Effective suppression of HIV-1 gene expression by a mammalian tRNA 3 ' processing endoribonuclease and external guide sequence oligozymes

We examined the suppression of virus expression by cleaveage of the HIV-1 R NA gene using a mammalian tRNA 3' processing endoribonuclease and an Extern al Guide Sequence Oligozyme (EGS) in vivo. We constructed an EGS expression vector that used the tRNA(met) promoter as an expression cassette for EGS. The EGS expression vector was targeted to the upstream region of gag, regi on. The EGS expression vector was co-transfected into COS cells with the HI V-1 gene plasmid vector. As compared with the EGS non-expressing cells and the EGS expressing cells, the EGS expressing cells with the targeted gag st art codon had a clearly decreased amount of the HIV-1 gag p24 protein. The EGS expressing cells with the targeted gag start codon showed effective sup pression of HIV-1 gene expression. Thus, these studies describe novel gene targeting agents for the inhibition of gene expression and antiviral activi ty.