Interferon gamma receptor extracellular domain expressed as IgG fusion protein in Chinese hamster ovary cells. Purification, biochemical characterization, and stoichiometry of binding.

摘要: Abstract Agents that antagonize the functions of interferon γ (IFNγ) are potential pharmaceuticals against several immunological and inflammatory disorders. IFNγ receptor-immunoglobulin G fusion proteins (IFNγR-IgG) function as antagonists endogenous have longer half-lives in vivo comparison with soluble receptors (sIFNγR), consisting extracellular region native sequence. A protein comprising domain human receptor hinge, CH2 CH3 domains IgG3 constant region, was expressed Chinese hamster ovary cells. The IFNγR-IgG3 secreted into culture medium a 175-kDa glycoprotein purified over Protein G-Sepharose, DEAE-Sepharose, size exclusion chromatography. bound solid phase assays ligand blots, competed for binding radiolabeled to cell surface Raji cells, inhibited IFNγ-mediated antiviral activity an efficiency at least one order magnitude higher than produced same expression system. Two two dimers forming complex approximately 380 kDa. In immunodiffusion assays, did not precipitate IFNγ. Dissociation from 2-fold slower sIFNγR insect