title: A novel type of cell death of lymphocytes induced by a monoclonal antibody without participation of complement.
abstract: A monoclonal antibody, RE2, raised by immunizing a rat with cell lysate of a mouse T cell clone, was found to directly kill interleukin 2-dependent T cell clones without participation of serum complement. Fab fragments of RE2 had no cytolytic activity, while the cross-linking of Fab fragments with anti-rat immunoglobulin reconstituted the cytotoxicity. The cytotoxicity was temperature dependent: the antibody could kill target cells at 37 degrees C but not at 0 degrees C. Sodium azide, ethylenediaminetetraacetic acid, and forskolin did not affect the cytolytic activity of RE2, while the treatment of target cells with cytochalasin B and D completely blocked the activity. This suggested that the cell death involves a cytoskeleton-dependent active process. Giant holes on the cell membrane were formed within 5 minutes after the treatment with RE2, as observed by scanning electron microscopy. There was no indication of DNA fragmentation nor swelling of mitochondria during the cytolysis, suggesting that the cell death is neither apoptosis nor typical necrosis. The antibody also killed T cell lymphomas and T and B cell hybridomas only when these cells were preactivated with concanavalin A, lipopolysaccharide, or phorbol myristate acetate. Preactivated peripheral T and B cells were sensitive to the cytotoxicity of RE2, while resting T and B cells were insensitive. These results provide evidence for a novel pathway of cell death of activated lymphocytes by membrane excitation.
authors.affiliation: Department of Immunology, Faculty of Medicine, University of Tokyo, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Matsuoka
authors.forename: Y
authors.initials: Y
authors.lastname: Asano
authors.forename: K
authors.initials: K
authors.lastname: Sano
authors.forename: H
authors.initials: H
authors.lastname: Kishimoto
authors.forename: I
authors.initials: I
authors.lastname: Yamashita
authors.forename: H
authors.initials: H
authors.lastname: Yorifuji
authors.forename: M
authors.initials: M
authors.lastname: Utsuyama
authors.forename: K
authors.initials: K
authors.lastname: Hirokawa
authors.forename: T
authors.initials: T
authors.lastname: Tada
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology; D016923:Cell Death / Q000276:immunology*; D002460:Cell Line; D002999:Clone Cells; D003165:Complement System Proteins / Q000502:physiology*; D006224:Cricetinae; D003602:Cytotoxicity, Immunologic; D006825:Hybridomas / Q000276:immunology; D007140:Immunoglobulin Fab Fragments / Q000494:pharmacology; D008214:Lymphocytes / Q000166:cytology* / Q000276:immunology* / Q000648:ultrastructure; D051379:Mice; D008809:Mice, Inbred C3H; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D051381:Rats; D017207:Rats, Sprague-Dawley; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D007140:Immunoglobulin Fab Fragments; D003165:Complement System Proteins