Colamonici O R, Domanski P
Department of Medicine, University of Chicago, Illinois 60637.
J Biol Chem. 1993 May 25;268(15):10895-9.
Expression in mouse cells of the cloned human IFN alpha receptor (IFN alpha R) subunit selectively confers response and binding to human IFN alpha 8, indicating that other subunits are involved in IFN alpha binding. We report here that a new monoclonal antibody (mAb), termed IFNaR beta 1, recognizes a novel IFN alpha R subunit different from the one recently cloned and distinct from the alpha subunit recognized by the IFN alpha R3 mAb. The IFNaR beta 1 mAb blocks the biological effect of seven different Type I IFNs. Immunoprecipitations after cell surface iodination demonstrate that the IFNaR beta 1 mAb recognizes a protein with a molecular mass of 100 kDa in Daudi and U-266 cells that express normal IFN alpha R. However, a 55-kDa protein instead of the 100-kDa product was immunoprecipitated in the IFN alpha-resistant U-937 cell line that express the variant form of the receptor. We also demonstrate that the gene that codes for this novel IFN alpha R subunit maps to human chromosome 21, as do the cloned IFN alpha R subunit and the alpha subunit, indicating the existence of a locus on this chromosome that regulates binding for Type I IFNs.
克隆的人干扰素α受体（IFNαR）亚基在小鼠细胞中的表达选择性地赋予了对人干扰素α8的反应性和结合能力，这表明其他亚基参与了干扰素α的结合。我们在此报告，一种名为IFNaRβ1的新型单克隆抗体（mAb）识别一种不同于最近克隆的新型干扰素αR亚基，且与IFNαR3单克隆抗体识别的α亚基不同。IFNaRβ1单克隆抗体可阻断七种不同I型干扰素的生物学效应。细胞表面碘化后的免疫沉淀表明，IFNaRβ1单克隆抗体在表达正常干扰素α受体的Daudi和U - 266细胞中识别一种分子量为100 kDa的蛋白质。然而，在表达受体变异形式的对干扰素α耐药的U - 937细胞系中，免疫沉淀的是一种55 kDa的蛋白质而非100 kDa的产物。我们还证明，编码这种新型干扰素αR亚基的基因定位于人类21号染色体，克隆的干扰素αR亚基和α亚基也是如此，这表明该染色体上存在一个调节I型干扰素结合的基因座。
