In vitro comparative study of cytolysis mediated by natural killer cells towards malignant cells preincubated with antioxidants.
We have previously reported that antioxidants such as beta-carotene, were able to enhance cytolytic activity of NK cells. The aim of the present study was to investigate whether preincubating YAC-1 tumor cells in culture with different antioxidants, affected their NK cell-mediated cytolysis. The antioxidants studied were enzymes (superoxide dismutase and catalase), hydroxyl radical scavengers (thiourea, mannitol, dimethyl sulfoxide) and a singlet oxygen quencher: beta-carotene. After 24 hours coincubation with the antioxidants, radiolabeled YAC-1 cells were submitted to the cytotoxic activity of NK cells for a 4 hour period. For some antioxidants, a moderate increase of cytotoxic potential occurred for weak NK cell number. By contrast, a clear decrease of cytotoxic potential was induced with high NK cell number. An antioxidant, with a protective effect which appeared stronger was thiourea, which induced 20, 58 and 36% decrease of cytolysis in the effector-target ratios 50:1, 100:1 and 200:1 respectively. These studies suggest that the malignant YAC-1 cells are vulnerable to treatment by different antioxidants.
Laboratoire de Biochimie, Université Joseph Fourier, Grenoble, France.
J
J
Riondel
D
D
Glise
T
T
Fernandez-Carlos
A
A
Favier
D000818:Animals; D000975:Antioxidants / Q000633:toxicity*; D002374:Catalase / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects / Q000276:immunology; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D005260:Female; D016166:Free Radical Scavengers / Q000494:pharmacology; D017665:Hydroxyl Radical; D007694:Killer Cells, Natural / Q000276:immunology*; D008223:Lymphoma / Q000276:immunology*; D008353:Mannitol / Q000494:pharmacology; D051379:Mice; D008819:Mice, Nude; D013154:Spleen / Q000276:immunology; D013482:Superoxide Dismutase / Q000494:pharmacology; D013890:Thiourea / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D019207:beta Carotene / Q000633:toxicity*
D000975:Antioxidants; D016166:Free Radical Scavengers; D019207:beta Carotene; D017665:Hydroxyl Radical; D008353:Mannitol; D002374:Catalase; D013482:Superoxide Dismutase; D013890:Thiourea; D004121:Dimethyl Sulfoxide