Stimulation of anti-influenza cytolytic T lymphocytes by CNBr cleavage fragments of the viral hemagglutinin

Purified hemagglutin of influenza virus, subtype A/Jap/305/57 (H2/N2) was cleaved with CNBr, and the resulting fragments were capable of stimulating H-2 restricted cytolytic T lymphocytes in vitro from spleen cells of mice immunized previously with A/Jap/305/57. When the peptides were separated by high-performance liquid chromatography, stimulatory activity was confined primarily to a series of peptides contained within a limited chromatographic range. The majority of the lytic activity was specific for cells infected with A/Jap virus, although a small amount of cross-reactive killing of A/PR/8/34-(HO/N1) infected cells could not be excluded. These results demonstrated that H-2-restricted influenza viral-specific CTL could be generated by fragments of a complex polypeptide antigen, the influenza hemagglutinin, and offer the possibility of analyzing specific antigenic determinants recognized by cytolytic T cells.