1 reservoirs in order to cure infected patients. However, the viral latency is a multifactorial process that depends on various cellular mechanisms. Since these new therapies mainly target viral transcription, their development requires a detailed and precise understanding of the regulatory mechanism underlying HIV-1 transcription. In this review, we discuss the complex molecular transcriptional network regulating HIV-1 gene expression by focusing on the involvement of host cell factors that could be used as potential drug targets to design new therapeutic strategies and, to a larger extent, to reach an HIV-1 functional cure.
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10
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Tagliafierro L, Ilich E, Moncalvo M, Gu J, Sriskanda A, Grenier C, Murphy SK, Chiba-Falek O, Kantor B. Lentiviral Vector Platform for the Efficient Delivery of Epigenome-editing Tools into Human Induced Pluripotent Stem Cell-derived Disease Models. J Vis Exp 2019. [PMID: 30985756 DOI: 10.3791/59241] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The use of hiPSC-derived cells represents a valuable approach to study human neurodegenerative diseases. Here, we describe an optimized protocol for the differentiation of hiPSCs derived from a patient with the triplication of the alpha-synuclein gene (SNCA) locus into Parkinson's disease (PD)-relevant dopaminergic neuronal populations. Accumulating evidence has shown that high levels of SNCA are causative for the development of PD. Recognizing the unmet need to establish novel therapeutic approaches for PD, especially those targeting the regulation of SNCA expression, we recently developed a CRISPR/dCas9-DNA-methylation-based system to epigenetically modulate SNCA transcription by enriching methylation levels at the SNCA intron 1 regulatory region. To deliver the system, consisting of a dead (deactivated) version of Cas9 (dCas9) fused with the catalytic domain of the DNA methyltransferase enzyme 3A (DNMT3A), a lentiviral vector is used. This system is applied to cells with the triplication of the SNCA locus and reduces the SNCA-mRNA and protein levels by about 30% through the targeted DNA methylation of SNCA intron 1. The fine-tuned downregulation of the SNCA levels rescues disease-related cellular phenotypes. In the current protocol, we aim to describe a step-by-step procedure for differentiating hiPSCs into neural progenitor cells (NPCs) and the establishment and validation of pyrosequencing assays for the evaluation of the methylation profile in the SNCA intron 1. To outline in more detail the lentivirus-CRISPR/dCas9 system used in these experiments, this protocol describes how to produce, purify, and concentrate lentiviral vectors and to highlight their suitability for epigenome- and genome-editing applications using hiPSCs and NPCs. The protocol is easily adaptable and can be used to produce high titer lentiviruses for in vitro and in vivo applications.
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Affiliation(s)
- Lidia Tagliafierro
- Department of Neurology, Duke University Medical Center; Center for Genomic and Computational Biology, Duke University Medical Center
| | | | | | - Jeffrey Gu
- Department of Neurology, Duke University Medical Center
| | - Ahila Sriskanda
- Department of Neurology, Duke University Medical Center; Center for Genomic and Computational Biology, Duke University Medical Center
| | - Carole Grenier
- Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Duke University Medical Center
| | - Susan K Murphy
- Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Duke University Medical Center
| | - Ornit Chiba-Falek
- Department of Neurology, Duke University Medical Center; Center for Genomic and Computational Biology, Duke University Medical Center;
| | - Boris Kantor
- Viral Vector Core, Duke University Medical Center;
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11
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Khoury G, Darcis G, Lee MY, Bouchat S, Van Driessche B, Purcell DFJ, Van Lint C. The Molecular Biology of HIV Latency. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1075:187-212. [PMID: 30030794 DOI: 10.1007/978-981-13-0484-2_8] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
HIV remains incurable due to the existence of a reservoir of cells that harbor intact integrated genomes of the virus in the absence of viral replication. This population of infected cells remains invisible to the immune system and is not targeted by the drugs used in the current antiretroviral therapies (cART). Reversal of latency by the use of inhibitors of chromatin-remodeling enzymes has been studied extensively in an attempt to purge this reservoir of latent HIV but has thus far not shown any success in clinical trials. The full complexity of latent HIV infection has still not been appreciated, and the gaps in knowledge prevent development of adequate small-molecule compounds that can effectively perturb this reservoir. In this review, we will examine the role of epigenetic silencing of HIV transcription, posttranscriptional regulation, and mRNA processing in promoting HIV-1 latency.
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Affiliation(s)
- Georges Khoury
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Australia
| | - Gilles Darcis
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Michelle Y Lee
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Australia
| | - Sophie Bouchat
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Benoit Van Driessche
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Damian F J Purcell
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Australia.
| | - Carine Van Lint
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Gosselies, Belgium.
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He DD, Lu Y, Gittelman R, Jin Y, Ling F, Joshua A. Positive selection of the TRIM family regulatory region in primate genomes. Proc Biol Sci 2017; 283:rspb.2016.1602. [PMID: 27733547 DOI: 10.1098/rspb.2016.1602] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Accepted: 09/13/2016] [Indexed: 12/13/2022] Open
Abstract
Viral selection pressure has acted on restriction factors that play an important role in the innate immune system by inhibiting the replication of viruses during primate evolution. Tripartite motif-containing (TRIM) family members are some of these restriction factors. It is becoming increasingly clear that gene expression differences, rather than protein-coding regions changes, could play a vital role in the anti-retroviral immune mechanism. Increasingly, recent studies have created genome-scale catalogues of DNase I hypersensitive sites (DHSs), which demark potentially functional regulatory DNA. To improve our understanding of the molecular evolution mechanism of antiviral differences between species, we leveraged 14 130 DHSs derived from 145 cell types to characterize the regulatory landscape of the TRIM region. Subsequently, we compared the alignments of the DHSs across six primates and found 375 DHSs that are conserved in non-human primates but exhibit significantly accelerated rates of evolution in the human lineage (haDHSs). Furthermore, we discovered 31 human-specific potential transcription factor motifs within haDHSs, including the KROX and SP1, that both interact with HIV-1 Importantly, the corresponding haDHS was correlated with antiviral factor TRIM23 Thus, our results suggested that some viruses may contribute, through regulatory DNA differences, to organismal evolution by mediating TRIM gene expression to escape immune surveillance.
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Affiliation(s)
- Dan-Dan He
- School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, People's Republic of China
| | - Yueer Lu
- School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, People's Republic of China
| | - Rachel Gittelman
- Department of Genome Sciences, University of Washington, Seattle, WA 98125, USA
| | - Yabin Jin
- School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, People's Republic of China
| | - Fei Ling
- School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, People's Republic of China
| | - Akey Joshua
- Department of Genome Sciences, University of Washington, Seattle, WA 98125, USA
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Integrase-Deficient Lentiviral Vector as an All-in-One Platform for Highly Efficient CRISPR/Cas9-Mediated Gene Editing. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2017; 5:153-164. [PMID: 28497073 PMCID: PMC5424571 DOI: 10.1016/j.omtm.2017.04.002] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 04/12/2017] [Indexed: 12/12/2022]
Abstract
The CRISPR/Cas9 systems have revolutionized the field of genome editing by providing unprecedented control over gene sequences and gene expression in many species, including humans. Lentiviral vectors (LVs) are one of the primary delivery platforms for the CRISPR/Cas9 system due to their ability to accommodate large DNA payloads and sustain robust expression in a wide range of dividing and non-dividing cells. However, long-term expression of LV-delivered Cas9/guide RNA may lead to undesirable off-target effects characterized by non-specific RNA-DNA interactions and off-target DNA cleavages. Integrase-deficient lentiviral vectors (IDLVs) present an attractive means for delivery of CRISPR/Cas9 components because: (1) they are capable of transducing a broad range of cells and tissues, (2) have superior packaging capacity compared to other vectors (e.g., adeno-associated viral vectors), and (3) they are expressed transiently and demonstrate very weak integration capability. In this manuscript, we aimed to establish IDLVs as a means for safe and efficient delivery of CRISPR/Cas9. To this end, we developed an all-in-one vector cassette with increased production efficacy and demonstrated that CRISPR/Cas9 delivered by the improved IDLV vectors can mediate rapid and robust gene editing in human embryonic kidney (HEK293T) cells and post-mitotic brain neurons in vivo, via transient expression and with higher gene-targeting specificity than the corresponding integrase-competent vectors.
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Fauquenoy S, Robette G, Kula A, Vanhulle C, Bouchat S, Delacourt N, Rodari A, Marban C, Schwartz C, Burny A, Rohr O, Van Driessche B, Van Lint C. Repression of Human T-lymphotropic virus type 1 Long Terminal Repeat sense transcription by Sp1 recruitment to novel Sp1 binding sites. Sci Rep 2017; 7:43221. [PMID: 28256531 PMCID: PMC5335701 DOI: 10.1038/srep43221] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 01/20/2017] [Indexed: 02/07/2023] Open
Abstract
Human T-lymphotropic Virus type 1 (HTLV-1) infection is characterized by viral latency in the majority of infected cells and by the absence of viremia. These features are thought to be due to the repression of viral sense transcription in vivo. Here, our in silico analysis of the HTLV-1 Long Terminal Repeat (LTR) promoter nucleotide sequence revealed, in addition to the four Sp1 binding sites previously identified, the presence of two additional potential Sp1 sites within the R region. We demonstrated that the Sp1 and Sp3 transcription factors bound in vitro to these two sites and compared the binding affinity for Sp1 of all six different HTLV-1 Sp1 sites. By chromatin immunoprecipitation experiments, we showed Sp1 recruitment in vivo to the newly identified Sp1 sites. We demonstrated in the nucleosomal context of an episomal reporter vector that the Sp1 sites interfered with both the sense and antisense LTR promoter activities. Interestingly, the Sp1 sites exhibited together a repressor effect on the LTR sense transcriptional activity but had no effect on the LTR antisense activity. Thus, our results demonstrate the presence of two new functional Sp1 binding sites in the HTLV-1 LTR, which act as negative cis-regulatory elements of sense viral transcription.
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Affiliation(s)
- Sylvain Fauquenoy
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Rue des Professeurs Jeener et Brachet 12, 6041 Gosselies, Belgium
| | - Gwenaëlle Robette
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Rue des Professeurs Jeener et Brachet 12, 6041 Gosselies, Belgium
| | - Anna Kula
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Rue des Professeurs Jeener et Brachet 12, 6041 Gosselies, Belgium
| | - Caroline Vanhulle
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Rue des Professeurs Jeener et Brachet 12, 6041 Gosselies, Belgium
| | - Sophie Bouchat
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Rue des Professeurs Jeener et Brachet 12, 6041 Gosselies, Belgium
| | - Nadège Delacourt
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Rue des Professeurs Jeener et Brachet 12, 6041 Gosselies, Belgium
| | - Anthony Rodari
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Rue des Professeurs Jeener et Brachet 12, 6041 Gosselies, Belgium
| | - Céline Marban
- Biomaterials and Bioengineering, Inserm UMR 1121, Faculty of Dentistry, University of Strasbourg, France
| | - Christian Schwartz
- Institut Universitaire de Technologie Louis Pasteur, University of Strasbourg, Schiltigheim, France
- Laboratory of Dynamic of Host-Pathogen Interactions (DHPI), EA7292, University of Strasbourg, Strasbourg, France
| | - Arsène Burny
- Laboratory of Experimental Hematology, Institut Jules Bordet, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Olivier Rohr
- Institut Universitaire de Technologie Louis Pasteur, University of Strasbourg, Schiltigheim, France
- Laboratory of Dynamic of Host-Pathogen Interactions (DHPI), EA7292, University of Strasbourg, Strasbourg, France
| | - Benoit Van Driessche
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Rue des Professeurs Jeener et Brachet 12, 6041 Gosselies, Belgium
| | - Carine Van Lint
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Rue des Professeurs Jeener et Brachet 12, 6041 Gosselies, Belgium
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Darcis G, Van Driessche B, Bouchat S, Kirchhoff F, Van Lint C. Molecular Control of HIV and SIV Latency. Curr Top Microbiol Immunol 2017; 417:1-22. [PMID: 29071474 DOI: 10.1007/82_2017_74] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The HIV latent reservoirs are considered as the main hurdle to viral eradication. Numerous mechanisms lead to the establishment of HIV latency and act at the transcriptional and post-transcriptional levels. A better understanding of latency is needed in order to ultimately achieve a cure for HIV. The mechanisms underlying latency vary between patients, tissues, anatomical compartments, and cell types. From this point of view, simian immunodeficiency virus (SIV) infection and the use of nonhuman primate (NHP) models that recapitulate many aspects of HIV-associated latency establishment and disease progression are essential tools since they allow extensive tissue sampling as well as a control of infection parameters (virus type, dose, route, and time).
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Affiliation(s)
- Gilles Darcis
- Service of Molecular Virology, Département de Biologie Moléculaire (DBM), Université Libre de Bruxelles (ULB), Rue des Professeurs Jeener et Brachet 12, 6041, Gosselies, Belgium.,Service des Maladies Infectieuses, Université de Liège, CHU de Liège, Domaine Universitaire du Sart-Tilman, B35, 4000, Liège, Belgium.,Laboratory of Experimental Virology, Department of Medical Microbiology, Academic Medical Center of the University of Amsterdam, Meibergdreef 15, 1105, AZ, Amsterdam, The Netherlands
| | - Benoit Van Driessche
- Service of Molecular Virology, Département de Biologie Moléculaire (DBM), Université Libre de Bruxelles (ULB), Rue des Professeurs Jeener et Brachet 12, 6041, Gosselies, Belgium
| | - Sophie Bouchat
- Service of Molecular Virology, Département de Biologie Moléculaire (DBM), Université Libre de Bruxelles (ULB), Rue des Professeurs Jeener et Brachet 12, 6041, Gosselies, Belgium
| | - Frank Kirchhoff
- Institute of Molecular Virology, Ulm University Medical Center, Meyerhofstraße 1, 89081, Ulm, Germany
| | - Carine Van Lint
- Service of Molecular Virology, Département de Biologie Moléculaire (DBM), Université Libre de Bruxelles (ULB), Rue des Professeurs Jeener et Brachet 12, 6041, Gosselies, Belgium.
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Raz S, Stark M, Assaraf YG. Binding of a Smad4/Ets-1 complex to a novel intragenic regulatory element in exon12 of FPGS underlies decreased gene expression and antifolate resistance in leukemia. Oncotarget 2015; 5:9183-98. [PMID: 25229333 PMCID: PMC4253427 DOI: 10.18632/oncotarget.2399] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Polyglutamylation of antifolates catalyzed by folylpoly-γ-glutamate synthetase (FPGS) is essential for their intracellular retention and cytotoxic activity. Hence, loss of FPGS expression and/or function results in lack of antifolate polyglutamylation and drug resistance. Members of the TGF-β/Smad signaling pathway are negative regulators of hematopoiesis and deregulation of this pathway is considered a major contributor to leukemogenesis. Here we show that FPGS gene expression is inversely correlated with the binding of a Smad4/Ets-1 complex to exon12 of FPGS in both acute lymphoblastic leukemia cells and acute myeloid leukemia blast specimens. We demonstrate that antifolate resistant leukemia cells harbor a heterozygous point mutation in exon12 of FPGS which disrupts FPGS activity by abolishing ATP binding, and alters the binding pattern of transcription factors to the genomic region of exon12. This in turn results in the near complete silencing of the wild type allele leading to a 97% loss of FPGS activity. We show that exon12 is a novel intragenic transcriptional regulator, endowed with the ability to drive transcription in vitro, and is occupied by transcription factors and chromatin remodeling agents (e.g. Smad4/Ets-1, HP-1 and Brg1) in vivo. These findings bear important implications for the rational overcoming of antifolate resistance in leukemia.
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Affiliation(s)
- Shachar Raz
- The Fred Wyszkowski Cancer Research Laboratory, Department of Biology, Technion-Israel Institute of Technology, Haifa, Israel
| | - Michal Stark
- The Fred Wyszkowski Cancer Research Laboratory, Department of Biology, Technion-Israel Institute of Technology, Haifa, Israel
| | - Yehuda G Assaraf
- The Fred Wyszkowski Cancer Research Laboratory, Department of Biology, Technion-Israel Institute of Technology, Haifa, Israel
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Colin L, Verdin E, Van Lint C. HIV-1 chromatin, transcription, and the regulatory protein Tat. Methods Mol Biol 2014; 1087:85-101. [PMID: 24158816 DOI: 10.1007/978-1-62703-670-2_8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
Upon integration into the host cell genome, the nucleosomal organization and epigenetic control of the HIV-1 provirus play an active role in its transcriptional regulation. Therefore, characterization of the chromatin changes that occur in the viral promoter region in response to different cellular stimuli or drug treatments represents an important aspect of our understanding of HIV-1 transcription. Moreover, the viral transactivator Tat protein potently activates HIV-1 transcription by recruiting the cellular positive transcription elongation factor p-TEFb to the TAR element located at the 5' end of all nascent viral transcripts, thereby promoting efficient elongation. This chapter describes two complementary techniques for analyzing chromatin structure. The first technique is called indirect end-labeling and uses DNase I, micrococcal nuclease (MNase) or specific restriction enzymes to provide a view of nucleosome positions and of nucleosome-free regions within genes that are usually associated with transcriptional regulatory elements. The second technique, called chromatin immunoprecipitation (ChIP), provides a detailed analysis of chromatin structure by determining the pattern of histone modification marks in the DNA region of interest and by identifying the transcription factors as well as the components of the transcriptional initiation and elongation machineries that are recruited in vivo to this chromosomal region.
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Affiliation(s)
- Laurence Colin
- Laboratory of Molecular Virology, Institut de Biologie et de Médecine Moléculaires (IBMM), University of Brussels (ULB), Brussels, Belgium
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18
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Cheng G, Liu L, Wang P, Zhang Y, Zhao YO, Colpitts TM, Feitosa F, Anderson JF, Fikrig E. An in vivo transfection approach elucidates a role for Aedes aegypti thioester-containing proteins in flaviviral infection. PLoS One 2011; 6:e22786. [PMID: 21818390 PMCID: PMC3144946 DOI: 10.1371/journal.pone.0022786] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Accepted: 07/04/2011] [Indexed: 02/07/2023] Open
Abstract
Mosquitoes transmit pathogens that cause infectious diseases of global importance. Techniques to easily introduce genes into mosquitoes, however, limit investigations of the interaction between microbes and their arthropod vectors. We now show that a cationic liposome significantly enhances delivery and expression of plasmid DNA in Aedes aegypti and Anopheles gambiae mosquitoes. We then introduced the genes for Ae. aegypti thioester-containing proteins (AeTEPs), which are involved in the control of flaviviral infection, into mosquitoes using this technique. In vivo transfection of AeTEP-1 into Ae. aegypti significantly reduced dengue virus infection, suggesting that the approach can further our understanding of pathogen-mosquito interactions.
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Affiliation(s)
- Gong Cheng
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Lei Liu
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Penghua Wang
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Yue Zhang
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Yang O. Zhao
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Tonya M. Colpitts
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Fabiana Feitosa
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - John F. Anderson
- Department of Entomology, Connecticut Agricultural Experiment Station, New Haven, Connecticut, United States of America
| | - Erol Fikrig
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
- * E-mail:
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Colin L, Vandenhoudt N, de Walque S, Van Driessche B, Bergamaschi A, Martinelli V, Cherrier T, Vanhulle C, Guiguen A, David A, Burny A, Herbein G, Pancino G, Rohr O, Van Lint C. The AP-1 binding sites located in the pol gene intragenic regulatory region of HIV-1 are important for viral replication. PLoS One 2011; 6:e19084. [PMID: 21526160 PMCID: PMC3079759 DOI: 10.1371/journal.pone.0019084] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Accepted: 03/15/2011] [Indexed: 01/06/2023] Open
Abstract
Our laboratory has previously identified an important intragenic region in the human immunodeficiency virus type 1 (HIV-1) genome, whose complete functional unit is composed of the 5103 fragment, the DNaseI-hypersensitive site HS7 and the 5105 fragment. These fragments (5103 and 5105) both exhibit a phorbol 12-myristate 13-acetate (PMA)-inducible enhancer activity on the herpes simplex virus thymidine kinase promoter. Here, we characterized the three previously identified AP-1 binding sites of fragment 5103 by showing the PMA-inducible in vitro binding and in vivo recruitment of c-Fos, JunB and JunD to this fragment located at the end of the pol gene. Functional analyses demonstrated that the intragenic AP-1 binding sites are fully responsible for the PMA-dependent enhancer activity of fragment 5103. Moreover, infection of T-lymphoid Jurkat and promonocytic U937 cells with wild-type and mutant viruses demonstrated that mutations of the intragenic AP-1 sites individually or in combination altered HIV-1 replication. Importantly, mutations of the three intragenic AP-1 sites led to a decreased in vivo recruitment of RNA polymerase II to the viral promoter, strongly supporting that the deleterious effect of these mutations on viral replication occurs, at least partly, at the transcriptional level. Single-round infections of monocyte-derived macrophages confirmed the importance of intragenic AP-1 sites for HIV-1 infectivity.
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Affiliation(s)
- Laurence Colin
- Laboratoire de Virologie Moléculaire, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Nathalie Vandenhoudt
- Laboratoire de Virologie Moléculaire, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Stéphane de Walque
- Laboratoire de Virologie Moléculaire, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Benoît Van Driessche
- Laboratoire de Virologie Moléculaire, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Anna Bergamaschi
- Institut Pasteur, Unité de Régulation des Infections Rétrovirales, Paris, France
| | - Valérie Martinelli
- Laboratoire de Virologie Moléculaire, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Thomas Cherrier
- IUT Louis Pasteur de Schiltigheim, University of Strasbourg, Schiltigheim, France
| | - Caroline Vanhulle
- Laboratoire de Virologie Moléculaire, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Allan Guiguen
- Laboratoire de Virologie Moléculaire, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Annie David
- Institut Pasteur, Unité de Régulation des Infections Rétrovirales, Paris, France
| | - Arsène Burny
- Laboratoire de Virologie Moléculaire, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Georges Herbein
- Department of Virology, EA3186, IFR133, Franche-Comte University, Hôpital Saint-Jacques, Besançon, France
| | - Gianfranco Pancino
- Institut Pasteur, Unité de Régulation des Infections Rétrovirales, Paris, France
| | - Olivier Rohr
- IUT Louis Pasteur de Schiltigheim, University of Strasbourg, Schiltigheim, France
| | - Carine Van Lint
- Laboratoire de Virologie Moléculaire, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
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20
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Colin L, Van Lint C. Molecular control of HIV-1 postintegration latency: implications for the development of new therapeutic strategies. Retrovirology 2009; 6:111. [PMID: 19961595 PMCID: PMC2797771 DOI: 10.1186/1742-4690-6-111] [Citation(s) in RCA: 172] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2009] [Accepted: 12/04/2009] [Indexed: 02/07/2023] Open
Abstract
The persistence of HIV-1 latent reservoirs represents a major barrier to virus eradication in infected patients under HAART since interruption of the treatment inevitably leads to a rebound of plasma viremia. Latency establishes early after infection notably (but not only) in resting memory CD4+ T cells and involves numerous host and viral trans-acting proteins, as well as processes such as transcriptional interference, RNA silencing, epigenetic modifications and chromatin organization. In order to eliminate latent reservoirs, new strategies are envisaged and consist of reactivating HIV-1 transcription in latently-infected cells, while maintaining HAART in order to prevent de novo infection. The difficulty lies in the fact that a single residual latently-infected cell can in theory rekindle the infection. Here, we review our current understanding of the molecular mechanisms involved in the establishment and maintenance of HIV-1 latency and in the transcriptional reactivation from latency. We highlight the potential of new therapeutic strategies based on this understanding of latency. Combinations of various compounds used simultaneously allow for the targeting of transcriptional repression at multiple levels and can facilitate the escape from latency and the clearance of viral reservoirs. We describe the current advantages and limitations of immune T-cell activators, inducers of the NF-κB signaling pathway, and inhibitors of deacetylases and histone- and DNA- methyltransferases, used alone or in combinations. While a solution will not be achieved by tomorrow, the battle against HIV-1 latent reservoirs is well- underway.
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Affiliation(s)
- Laurence Colin
- Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles (ULB), Gosselies, Belgium.
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Ngandu NK, Scheffler K, Moore P, Woodman Z, Martin D, Seoighe C. Extensive purifying selection acting on synonymous sites in HIV-1 Group M sequences. Virol J 2008; 5:160. [PMID: 19105834 PMCID: PMC2666660 DOI: 10.1186/1743-422x-5-160] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2008] [Accepted: 12/23/2008] [Indexed: 11/26/2022] Open
Abstract
Background Positive selection pressure acting on protein-coding sequences is usually inferred when the rate of nonsynonymous substitution is greater than the synonymous rate. However, purifying selection acting directly on the nucleotide sequence can lower the synonymous substitution rate. This could result in false inference of positive selection because when synonymous changes at some sites are under purifying selection, the average synonymous rate is an underestimate of the neutral rate of evolution. Even though HIV-1 coding sequences contain a number of regions that function at the nucleotide level, and are thus likely to be affected by purifying selection, studies of positive selection assume that synonymous substitutions can be used to estimate the neutral rate of evolution. Results We modelled site-to-site variation in the synonymous substitution rate across coding regions of the HIV-1 genome. Synonymous substitution rates were found to vary significantly within and between genes. Surprisingly, regions of the genome that encode proteins in more than one frame had significantly higher synonymous substitution rates than regions coding in a single frame. We found evidence of strong purifying selection pressure affecting synonymous mutations in fourteen regions with known functions. These included an exonic splicing enhancer, the rev-responsive element, the poly-purine tract and a transcription factor binding site. A further five highly conserved regions were located within known functional domains. We also found four conserved regions located in env and vpu which have not been characterized previously. Conclusion We provide the coordinates of genomic regions with markedly lower synonymous substitution rates, which are putatively under the influence of strong purifying selection pressure at the nucleotide level as well as regions encoding proteins in more than one frame. These regions should be excluded from studies of positive selection acting on HIV-1 coding regions.
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Affiliation(s)
- Nobubelo K Ngandu
- National Bioinformatics Network Node, Institute of Infectious Diseases and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Anzio Road, Observatory, 7925, South Africa.
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de Walque S, Vanhulle C, Vandenhoudt N, Van Driessche B, Burny A, Van Lint C. Transcription factor binding aites in the pol gene intragenic regulatory region of HIV-1 are important for virus infectivity. Retrovirology 2006. [PMCID: PMC1716951 DOI: 10.1186/1742-4690-3-s1-s41] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Transcription factor binding sites in the pol gene intragenic regulatory region of HIV-1 are important for virus infectivity. Retrovirology 2006. [PMCID: PMC1716832 DOI: 10.1186/1742-4690-3-s1-p14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Kim SY, Kim DH, Hyun JW, Henson JW, Kim HS. Irisolidone, an isoflavone metabolite, represses JC virus gene expression via inhibition of Sp1 binding in human glial cells. Biochem Biophys Res Commun 2006; 344:3-8. [PMID: 16630573 DOI: 10.1016/j.bbrc.2006.03.165] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2006] [Accepted: 03/26/2006] [Indexed: 05/08/2023]
Abstract
Progressive multifocal leukoencephalopathy (PML) is a fatal demyelinating disease that results from an oligodendrocyte infection caused by the JC virus. Therefore, inhibiting the expression of JC virus is important for preventing and/or treating PML. This study found that irisolidone, an isoflavone metabolite, significantly inhibited the JC virus expression in primary cultured human astrocytes and glial cell lines. Studies examining the underlying mechanism revealed that a mutation of the Sp1 binding site downstream of the TATA box (Sp1-II) dramatically diminished the inhibitory activity of irisolidone. In addition, an irisolidone treatment repressed Sp1 binding to Sp1-II site, which is important for the basal JC virus promoter activity. The results suggest that the inhibitory effect of irisolidone against the JC virus may be attributed at least in part to the suppression of Sp1 binding to the JC virus promoter region. Therefore, the inhibition of the JC virus expression by irisolidone might provide therapeutic potential for PML caused by the JC virus.
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Affiliation(s)
- So-Young Kim
- Department of Neuroscience and Medical Research Institute, College of Medicine, Ewha Womans University, Seoul, Republic of Korea
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