Resistance to Listeria monocytogenes in Mice: Genetic Control by Genes That Are Not Linked to the H-2 Complex

After mice of several inbred strains were injected with Listeria monoyctogenes, two parameters of resistance, the 50% lethal dose and the suppression of bacterial proliferation in spleen, were determined. The strains of mice tested could be segregated into two groups: the resistant C57BL/10Sn mice and the sensitive A/J and DBA/2J mice. Congenic resistant strains of mice were used because they would express the H-2 haplotype of the sensitive strains (H-2a or H-2d) on the background of a resistant strain, C57BL/10Sn. Both the B10.A/SgSn (H-2a) and the B10.D2/Sn (H-2d) mice were as resistant as mice from their background strain and were significantly more resistant than the strains that donated their H-2 locus (A/J or DBA/2J). Therefore, the resistance of mice to Listeria, although genetically controlled, is not controlled by gene (s) linked to the H-2 haplotype. On the other hand, the level of specific immunity to listeria antigens (as indicated by the footpad reaction) was higher in the C57BL/10Sn (H-2b) mice than in either the A/J and B10.A/SgSn (H-2a) mice or the DBA/2J and B10.D2/Sn (H-2d) mice. This observation suggests an H-2 linkage of specific immunity to Listeria.