AN ELECTROPHYSIOLOGICAL STUDY OF CALCIUM-ENTRY DURING NORMAL HUMAN T-LYMPHOCYTE ACTIVATION

Our aim was to observe whether normal human T-cells respond to mitogen ic stimulation with large whole-cell inward currents (composed of iden tifiable single-channel contributions) when [Ca2+](i) is not markedly lowered but instead kept normal or moderately low, as has been reporte d in human leukaemic Jurkat T-cell line and T-cell clones [Kuno et al, (1986) Nature 323, 269-73; Kuno and Gardner (1987) Nature 326, 301-30 4; Gardner (1990) Annu, Rev, Immunol. 8, 231-252]. Whole-cell patch re cordings showed no such currents in cells otherwise normally respondin g to depolarisation with the macroscopic I-K described in T-lymphocyte s and thus deemed viable, in agreement with the notion that Ca2+ influ x in normal T-cells enterily depends on depletion of internal stores [ Putney (1986) Cell Calcium 7, 1-12; Putney (1990) Cell Calcium 11, 611 -624].