Background and aims: RNA interference (RNAi) has emerged as a potential new approach against hepatitis B virus (HBV) infection but unfortunately it also selects resistant virus mutants. In this study we combined the advantages of artificial micro RNAs (amiRNAs) reported previously with the purpose of constructing a more practical amiRNA with high inhibition effects against HBV.
Method: Aiming at conserved sites, we constructed singular-sequence vectors amiRNA-HBV1, amiRNA-HBV2, amiRNA-HBV3 and amiRNA-HBV4. We chose the two sequences of high efficiency, then built the tandem-sequence vector amiRNA-HBV3-HBV4. These vectors were transfected into HepG2.2.15 transiently. The secreted HBV surface antigen (HBsAg) and HBV 'e' antigen (HBeAg) were measured with a chemiluminescent microparticle immunoassay, and intracellular and extracellular HBV DNA was quantified by real-time PCR.
Results: Our results demonstrated that amiRNA-HBV1, amiRNA-HBV2, amiRNA-HBV3, and amiRNA-HBV4 achieved a maximum inhibition of HBV mRNA expression of 29.3%, 14.9%, 61.2%, and 75.6%, respectively, while the tandem amiRNA-HBV3-HBV4 vector led to an inhibition of 87.2%.
Conclusion: Taken together, our data suggest that vector-based multiple artificial microRNAs are a promising therapeutic approach for chronic HBV infection.