DISSOCIATION IN EXPRESSION OF MB1/MT1 AND DR1 ALLOANTIGENS IN MUTANTS OF A LYMPHOBLASTOID CELL-LINE

  • 1 January 1983
    • journal article
    • research article
    • Vol. 131  (3) , 1318-1321
Abstract
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 [LCL 721]. The initial cell line contained just 1 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 4 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 [major histocompatibility complex].