Induction of IFN-γ by a panel of T-cell mitogenic stimuli is impaired in HIV-infected PBMC compared with controls. (A) PBMC from controls and patients were incubated at 2 × 10⁶/mL for 48 hours with medium alone, -CD3 (soluble or platebound) + -CD28, TPA + ionomycin, or PHA. Cell-free supernatants were harvested and assayed for IFN-γ. The Pvalues comparing the control group versus patient group in each category of stimulation are listed and were calculated via an unpaired student’s t-test. Data are derived from 10 patients and 10 controls. (B) PBMC from controls and patients were cultured for 48 hours with medium, -CD3 (soluble), PHA, or IL-2 in the presence or absence of IL-12. Cell-free supernatants were harvested and assayed for IFN-γ. The P values comparing the control group versus patient group in each category of stimulation are listed and were calculated via an unpaired student’s t-test. Data are from individual donors (n = 21 for HIV⁺ and n = 17 for HIV⁻).