title: Intracellular mediators of granulysin-induced cell death.
abstract: Granulysin, a molecule present in the granules of CTL and NK cells, is cytolytic against microbes and tumors. Granulysin induces apoptosis of mammalian cells by damaging mitochondria and causing the release of cytochrome c and apoptosis-inducing factor, resulting in DNA fragmentation. Here we show that Ca2+ and K+ channels as well as reactive oxygen species are involved in granulysin-mediated Jurkat cell death. The Ca2+ channel blockers, nickel and econazole, and the K+ channel blockers, tetraethylammonium chloride, apamin, and charybdotoxin, inhibit the granulysin-induced increase in intracellular Ca2+ ([Ca2+](i)), the decrease in intracellular K+, and apoptosis. Thapsigargin, which releases Ca2+ from the endoplasmic reticulum, prevents a subsequent granulysin-induced increase in [Ca2+](i) in Jurkat cells, indicating that the initial increase in [Ca2+](i) is from intracellular stores. The rise in [Ca2+](i) precedes a decrease in intracellular K+, and elevated extracellular K+ prevents granulysin-mediated cell death. In granulysin-treated cells, electron transport is uncoupled, and reactive oxygen species are generated. Finally, an increase in intracellular glutathione protects target cells from granulysin-induced lysis, indicating the importance of the redox state in granulysin-mediated cell death.
authors.affiliation: Division of Immunology and Transplantation Biology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Okada
authors.forename: Qing
authors.initials: Q
authors.lastname: Li
authors.forename: John C
authors.initials: JC
authors.lastname: Whitin
authors.forename: Carol
authors.initials: C
authors.lastname: Clayberger
authors.forename: Alan M
authors.initials: AM
authors.lastname: Krensky
mesh_terms: D000945:Antigens, Differentiation, T-Lymphocyte / Q000633:toxicity*; D017209:Apoptosis / Q000187:drug effects / Q000276:immunology; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology / Q000502:physiology; D016923:Cell Death / Q000187:drug effects / Q000276:immunology*; D017077:Culture Media, Conditioned / Q000494:pharmacology; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D015536:Down-Regulation / Q000276:immunology; D016257:Fura-2 / Q000494:pharmacology; D005978:Glutathione / Q000494:pharmacology; D006801:Humans; D007424:Intracellular Fluid / Q000166:cytology / Q000276:immunology / Q000502:physiology*; D019169:Jurkat Cells; D008928:Mitochondria / Q000187:drug effects / Q000276:immunology / Q000378:metabolism / Q000648:ultrastructure; D010455:Peptides / Q000633:toxicity; D011188:Potassium / Q000037:antagonists & inhibitors / Q000502:physiology; D021381:Protein Transport / Q000187:drug effects / Q000276:immunology; D011761:Pyrrolidonecarboxylic Acid; D017382:Reactive Oxygen Species / Q000378:metabolism; D013844:Thiazoles / Q000494:pharmacology; D053778:Thiazolidines; D015854:Up-Regulation / Q000276:immunology
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D017077:Culture Media, Conditioned; C075005:GNLY protein, human; D010455:Peptides; D017382:Reactive Oxygen Species; D013844:Thiazoles; D053778:Thiazolidines; D005978:Glutathione; D011188:Potassium; D002118:Calcium; D011761:Pyrrolidonecarboxylic Acid; D016257:Fura-2; C029536:2-oxothiazolidine-4-carboxylic acid