[The effect of ribozyme RzDS on duck hepatitis B virus]

To study the effect of ribozyme in vivo, the hammerhead ribozyme RzDS was designed and synthesized, which aims at the pregenome RNA of DHBV(LJ-76) at the 736 site of the genome. The RzDS cleaved efficiently its substrate in vitro. We constructed pJ-RzDS, in which RzDS was inserted into pJ120 plasmid under the control of PII promoter. After homogenous recombination with the vaccinia virus, Tian Tan strain, we got the recombinant(V-RzDS) which carried RzDS. V-RzDS was injected into nestling Beijing ducks preinfected with DHBV. On the tenth day after intravenous injection, DHBV DNA and DHBsAg in serum were detected. The quantity of DHBV DNA and DHBsAg were evidently lower than that of the controls, when V-RzDS injection was simultaneously given with DHBV. It suggests that RzDS can block replication and expression of DHBV in vivo.