HBV的小鼠模型研究进展

Effects of glycosaminoglycan extracted from Stichopus japonicus Selenka on the expression of HBV-associated antigens in the liver of HBV transgenic mice

AIM: To study the potential anti-hepatitis B virus (HBV) effects of glycosaminoglycan extracted from Stichopus japonicus Selenka (SJ-GAG) in vivo.

METHODS: Thirty HBV transgenic mice were divided into five groups: saline group, interferon (IFN) group, and low-, medium- and high-dose SJ-GAG group, which were intraperitoneally injected with normal saline, IFN-α2b (45 U/kg), and SJ-GAG (30, 40 and 50 mg/kg, respectively) once daily for 30 d, respectively. After treatment, all mice were killed to take liver samples for analysis of the expression of HBsAg and HBcAg by immunohistochemistry.

RESULTS: Compared to the saline group, the expression of HBsAg and HBcAg in the liver of HBV transgenic mice was dose-dependently inhibited in all the SJ-GAG groups (4.93 ± 1.43, 3.57 ± 1.02, 3.27 ± 0.64 vs 6.97 ± 0.75; 5.73 ± 1.62, 4.27 ± 1.03, 4.27 ± 1.03 vs 7.23 ± 0.53; P < 0.01 or 0.05). However, SJ-GAG has lower inhibitory effects on the expression of HBsAg and HbcAg than IFN (P < 0.01 or 0.05).

CONCLUSION: SJ-GAG has anti-HBV activity in vivo.

Establishment of a novel cell model of hepatitis B virus infection

AIM: To establish a hybrid cell line (by fusing HepG2 cells with primary human hepatocytes) that can be infected by hepatitis B virus (HBV) and be serially subcultured in vitro, and to evaluate the infection ability of HBV in this hybrid cell line.

METHODS: Normal human hepatocytes were isolated and cultured. Primary human hepatocytes were then fused with HGPRT-deficient HepG2 cells (induced with ethyl methanesulfonate). The hybrid cells were identified by the trypsin G-banding method. After the hybrid cells and normal HepG2 cells were infected with serum-derived HBV virions, intracellular and secreted HBV DNA as well as intracellular HBV cccDNA (covalent closed circle DNA) were detected by nested polymerase chain reaction (PCR). HBcAg in infected cells was analyzed by indirect immunofluorescence. HBsAg and HBeAg in the supernatants of infected cells were identified by electrochemiluminescence.

RESULTS: A hybrid cell line was established successfully by fusing HepG2 cells with primary human hepatocytes. This hybrid cell line could be subcultured in vitro. Karyotype analysis showed that the modal chromosome number of hybrid cells was 99. HBV DNA was detected consistently in both hybrid cells and their culture medium 4 days post-infection. HBV cccDNA was detected consistently 3 days post-infection. HBcAg, HBsAg and HBeAg were also detected consistently 4 days post-infection. In contrast, negative results were obtained in control HepG2 cells infected with HBV virions.

CONCLUSION: A new hybrid cell line that can be used for establishing an in vitro cell model of HBV infection is established successfully. This new hybrid cell line inherits the characteristics of both HepG2 cells and primary human hepatocytes.