Effect of stage of HIV disease on generation of CD4^dimCD8^bright T-cell phenotype. CD8⁺ T cells from HIV⁺ patients in early (n = 5), moderate (n = 5), and advanced (n = 6) stages of HIV disease were stimulated with SEB or anti-CD3/CD28 costimulation, as previously described. Percentage of expression of CD4^dimCD8^bright was determined by gating on CD3⁺CD8⁺ T cells (A). Values represent median percentage of expression of CD4^dimCD8^bright T cells, and a representative diagram from 1 donor each in early, moderate, and advanced HIV disease stage is shown in panel B.