Inhibition of influenza A virus reproduction by a ribozyme targeted against PB1 mRNA

A ribozyme gene directed at a specific cleavage of mRNA coding for PB1 protein, a component of RNA-dependent RNA-polymerase of influenza A virus, was constructed. The avian adenovirus CELO virus-associated RNA (VA RNA CELO) promoter and human cytomegalovirus (CMV) promoter were used for the permanent expression of the ribozyme in cell lines. The cells were infected with influenza A virus strains A/Singapore/1/57 and A/WSN/33, and the suppression of the virus reproduction and virus-specific protein synthesis was measured. The maximal level of the inhibition of virus reproduction as compared to the reproduction in non-transformed cells was 93.5%. Defective recombinant adenoviruses were constructed carrying the genes of functional and non-functional ribozymes under the control of human cytomegalovirus (CMV) promoter. The reproduction of A/WSN/33 virus in CV-1 cells preinfected with recombinant adenoviruses was shown to be suppressed.