HIV persists in the face of highly active antiretroviral therapy (HAART) due to constitutive low-level replication in sites that are poorly accessible to drugs and the development of latent infections in a variety of types including the long-lived memory CD4+ T cell population, macrophages, and microglial cells in the brain - cells that play a critical role in neurologic dysfunction and neurotoxicity. The persistence of HIV mandates that patients be maintained on life-long therapy with its attendant costs and side effects. Furthermore, although HAART has greatly extended survival to patients infected with HIV-1, current therapy has failed to decrease the prevalence of HIVneurological diseases especially in individuals who abuse drugs. This proposal focuses on defining the molecular basis for HIV silencing, the impact of drugs of abuse on the creation and reactivation of the latent viral reservoir in microglial cells, and the development of novel therapeutic approaches to attacking HIV latency. Key questions about HIV silencing that remain to be answered include: What are the primary sequence triggers and mechanisms that induce silencing (i.e. protein repressors and/or viralderived RNA)? What conditions lead to proviral DNA methylation? Do similar silencing mechanisms operate in each of the cell types infected by HIV? How do drugs of abuse reactivate HIV? In partial answer to these questions we have demonstrated that distinct epigenetic silencing mechanisms lead to viral persistence in different cell types. Using novel unbiased shRNA screens we have shown that in T-cells, the polycomb repressive complex 2 (PCR2) plays a central role in maintaining proviral latency, whereas in microglial cells, PCR2 is absent and silencing is mediated by the SMRT and CoREST silencing machinery. Because of these differences in the silencing machinery we have been able to identify selective activators of HIV transcription in the two different cell types. Similarly, methamphetamine is able to reverse proviral latency in microglial cells through a novel activation pathway leading to NF-kB mobilization. This mechanism may outline the initial biochemical events leading to the observed increased neurodegeneration in HIV-positive individuals who use METH. Extending this work we plan to develop novel technologies allowing exploitation a natural epigenetic silencing mechanisms involving both histone and DNA methylation, to block HIV transcription.

Agency
National Institute of Health (NIH)
Institute
National Institute on Drug Abuse (NIDA)
Type
NIH Director’s Pioneer Award (NDPA) (DP1)
Project #
5DP1DA028869-04
Application #
8311081
Study Section
Special Emphasis Panel (ZDA1-NXR-B (12))
Program Officer
Satterlee, John S
Project Start
2009-09-30
Project End
2014-08-31
Budget Start
2012-09-01
Budget End
2013-08-31
Support Year
4
Fiscal Year
2012
Total Cost
$753,836
Indirect Cost
$273,686
Name
Case Western Reserve University
Department
Biochemistry
Type
Schools of Medicine
DUNS #
077758407
City
Cleveland
State
OH
Country
United States
Zip Code
44106
Li, Qing; Karim, Ahmad F; Ding, Xuedong et al. (2016) Novel high throughput pooled shRNA screening identifies NQO1 as a potential drug target for host directed therapy for tuberculosis. Sci Rep 6:27566
Mbonye, Uri R; Wang, Benlian; Gokulrangan, Giridharan et al. (2015) Phosphorylation of HEXIM1 at Tyr271 and Tyr274 Promotes Release of P-TEFb from the 7SK snRNP Complex and Enhances Proviral HIV Gene Expression. Proteomics 15:2078-86
Das, Biswajit; Dobrowolski, Curtis; Shahir, Abdel-Malek et al. (2015) Short chain fatty acids potently induce latent HIV-1 in T-cells by activating P-TEFb and multiple histone modifications. Virology 474:65-81
Chen, Yupeng; Zhang, Lirong; Estarás, Conchi et al. (2014) A gene-specific role for the Ssu72 RNAPII CTD phosphatase in HIV-1 Tat transactivation. Genes Dev 28:2261-75
Jadlowsky, Julie K; Wong, Julian Y; Graham, Amy C et al. (2014) Negative elongation factor is required for the maintenance of proviral latency but does not induce promoter-proximal pausing of RNA polymerase II on the HIV long terminal repeat. Mol Cell Biol 34:1911-28
Mbonye, Uri; Karn, Jonathan (2014) Transcriptional control of HIV latency: cellular signaling pathways, epigenetics, happenstance and the hope for a cure. Virology 454-455:328-39
Tilton, Carisa A; Tabler, Caroline O; Lucera, Mark B et al. (2014) A combination HIV reporter virus system for measuring post-entry event efficiency and viral outcome in primary CD4+ T cell subsets. J Virol Methods 195:164-9
Karn, Jonathan (2013) A new BET on the control of HIV latency. Cell Cycle 12:545-6
Mbonye, Uri R; Gokulrangan, Giridharan; Datt, Manish et al. (2013) Phosphorylation of CDK9 at Ser175 enhances HIV transcription and is a marker of activated P-TEFb in CD4(+) T lymphocytes. PLoS Pathog 9:e1003338
Wires, Emily S; Alvarez, David; Dobrowolski, Curtis et al. (2012) Methamphetamine activates nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and induces human immunodeficiency virus (HIV) transcription in human microglial cells. J Neurovirol 18:400-10

Showing the most recent 10 out of 15 publications