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

Interferons, which induce several intracellular antiviral proteins, also induce an extracellular soluble protein that inhibits vesicular stomatitis virus (VSV) infection. This 28-kilodalton soluble protein was purified to homogeneity and identified by protein sequencing as the ligand-binding domain of the human 160-kilodalton low density lipoprotein receptor (LDLR). The existence of an antiviral soluble LDLR was confirmed by immunoaffinity chromatography with monoclonal antibody to LDLR. This soluble receptor mediates most of the interferon-triggered antiviral activity against VSV, apparently by interfering with virus assembly or budding, and not by inhibiting virus attachment to cells.