Early events during primary activation of T cells: antigen receptor cross-linking and interleukin 1 initiate proliferative response of human T cells.
To study early events during primary activation of human T cells, a simple method was developed which simultaneously allows positive selection of T cells from peripheral blood lymphocytes (PBL) and their polyclonal, antigen receptor-mediated stimulation with anti-T3 monoclonal antibodies. In the absence of accessory cells, T cells activated with matrix-bound OKT3 express high levels of the Tac antigen within 15 h and produce interleukin 2 (IL2). Tac expression was further enhanced by addition of exogenous IL2. However, under these conditions purified T cells were unable to mount a proliferative response, whereas unfractionated PBL proliferated already after 24 h of culture. This unresponsiveness of purified T cells could be overcome by either re-addition of low numbers of autologous accessory cells or semipurified human IL1. As IL1 had no significant effect on Tac expression of T3-stimulated T cells, we conclude from these data that IL1 exerts in addition to its influence on IL2 production an effect, which allows antigen receptor-triggered T cells to enter the cell cycle.
D000911:Antibodies, Monoclonal / Q000502:physiology; D000938:Antigen-Presenting Cells / Q000276:immunology / Q000378:metabolism; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000276:immunology; D002448:Cell Adhesion; D002469:Cell Separation / Q000379:methods; D002478:Cells, Cultured; D006801:Humans; D007375:Interleukin-1 / Q000502:physiology*; D007399:Interphase; D008213:Lymphocyte Activation; D010969:Plastics; D011946:Receptors, Antigen / Q000502:physiology*; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D007375:Interleukin-1; D010969:Plastics; D011946:Receptors, Antigen