Interferons are known to potentiate various biological effects of tumor necrosis factor (TNF). Recently, two different types of TNF receptors with molecular masses of 60 kDa (p60) and 80 kDa (p80), primarily expressed by epithelial cells and myeloid cells, respectively, have been identified. In the present report, we examined the effect of interferon-γ (IFN-γ) on each type of TNF receptor. Our results indicate that IFN-γ induces TNF receptors on both myeloid (e.g. HL-60) and epithelial cells (e.g. HeLa). Furthermore, by using antibodies specific to each type of receptor, we demonstrate that both TNF receptors are equally inducible by IFN-α, IFN-β and IFN-γ. Thus, the increase in TNF receptors by interferons may play a role in their synergistic cellular response.
