Random depletion of T cells that bear specific T cell receptor V beta sequences in AIDS patients.

A cross-sectional PCR analysis of the TCR V beta repertoires in HIV-1 seronegative controls and HIV-1 infected individuals with either clinically or immunologically defined AIDS [1] was performed to examine the proposed superantigen model for HIV-1 pathogenesis. In contrast to previous reports, we find neither uniform specific losses nor uniform clonal expansions of particular TCR V beta gene families in subjects with AIDS. Instead our study, which was designed specifically to qualitatively determine the presence or absence of TCR V beta families in both subject populations, indicates an overall diminution in the expression of TCR V beta gene families in HIV-1 infected individuals with AIDS compared with controls. This is commensurate with the decrease in CD4 T cells in the AIDS population. Our data are therefore not directly suggestive of a common superantigen model of HIV-1 induced T cell clonal depletion or anergy, but instead emphasize a broad decrease in signals throughout the TCR V beta repertoire in AIDS versus control groups. This random depletion in the TCR V beta repertoire is most likely caused by aspects of HIV-1 pathogenesis other than virus-encoded superantigens.