Human carcinoembryonic antigen and biliary glycoprotein can serve as mouse hepatitis virus receptors

Receptors for murine coronavirus mouse hepatitis virus (MHV) are members of the murine carcinoembryonic antigen (CEA) gene family. Since MHV can also infect primates and cause central nervous system lesions (G. F. Cabirac et al., Microb. Pathog. 16:349-357, 1994; R. S. Murray et al., Virology 188:274-284, 1992), we examined whether human CEA-related molecules can be used by MHV as potential receptors. Transfection of plasmids expressing human carcinoembryonic antigen (hCEA) and human biliary glycoprotein into COS-7 cells, which lack a functional MHV receptor, conferred susceptibility to two MHV strains, A59 and MHV-2. Domain exchange experiments between human and murine CEA-related molecules identified the immunoglobulin-like loop I of hCEA as the region conferring the virus-binding specificity. This finding expands the potential MHV receptors to primate species.