Epigenetic Silencing of HIV Transcription Through Formation of Restrictive Chromatin Structures at the Viral LTR Drives the Progressive Entry of HIV into Latency

Bibliographic Details
Main Author:	Pearson, Richard
Language:	English
Published:	Case Western Reserve University School of Graduate Studies / OhioLINK 2009
Subjects:	Virology HIV Latency chromatin epigenetics
Online Access:	http://rave.ohiolink.edu/etdc/view?acc_num=case1223040734

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spelling	ndltd-OhioLink-oai-etd.ohiolink.edu-case12230407342021-08-03T05:32:55Z Epigenetic Silencing of HIV Transcription Through Formation of Restrictive Chromatin Structures at the Viral LTR Drives the Progressive Entry of HIV into Latency Pearson, Richard Virology HIV Latency chromatin epigenetics The clinical relevance of HIV latency is now well understood but the molecular mechanisms that are utilized by HIV to enter into a latent state are yet to be determined. The development of a suitable experimental system for studying HIV latency, which permits detailed biochemical analysis and drug screening, is a critical step in the effort to develop therapeutic strategies that will lead to viral eradication. The work outlined in this thesis reports that, when Jurkat T-cells are infected with lentiviral vectors that express the transactivator protein (Tat) in cis, HIV gene expression is gradually silenced. Silencing is enhanced when the lentiviral vectors carry an attenuated Tat gene. Following these observations we were able to develop a Jurkat cell-based model system of HIV latency. Detailed analysis of transcription initiation and elongation using chromatin immunoprecipitation (ChIP) assays confirms that Tat levels are restricted in latently infected cells but rise during proviral reactivation. ChIP assays using clones of latently infected cells demonstrate that the latent proviruses carry markers of repressive chromatin structure that were lost after TNF-alpha activation and replaced with a more transcriptionally permissive state. The progressive shutdown of HIV transcription suggests that epigenetic mechanisms targeting chromatin structures selectively restrict the HIV LTR.The information gained from the development and analysis of the Jurkat T-cell model has been applied to the development of a novel primary T-cell model. Primary CD4+ T-cells isolated from peripheral blood were activated and amplified by antibodies to the T-cell receptor (TCR) and then infected with lentiviral vectors carrying attenuated Tat. After sorting for the infected cells and re-amplification, the infected cells were allowed to spontaneously enter latency by long-term cultivation on feeder cell lines in the absence of TCR stimulation. Examination of the chromatin status of the latent provirus before and after TCR re-activation allowed for the corroboration of the reversal of heterochromatin structures to active chromatin structures seen in the Jurkat T-cell model. Thus, restrictive chromatin structures at the HIV LTR contribute to transcriptional silencing leading to latency in primary CD4+ T-cells. 2009 English text Case Western Reserve University School of Graduate Studies / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=case1223040734 http://rave.ohiolink.edu/etdc/view?acc_num=case1223040734 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.
collection	NDLTD
language	English
sources	NDLTD
topic	Virology HIV Latency chromatin epigenetics
spellingShingle	Virology HIV Latency chromatin epigenetics Pearson, Richard Epigenetic Silencing of HIV Transcription Through Formation of Restrictive Chromatin Structures at the Viral LTR Drives the Progressive Entry of HIV into Latency
author	Pearson, Richard
author_facet	Pearson, Richard
author_sort	Pearson, Richard
title	Epigenetic Silencing of HIV Transcription Through Formation of Restrictive Chromatin Structures at the Viral LTR Drives the Progressive Entry of HIV into Latency
title_short	Epigenetic Silencing of HIV Transcription Through Formation of Restrictive Chromatin Structures at the Viral LTR Drives the Progressive Entry of HIV into Latency
title_full	Epigenetic Silencing of HIV Transcription Through Formation of Restrictive Chromatin Structures at the Viral LTR Drives the Progressive Entry of HIV into Latency
title_fullStr	Epigenetic Silencing of HIV Transcription Through Formation of Restrictive Chromatin Structures at the Viral LTR Drives the Progressive Entry of HIV into Latency
title_full_unstemmed	Epigenetic Silencing of HIV Transcription Through Formation of Restrictive Chromatin Structures at the Viral LTR Drives the Progressive Entry of HIV into Latency
title_sort	epigenetic silencing of hiv transcription through formation of restrictive chromatin structures at the viral ltr drives the progressive entry of hiv into latency
publisher	Case Western Reserve University School of Graduate Studies / OhioLINK
publishDate	2009
url	http://rave.ohiolink.edu/etdc/view?acc_num=case1223040734
work_keys_str_mv	AT pearsonrichard epigeneticsilencingofhivtranscriptionthroughformationofrestrictivechromatinstructuresattheviralltrdrivestheprogressiveentryofhivintolatency
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Epigenetic Silencing of HIV Transcription Through Formation of Restrictive Chromatin Structures at the Viral LTR Drives the Progressive Entry of HIV into Latency

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