(1) Replication method The tree shrews were inoculated with 0.5ml of serum from hepatitis B virus positive hepatitis B virus surface antigen (HBsAg) and hepatitis B virus e antigen (HBeAg) through the femoral vein. Three days later, the same amount of the same serum was injected into the abdominal cavity once. After 10 days, blood was drawn once a week. One week before inoculation, blood was drawn from each animal as a self-control; and 2 animals were randomly selected for liver biopsy as self-tissue control. At the third weekend after vaccination, the ALT value rose from 3U to 188U. HBsAg appeared in the tree shrew serum from the 4th week; anti-HBc appeared at the 8th week; HBeAg-positive at the 14th week; blood was collected at the 30th week and the serum HBV DNA was strongly positive by dot blotting. In addition, HBV DNA probes labeled with biotin were used for in situ molecular hybridization to detect HBV DNA in the liver cytoplasm of model animals. The liver tissues of some model animals showed mild inflammatory lesions, such as ballooning, steatosis, eosinophilia, punctate or small focal necrosis, and inflammatory cell infiltration, and some animals had mild swelling of liver cells. The livers of some model animals showed chronic hepatitis and mild fibrous tissue hyperplasia; the liver cells in some liver tissues were arranged in a glandular tube shape, with hepatocyte hyperplasia or nodules, and a small amount of scattered or aggregated dysplastic liver cell.
(2) Model characteristics After HBV infection, HBsAg, anti-HBs or HBV DNA can be detected in the blood of model animals; HBsAg and/or HBcAg can be seen in liver tissue immunohistochemistry; Southern hybridization can be detected in liver tissue in integrated form HBV DNA; elevated serum ALT can occur in model animals.
(3) Comparative medicine After tree shrews are inoculated with human HBV, the conversion of serological markers in juvenile tree shrews is similar to human acute self-limiting hepatitis B. HBV has a shorter duration in most infected animals, and most infected animals appear The pathological changes of the liver are mild, and it is difficult to form chronic hepatitis or chronic HBV carrier state. Viral antigenemia in adult tree shrews quickly transformed into anti-HBe, anti-HBs and anti-HBcemia. Juvenile tree shrews are more susceptible than adult tree shrews. Serum HBsAg positive in young tree shrews can last for 10 weeks after being infected with HBV. Adult tree shrews can turn into positive serum anti-HBs within 2 to 3 weeks. Tree shrews are higher than marmots and ducks in biological evolution. They belong to lower primates and are closer to humans in taxonomy. They can infect human HBV and are expected to become a reliable animal model for human HBV.