Inhibition of cellular responsiveness to interferon-gamma (IFN gamma) induced by overexpression of inactive forms of the IFN gamma receptor.
Herein, we report that overexpression of either human or murine interferon-gamma (IFN-gamma) receptors lacking their entire intracellular domains in cells bearing functionally active IFN gamma receptors ablates responsiveness to homologous ligand in a dominant negative manner. Unresponsiveness could also be induced in murine cells overexpressing murine IFN gamma receptor mutants that either lack 39 COOH-terminal amino acids or contain an alanine substitution for a functionally critical tyrosine. Overexpression of the full-length receptor did not alter cellular responsiveness to IFN gamma. The inhibitory activities of the receptor mutants were dose-dependent, generalizable to a variety of cellular responses, and specific. Cells expressing 100:1 ratios of mutant to wild-type receptor were unresponsive to IFN gamma even at doses 30,000 times greater than that required to induce a maximal response in wild-type cells. These results provide an example of a dominant negative mutation that effects the complete inactivation of a transmembrane receptor lacking a kinase domain and suggest a more general utility for dominant negative mutations in the study of cytokine receptor function.
Department of Pathology, Washington University School of Medicine, St. Louis, Missouri 63110.
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D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002891:Chromosomes, Human, Pair 21; D004305:Dose-Response Relationship, Drug; D015870:Gene Expression / Q000187:drug effects; D005805:Genes, MHC Class I / Q000187:drug effects; D005802:Genes, MHC Class II / Q000187:drug effects; D006801:Humans; D007370:Interferon Type I / Q000494:pharmacology; D007371:Interferon-gamma / Q000494:pharmacology*; D007739:L Cells; D051379:Mice; D008969:Molecular Sequence Data; D009569:Nitric Oxide / Q000378:metabolism; D009838:Oligodeoxyribonucleotides; D010957:Plasmids; D017471:Receptors, Interferon / Q000096:biosynthesis* / Q000235:genetics*; D011994:Recombinant Proteins; D014162:Transfection; D014721:Vesicular stomatitis Indiana virus / Q000187:drug effects / Q000254:growth & development
D007370:Interferon Type I; D009838:Oligodeoxyribonucleotides; D017471:Receptors, Interferon; D011994:Recombinant Proteins; D009569:Nitric Oxide; D007371:Interferon-gamma