Presence of receptors for polymerized albumin in HBsAg-containing hepatocytes and hepatoma cell line.

Recent evidence suggests that hepatitis B virions (HBV) and HBsAg particles contain receptors for polymerized human serum albumin (pHSA). We studied, by immunohistochemical techniques, the relationship between HBsAg and pHSA receptors in liver tissue from eight patients with chronic HBV infection and in a human hepatocellular carcinoma cell line (PLC/PRF/5) producing HBsAg. Both parallel sections and double fluorescent antibody staining of liver tissue demonstrated that only HBsAg-containing hepatocytes expressed pHSA receptors. The receptors could not be demonstrated in eight HBsAg negative livers. Sequential studies of PLC/PRF/5 cells revealed that pHSA and HBsAg emerged simultaneously in the cytoplasm, on the cell surface, and in the supernatant culture media. These findings indicate that pHSA receptors are closely associated with HBsAg during its synthesis and secretion by hepatocytes and suggest that the receptors are HBV-specific.