Maintenance of CD4+ T cell TCR Vbeta repertoire heterogeneity is characteristic of apathogenic SIV infection in non-human primate model of AIDS.

A PCR-based assay was established to screen for potential changes in the heterogeneity of Vbeta TCR expressing CD4+ T cells from rhesus macaques (RM) and sooty mangabeys (SM) prior to and following SIV infection. The rationale for these studies was to determine whether the progressive CD4+ T cell loss in SIV-infected disease susceptible RM and the moderate CD4+ T cell loss in disease resistant SM leads to the depletion of select Vbeta TCR families of CD4+ T cells. Results show that whereas SIV infection leads to the loss of Vbeta TCR heterogeneity in disease susceptible RM, the CD4+ T cells from SM retain their degree of Vbeta TCR heterogeneity, suggesting that the mechanism(s) of SIV induced CD4+ T cell loss maybe distinct in these 2 species and contribute to the differences in the clinical outcome.