Inhibition of human mixed lymphocyte culture stimulation by anti-HLA-D-associated antisera: studies with primed responding cells.

The inhibitory effects of HLA-D-associated antisera on stimulating lymphocytes when cultured together with allogeneic primed responding lymphocytes were investigated. The responding lymphocytes were primed for either the HLA-Dw2 or Dw3 determinants. The presence of HLA-D-associated (Ia-like) antibodies during the culture period specifically inhibited the stimulatory capability of lymphocytes possessing the HLA-D determinants with which the antisera were apparently reacting, as long as the stimulating cells carried the determinant for which the responding cells were primed. HLA-D-associated antisera of other specificities caused no decrease in the stimulatory capability. These antisera, therefore, apparently contain antibodies which are reactive with determinants closely associated or identical to the HLA-D determinants and may be human analogues to the mouse Ia antigens.