| Hepatitis B virus (HBV) infection is a serious worldwide public health problem that causes acute and chronic hepatitis. It is also associated with a high incidence of cirrhosis and hepatocellular carcinoma (HCC). Hepatitis B virus has narrow host. In natural condition, HBV could not infect mouse, which is commonly used in medical scientific research. In 1980s, hepatitis B virus transgenic mouse strain was established in some developed countries and areas by transgenic technology. Because of the limiting of intellectual asset and patent, these transgenic mice could not introduce into China yet. It is essential for us to establish a HBV complete genome transgenic mice model ourselves, according with international standard and extending application widely. HBV has at least 4 serosubtypes, ayw, adr, ayr, and adw, among which adr is the most prevailing subtype in China. Therefore we need the HBV transgenic mice harbouring adr subtype genomic DNA. In the current study, we try to study the biological Characteristics including DNA, RNA, protein, virology, pathology and immunology of F6-F17 transgenic mice from transgenic mouse line C57-TgN (HBVadr2.0 ) SMMU 3, which was generated and selected in our laboratory harbouring 2 copies HBV complete genomic DNA (adr subtype).In this study, integration of hepatitis B virus gene in transgenic mice genomic DNA was estimated by PCR, Southern blotting and DNA sequencing. Hepatitis B virus genomic DNA was integrated in C57-TgN (HBVadr2.0) SMMU 3 transgenic mice and genetically transmitted from parents to offsprings. Hepatitis B virus mRNAs were evaluated by RT-PCR and real-time RT-PCR using total RNA from transgenic mouse liver tissue. All HBV mRNAs were easily detected in liver tissue. Expression and secretion of virus proteins were estimated by immunohistochemistry, Western blotting and ELISA in transgenic mice. HBsAg, HBcAg and X protein were detected in liver tissue of 85.82% 58.25% and 49.61% transgenic mice respectively by immunohistochemistry. HBsAg was distributed mainly in hepatocytes cytoplasm. HBcAg and X protein were distributed in hepatocytes cytoplasm and/or nuclear of transgenic mice. With Western blotting and ELISA, it was suggested that HBsAg and- 6 -HBeAg was secreted into serum in 55.20% and 25.00% transgenic mice. HBsAg level and HBeAg were not parallel in different mice at same development time. And expression of HBsAg was developmental regulation and sexual dimorphism. Hepatitis B virus DNA was detected in serum of transgenic mice by serum DNA PCR and real-time PCR. These results suggested that the hepatitis B virus DNA integrated in transgenic mice could replicate, package up virus particles and secret into serum of transgenic mice.We also analyzed the pathological and immunological Characteristics of this transgenic mouse line. Nearly half of them developed chronic liver histopathological lesion including hepatocyte degeneration (45.52%, 61/134), mononuclear inflamed cells infiltrate 47.01% (63/134) in liver tissue by Hematoxylin-Eosin stain. 39 of 134 (29.10%) transgenic mice developed fibers hyperplasia located in portal tract of live by silver stain. It was positive correlation between the frequency and degree of chronic liver lesion and development, and negative correlation between hepatocyte degeneration and expression of virus proteins. Chronic Ultramicro-pathological lesions in liver and kidney were also found including mitochondria swelling, mitochondrial cristae disappearing, endoplasmic reticulum expanding, collagen fibers increasing by ultrahistological analysis. Glycogen enhancing, lipid droplet store and cytolysis were also found in hepatocyte, and basement membrane thickening, immunocomplex depositing on basement membrane and vacuolar degeneration of nuclei were found in kidney. Serum ALT and AST was increased in some transgenic mice. The histopathological changes were similar to human chronic asymptomatic HBV carrier. The CD3\ CD4+, CD8+ T lymphocytes in peripheral blood and CD4*/CD8+ were decreased in transgenic mice by flow cytometry. M...
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