In vitro effects of IL-12 on HIV-1-specific CTL lines from HIV-1-infected children.
We studied the in vitro effects of IL-12 on HIV-1-specific CTL lines derived from PBMC of HIV-1-infected children. HIV-1-specific CTL lines were derived by limiting dilution following Ag-specific stimulation of PBMC from HIV-1-infected children and were maintained with repeated anti-CD3 stimulation. Following incubation with IL-12 for 5 to 7 days, HIV-1-specific cytotoxicity was augmented in a dose-dependent fashion (mean increase, 94 +/- 83 lytic units; p = 0.0006). Experiments performed with CD3-blocking Abs and MHC-mismatched targets demonstrated that the IL-12-enhanced activity was MHC restricted and dependent on cells bearing CD3. The effect of IL-12 on proliferation of the CTL lines as tested by [3H]TdR uptake was minimal, with stimulation indexes ranging from 1.25 to 4.9. The effects of IL-12 on cytotoxicity were not significantly altered by addition of Ab to the IL-2R (anti-Tac) in quantities sufficient to block exogenous IL-2 (p = 0.15), demonstrating that endogenous IL-2 activity is not required for IL-12-enhanced cytolytic activity. Likewise, addition of neutralizing Ab specific for IFN-gamma did not change IL-12-enhanced cytotoxicity (p = 0.61). The in vivo role of IL-12 in the generation and the stimulation of CTL remains to be determined; however, its ability to augment HIV-1-specific CTL in vitro adds additional support for IL-12 as a candidate for immune-based therapy of HIV-1.
McFarland
E J
EJ
Department of Pediatrics, University of Colorado Health Sciences Center, Veterans Affairs Medical Center, Denver 80262, USA.
Harding
P A
PA
MaWhinney
S
S
Schooley
R T
RT
Kuritzkes
D R
DR
D000293:Adolescent; D000956:Antigens, Viral / Q000276:immunology; D002455:Cell Division / Q000187:drug effects / Q000276:immunology; D002460:Cell Line; D002648:Child; D002675:Child, Preschool; D003601:Cytotoxicity Tests, Immunologic; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D015658:HIV Infections / Q000276:immunology* / Q000473:pathology; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D007371:Interferon-gamma / Q000502:physiology; D018664:Interleukin-12 / Q000494:pharmacology*; D007376:Interleukin-2 / Q000502:physiology; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000473:pathology; D008213:Lymphocyte Activation / Q000187:drug effects; D007959:Lymphocyte Culture Test, Mixed; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000821:virology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000821:virology
D000956:Antigens, Viral; D018984:Epitopes, T-Lymphocyte; D007376:Interleukin-2; D018664:Interleukin-12; D007371:Interferon-gamma