Studies of H-2Kb mutant mice. II. Definition of new H-2 specificities (H-2.68, 69, 71, 72) using the H-2Kb mutant, B6.C-H-2bm10.

Using the H-2Kb mutant strain, B6.C-H-2bm10, antibodies were produced which define four new H-2 specificities. This is in contrast to other H-2Kb mutant strains in which attempts to produce antibodies against the mutation have failed with the exception of H-2bm3 in which a new specificity, H-2.62, was described by absorption analysis of an H-2.33 antiserum. With the mutant strain as immunization donor in the combination (C57BL/10 x 129)F1 anti B6.C-H-2bm10, two new H-2 specificities, H-2.68 and H-2.69, were produced. H-2.68 is found only on B6.C-H-2bm10, while H-2.69 is present on B6.C-H-2bm10 and on all cells of the H-2k haplotype. By testing the appropriate H-2 recombinant strains, the reaction with the H-2k haplotype could be mapped to the H-2D locus, whereas in B6.C-H-2bm10 it must have occurred in the H-2Kb gene. The reciprocal immunization of congenic strains failed, but with B6.C-H-2bm10 anti-A.BY, the specificities H-2.71 and H-2.72 were produced: H-2.71 was present on cells of the b,d, and k haplotypes, while H-2.72 was found only on the b haplotype. Genetic mapping using H-2 recombinant strains showed the H-2.72 reaction to be associated with the H-2Kb, H-2Dd and H-2Kk genes. The specificities described were shown to be of the H-2 type by their reactivity with H-2 congenic and recombinant strains, their segregation in a backcross and their ability to precipitate a molecule of 45,000 daltons molecular weight on SDS-PAGE. Therefore, the mutation carried by B6.C-H-2bm10, which resulted in a marked alteration of the H-2Kb specificities H-2.33 and H-2.5, is such that specific antibodies were able to be produced against both the gain and loss alterations produced by the mutation.