INHIBITION OF RESPIRATORY SYNCYTIAL VIRUS-REPLICATION BY ANTISENSE OLIGODEOXYRIBONUCLEOTIDES

Oligodeoxyribonucleotides targeted against respiratory syncytial virus (RSV) genomic RNA inhibited RSV replication in cell culture by an app arent antisense mechanism. HEp-2 cells were infected with RSV strain A 2 and incubated in the presence of oligonucleotides. Virus replication was measured by enzyme-linked immunosorbent assay (ELISA), virus yiel d assay, or production of specific RSV mRNAs. Using ELISA, 50% effecti ve concentration (EC(50)) values were about 0.5-1 pM for an antisense oligonucleotide targeted to the start of the NS2 gene. All oligonucleo tides inhibited virus antigen production as measured by ELISA. In all assays, this antisense oligonucleotide was more potent than: (1) a con trol oligonucleotide containing the reverse sequence; (2) oligonucleot ides targeted at RSV mRNA; (3) a random sequence oligonucleotide; and (4) ribavirin. Reverse transcriptase polymerase chain reaction (RT-PCR ) showed sequence-specific depletion of the genomic RNA target followi ng treatment of cells with the antisense oligonucleotide. Specific cle avage of the genomic target RNA has been detected at the antisense oli gonucleotide binding site, suggesting that cellular RNase H participat es in the reaction. These results indicate that antisense oligonucleot ides targeted against RSV genomic RNA can effectively inhibit RSV repl ication and may have therapeutic value. (C) 1997 Elsevier Science B.V.