INHIBITION OF PROLIFERATION OF ALLOREACTIVE T CELL CLONES BY SERA FROM MULTIPLE BLOOD OR PLATELET TRANSFUSED PATIENTS

Sera from some multiple blood or platelet transfused patients inhibited the proliferation of alloreactive T cell clones which were stimulated and proliferated with the stimuli of allo major histocompatibility antigens (allo-MHC). The serum factors which were responsible for the inhibition appeared to bind to T cell clones, but not to stimulator cells. Further analysis revealed that one factor was included in immunoglobulin G fraction of the sera. From the competitive experiment with various monoclonal antibodies to membrane antigens of T cell clones, it was appeared that some sera contained antibody to T cell receptor (TCR) of some T cell clones. With the view of clone specific binding of anti-TCR antibody, it was proved that the antibody was anti-idiotypic antibody.