Fine-specificity of the immune response to oxazolones. II. Cytolytic T cells.

Hapten-specific cytolytic T lymphocytes (CTL) were generated either by culturing live mouse spleen cells together with syngeneic haptenated mitomycin-treated spleen cells, or by painting cyclophosphamide-treated mice with the (chemically reactive) haptens. The specificity of the CTL was then tested by using lymphoblast targets coupled with the immunizing hapten or its analogs. Four haptens of the 5-oxazolone family were used. They couple to proteins via carbon atom 4 and had different substitutions at carbon atom 2. CTL originating from the in vivo or in vitro immunization gave identical results. They were specific for the genotype of the immunizing cell and for the hapten (oxazolone family). Syngeneic targets coupled with an unrelated hapten were not killed, nor were allogeneic (H-2-incompatible) targets coupled with any of the oxazolones. Oxazolone-specific CTL could be generated with all 4 oxazolones tested, but all 4 types of killer cells preferred targets coupled with 1 hapten, propenyl Ox. CTL generated with phenyl Ox, furyl Ox, or F-phenyl Ox were thus "heteroclitic" (preference for a chemical analog over the immunogen).