Understanding the mechanism of HIV-1 latency is crucial to eradication of the viral reservoir in HIV-1-infected individuals. However, the role of histone methyltransferase (HMT) G9a-like protein (GLP) in HIV-1 latency is still unclear. In the present work, we established four clonal cell lines containing HIV-1 vector. We found that the integration sites of most clonal cell lines favored active gene regions. However, we also observed hypomethylation of CpG of HIV 5'LTR in all four clonal cell lines. Additionally, 5'-deoxy-5'-methylthioadenosine (MTA), a broad-spectrum histone methyltransferase inhibitor, was used to examine the role of histone methylation in HIV-1 latency. MTA was found to decrease the level of H3K9 dimethylation, causing reactivation of latent HIV-1 in C11 cells. GLP knockdown by small interfering RNA clearly induced HIV-1 LTR expression. Results suggest that GLP may play a significant role in the maintenance of HIV-1 latency by catalyzing dimethylation of H3K9.
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http://dx.doi.org/10.1016/j.virol.2013.02.022 | DOI Listing |
bioRxiv
January 2025
Department of Microbiology, Immunology, and Cancer Biology, School of Medicine, University of Virginia, Charlottesville, Virginia, USA.
The HIV-1 Rev-RRE regulatory axis plays a crucial role in viral replication by facilitating the nucleo-cytoplasmic export and expression of viral mRNAs with retained introns. In this study, we investigated the impact of variation in Rev-RRE functional activity on HIV-1 replication kinetics and reactivation from latency. Using a novel HIV-1 clone with an interchangeable Rev cassette, we engineered viruses with different Rev functional activities and demonstrated that higher Rev-RRE activity confers greater viral replication capacity while maintaining a constant level of Nef expression.
View Article and Find Full Text PDFJ Virol
January 2025
Institute for Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, Tübingen, Germany.
One key determinant of HIV-1 latency reversal is the activation of the viral long terminal repeat (LTR) by cellular transcription factors such as NF-κB and AP-1. Interestingly, the activity of these two transcription factors can be modulated by glucocorticoid receptors (GRs). Furthermore, the HIV-1 genome contains multiple binding sites for GRs.
View Article and Find Full Text PDFJ Virus Erad
December 2024
HIV Pathogenesis Programme, The Doris Duke Medical Research Institute, Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa.
Sub-Saharan Africa accounts for almost 70 % of people living with HIV (PLWH) worldwide, with the greatest numbers centred in South Africa where 98 % of infections are caused by subtype C (HIV-1C). However, HIV-1 subtype B (HIV-1B), prevalent in Europe and North America, has been the focus of most cure research and testing despite making up only 12 % of HIV-1 infections globally. Development of latency models for non-subtype B viruses is a necessary step to address this disproportionate focus.
View Article and Find Full Text PDFCell Rep
January 2025
Gladstone Institutes, San Francisco, CA, USA; Department of Urology, UCSF, San Francisco, CA, USA. Electronic address:
We developed viral sensor and restriction factor-cytometry by time of flight (VISOR-CyTOF), which profiles 19 viral sensors and restriction factors (VISORs) simultaneously in single cells, and applied it to 41 postmortem tissues from people with HIV. Mucosal myeloid cells are well equipped with SAMHD1 and sensors of viral capsid and DNA while CD4 T cells are not. In lymph node CD4 Tfh, VISOR expression patterns reflect those favoring integration but blocking HIV gene expression, thus favoring viral latency.
View Article and Find Full Text PDFPLoS Pathog
January 2025
Department of Experimental Immunology, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands.
Identifying cellular and molecular mechanisms maintaining HIV-1 latency in the viral reservoir is crucial for devising effective cure strategies. Here we developed an innovative flow cytometry-fluorescent in situ hybridization (flow-FISH) approach for direct ex vivo reservoir detection without the need for reactivation using a combination of probes detecting abortive and elongated HIV-1 transcripts. Our flow-FISH assay distinguished between HIV-1-infected CD4+ T cells expressing abortive or elongated HIV-1 transcripts in PBMC from untreated and ART-treated PWH from the Amsterdam Cohort Studies.
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