As summarized in Table 1, Bortezomib price analysis of the serum of the recipients indicated recovery of metabolic functionality after liver xeno-repopulation. Table 1 Biochemical Analysis of Metabolic Function after Human Hepatocyte Transplantation The presence of human hepatocytes in Fah?/?Rag2?/? mice was further proven by a molecular assay. We used PCR and real-time PCR assays to detect human Alu gene-specific DNA sequences and human AAT gene sequences in the chimeric livers (Supplemental Figure S4 at http://ajp.amjpathol.org). HBV Infection of Fah?/?/Rag2?/? Mice after Liver Xeno-Repopulation HBV infection is one of the most sensitive markers for function of human hepatocytes. The Fah?/?Rag2?/? recipients with high levels of xeno-repopulation, as determined by expression of human albumin in liver biopsies (Figure 5, A and B), were infected with HBV serum.

Two Fah?/?/Rag2?/? mice with humanized livers and two Fah?/?Rag2?/? mice littermates without transplantation were injected with HBV-positive human serum. At 8 and 14 weeks postinfection, increasingly positive levels of HBV DNA were detected in the sera of two Fah?/?Rag2?/? mice with humanized livers (3.0 and 0.9 �� 103 IU/ml at eight weeks, and 2.16 and 0.64 �� 106 IU/ml at 14 weeks), but no viral DNA was detectable in nontransplantation control mice that were also injected with the HBV-positive serum (Figure 5G). The absence of HBV-DNA in controls demonstrated that the positive result was not due to the original injection and that mice without human hepatocytes are not susceptible to HBV infection.

At the same time, immunohistochemistry for HBsAg and HBcAg expression were systematically performed on liver specimens of transplanted and infected mice. HBsAg was distributed mainly in the cytoplasm of human hepatocytes (Figure 5, C and D), and HBcAg was distributed mainly in nuclear and occasionally some cytoplasm (Figure 5, E and F). Furthermore, HBsAg and HBeAg proteins were found in sera of infected chimeric mice (Figure 5, H and I), which suggested that viral proteins in human hepatocytes of Fah?/?Rag2?/? mice could be released into blood of the chimeric mice. Figure 5 Expression of HBV proteins and quantification of HBV DNA in transplanted mice. Alb staining of functional human hepatocytes in high liver xeno-repopulation (A; original magnification, ��40; B; original magnification, ��100); HBS staining .

.. Discussion In comparison with other mouse models that have been used to generate humanized livers, Fah?/?Rag2?/? mice have several advantages including easier genotyping and the low mortality during colony breeding and cell transplantation. Thus, Fah?/?Rag2?/? mice were chosen by us to test the possibility of liver xeno-repopulations by human hepatocytes. We enhanced immunodeficiency in Fah?/?Rag2?/? mice by pharmacological treatments to deplete NK cells at the time of Entinostat cell transplantation, which made robust liver xeno-repopulation possible.