Although the recent sporadic outbreaks of influenza A virus H5N1 and of a new variant of H1N1 in 2009 were less serious than initially feared, public health responses gave an indication of the potential for pandemic influenza A to wreak havoc amongst human populations. Timely development of vaccines should help to contain future outbreaks, but effective antiviral medicines will also be needed. Circulating strains of influenza A virus with resistance to existing neuraminidase inhibitors have already been discovered, and new molecular targets would provide additional protection in the event of a fresh outbreak.
Researchers led by a team at the University of Hong Kong have now identified a compound, nucleozin, which can aggregate the viral nucleoprotein and prevent its transport into the nucleus. The nucleoprotein plays critical roles in viral RNA replication and genome assembly, and nucleozin was shown to block replication of H1N1, H3N2, and H5N1 viruses in cell culture experiments and also to protect mice from lethal challenge with highly pathogenic avian influenza virus A H5N1.
The study, which is published in Nature Biotechnology, shows that the nucleoprotein is a viable drug target and could lead to the development of new treatments to control the impact of future influenza A outbreaks. Potential binding sites for nucleozin on the influenza nucleoprotein were also predicted using molecular docking models.