Modulation of the intracellular Ca²⁺ and inositol trisphosphate concentrations in murine T lymphocytes by the glycosylphosphatidylinositol-anchored protein sgp-60

Stimulation of T lymphocytes via the TCR/CD3 complex initiates a series of intracellular biochemical events. Among the earliest cellular responses are the stimulation of the turnover of phosphatidylinositol and an increase in the intracellular Ca2+ concentration. The significance of these second messengers for distal cellular responses such as lymphokine production or cell proliferation is not understood. We have previously shown that a hamster mAb to the murine glycosylphosphatidylinositol-anchored protein sgp-60 can inhibit IL-2 production, IL-2R expression, and cell proliferation, events normally observed after stimulation of T cells with an antibody to the TCR/CD3 complex or with the lectin Con A. We now show that the anti-sgp-60 mAb inhibits the activationinduced increase in intracellular Ca2+ concentration. Additional analysis demonstrates that the mAb interferes with the release of Ca2+ from intracellular stores and with the generation of inositol 1,4,5-trisphosphate. Our findings suggest a role for this glycosylphosphatidylinositol-anchored protein in the generation of second messenggers in signal transduction through the TCR/CD3 complex in murine T lymphocytes. Copyright ©1993 by The American Association of Immunologists.

Duke Scholars

Author Philip Martin Rosoff Pediatrics, Hematology-Oncology