Heterogeneity of HLA-D(DR)4 detected by primary and secondary mixed-lymphocyte-culture reactions and by individual HLA-DR4 antisera.
One of our panel families (Sb), in which the paternal haplotypes Dw4, DR4 (a) and Dwblank, DR4 (b) segregate, was tested in primary mixed lymphocyte culture (1.MLC) and in the primed lymphocyte test (PLT). In the 1.MLC, cells which carry the a haplotype strongly stimulate b-haplotype cells, and vice versa. For the PLT, lymphocytes of two family-members were primed against the a haplotype and two against the b haplotype. A strong positive restimulation (RR greater than or equal to 60%) occurred only with cells bearing the original stimulating haplotype. The PLs were tested later against families St and Sm, which possess DR4 haplotypes, and against a panel of 73 unrelated persons. The results show heterogeneity of D(DR)4, suggesting at least three different subgroups: D(DR)4a, present on DR4 cells which strongly restimulate the anti-a PLs; D(DR)4b, on DR4 cells which strongly restimulate the anti-b PLs, and D(DR)4c, on the DR4 cells, which do not restimulate any of the PLs tested here. It seems also possible to differentiate between these subgroups with conventional DR-serology, as the 8W sera 903 and 981 react only with a-haplotype cells of family Sb, and ths 8W sera 872 and 1045 react only with b-haplotype cells.
D000961:Antilymphocyte Serum / Q000276:immunology; D005260:Female; D005802:Genes, MHC Class II; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D006801:Humans; D007959:Lymphocyte Culture Test, Mixed; D008297:Male; D008433:Mathematics; D010375:Pedigree; D010641:Phenotype; D013601:T-Lymphocytes / Q000276:immunology
D000961:Antilymphocyte Serum; D000949:Histocompatibility Antigens Class II