Dissection of thymocyte signaling pathways by in vivo expression of pertussis toxin ADP-ribosyltransferase.

摘要: Stimulation of the T lymphocyte antigen receptor-CD3 complex (TCR-CD3) causes cell activation by a process associated with increased phosphatidylinositol-specific phospholipase C (PI-PLC) activity. Evidence exists suggesting that GTP-binding (G) proteins, particularly pertussis toxin (PT)-sensitive Gi participate in this signal transduction pathway. To clarify role proteins TCR-CD3 signaling, and to investigate other possible functions molecules cells, we expressed S1 subunit PT thymocytes transgenic mice using lymphocyte-specific lck promoter. Transgenic contained activity exhibited profound depletion protein substrates manner their inactivation vivo. Nevertheless, treatment mitogenic stimuli provoked normal increases intracellular free Ca2+ concentrations IL-2 secretion, indicating are not required for activation. These signaling responses notwithstanding, mature accumulated lck-PT did appear secondary lymphoid organs or circulation. Viewed context known features Bordetella infection, our results suggest PT-sensitive process, probably involving regulates thymocyte emigration.