ObjectiveTo research the hepatitis B virus (HBV) replication and immune tolerance status of transgenic mice for elucidating the pathogenesis of hepatitis B and evaluating new drugs against HBV.Methods SPE grade HBsAg negative nontransgenic and transgenic mice with the same genetic background were recruited in this study.HBsAg,HBeAg and HBV DNA were detected by chemiluminescent method.Pre-S1 and HBcAg were detected by enzyme linked immunosorbont assay (ELISA).Liver pathology was examined and HBsAg expressions at different stages were determined by immunohistochemical staining.The lymphocyte proliferation of mice was detected by flow cytometry and interferon (IFN)γ-producing T lymphocytes was determined by enzyme linked immunospot (ELISPOT).The expressions of Toll-like receptor (TLR)2 and TLR9 in splenocyte suspension and splenic dendrite cells (DC) were determined by double-labeling immunofluorescence.The data were analyzed by t test and F test.ResultsHBsAg,preS1,HBeAg,HBcAg were expressed and HBV DNA was replicated in HBV transgenic mice,while anti-HBs,anti-HBc,and anti-HBe were all negative.There were no obvious pathological changes in liver tissues.HBsAg was expressed in cytoplasm and HBcAg in nucleus of hepatocytes.After stimulated with HBsAg,T lymphocyte proliferation capacity of HBV transgenic mice was (697.6±67.3) cpm,which was much lower than that of nontransgenic mice [( 1315.5 ±191.6) cpm].The number of spot forming cells of IFNγ-producing splenocytes from transgenic mice after HBsAg stimulation was 8.25 ± 1.10,which was obviously lower than that of nontransgenic mice (28.50±4.21) (F=155.967,P=0.000).The expressions of CD11c+,TLR2 and TLR9 on DC from both HBV transgenic and nontransgenic mice were not different significantly (all P＞0.05).The HBsAg expressions in liver tissues were observed in 18-day-old fetal mice and 1-day-old newborn mice.ConclusionsThe HBV transgenic mice can express HBV-related antigens,and are immune tolerant to the antigens.The innate and acquired immunity of the HBV transgenic mice are normal,which is similar to chronic asymptomatic HBV carriers of human.Therefore,HBV transgenic mouse is an ideal animal model.

AIM:To investigate atrial natriuretic peptide(ANP) circadian in the encapsulated human ANP(hANP) cDNA transfected cells,to alter the ANP circadian by artificial control to achieve the objective of effectively treat hypertension or congestive heart failure(CHF). METHODS:ANP cDNA was transfected into Chinese hamster ovary(CHO) cells,which were encapsulated in polycarprolactone(PCL) tubes.The longterm survival of transfected CHO cells and the levels of ANP secreted were detected.Circadian rhythm of ANP secreted by encapsulated transfected cells was also studied,which was regulated by melatonin. RESULTS:During culturing,the ANP level secreted by transfected CHO cells in 2 mL of culture medium within 24 hours could reach 210.3 ng/L in a 20 mm-long and 2 mm-diameter PCL tube.The section of ANP displayed a circadian variation:higher in daytime,but lower at night.The acrophase of circadian rhythm was 4:15 but could be shifted to 7:55 after melatonin management. CONCLUSION:ANP cDNA transfected CHO cells that encapsulated into PCL tube can secret ANP,which might be suitable for the future implantation into human body.Our research provides a new approach in the treatment of hypertension and CHF by ANP.