title: Interferon-gamma-induced alterations of monocyte susceptibility to lysis by autologous lymphokine-activated killer (LAK) cells.
abstract: Interleukin-2 (IL-2)-activated killer (LAK) cells specifically lyse human monocytes, which may account for some of the toxicity seen during LAK/IL-2 immunotherapy of cancer patients. In an effort to protect autologous monocytes, we treated monolayer cultures of monocytes with various doses of recombinant human interferon-gamma (IFN-gamma) and assessed their sensitivity to LAK-mediated lysis. IFN-gamma lessens the sensitivity of monocytes to lysis in a dose-dependent manner. Treatment of FMEX, an NK-resistant melanoma tumor cell line, with IFN-gamma did not affect its susceptibility to LAK lysis. Kinetic studies demonstrated that as little as 2 hr incubation with IFN-gamma was sufficient for protection to occur, and that monocytes which were treated with IFN-gamma for 2 hr, washed, and then cultured in medium alone retained their resistance to lysis for at least 4 days. Cold target inhibition studies showed that IFN-treated and untreated monocytes could effectively compete with each other for binding sites on LAK cells. Finally, binding studies demonstrated that there was no significant difference between the number of conjugates formed using either IFN-treated or untreated monocytes. This indicates that resistance to lysis induced by IFN treatment affects a post-binding event and not an initial recognition signal.
mesh_terms: D001688:Biological Products / Q000494:pharmacology; D003115:Colony-Stimulating Factors / Q000494:pharmacology; D016207:Cytokines; D003602:Cytotoxicity, Immunologic / Q000187:drug effects*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D006133:Growth Substances / Q000494:pharmacology; D006801:Humans; D007213:Indomethacin / Q000494:pharmacology; D007371:Interferon-gamma / Q000494:pharmacology*; D007376:Interleukin-2 / Q000494:pharmacology*; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology*; D007700:Kinetics; D009000:Monocytes / Q000187:drug effects* / Q000378:metabolism; D013997:Time Factors; D014407:Tumor Cells, Cultured / Q000187:drug effects
chemical_list: D001688:Biological Products; D003115:Colony-Stimulating Factors; D016207:Cytokines; D006133:Growth Substances; D007376:Interleukin-2; D007371:Interferon-gamma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D007213:Indomethacin