Abstract: | A significant amount of information concerning immunologic domains of an antigenic molecule can be obtained by studying its peptides. We describe a method for identifying and characterizing immunologically relevant T-cell and B-cell epitopes in S-antigen, a well-characterized, highly pathogenic retinal autoantigen for the induction of experimental autoimmune uveitis. The method involves the generation of peptide fragments by enzymatic treatment of native S-antigen and by the simultaneous synthesis of large numbers of peptides in small quantities for screening and testing. Peptides demonstrating T- or B-cell activity are then synthesized in large quantity for additional studies. Although useful information was obtained by the use of enzymatically generated peptides, synthetic peptides provided the greatest flexibility and specificity, allowing the precise localization of amino acid sequences of S-antigen required for a particular immunological function such as antibody binding, T-cell proliferative responses, pathogenicity, and the induction of tolerance. These studies have wide applicability to the study of other antigenic molecules and have led to a better understanding of the immune mechanisms involved in the pathogenesis of experimental autoimmune uveitis. This, in turn, provides a basis for the processes that may be occurring in certain forms of human uveitis. |