Oligodeoxyribonucleoside methylphosphonates which have sequences complementary to the initiation codon regions of N, NS, and G vesicular stomatitis virus (VSV) mRNAs were tested for their ability to inhibit translation of VSV mRNA in a cell-free system and in VSV-infected mouse L cells. In a rabbit reticulocyte lysate cell-free system, the oligomers complementary to N (oligomer I) and NS (oligomer II) mRNAs inhibited translation of VSV N and NS mRNAs whereas oligomer III had only a slight inhibitory effect on N protein synthesis. At 100 and 150 μM, oligomer I specifically inhibited N protein synthesis in the lysate. In contrast, at 150 μM, oligomer II inhibited both N and NS protein synthesis. This reduced specificity of inhibition may be due to the formation of partial duplexes between oligomer II and VSV N mRNA. The oligomers had little or no inhibitory effects on the synthesis of globin mRNA in the same lysate system. Oligomers I—III specifically inhibited the synthesis of all five viral proteins in VSV-infected cells in a concentration-dependent manner. The oligomers had no effects on cellular protein synthesis in uninfected cells nor on cell growth. An oligothymidylate which forms only weak duplexes with poly(rA) had just a slight effect on VSV protein synthesis and yield of virus. Oligomers I—III have extensive partial complementarity with the coding regions of L mRNA. The nonspecific inhibition of viral protein synthesis in infected cells may reflect the role of N, NS, and/or L proteins in the replication and transcription of viral RNA or result from duplex formation between the oligomers and complementary, plus-strand viral RNA. The results of this study indicate that inhibition of viral protein synthesis in a cell-free lysate and in infected cells is primarily due to the interaction of oligomers I—III with complementary VSV mRNAs. Oligomers I—III also significantly inhibited VSV production in a manner corresponding to their effects on VSV protein synthesis. These results demonstrate that oligonucleoside methylphosphonates can be used to study viral gene expression and to control virus production.
ASJC Scopus subject areas