Cytokine requirements for production of a novel anti-CD8-resistant CTL population.
A population of CD8+ CTL can be generated in vitro in the presence of anti-CD8 mAb. Due to their apparent high avidity characteristic, these anti-CD8-resistant CD8+ CTL may have important functional in vivo roles in graft rejection, and may be important in antiviral and antitumor responses. We have previously reported that this anti-CD8-resistant subset of CD8+ CTL demonstrates functional differences from anti-CD8-sensitive CD8+ CTL. One important difference between the subsets is the markedly greater dependence of anti-CD8-resistant CTL upon exogenous cytokines for their generation in vitro. In this study, we have investigated in detail the cytokine requirements for the generation of allospecific CD8+ CTL in vitro and have found that IL-4 can augment the generation of anti-CD8-sensitive but not anti-CD8-resistant CTL, whereas IL-2 or IL-12 can augment the generation of both anti-CD8-sensitive and anti-CD8-resistant CTL. However, anti-CD8-resistant CTL require at least 10-fold higher concentrations of IL-2 than do anti-CD8-sensitive CTL. This more stringent IL-2 requirement precludes the efficient generation of anti-CD8-resistant CTL in vitro in the absence of exogenous IL-2 because they cannot produce sufficient IL-2 to meet their needs, in contrast to anti-CD8-sensitive CTL. By providing exogenous cytokines to allospecific CTL generation cultures, we further demonstrate that anti-CD8-resistant CTL can be functionally skewed to the Tc1 subset, but differ from anti-CD8-sensitive conventional CTL in that they cannot be skewed to the Tc2 subset.
Lamousé-Smith
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ES
Immunology Graduate Training Program, Department of Surgery, University of Pittsburgh School of Medicine, PA 15213, USA.
Dougall
D S
DS
McCarthy
S A
SA
D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D016827:CD8 Antigens / Q000276:immunology*; D002454:Cell Differentiation / Q000276:immunology; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis / Q000502:physiology*; D003602:Cytotoxicity, Immunologic; D007113:Immunity, Innate; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000378:metabolism; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology
D000911:Antibodies, Monoclonal; D016827:CD8 Antigens; D016207:Cytokines