The ineptness of highly active anti-retroviral therapy (HAART) regimen against HIV-associated dementia patients (HAD) necessitates continuous development of new drugs against brain infections. The long-term goal is to develop an anti-HIV therapeutic strategy using inducible chaperone family proteins, specifically small heat shock proteins. The objective of this particular application is to determine the role of heat shock protein-22 (Hsp22) in the post-transcriptional regulation of HIV-1 gene expression. The central hypothesis of this application is that Hsp22 interferes with the nuclear uptake of Rev, thus impairing Rev function and subsequent HIV-1 production in astrocytes. The hypothesis has been formulated from the preliminary data, showing that Hsp22 is expressed at high levels in astrocytes and inhibits Rev function. The rationale for the proposed project is that, once the mechanism of how Hsp22 inhibits Rev function is known, using new and innovative strategies, its production can be either up- or down-regulated pharmacologically to the prevention and treatment of AIDS, including HAD. Guided by preliminary data, the central hypothesis will be tested to accomplish the objective of this application by pursuing the following two specific aims: 1. Determine the role of Hsp22 in the post-transcriptional regulation of HIV-1 gene expression. The working hypothesis is that Hsp22 interacts with Rev and interferes with its function by perturbing its intracellular localization, thus resulting in inhibition of HIV-1 production in target cells. Under this aim, using biochemical approaches, such as in vitro and in vivo binding assays, the physical interaction between Hsp22 and Rev will be tested. Furthermore, using Northern analysis the functional relevance of these interactions will be determined. 2. Determine the role of Hsp22 in HIV-1 latency in astrocytes. The working hypothesis of this aim is that high levels of Hsp22 in astrocytes contributes to the cytoplasmic predominance of Rev, which in turn will interfere with the nuclear uptake of Rev, and subsequent inhibition of HIV-1 production. Under this aim, well proven RNA interference (siRNA) approach will be used to inhibit the expression of Hsp22 in astrocytes, after which Rev localization will be examined by immuno-fluorescence microscopy and Rev-mediated RRE-RNA export will be analyzed by Northern analysis. The proposed work is innovative, because no cytoplasmic protein(s), specifically Hsp22, was previously shown to participate in the post-transcriptional regulation of HIV-1 gene expression. The research proposed in this application is significant because it is expected to provide the knowledge needed to develop pharmacologic strategies to eliminate the HIV-1 reservoirs or to maintain the viral latency eternally. In either scenario, cellular activities that disrupt the nucleocytoplasmic transport of viral RNAs are expected to become valuable antiviral weapons in combating the HIV-1 infection. Project Narrative: The proposed research is relevant to public health, because, understanding the role of Hsp22 will shed light on the molecular basis of HIV-1 latency operating at the level of RNA metabolism in CNS-based cell type and would lead to novel HSP-based therapeutic and vaccine approaches for the control of HIV-1 infection. One of the advantages of Hsp22 over viral proteins is that the antiviral affect will be broadly effective against all HIV-1 isolates and clades, including the CNS strains. Thus, the results are expected to be applicable to the health of human beings. ? ? ?
| Modem, Suhasini; Chinnakannu, Kannagi; Bai, Uma et al. (2011) Hsp22 (HspB8/H11) knockdown induces Sam68 expression and stimulates proliferation of glioblastoma cells. J Cell Physiol 226:2747-51 |
| Suhasini, Modem; Reddy, Thipparthi R (2009) Cellular proteins and HIV-1 Rev function. Curr HIV Res 7:91-100 |
