Effect of lipopolysaccharides, lipid A and interferon on the cell-mediated cytotoxicity of human leukocytes against K-562 tumor cells.
The effect of lipopolysaccharides (LPS), lipid A and interferon on cell-mediated cytotoxicity was investigated using 51Cr-labeled K-562 tumor cells as targets. As effectors, peripheral blood mononuclear cells from healthy blood donors were obtained by Ficoll gradient centrifugation: mononuclear phagocytes were eliminated by iron phagocytosis and plastic adherence. A T cell-enriched population was obtained by passing mononuclear phagocyte-depleted mononuclear cells through nylon wool columns. LPS and lipid A augmented cell-mediated cytotoxicity provided mononuclear phagocytes were present. Supernatants from LPS-treated mononuclear phagocytes and T cells enhanced mononuclear phagocyte-mediated cytotoxicity to a higher degree than LPS and lipid A alone. This finding suggests the participation of a lymphokine. In contrast, the interferon preparation increased the cell-mediated cytotoxicity both of mononuclear phagocyte-containing and of mononuclear phagocyte-depleted effectors. Here, the participation of natural killer cells as effectors is suggested.
D002460:Cell Line; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D004926:Escherichia coli; D006801:Humans; D007370:Interferon Type I / Q000494:pharmacology*; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology; D008050:Lipid A / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008222:Lymphokines / Q000502:physiology; D009000:Monocytes / Q000187:drug effects / Q000276:immunology; D009369:Neoplasms; D012475:Salmonella
D007370:Interferon Type I; D008050:Lipid A; D008070:Lipopolysaccharides; D008222:Lymphokines