Capability of Tissue Stem Cells to Organize into Salivary Rudiments
Figure 3
Transplantation of human SGP cells into the hepatectomized liver. RAG−/− mice (4 to 6 weeks old) served as recipients for cell transplantation into the liver. Mice were hepatectomized under anesthesia according to the methods described by Higgins and Anderson immediately before cell transplantation. Cultured human SGP cells (approximately cells/μL) were suspended in Dulbecco’s medium. For transplantation, a cell suspension (5 μL, cells/mouse) was injected into the residual lobe (right anterior lobe) of hepatectomized recipient mice with a Hamilton syringe. Several focal necrotic lesions became apparent in the recipient liver as early as 2 days after cell transplantation. Tumor formation was not observed microscopically in the regenerating liver 4 weeks after transplantation. In order to detect cells of human origin in transplanted mouse liver specimens, we performed immunohistochemical analysis with an anti-human hepatocyte-specific antigen (HSA) antibody (Ab) (clone OCH1E5, DAKO Cytomation) and an anti-human albumin Ab (DAKO Cytomation). Clone OCH1E5 is an anti-human hepatocyte-specific antibody, and the antigen recognized by this antibody is present in normal human hepatocytes. The antibody reacts with human hepatocytes to produce a distinct, granular, cytoplasmic stain, but does not react with mouse hepatocytes. Immunofluorescence staining for HSA and human albumin in the recipient mice liver 4 weeks after human SGP cell transplantation. (a) shows HSA staining and (b) shows albumin staining. The anti-human albumin Ab weakly cross-reacted with mouse albumin. (c) is a merged image of (a) and (b). Nuclei were counterstained with DAPI. Original magnification, ×200.
