BINDING MOTIFS PREDICT MAJOR HISTOCOMPATIBILITY COMPLEX CLASS-II-RESTRICTED EPITOPES IN THE SENDAI-VIRUS M-PROTEIN

Major histocompatibility complex (MHC) class I ligand motifs have been defined for a number of class I molecules and have been successfully used to identify class I-restricted cytotoxic T-cell epitopes. In contrast, the relative degeneracy of sequence motifs in naturally processed MHC class II ligands has suggested that they may be of more limited use. Here, we use a predicted I-A(b) ligand motif to identify antigenic peptides in the Sendai virus Enders strain matrix (M) protein. The entire coding sequence of the M protein was derived, and seven peptide sequences that contained the predicted I-A(b) motif were identified. Analysis of I-A(b)-restricted M-specific T-cell hybridomas for reactivity to these synthetic peptides identified two distinct epitopes. These data demonstrate that MHC class II motifs can be valuable in predicting T-cell epitopes.