title: A subpopulation of T cells bearing Fc receptors.
abstract: A wide range of cell populations were examined for Fc receptor (FcR)-bearing T cells: thymus, spleen, peritoneal cells, and T cells activated to H-2 antigens in spleen (ATC spleen) and in thoracic duct lymph (T-TDL). In addition, B lymphocytes from thoracic duct lymph of athymic nude mice and a Thy-1-positive, FcR-positive thymoma served as control cell populations. Reagents used were aggregates of human gamma-globulin and of various mouse myeloma proteins (IgG1, IgG2a, IgG2b), radioiodinated antigen-antibody complexes, and sheep erythrocyte antibody rosettes. Labeling techniques involving radioautography and immunofluorescence were used to demonstrate FcR by one of the above reagents and to identify T cells either by staining with anti-Thy-1.2 or by a specific rabbit anti-mouse T cell serum, or by failure to stain with anti-mouse immunoglobulin. In some experiments phagocytic cells were removed whereas in others they were identified by their capacity to engulf latex particles. Approximately 25% of cells with T cell markers were FcR-bearing cells in thymus, normal spleen, and peritoneal cavity, and 17% in ATC spleen. FcR on T cells in peripheral lymphoid tissues were detectable by aggregates of HGG and myeloma proteins and by radioiodinated immune complexes. Those on T cells in thymus were revealed only by aggregates of HGG. Circulating T cells (T.TDL) failed to display FcR: a) despite the use of a wide range of the above labeling techniques, each of which was shown to detect FcR on other T cells, thymoma cells, and B cells, and b) even after removal of Ig associated with their cell membranes. In contrast to B cell FcR which bound IgG1 preferentially, those on T cells bound both IgG1 and IgG2, raising the possibility that the FcR on T cell is distinct from that on B cell. It is concluded that FcR-bearing T cells represent a subpopulation of cells within the thymus and the secondary lymphoid tissues.
mesh_terms: D000818:Animals; D000961:Antilymphocyte Serum / Q000302:isolation & purification; D002448:Cell Adhesion; D002460:Cell Line; D004912:Erythrocytes / Q000276:immunology; D005455:Fluorescent Antibody Technique; D007140:Immunoglobulin Fab Fragments / Q000302:isolation & purification; D007141:Immunoglobulin Fc Fragments / Q000032:analysis; D008214:Lymphocytes / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008819:Mice, Nude; D011817:Rabbits; D011828:Radiation Chimera; D011947:Receptors, Antigen, B-Cell / Q000378:metabolism; D011955:Receptors, Drug; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000961:Antilymphocyte Serum; D007140:Immunoglobulin Fab Fragments; D007141:Immunoglobulin Fc Fragments; D011947:Receptors, Antigen, B-Cell; D011955:Receptors, Drug