The major histocompatibility complex of the guinea-pig. II. Relationship between mixed leucocyte reactivity and serologically-defined phenotypes of the GPLA B locus and I region.

Abstract

The relationship between the mixed leucocyte reaction (MLR) and the serologically-defined antigens controlled by genes in the guinea-pig B locus (equivalent to the murine D or K region) and I region was investigated in various inbred and partially inbred strains and in guinea-pig families homozygous for their GPLA alleles. No MLR reactions could be detected among guinea-pig families of a closed colony which had been bred to homozygosity for their GPLA antigens. By contrast, animals which differed in their I region showed strong MLR reactivity. Animals with identical I regions as judged by four serologically-defined specificities only, but differ with respect to B locus determinants, yield appreciably lower MLR responses. It appears that in the guinea-pig, as in other mammalian species, the antigenic systems responsible for MLR reactivity are controlled primarily by genes identical with or closely linked to the I region of the major histocompatibility complex.