HIV reactivation from latency - role of CD4 T cell maturation phenotype

NIH RePORTER · VA · IK2 · · view on reporter.nih.gov ↗

Abstract

 DESCRIPTION (provided by applicant): The "shock and kill" treatment strategy has been envisioned as a controlled induction of virus reactivation in the presence of combination antiretroviral therapy (cART) to reveal latently infected cells for immune system recognition and destruction. Histone deacetylase inhibitors (HDACis) have potential for HIV reactivation in patients; however, further optimization of these strategies is needed to effectively reduce the size of latent reservoir. Emerging evidence from gene expression studies points to existence of secondary mechanisms of action of HDACis that may interfere with induction of HIV expression. Based on differences in the degree of HIV reactivation in response to HDACis in model systems that use different cell types, we propose that these inhibitory effects may vary among CD4+ T cells of different maturation phenotypes. The optimal reactivation strategy would be able to induce HIV expression from all CD4+ T cells with a minimal number of additional interventions; however, it is possible that maturation phenotype-specific interventions would be required. The objective of this proposal is to identify host genes and proteins modulated by HDACis in CD4+ T cells of various maturation phenotypes that can be therapeutically targeted to enhance the activation effect of HDACis. The central hypothesis is that HIV is reactivated by HDACis with different potencies and via different mechanisms depending on CD4+ T cell maturation state, and that reactivation may be augmented by counteracting the secondary effects of HDACis that interfere with HIV expression. The rationale for this study is to improve on existing strategies for HIV reactivation by identifying possible targets to counteract inhibitory effects of HDACis across cells of all majo maturation phenotypes to ensure HIV eradication from the entire CD4+ T cell reservoir. To achieve our goals, we will measure induction of HIV expression in naïve, central memory and effector memory cells using the in vitro latency model developed by Dr. Spina. We will then characterize global gene and protein expression changes induced by HDACis by methods of RNA-Seq and liquid chromatography mass spectrometry (LC-MS), and identify effects that may specifically interfere with HIV expression in CD4+ T cell subsets. Based on RNA-Seq and LC-MS data, a set of targets will be selected for validation studies, including validating changes in expression in a time course and in another latency model (developed by Dr. Karn), and knockdown / overexpression studies in the presence of HDACi to test for synergy. The expected positive impact of this work is identification of therapeutic candidates with strong potential to improve HIV reactivation currently achieved. Dr. Beliakova-Bethell will work with one primary mentor and three co-mentors, who are leaders in the field of HIV research. Exposure to a collaborative and diverse scientific environment, as part of the VA Healthca...

Key facts

NIH application ID
9932266
Project number
5IK2BX002731-05
Recipient
VA SAN DIEGO HEALTHCARE SYSTEM
Principal Investigator
Nadejda S Beliakova-Bethell
Activity code
IK2
Funding institute
VA
Fiscal year
2020
Award amount
Award type
5
Project period
2016-07-01 → 2021-09-30