Inhibition of pokeweed mitogen-induced Ig secretion by IgG monoclonal antibodies to MHC class I and class II molecules requires binding of the intact antibody.

Seven purified IgG monoclonal antibodies reactive with different epitopes on DQw1, DR, HLA-A3 or p85 glycoprotein of human lymphocytes have each been shown to inhibit pokeweed mitogen (PWM)-induced IgG and IgM secretion in a dose-dependent manner. Binding of these antibodies to their target antigens was required for the suppression. Antibodies of IgG1, IgG2 alpha, and IgG2b subclasses were able to inhibit both IgG and IgM secretion in the PWM system.

A reevaluation of the putative association between the Fc gamma receptor and histocompatibility antigens on human mononuclear leukocytes.

The controversial question of an association between human Ia antigens and the FcR for immunoglobulin G has been examined. The experimental basis upon which such a relationship has been predicted was reevaluated. Human allosera with specificity for classical transplantation antigens, HLA-DR, and the related supertypic specificities MB and MT have been tested for their capacities to inhibit homologous EA rosette formation by PBM and B-CLL cells.