Abstract
Both natural killer cell- and macrophage-mediated spontaneous in vitro cytotoxicity for tumor targets is rapidly and strongly augmented by interferon. Macrophage-activating lymphokines considerably enhance macrophage-tumoricidal activity but did not affect natural killer cell-type cytotoxicity. Augmentation of cytolytic capacity by interferon and by macrophage-activating lymphokines is prevented by the tumor-promoting phorbol ester, 12-O-tetradecanoylphorbol-13-acetate. However, the classical antiviral activity and the specific binding of interferon to cell surface receptors remains unaffected by 12-O-tetradecanoylphorbol-13-acetate.
Footnotes
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↵1 This work was supported by the Swiss National Science Foundation (Grants 3.173.77 and 3.609.80) and the Direction des Etudes Recherche et Technique (Contracts 78-34-210/80-34-522).
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↵2 Supported by the Canton of Zurich. To whom requests for reprints should be addressed.
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↵3 Supported by the Association pour le Développement de la Recherche sur le Cancer à Villejuif.
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↵4 Recipient of Fellowship Sti 71/1-1 from Deutsche Forschungsgemeinschaft.
- Received October 13, 1981.
- Accepted January 7, 1982.
- ©1982 American Association for Cancer Research.