The role of gene products of non-H-2 loci and M locus in secondary MLC response.

The response in the secondary MLC after priming in vivo was studied in combinations of mouse strains H-2 identical and differing at genetic loci that segregate independently of the H-2 system (non H-2 loci including M locus). After priming with gene products of non-H-2 loci and M locus the response in secondary MLC in H-2-identical strains is influenced by the H-2 genotype (combinations compatible for H-2b and H-2k haplotypes were compared). With the H-2k compatibility, the type of secondary MLC response depends on the non-H-2 genotype of the responder strain. The same gene products of the M locus activate a cell suppressor mechanism, which suppresses the blastic response of lymphocytes, in some responder strains and an early proliferative response in others.