Apoptosis and apoptosis-associated perturbations of peripheral blood lymphocytes during HIV infection: Comparison between AIDS patients and asymptomatic long-term non-progressors

This study was designed to compare the degree of lymphocyte apoptosis and Fas-Fas ligand (FasL) expression in AIDS patients and long-term non-progressors (LTNPs) and correlate these parameters with apoptosis-associated perturbations in lymphocyte function. LTNPs had a lower frequency of apoptotic CD4⁺ and CD8⁺ T cells compared with subjects with AIDS. This correlated with a lower frequency of cells expressing Fas and FasL. The frequency of selected lymphocyte populations exhibiting a disrupted mitochondrial transmembrane potential (Δψ(m)) and increased superoxide generation was lower in LTNPs than in patients with AIDS; these abnormalities were associated with lower levels of caspase-1 activation in LTNPs. The results indicate a significantly reduced level of apoptosis and apoptosis-associated parameters in LTNPs than in patients developing AIDS. Based on these findings, a crucial role for mitochondria can be predicted in the process of lymphocyte apoptosis during the evolution of AIDS.