Antigen-specific primary cytotoxic T lymphocyte (CTL) responses in acquired immune deficiency syndrome (AIDS) and AIDS-related complexes (ARC).

Alloantigen specific primary cytotoxic T lymphocyte (CTL) responses were examined in vitro in 10 patients with AIDS and nine with AIDS-related complex (ARC). The lymphocytes from patients with AIDS and ARC expressed significantly less (P less than 0.01) CTL activity (mean +/- s.d.; 4.7 +/- 9% and 10 +/- 11% respectively) when compared with CTL activity in normal healthy heterosexual controls (28 +/- 9.5%). When data were analysed for individual patients, lymphocytes from nine of 10 patients with AIDS and six of nine with ARC had deficient or no CTL activity. In vitro addition of purified human interleukin-2 (IL-2) during the generation of CTL resulted in significant enhancement (P less than 0.05) of CTL activity in ARC group (mean +/- s.d.; 27 +/- 18) but not in AIDS group (mean +/- s.d.; 8 +/- 8%). The presence of IL-2 augmented the induction of CTL activity in three of nine patients in AIDS group and in five of six in ARC group. In vitro addition of lectin-free supernatant (SN) obtained from cultures stimulated with PHA as well as with lymphoid cell restored the CTL functions in three of six AIDS patients and in one patient with ARC who did not respond to exogenous IL-2. The CTL activity developed in the presence of SN was higher than that manifested in the presence of IL-2 in both AIDS (SN versus IL-2; mean +/- s.d., 18 +/- 15.6% versus 8 +/- 8%) and in the ARC group (SN versus IL-2; mean +/- s.d., 35 +/- 13.9% versus 27 +/- 18.3%). Lymphocytes from three AIDS patients, however, failed to develop any CTL activity in the presence of either IL-2 or SN. These results demonstrate that: (i) the lymphocytes from majority of patients with AIDS and with ARC have deficient ability to develop into alloantigen specific primary CTL effectors, and (ii) the defective CTL functions are restored by the addition of purified IL-2 or SN in all patients with ARC and only in a subset of patients with AIDS, suggesting heterogeneity of pre-CTL to respond to IL-2 and some differentiation factor in order to differentiate in CTL effectors.