An inhibitor specific for the mouse T-cell associated serine proteinase 1 (TSP-1) inhibits the cytolytic potential of cytoplasmic granules but not of intact cytolytic T cells.
We have investigated a proteinase inhibitor, designed according to the preferred amino acid sequence that is cleaved by the murine T-cell specific serine proteinase 1 (TSP-1) for its effect on the cytolytic potential of cloned cytotoxic T-cell lines (CTLL) and of cytoplasmic granules, derived from these cells. Pretreatment of effector cells with H-D-Pro-Phe-Arg-chloromethyl-ketone (PFR-CK) prior to the cytotoxicity assay did not result in inhibition of cytolytic activity of three independent CTLL and did not effect their granule-associated TSP-1 activity after extraction with Triton X-100. Furthermore, PFR-CK did not interfere with cytolysis of target cells by CTLL when present for the entire incubation period. In contrast, PFR-CK inhibited in a dose-dependent manner both TSP-1 activity and the hemolytic/cytolytic potential of isolated cytoplasmic granules after their pretreatment with high-salt concentration. We interpret these results to mean that cytolysis of target cells by CTLL involves the granule-associated proteinase TSP-1, which probably becomes active upon exocytosis following effector-target cell interactions.
Simon
M M
MM
Max-Planck-Institut für Immunbiologie, Freiburg, Germany.
Prester
M
M
Kramer
M D
MD
Fruth
U
U
D000818:Animals; D002458:Cell Fractionation; D002478:Cells, Cultured; D003594:Cytoplasmic Granules / Q000378:metabolism*; D003602:Cytotoxicity, Immunologic; D004790:Enzyme Induction; D005260:Female; D053804:Granzymes; D051379:Mice; D012697:Serine Endopeptidases / Q000096:biosynthesis / Q000378:metabolism*; D015842:Serine Proteinase Inhibitors; D013601:T-Lymphocytes / Q000201:enzymology*
D015842:Serine Proteinase Inhibitors; D053804:Granzymes; D012697:Serine Endopeptidases