Premium
Hydrolysis of Phosphatidylinositol 4, 5‐Bisphosphate and Increase in Cytosolic Free Ca 2+ ‐Concentration Induced in a Human T Cell Leukemia Line, JURKAT, by Monoclonal Antibodies against the T3 Complex
Author(s) -
Sasaki Terukatsu,
Takei Takashi,
HasegawaSasaki Hiroko
Publication year - 1987
Publication title -
microbiology and immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.664
H-Index - 70
eISSN - 1348-0421
pISSN - 0385-5600
DOI - 10.1111/j.1348-0421.1987.tb03119.x
Subject(s) - jurkat cells , phosphatidylinositol , inositol , monoclonal antibody , phosphatidic acid , biology , microbiology and biotechnology , antigen , fetal bovine serum , cell culture , biochemistry , antibody , t cell , receptor , signal transduction , immunology , cell , phospholipid , immune system , genetics , membrane
The monoclonal antibodies against the T3 complex on human T lymphocytes, anti‐Leu‐4, OKT3, and T3, induced an accumulation of inositol phosphates in a human T cell leukemia line, JURKAT, in the presence of LiCl. The monoclonal antibodies also induced an increase in the cytosolic free Ca 2+ ‐concentration ([Ca 2+ ]i) in JURKAT. The accumulation of inositol phosphates and the increase in [Ca 2+ ]i were specifically induced by the monoclonal antibodies against the T3 complex. Other monoclonal antibodies against differentiation antigens on human T lymphocytes were not active in inducing these responses in JURKAT. Stimulation of JURKAT by anti‐Leu‐4 induced a rapid and immediate decrease in phosphatidylinositol 4,5‐bisphosphate [PtdIns(4,5) P 2 ] and an increase in the 32 P‐labeling of phosphatidic acid, which occurred after a short lag period. An analysis of inositol phosphates formed in the anti‐Leu‐4‐stimulated JURKAT indicated the formation of inositol trisphosphate. These results strongly suggested that the T3 complex or T3/antigen receptor (Ti) complex functions as a receptor which transduces antigen signal, presented by either antigen‐presenting cells or target cells, into the hydrolysis of PtdIns(4,5) P 2 . Fetal bovine serum at a dose of 1–20 μ l/ml induced a marked and transient [Ca 2+ ]i increase in JURKAT immedately after addition. However, the level of formation of inositol phosphates was very small in cells stimulated by fetal bovine serum. Fetal bovine serum induced an immediate increase in the 32 P‐labeling of phosphatidic acid in JURKAT. These and other results suggested that serum increased [Ca 2+ ]i in JURKAT by a mechanism different from that for the anti‐Leu‐4‐induced [Ca 2+ ]i response.