Analysis of the B10.D2-H-2dml mutant with monoclonal antibodies

We compared H-2D products of B10.D2 and the mutant B10.D2-H-2dml spleen cells using two monoclonal antibodies designated D3.179 and S11.7. D3.179 reacts with public specificities and appears to define more than one product as shown by cytotoxicity and binding studies. Strong reactivity was obtained in both binding and cytotoxicity to B10.D2 and marginal cytotoxicity and low binding were observed with B10.D2-H-2dml cells. The second monoclonal antibody S11.7, in contrast, reacts only with H-2Dd bearing strains and gave strong binding to B10.D2-H-2dml and weaker binding to B10.D2. Taken together, the observations indicate that the mutant not only expresses H-2D encoded antigens but bears quantitatively greater amounts of some specificities than the parent. A product of approximately 46,000 daltons was immunoprecipitated from B10.D2 cells by D3.179. Very small amounts of this product were seen in B10.D2-H-2dml immunoprecipitates.