title: Cytotoxicity with target DNA breakdown by rat basophilic leukemia cells expressing both cytolysin and granzyme A.
abstract: The noncytotoxic rat mast cell tumor line RBL was transfected with genes for the cytotoxic lymphocyte granule proteins cytolysin (perforin) and granzyme A, giving transfectants with mRNA and protein expression levels comparable with cloned cytotoxic T lymphocytes. Both RBL-cytolysin and RBL-cytolysin-granzyme A transfectants showed extremely potent killing of red cell targets and lysed 20%-60% of EL4 lymphoma targets at an effector-to-target ratio of 30. RBL transfectants expressing only granzyme A were not cytotoxic. Significant EL4 DNA breakdown accompanying lysis was observed only with RBL that was transfected with both cytolysin and granzyme A. These results support the granule-exocytosis model for lymphocyte cytotoxicity and show that effector granzyme A plays a role in target cell DNA breakdown.
authors.affiliation: National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892.
authors.forename: J W
authors.initials: JW
authors.lastname: Shiver
authors.forename: L
authors.initials: L
authors.lastname: Su
authors.forename: P A
authors.initials: PA
authors.lastname: Henkart
mesh_terms: D000818:Animals; D017209:Apoptosis; D001491:Basophils / Q000276:immunology*; D003602:Cytotoxicity, Immunologic / Q000276:immunology*; D004249:DNA Damage; D005089:Exocytosis; D053804:Granzymes; D008562:Membrane Glycoproteins / Q000276:immunology; D008565:Membrane Proteins / Q000276:immunology*; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D051381:Rats; D012697:Serine Endopeptidases / Q000276:immunology*; D014162:Transfection; D014407:Tumor Cells, Cultured
chemical_list: D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D052899:Pore Forming Cytotoxic Proteins; D054353:Perforin; D053804:Granzymes; D012697:Serine Endopeptidases