Prediction and identification of a T cell epitope in the fusion protein of measles virus immunodominant in mice and humans.

Amino acid residues 288 to 302 of the fusion protein of measles virus were predicted by a variety of methods to represent a putative T cell epitope. This sequence was synthesized and the peptide was injected into mice of six inbred strains to test this possibility. Lymphocytes from peptide-immunized mice from all six H-2 disparate strains were able to mount a proliferative response following in vitro culture with the peptide. In addition, lymphocytes from three strains also proliferated in the presence of live measles virus. The peptide also behaved as a B cell epitope in that immunization with free peptide in adjuvant resulted in anti-peptide antibody production in all mouse strains. However, these antibodies did not react with the virus in either a solid-phase immunoassay or a virus neutralization assay. Peripheral blood lymphocytes from 10 laboratory personnel with a prior history of exposure to measles virus were tested in a proliferation assay with the peptide and with the virus. Lymphocytes from all 10 individuals proliferated in response to culture with the virus and those from eight responded to the peptide. These results give further support to the concept of permissive interaction of antigenic peptides with a wide range of class II major histocompatibility complex molecules both in mice and man and indicate the possibility of designing peptides that could be used as components of a synthetic vaccine for use in man.