Antigen receptor-triggered secretion of a trypsin-type esterase from cytotoxic T lymphocytes.
Exocytosis of cytolysin-containing granules from cytotoxic T lymphocytes (CTL) was studied with the use of granule enzyme (BLT esterase) as a convenient biochemical marker. Using cloned CTL, we demonstrate here that BLT esterase secretion into the supernatant is specifically triggered by antigen-bearing target cells and that this secretion is inhibited by soluble monoclonal antibodies against the antigen-specific T cell receptor (TcR). Immobilized anti-receptor antibodies induced efficient enzyme secretion in the absence of target cells, thus implying a direct involvement of TcR complex in triggering exocytosis of granules. These results support the role of the granule exocytosis in CTL functions and provide a quantitative and direct assay of a rapid CTL functional response to antigenic stimulation.
D000818:Animals; D000911:Antibodies, Monoclonal; D002460:Cell Line; D003594:Cytoplasmic Granules / Q000201:enzymology / Q000502:physiology; D003602:Cytotoxicity, Immunologic; D004950:Esterases / Q000378:metabolism*; D005089:Exocytosis; D051379:Mice; D011948:Receptors, Antigen, T-Cell / Q000502:physiology*; D012995:Solubility; D013602:T-Lymphocytes, Cytotoxic / Q000201:enzymology*
D000911:Antibodies, Monoclonal; D011948:Receptors, Antigen, T-Cell; D004950:Esterases; C022635:serine esterase