Association between Ia antigens and the Fc receptors of certain T lymphocytes.

Abstract

The Fc receptors of [mouse] thymic and splenic T [thymus-derived] lymphocytes were detected using indirect immunofluorescence and soluble antigen-antibody complexes. Of the thymocytes, 10-20% and of the Thy-1-positive splenic lymphocytes, 40-50% bound antigen-complexed Ig [immunoglobulin]. The binding to thymocytes was partially inhibited (45-74%) by antibodies against antigens determined by the I [immune] region of the H-2 complex, but not by antibodies against K- or D-region antigens or Thy-1 antigen. The inhibition did not require the Fc portion of the inhibiting antibody. Ia [immune response associated] antigens and the Fc receptors of some T lymphocytes are apparently associated, and the populations of T cells which bear these moieties probably at least partially overlap.