Studies on replication and expression of cloned hepatitis B virus DNA in transfected kidney cells and hepatocytes

Objective To compare the replication and expression of HBV DNA in kidney cells and hepatocytes. Methods Cloned recombinant plasmid HBV DNAs (p177,p3.8Ⅱ,pCMV3.9) were used to transfect HepG2 and 293 cell lines respectively. Besides, p177 and p3.8Ⅱ were also used to transfect the primary kidney cells. Supernatant from transfected cells were collected and assayed for HBsAg and HBeAg. DNAs and RNAs were extracted from transfected cell lines and Southern and Northern blots were hybridized with HBV probes.Results After being transfected, HepG2 cells expressed high levels of HBsAg and HBeAg, and specific HBV DNA signals were detected by Southern and Northern blots. However, expression of HBsAg and HBeAg were very low in transfected 293 cells. By Southern and Northern blots hybridization signals could only be detected in pCMV 3.9 transfected 293 cells, while no replication of HBV was detected under its native promoters.Conclusion Cloned HBV DNA replicated and expressed HBsAg and HBeAg in HepG2 cells, while only very low levels of HBsAg and HBeAg could be detected in transfec ted 293 cells. No replication of HBV DNA was detected in 293 cells except when HBV genome in the recombinant plasmid was driven by a strong promoter (pCMV) used in transfection study. Our data do not support that HBV can replicate in kidney tissue.(Shanghai Med J, 1999,22∶585 588)