Cell-mediated lympholytic responses against autologous cells modified with haptenic sulfhydryl reagents. V. H-2Ld self products are recognized by anti-AED-specific cytotoxic T cells.

The present studies were designed to examine the restriction elements involved in the H-2d haplotype CTL response against AED-self. BALB/c mice were immunized by in vivo administration of syngeneic BALB/c spleen cells conjugated with the sulfhydryl reactive haptenic reagent I-AEDANS. The cytotoxic T cell response generated by subsequent in vitro stimulation with AED-self was found to contain H-2K and H-2D region-specific components. In contrast to the predominant H-2D hapten-self CTL responses induced by amino-reactive haptenic reagents like TNBS and FITC, the AED-self response was predominantly directed against H-2K self products. Antibody inhibition analysis demonstrated that the H-2D region component contained Ld-AED-self CTL, as well as Dd-AED-self CTL. However, although both Ld- and Dd-restricted components could be identified shortly (less than 1 wk) after priming, the H-2D region AED-self CTL response shifted to a single restricting molecule, namely Dd, 1 wk and later after immunization. The results of this study provide the first demonstration that the H-2L locus encodes a cell surface product that can function as a restricting molecule for hapten-self-specific CTL. The shift from Ld and Dd AED-specific CTL to Dd only suggests the existence of a highly specific regulatory mechanism directed against antigen (i.e., hapten) plus self.