Oligonucleotides derived from the packaging signal at the 5′ end of the viral PB2 segment specifically inhibit influenza virus in vitro

Abstract

The development of new antiviral molecules to fight the possible emergence of influenza viruses with pandemic potential is needed. In this study, phosphorothioate oligonucleotides (S-ONs) derived from the packaging signals in the 3' and 5' ends of the viral PB2 RNA were associated with liposomes and tested against influenza virus in vitro. A 15-mer S-ON derived from the 5' end of the viral PB2 RNA, complementary to the 3' end of its coding region (nucleotides 2279-2293) and designated 5-15b, proved markedly inhibitory. The antiviral activity of 5-15b was dose- and time-dependent but was independent of the cell substrate and multiplicity of infection used. Importantly, inhibition of influenza A and B viruses required S-ONs reproducing the respective packaging signals. Furthermore, 5-15b and its antisense derivative S-ON activity did not affect intracellular accumulation of viral RNA. Confocal microscopy showed that 5-15b is clearly nucleophilic. These findings indicate that the packaging signal at the 5' end of the PB2 RNA is an interesting target for the design of new anti-influenza-virus compounds.

Antisense oligonucleotides targeting the RNA binding region of the NP gene inhibit replication of highly pathogenic avian influenza virus H5N1

“…AS ODNs inhibit the influenza virus by interfering with viral gene expression in a sequence-specific manner. Previous studies of AS ODNs focused on the PA, PB1, NP and PB2 of the H1N1 influenza virus, and targeted the AUG initiation codon of viral genes [13,17,24].…”

Genome packaging in influenza A virus

“…This may be exploitable for intervention strategies. For instance, it has been suggested that packaging signals are good targets for oligonucleotide-based inhibition (Giannecchini et al, 2009). In a similar vein, the M2 ectodomain has been proposed as a candidate immunogen for a 'universal' influenza vaccine, for which antigenic escape mutants will be less likely to develop because the M2e coding region is either congruent with or overlaps that of M1 (Saelens, 2008).…”

Small RNAs targeting the 5′ end of the viral polymerase gene segments specifically interfere with influenza type A virus replication

“…Thus, these sequences appear to be good targets for the development of innovative nucleic acid-based antiviral strategies. Indeed, it has been previously demonstrated that influenza virus replication can be inhibited by phosphorothioate oligonucleotides (S-ONs), targeting the conserved untranslated region mapping within the 5 ends of the genomic segments encoding for the viral polymerase subunits (PA, PB1 and PB2) (Giannecchini et al, 2009(Giannecchini et al, , 2011 …”

“…Oligonucleotide s u sed for the gene ration of an tisen se RN As Oligonucleotide s u sed for the gene ration of miRN As (Giannecchini et al, 2009(Giannecchini et al, , 2011. (B) Sequences of the forward (F) and reverse (R) complementary oligonucleotides employed to generate small RNAs targeting the PB1, PB2, PA selected regions.…”