Isolation and Antigenic Characterization of the Product of a Third Polymorphic H-2 Locus, H-2L

Abstract

The serology, immunochemistry and genetics of the product(s) of a 3rd H-2 locus, H-2L (previously designated D'') were studied using an antiserum raised in BALB/c-H-2db mutant mice against tissues from the wild type strain, BALB/c. Genetic mapping studies and sequential immunoprecipitation experiments indicated that this antiserum reacts specifically with L molecules. An H-2L product may be antigenically undetectable in BALB/c-H-2db mice and the lesion in this mutant may be confined to the H-2L and not the H-2D locus. Twe new specificities, H-2.64 and H-2.65, were defined by the reactivity of anti-L serum on allogeneic cells, and the strain distribution of these specificities suggests the existence of at least 3 H-2L alleles. This 3rd H-2 locus is polymorphic and similar to the H-2K and H-2D loci. It must be considered in any evolutionary models dealing with the origin of multiple subloci of the major histocompabilitiey complex.