The major obstacle to eradicate HIV is the inability of present therapies to purge latent HIV proviruses form patients. The lack of knowledge regarding any unique signature biomarker of latently infected cells makes their phenotypic distinction impossible from their uninfected counterparts. Presently, no method is available to identify and isolate pure population of latently infected cells from HIV patients, a prerequisite step before selectively targeting them in HIV patients.
The rare availability of latently infected cells in patients (~1 in 106 of resting T cells), makes it almost impossible to isolate them in sufficient numbers to be able to do characterization studies. To overcome this limitation, recently we have developed a novel primary CD4+ T cell based ex vivo model system for HIV latency. The unique advantages of our model is that by using this model we can generate large quantities of pure latently infected primary CD4+ T cells, which provide sufficient material and opportunity to characterize and determine the presence of unique biomarkers of latently infected primary T cells. We will compare the proteome of cell membranes from both latently infected and resting uninfected cells. The differentially expressing protein(s) on latently versus uninfected resting T cells can be used as biomarkers.
Moreover, in this study, we will utilize a recently developed innovative method for the isolation of plasma membrane-associated proteins based on the use of biotin to label cell surface proteins [2]. This biotinstreptavidin affinity method has several advantages over common traditional approaches to isolate plasma membrane proteins, including the significant reduction in contamination by mitochondrial/endoplasmic reticulum membrane proteins, higher yield of plasma membrane proteins, higher reproducibility and less preparation time. The differentially expressing protein(s) on latently versus uninfected resting T cells can be used as biomarkers. Those biomarkers could be exploited to identify and target selective pool of resting T cells that harbor latent HIV proviruses. Eventually, the findings could be translated to develop therapeutic interventions targeting HIV elimination.