title: TNF-alpha is not the sole mediator of WEHI-164 tumour cell killing in natural cytotoxicity.
abstract: Using a mAb to NC-1.1, a receptor involved in recognition of tumour targets, the authors have examined the dogma that murine natural cytotoxicity (NC) is exclusively mediated by TNF-alpha. Three different NC-1.1+ spleen cells, WEHI-3BR1 myelomonocytic cells and an uncloned mast cell line-MCL) were reacted with NC-sensitive WEHI-164 targets in vitro, and the induction of TNF-alpha mRNA, surface expression of TNF-alpha, and the appearance of apoptotic bodies in the culture were simultaneously measured. NC-1.1+ spleen cells and WEHI-3BR1 cells showed marked induction of TNF-alpha mRNA within 30 min and this was maintained for up to 18 h. Only transient TNF-alpha mRNA induction was observed in MCL cells at 30 min. Surface TNF-alpha was detected on WEHI-3BR1 cells by 4 h, but was not detected on MCL cells. All three effector cell types mediated NC against WEHI-164 targets within 18 h, but they responded differently to the addition of anti-TNF-alpha mAb: anti-TNF-alpha completely blocked WEHI-3BR1 NC, blocked NC-1.1+ spleen cell NC by approximately 70%, and did not block NC by MCL cells. This indicates that TNF-alpha is induced during NC by WEHI-3BR1 effectors and NC-1.1+ spleen cells, is the sole mediator of NC by WEHI-3BR1, and appears to play no role in NC by MCL cells.
authors.affiliation: Discipline of Surgical Science, Faculty of Medicine and Health Sciences, University of Newcastle, N.S.W., Australia.
authors.forename: G R
authors.initials: GR
authors.lastname: Clarke
authors.forename: H
authors.initials: H
authors.lastname: Shirzadeh
authors.forename: G
authors.initials: G
authors.lastname: Pang
authors.forename: K W
authors.initials: KW
authors.lastname: Beagley
authors.forename: R C
authors.initials: RC
authors.lastname: Burton
authors.forename: Y C
authors.initials: YC
authors.lastname: Smart
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000276:immunology; D002460:Cell Line; D003601:Cytotoxicity Tests, Immunologic; D003602:Cytotoxicity, Immunologic / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D007113:Immunity, Innate; D007700:Kinetics; D008297:Male; D008407:Mast Cells; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D013154:Spleen / Q000166:cytology; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000276:immunology* / Q000502:physiology*
chemical_list: D014409:Tumor Necrosis Factor-alpha