Evidence of an activated T-cell system with augmented turnover of interleukin 2 in rheumatoid arthritis. Stimulation of human T lymphocytes by dendritic cells as a model for rheumatoid T-cell activation.
The stage of activation of synovial inflammatory T cells was studied in rheumatoid arthritis and compared with that of normal T cells stimulated in vitro by dendritic cells. Increased numbers of rheumatoid inflammatory T cells expressed activation antigens such as HLA-DR, interleukin 2 receptors (Tac), and transferrin receptors. These T cells also had high spontaneous proliferation. Peripheral blood T cells stimulated by autologous dendritic cells showed a similar expression of activation antigens and had high proliferation. Resting T cells and T cells cocultured with monocytes expressed much less activation markers. Exogenous interleukin 2 significantly increased the proliferation of the various T cells. All responses were inhibited by an antibody which blocks the interleukin 2 receptor. Supernatants from mitogen-stimulated rheumatoid inflammatory mononuclear cells and mitogen-stimulated T cells preactivated by dendritic cells usually contained less interleukin 2 than supernatants from mitogen-stimulated normal T cells. Furthermore, the various in vivo and in vitro-activated Tac-positive T cells, in contrast to nonactivated Tac-negative T cells from peripheral blood of patients and controls, significantly absorbed interleukin 2. The results indicate a turnover of interleukin 2 in rheumatoid inflammatory T cells comparable to that of T cells activated by dendritic cells.
D001172:Arthritis, Rheumatoid / Q000276:immunology*; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D006801:Humans; D007376:Interleukin-2 / Q000378:metabolism*; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D009000:Monocytes / Q000276:immunology; D011990:Receptors, Transferrin / Q000032:analysis; D013582:Synovial Fluid / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
D000949:Histocompatibility Antigens Class II; D007376:Interleukin-2; D011990:Receptors, Transferrin