AN ANTIVIRAL SOLUBLE FORM OF THE LDL RECEPTOR-INDUCED BY INTERFERON

Interferons, which induce several intracellular antiviral proteins, al so induce an extracellular soluble protein that inhibits vesicular sto matitis virus (VSV) infection. This 28-kilodalton soluble protein was purified to homogeneity and identified by protein sequencing as the li gand-binding domain of the human 160-kilodalton low density lipoprotei n receptor (LDLR). The existence of an antiviral soluble LDLR was conf irmed by immunoaffinity chromatography with monoclonal antibody to LDL R. This soluble receptor mediates most of the interferon-triggered ant iviral activity against VSV, apparently by interfering with virus asse mbly or budding, and not by inhibiting virus attachment to cells.