Dissociation in expression of MB1/MT1 and DR1 alloantigens in mutants of a lymphoblastoid cell line.
Cytotoxicity tests with alloantisera were used to study the expression of HLA-D region antigens in HLA-DR-null mutants of a human lymphoblastoid cell line. The initial cell line contained just one copy of the MHC as a haplotype that included DR1 and MB1/MT1. Gamma ray mutagenesis of the single haplotype cells followed by selection with complement and an anti-DR monoclonal antibody were then used to isolate DR-null mutants. Two categories of mutants were identified with a panel of alloantisera. Expressions of DR1 and MB1/MT1 were simultaneously lost in four mutants. Nine mutants still expressed MB1/MT1 but had lost the expression of DR1. The dissociated loss of expression of MB1/MT1 and DR1 antigens is evidence for separate genetic control of these alloantigens. The methods used exemplify a versatile approach for conveniently inducing separations of closely linked loci of the MHC.
D002460:Cell Line; D005802:Genes, MHC Class II; D006684:HLA-DR Antigens; D015798:HLA-DR1 Antigen; D006238:Haploidy; D000949:Histocompatibility Antigens Class II / Q000032:analysis*; D006650:Histocompatibility Testing; D006801:Humans; D008213:Lymphocyte Activation; D009154:Mutation
D006684:HLA-DR Antigens; D015798:HLA-DR1 Antigen; D000949:Histocompatibility Antigens Class II