Peritoneal mouse macrophages elicited by proteose-peptone (pMΦ) were treated in vitro with IFN-α, IFN-β, or IFN-γ in the presence or absence of cycloheximide (Cy), a reversible inhibitor of protein synthesis, and were assayed for cytolytic activity against tumor cells. Inhibition of protein synthesis during treatment of pMΦ with IFN-α or IFN-β prevented the development of cytotoxic activity. In contrast, IFN-γ was fully capable of inducing cytotoxic pMΦ in the presence of Cy. Moreover, pMΦ treated with mixtures of IFN in the presence of Cy were activated for cytotoxicity only by IFN-γ together with IFN-α or IFN-β, but not by IFN-α plus IFN-β. These results indicate that the activation of pMΦ by IFN-γ is independent of new protein synthesis, whereas the activation of pMΦ by IFN-α and/or IFN-β requires active protein synthesis, suggesting that the mechanism of induction of cytotoxic pMΦ by IFN-γ differs from that by the other types of IFN.
|Number of pages||3|
|Journal||Journal of Immunology|
|Publication status||Published - 1984|
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