Infection of human hepatocyte chimeric mouse with genetically engineered hepatitis B virus

Abstract

H epatitis B virus (HBV) is a small enveloped DNA virus and causes chronic infection of the liver that often leads to chronic hepatitis, cirrhosis, and hepatocellular carcinoma. [1][2][3][4] The lack of a practical small animal model has impeded the study of the biology of this virus and the development of effective antiviral therapies. Chimpanzee is the only natural host that allows active replication of HBV. [5][6][7] Although this animal is a valuable model for the study of hepatitis viruses, 8 the practical use of chimpanzees is severely limited both ethically and economically.Several small animal models of HBV infection have been reported. The HBV transgenic mouse is a very useful model for the study of virology and evaluation of antiviral drugs. [9][10][11][12] However, the liver cells of this model are not permissive for HBV infection; therefore, studying virus-cell interactions such as receptor binding and entry is not possible. The HBVtrimera mouse is another useful mouse model. 13 In this model, ex vivo HBV-infected human liver fragments are implanted into lethally irradiated mice after SCID mouse bone marrow transplantation. Approximately 80% of the mice develop viremia 2 to 3 weeks after infection. However, the rate of positivity subsequently decreases to less than 20% 6 weeks after infection. The level viremia is approximately 10 5 copies/mL. More recently, HBV-containing human serum samples were used to infect human hepatocyte repopulated mice. 14 A high-level viremia (4.5 and 10 ϫ 10 8 copy/ mL) and HBs antigenemia are observed 8 weeks after injection. This mouse model is promising because HBV replicates in natural host cells, human hepatocytes. However,

GH enhances proliferation of human hepatocytes grafted into immunodeficient mice with damaged liver

“…Recent technological improvements enabled us to yield children's hepatocyte-chimeric mice with RIO96%. The chimeric mice have been proven to be a useful animal model to examine biological and pathological features of h-hepatocytes in vivo (Tateno et al 2004, Tsuge et al 2005.…”

Single lymphocyte analysis with a microwell array chip

“…To demonstrate the neutralization activity, we constructed an estimation system using chimeric mice transplanted with human hepatocytes (16). As HBV can infect only fresh human hepatocytes or that of primates, but not that of rodents, examination of neutralization activity has mostly been performed on chimpanzees (27), which is very expensive and might be contrary to the principles of animal welfare.…”

“…The chimeric mice were produced by transplanting human hepatocytes into albumin enhancer/promoter-driven urokinasetype plasminogen activator-transgenic SCID mice (uPA/SCID mice) (15). The transplanted human hepatocytes were shown to be infected with hepatitis C virus and HBV (16,17). Human serum albumin produced from the transplanted human hepatocytes was in the range of 1.3-5.2 mg/ml, indicating that 32-66% of the liver cells were replaced with those of human origin.…”

“…Serum of a chronic hepatitis B patient was used for the preparation of HBV. The titer of the virus was determined by quantitative PCR of the virus genome as previously described (16). Primers for PCR are listed in supplementary Table 1.…”

Usefulness of humanized cDNA-uPA/SCID mice for the study of hepatitis B virus and hepatitis C virus virology

“…10 % FBS at 37 C and <5 % CO 2 . Transfection of HepG2 cells with 1.4 genome length HBV DNA was performed as described previously [21]. Three to five days after transfection, the culture supernatant was collected for mouse infection.…”