Induction of Kb-restricted anti-influenza cytotoxic T cells in C57BL mice: importance of stimulator cell type and immunization route.

C57BL/6 mice generate influenza-specific cytotoxic T cells (Tc) which are predominantly restricted to Db. The induction of a Kb-restricted response in H-2b mice has been controversial. We show here that the magnitude of Kb-restricted anti-influenza Tc responses is affected by the type of stimulator cell. Both in vivo and in vitro, secondary responses in the spleen show strong selection for Db-restricted Tc. However, limiting dilution analyses show that intranasal (i.n.) influenza infection primes Kb- as well as Db-restricted Tc in C57BL mice at a ratio of 1:2--but different cell types acting as stimulator cells vary in their ability to induce secondary Kb-restricted influenza-specific Tc (B lymphoblasts greater than macrophages greater than spleen cells greater than T lymphoblasts). Thus, the site of infection and antigen presentation can determine the MHC restriction of T-cell responses.