Phosphoinositide hydrolysis in mitogen-stimulated human peripheral-blood T lymphocytes.
Both phytohaemagglutinin and antibodies to the CD3 molecule induced proliferation and phosphoinositide hydrolysis in human peripheral-blood T lymphocytes, but the magnitude of the inositol phosphate response was small and the rate of accumulation slow [significant increases in Ins(1,4,5)P3 were observed only after 10 min]. Hence this response differs from the well-characterized Ins(1,4,5)P3 responses of many other systems. This slow response, its abrogation in Ca2+-depleted medium, the slow and maintained increase in Ca2+ as measured by Quin-2, and the ability of the Ca2+ ionophore A23187 to stimulate Ins(1,4,5)P3 accumulation all suggest that the increase in Ins(1,4,5)P3 occurs, at least in part, as a result of receptor-mediated Ca2+ influx in mitogen-stimulated T lymphocytes.
King
S
S
Department of Immunology, St. George's Hospital Medical School, London, U.K.
Whitley
G
G
Salmon
M
M
Johnstone
A
A
D000911:Antibodies, Monoclonal / Q000378:metabolism; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000097:blood; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D008213:Lymphocyte Activation; D008938:Mitosis / Q000187:drug effects; D010716:Phosphatidylinositols / Q000097:blood*; D010835:Phytohemagglutinins / Q000494:pharmacology; D013601:T-Lymphocytes / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D010716:Phosphatidylinositols; D010835:Phytohemagglutinins; D000001:Calcimycin; D002118:Calcium