title: Identification of effector cells for TNFalpha-mediated cytotoxicity against WEHI164S cells.
abstract: WEHI164S cells were found to be very sensitive targets for in vitro killing in a 6-h culture when liver or splenic lymphocytes were used as effector cells in mice. Of particular interest, a limiting cell-dilution analysis showed that effector cells were present in the liver with a high frequency (1/4,300). In contrast to YAC-1 cells as NK targets, perforin-based cytotoxicity was not highly associated with WEHI164S killing. The major killer mechanism for WEHI164S targets was TNFalpha-mediated cytotoxicity. By cell sorting experiments, both NK cells and intermediate T cells (i.e., TCR(int) cells) were found to contain effector cells against WEHI164S cells. However, the killer mechanisms underlying these effector cells were different. Namely, NK cells killed WEHI164S cells by perforin-based cytotoxicity, TNFalpha-mediated cytotoxicity, Fas ligand cytotoxicity, and other mechanisms, whereas intermediate T cells did so mainly by TNFalpha-mediated cytotoxicity. These results suggest that TNFalpha-mediated cytotoxicity mediated by so-called natural cytotoxic (NC) cells comprised events which were performed by both NK and intermediate T cells using somewhat different killer mechanisms. Intermediate T cells which were present in the liver were able to produce TNFalpha if there was appropriate stimulation.
authors.affiliation: Department of Immunology, Niigata University School of Medicine, Niigata 951-8510, Japan.
authors.forename: Chikako
authors.initials: C
authors.lastname: Miyaji
authors.forename: Hisami
authors.initials: H
authors.lastname: Watanabe
authors.forename: Ryoko
authors.initials: R
authors.lastname: Miyakawa
authors.forename: Hisashi
authors.initials: H
authors.lastname: Yokoyama
authors.forename: Chika
authors.initials: C
authors.lastname: Tsukada
authors.forename: Yuiko
authors.initials: Y
authors.lastname: Ishimoto
authors.forename: Shinobu
authors.initials: S
authors.lastname: Miyazawa
authors.forename: Toru
authors.initials: T
authors.lastname: Abo
mesh_terms: D000818:Animals; D003602:Cytotoxicity, Immunologic / Q000276:immunology; D053222:Fas Ligand Protein; D005434:Flow Cytometry; D007694:Killer Cells, Natural / Q000276:immunology; D008099:Liver / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000172:deficiency / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008817:Mice, Mutant Strains; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D011948:Receptors, Antigen, T-Cell; D013154:Spleen / Q000166:cytology / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D013997:Time Factors; D014407:Tumor Cells, Cultured / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000276:immunology*
chemical_list: D053222:Fas Ligand Protein; C505658:Fasl protein, mouse; D008562:Membrane Glycoproteins; D052899:Pore Forming Cytotoxic Proteins; D011948:Receptors, Antigen, T-Cell; D014409:Tumor Necrosis Factor-alpha; D054353:Perforin