Fine antigenic specificity and genetic restriction of lysozyme-specific suppressor T cell factor produced by radiation leukemia virus-transformed suppressor T cells.

Culture supernatants obtained from a radiation leukemia virus-transformed, hen egg-white lysozyme (HEL)-specific, suppressor T cell line are able, when injected into mice, to specifically suppress the anti-HEL antibody response. Suppression is observed on both primary and secondary anti-HEL antibody responses evaluated by direct and developed hemolytic plaque assays. Culture supernatants from this HEL-specific suppressor T cell line do not suppress the antibody response induced by a structurally related lysozyme, demonstrating the presence in the culture supernatant of a suppressor factor endowed with fine antigenic specificity. The suppressor factor is able to selectively suppress the anti-HEL antibody response induced by the N-terminal C-terminal peptide of the HEL molecule indicating that the fine specificity of this factor is restricted to an antigenic epitope present in this region of the HEL molecule. The suppressive activity is restricted by genes located within the H-2 complex and analysis of the suppression induced in recombinant mice demonstrates that the interaction between HEL-specific suppressor T cell factor and its cellular target requires identity in the I-J region of the H-2 complex.