Surface Cathepsin B Protects Cytotoxic Lymphocytes from Self-destruction after Degranulation
Open Access
- 19 August 2002
- journal article
- Published by Rockefeller University Press in The Journal of Experimental Medicine
- Vol. 196 (4), 493-503
- https://doi.org/10.1084/jem.20011836
Abstract
The granule exocytosis cytotoxicity pathway is the major molecular mechanism for cytotoxic T lymphocyte (CTL) and natural killer (NK) cytotoxicity, but the question of how these cytotoxic lymphocytes avoid self-destruction after secreting perforin has remained unresolved. We show that CTL and NK cells die within a few hours if they are triggered to degranulate in the presence of nontoxic thiol cathepsin protease inhibitors. The potent activity of the impermeant, highly cathepsin B–specific membrane inhibitors CA074 and NS-196 strongly implicates extracellular cathepsin B. CTL suicide in the presence of cathepsin inhibitors requires the granule exocytosis cytotoxicity pathway, as it is normal with CTLs from gld mice, but does not occur in CTLs from perforin knockout mice. Flow cytometry shows that CTLs express low to undetectable levels of cathepsin B on their surface before degranulation, with a substantial rapid increase after T cell receptor triggering. Surface cathepsin B eluted from live CTL after degranulation by calcium chelation is the single chain processed form of active cathepsin B. Degranulated CTLs are surface biotinylated by the cathepsin B–specific affinity reagent NS-196, which exclusively labels immunoreactive cathepsin B. These experiments support a model in which granule-derived surface cathepsin B provides self-protection for degranulating cytotoxic lymphocytes.Keywords
This publication has 60 references indexed in Scilit:
- Epoxysuccinyl peptide‐derived affinity labels for cathepsin BFEBS Letters, 2000
- CD8+ T Cell Effector Mechanisms in Resistance to InfectionAnnual Review of Immunology, 2000
- Perforin Gene Defects in Familial Hemophagocytic LymphohistiocytosisScience, 1999
- Human Cathepsins F and W: A New Subgroup of CathepsinsBiochemical and Biophysical Research Communications, 1999
- Structural basis of inhibition of cysteine proteases by E-64 and its derivativesPeptide Science, 1999
- A Cytosolic Granzyme B Inhibitor Related to the Viral Apoptotic Regulator Cytokine Response Modifier A Is Present in Cytotoxic LymphocytesJournal of Biological Chemistry, 1996
- Effects of cognate peptides on cytolytic and proliferative activities of cloned cytotoxic T lymphocytesInternational Immunology, 1992
- Similar molecular requirements for antigen receptor-triggered secretion of interferon and granule enzymes by cytolytic T lymphocytesCellular Immunology, 1989
- Resistance of cytotoxic T lymphocytes to the lytic effects of their toxic granules.The Journal of Experimental Medicine, 1987
- Resistance of cloned cytotoxic T lymphocytes to cell-mediated cytotoxicity.The Journal of Experimental Medicine, 1987