Differential effect on fresh and cultured T cells of PHA-induced changes in free cytoplasmic calcium: relation to IL-2 receptor expression, IL-2 production, and proliferation.
PHA stimulation of both freshly isolated and IL-2-dependent cultured T cells induced a rapid rise in intracytoplasmic calcium concentration. Chelation of extracellular calcium with EGTA resulted in a failure of PHA to induce a rise in intracytoplasmic calcium, resulting in the fresh T cells in an inhibition of IL-2 production, IL-2 receptor expression, and proliferation. However, cultured T cells grown in recombinant IL-2 were able to re-express IL-2 receptors and proliferate in response to PHA stimulation in the presence of EGTA. Thus the PHA-induced signal for expression of IL-2 receptors and T-cell proliferation differs in fresh and cultured T cells and required extracellular calcium in fresh but not in cultured T cells.
D002118:Calcium / Q000502:physiology*; D002478:Cells, Cultured; D004533:Egtazic Acid / Q000494:pharmacology; D005110:Extracellular Space / Q000502:physiology; D007376:Interleukin-2 / Q000502:physiology*; D008213:Lymphocyte Activation; D010835:Phytohemagglutinins / Q000494:pharmacology; D011971:Receptors, Immunologic / Q000502:physiology*; D015375:Receptors, Interleukin-2; D013601:T-Lymphocytes / Q000166:cytology / Q000502:physiology*
D007376:Interleukin-2; D010835:Phytohemagglutinins; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D004533:Egtazic Acid; D002118:Calcium