The ability of interspecies crossreactive anti-Ia murine alloantibodies to eliminate a subpopulation of human adherent cells responsible for induction of alloimmunity.
Certain anti-Ia murine alloantibodies react with the Ia-positive B cells of almost all mammalian species. In this report, the effect of such murine alloantibodies on the function of accessory cells in induction of human immune responses was studied by using human peripheral blood lymphocytes pretreated with anti-Iak murine alloantibodies and complement. The induction of allogeneic mixed lymphocyte reactions and allogeneic cytotonic T cells was drastically reduced by means of pretreatment of the stimulator population with anti-Ia and complement. When both responder and stimulator were pretreated with these reagents, inductions of the residual responses were completely eliminated. Cells with quite similar characteristics (i.e., adherence to the petri dish and crossreaction with the anti-Ia murine alloantibodies) were also found to be essential in the induction of in vitro T cell proliferative responses to purified protein derivate and concanavalin A. These results seem to indicate that the interspecies crossreactive anti-Ia murine alloantibodies react with the human homologue of murine Ia-positive macrophagelike cells that are recognized as antigen-presenting cells. It is also concluded that, in induction of alloimmunity, Ia-positive adherent cells of the stimulator population are the major source of the stimulation.
D000818:Animals; D002448:Cell Adhesion; D003429:Cross Reactions; D000939:Epitopes; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D006801:Humans; D007111:Immunity, Cellular; D007518:Isoantibodies / Q000276:immunology*; D008213:Lymphocyte Activation; D008264:Macrophages / Q000276:immunology*; D051379:Mice; D013045:Species Specificity; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology
D000939:Epitopes; D000949:Histocompatibility Antigens Class II; D007518:Isoantibodies