Respective contribution of intracellular calcium release and extracellular calcium influx for interleukin-2 synthesis in activated T-cell hybrids.
Triggering of the T-cell receptor (TcR)alpha beta/CD3 receptor complex with anti-allotypic antibodies or concanavalin A (Con A) induced a rapid release of intracellular calcium in a murine T-cell hybridoma model system. Internal calcium release preceded the influx of extracellular calcium, as judged by comparative analysis of time-dependent changes in Quin 2 fluorescence following T-cell activation in the presence and absence of extracellular calcium. The magnitude of intracellular calcium release and extracellular calcium influx depended on the degree of receptor-occupancy and cross-linking. Correlations between the concentration of stimulating ligand, cytosolic calcium increase and IL-2 synthesis indicated a positive but non-linear relationship. Our data suggest that TcR cross-linking may provide a third T-cell activation signal which, in conjunction with protein kinase C activation and cytosolic calcium elevation, together form a signal triad responsible for interleukin-2 (IL-2) synthesis.
Williams
D B
DB
Department of Immunology, Faculty of Medicine, University of Toronto, Ontario, Canada.
Perera
M A
MA
Dorrington
K J
KJ
Klein
M H
MH
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D002118:Calcium / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D005110:Extracellular Space / Q000378:metabolism*; D006825:Hybridomas / Q000378:metabolism; D007126:Immunoglobulin Allotypes / Q000276:immunology; D007376:Interleukin-2 / Q000096:biosynthesis*; D008213:Lymphocyte Activation; D051379:Mice; D011948:Receptors, Antigen, T-Cell / Q000502:physiology; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D007126:Immunoglobulin Allotypes; D007376:Interleukin-2; D011948:Receptors, Antigen, T-Cell; D002118:Calcium