title: Human cytotoxic T lymphocytes. II. Frequency analysis of cyclosporin A-sensitive alloreactive cytotoxic T-lymphocyte precursors.
abstract: A limiting dilution (LD) culture system was used to investigate the effect of cyclosporin A (CsA) on the activation and differentiation of human alloreactive cytotoxic T-lymphocyte precursors (CTL-p). CsA reduced in a dose-dependent fashion the frequency of alloantigen-inducible CTL-p. With most normal individuals tested there was a 20- to 50-fold reduction of alloreactive CTL-p frequencies in the presence of 500-1000 ng/ml CsA. Both unseparated T cells and CD8+ T cells were CsA-sensitive under LD culture conditions. Importantly, however, alloreactive CTL-p from two out of 21 normal individuals were found to be largely CsA-resistant. CsA did not affect the growth of MLR-primed CTL in secondary LD culture. Furthermore, CsA slightly inhibited the cytolytic activity of some alloantigen-specific CTL clones. These results are discussed with respect to the clinical use of CsA in transplantation medicine.
mesh_terms: D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000032:analysis; D002454:Cell Differentiation / Q000187:drug effects; D003524:Cyclosporins / Q000494:pharmacology*; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D004306:Dose-Response Relationship, Immunologic; D006801:Humans; D008213:Lymphocyte Activation / Q000187:drug effects*; D013602:T-Lymphocytes, Cytotoxic / Q000166:cytology / Q000187:drug effects / Q000276:immunology*
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D003524:Cyclosporins