Presence of "La-like" antigens on human T lymphocytes bearing receptors for IgG.

Human peripheral blood T cells bearing receptors for the Fc portion of immunoglobulins were characterized by the formation of double rosettes with sheep red blood cells and IgG-coated chicken erythrocytes (EA). Treatment of cells by anti-"Ia-like" antisera inhibits the binding of EA. Inihbition appeared to be specific since anti-HLA-A and HLA-B antibodies did not inhibit the formation of EA rosettes, whereas F (ab')2 fragments of anti-Ia-like IgG were found to be as potent inhibitors as the whole IgG. This result shows that in human and in mice, Ia-like determinants arepresent, close to Fc gamma receptors, on the surface of the T lymphocytes bearing such receptors.