Somatic cell mapping of the bovine interferon-α receptor

The bovine interferon-α receptor (BoIFN-αR) mediates the activity of bovine IFN-αs and IFN-β. In addition, human IFN-αs have uniformly high biological activity on bovine cells. A ³²P-labeled derivative of human recombinant IFN-αA (HuIFN-αA-P1) binds well and can form a characteristic 130-kDa complex on bovine cells, but not on hamster cells. We have, therefore, analyzed the binding and covalent crosslinking of [³²P]HuIFN-αA-P1 to a panel of bovine-hamster somatic cell hybrids. Binding to several bovine-hamster hybrid cell lines was strong (about 30-50% of that seen with bovine MDBK cells) and specific. The binding correlated uniquely with bovine syntenic group U10. In several of the hybrid lines, the ability of human IFN-αB to enhance the expression of endogenous MHC class I molecules correlated with the binding results. We thus conclude that the bovine IFN-αR structural gene (locus designation IFNAR) localizes to syntenic group U10. This group includes a number of other genes whose homologs map to human Chromosome (Chr) 21.