Non-H-2 T-lymphocyte-mediated cytotoxicity after primary in vivo sensitization

A low level of T-lymphocyte-mediated cytotoxic activity was demonstrated after primary in vivo immunization in an H-2-compatible strain combination (B10.D2--DBA2). This phenomenon was demonstrated in a second responder strain (BALB/c) and was thus shown not to be restricted to the B10.D2 genetic background. Results on F1 hybrid mice indicate that the M-locus determinant might be involved in this reaction. It is possible that it is involved in the afferent, efferent, or both limbs of the reaction.