Mitogenic and non-mitogenic ligands trigger a calcium-dependent cytosolic acidification in human T lymphocytes
Cheung, R.K.; Grinstein, S.; Gelfand, E.W.
Journal of Immunology 141(5): 1648-1651
1988
ISSN/ISBN: 0022-1767 PMID: 3261756 Document Number: 321799
We have investigated the patterns of cytosolic pH and Ca2+ ([Ca2+]i) changes after exposure of human peripheral blood T cells to different mitogenic and non-mitogenic ligands. Using ligands that have different accessory cell requirements and varying effect on [Ca2+]i or cell proliferation, we observed that intracellular acidification occurred only with agents that increased [Ca2+]i. However, treatment of the cells with the phorbol ester, 12-O-tetradecanoylphorbol-13-acetate, results in significant cytosolic alkalinization without detectable acidification, but did not affect the proliferative responses to mitogenic ligands and was a potent co-mitogen with non-mitogenic ligands. These data indicate that initial acidification or alkalinization responses are not essential for early activation or triggering of DNA synthesis.