# Establishing HIV-1 chromatin in resting T cells: Vpr, latency, and H2A.Z

> **NIH NIH R01** · NEW YORK UNIVERSITY · 2020 · $396,250

## Abstract

Project Summary
Latent HIV infection of resting CD4 T cells present a formidable challenge in the pursuit of treatments to purge
HIV from the body. Latency is established and regulated in large part through the modifications of the
nucleosomes that are bound around the viral promoter region. Drugs that reactivate latent HIV must influence
these structures in order to allow HIV transcription and virus expression. However, for unknown reasons not all
intact proviruses respond to latency reversing agents and thus present a particularly troublesome barrier to cure.
A greater understanding of the regulation of HIV-1 chromatin, the installation of nucleosomes and their histone
post translational modifications (PTM) will contribute greatly to the development of therapeutic control over HIV-
1 latency. This project seeks such an understanding and builds upon extensive preliminary studies revealing
important new insights into these processes. For the first time we investigate the initial stages of HIV-1 chromatin
installation, finding that it occurs either contemporaneously or soon after reverse transcription, and before
integration into the cellular DNA. We find that repressive chromatin is installed in the absence of the viral protein
Vpr being delivered in the virion. Virion Vpr dramatically increases the number of transcriptionally active
proviruses in the first 4 days after infection of resting CD4 T cells. When Vpr is present, the nucleosomes that
control HIV expression are modified in ways that facilitate HIV replication and block installation of repressive
chromatin. For example, the alternate histone H2A.Z is installed only when virion Vpr is available, and H2A.Z is
a central organizer of paused but responsive promoters. Without Vpr, the chromatin of latent proviruses takes
on a more repressed structure, resulting in more proviruses that do not respond to latency reversing agents.
Novel RNA-seq data demonstrate that virion Vpr reprograms gene expression pathways central to chromatin
organization and transcriptional regulation. This project will describe both the initial steps in HIV chromatization
and the long term processes that lead to reversible latency and irreversible repression. Aim 1 will systematically
analyze early proviral chromatin in resting CD4 T cells and the influence of Vpr and Tat-directed transcription on
the epigenetic landscape. Our central hypothesis is that Vpr directs installation of the transcriptional pre-initiation
complex for basal pre-Tat transcription in resting T cells. Aim 2 will analyze Vpr-dependent pathways leading to
these structures. RNA-seq data will be expanded and used to study novel Vpr targets of regulation, and known
Vpr pathways will be investigated for their influence on early events. Aim 3 will examine long term infection and
latency under the influence the structures and pathways gleaned from Aims 1 and 2. Our hypothesis is that Vpr
protects the provirus from epigenetic repression and irreversible lat...

## Key facts

- **NIH application ID:** 9858254
- **Project number:** 5R01AI145753-02
- **Recipient organization:** NEW YORK UNIVERSITY
- **Principal Investigator:** DAVID N LEVY
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $396,250
- **Award type:** 5
- **Project period:** 2019-02-01 → 2024-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9858254

## Citation

> US National Institutes of Health, RePORTER application 9858254, Establishing HIV-1 chromatin in resting T cells: Vpr, latency, and H2A.Z (5R01AI145753-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9858254. Licensed CC0.

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