RESUMO
<p><b>OBJECTIVE</b>To study the effect of human spastic paraplegia 21 protein (SPG21) on the replication of hepatitis B virus(HBV) and its regulatory mechanism.</p><p><b>METHODS</b>HBV infectious clone pHBV1.3 and its promoter pHBV-Luc were transfected respectively into HepG2 cells with SPG21 of different concentrations, HBsAg and HBeAg in the supernatants were measured by enzyme linked immunosorbent assay (ELISA), expression of HBV core mRNA and protein were detected by RT-PCR and western blot, covalently closed circular DNA(ccc DNA) levels were measured by real-time PCR, and HBV promoter activity was measured by luminometer fluorescence detector.</p><p><b>RESULTS</b>Expression of HBsAg, HBeAg, HBV core protein and cccDNA were upregulated by SPG21 as well as HBV promoter activity in a dose-dependent approach. The activity of HBV promoter increased to 1.63, 3.09 and 4.66 times in HepG2 cells treated with 50mug/ml, 100mug/ml and 200mug/ml SPG21 respectively during 48 hour-treated ( P less than 0.05), as compared to the control group.</p><p><b>CONCLUSIONS</b>SPG21 can enhance the replication of HBV in HepG2 cells.</p>