Inhibition of HIV replication by CD8+ T cells correlates with CD4 counts and clinical stage of disease.

We sought to evaluate the relationship of CD8- T cell-mediated inhibition of autologous HIV replication in vitro to disease stage in HIV+ individuals, Depletion of CD8+ T cells from peripheral blood lymphocytes of lb HIV+ subjects increased the percentage of virus-producing cultures from 56% to 81%. CD4+ I cells were purified from 52 HIV+ individuals and cultured alone or in the presence of autologous CD8+ T cells. In 13 (25%) subjects HIV replication was only detected in the absence of CD8+ T cells (inhibition positive): in 26 (50%) viral replication occurred both in the absence and presence of CDS cells (inhibition negative). In the remaining 13 (25%) subjects. CD8+ T cell-mediated inhibitory activity could not be evaluated because stimulation of their purified CD4 T cells did not result in p24 production. In some virus culture-negative individuals. the inability to demonstrate HIV replication was due to the presence of low numbers of CD8+ T cells that co-purified with CD4+ T cells. Detection of inhibitory CDS T cells was associated with significantly higher CD4 counts and better clinical status compared with inhibition-negative subjects. These results demonstrate that cur T cell-mediated inhibition of HIV replication correlates with disease stage. and thus may play a role in preventing disease progression. CD8+ I cells did not inhibit autologous HIV replication across a semipermeable membrane. Further, the ability of CD8+ T cells to prevent HIV replication did not correlate with lysis of autologous CD4 T cells. Thus. CD8+ T cells inhibited autologous HIV replication in vitro through a contact- mediated non lytic mechanism. [ABSTRACT FROM AUTHOR]