Flow Cytometry Evaluation of the T-Cell ReceptorVβ Repertoire Among HIV-1 Infected Individuals Before and After Antiretroviral Therapy

HIV-1 infection leads to serious impairment of the immune system and perturbations in the T cell receptor Vβ repertoire are also described. Immune reconstitution can be potentially achieved in response to HAART. In the present study 10 patients were investigated for the Vβ pattern expression before and after six months of HAART. TCR were analyzed for T CD4+ and CD8+ subsets, separately, by flow cytometry, using a monoclonal antibody set of 24 different Vβ chains. Compared to eight Brazilian healthy controls, no differences in Vβ pattern of expression was observed for patients before or on antiretroviral therapy. Some chains such as Vβ 3, 14, 16, 20 and 21.3 were over utilized by both T subsets, independently of HIV infection and/or antiretroviral treatment, differing from the ones described for individuals of other nationalities. However, when each patient was taken individually, particular alterations were detected for the Vβ gene usage, compared to controls, for all individuals. After treatment, significant Vβ usage changes were observed for seven patients. One or more chains on both T subsets were engaged in this process, defining a preferential oligoclonal profile for TCR repertoire distribution, after HAART. Although no pattern of specific Vβ changes was detected in the circulating T cells, we cannot exclude that differential immune responses to HIV or other important antigens are being focused by these cells.