Two different murine monoclonal antibodies B2 and H2 which are specific for human hepatocytes

Two different monoclonal antibodies (McAb) designated H2 and B2 which were specific for human hepatocytes were developed by fusing P3-NS1 with spleen or lymphnode cells from BALB/c mice sensitized by a fractionated soluble phase of a human liver homogenate. It was demonstrated by immunoperoxidase technique that the reactivities of these McAb were restricted to human hepatocytes. Twenty four other organs, rat, rabbit livers were negative in staining. The cytoplasm of hepatocytes was stained by the both McAb although the cell membrane was also stained by H2 McAb. These results suggest that the antigens defined by these are different from LSP which is known to be species-nonspecific and localized exclusively on cell membrane and other liver-specific antigens already known. It is proposed that the antigen defined by H2 McAb is designated human liver-specific antigen 1 (HLSA1) and that the antigen defined by B2 McAb is designated human liver-specific antigen 2 (HLSA2).