NS1 Influenza Protein - Pathogenicity

Pathogenicity

The fact that NS1 is involved in the pathogenicity of influenza A viruses makes it a good target to attenuate these viruses. Several studies demonstrated that influenza viruses with partial deletions in NS1 proteins are attenuated and do not cause disease, but induce a protective immune response in different species including mice, pigs, horses, birds and macaques. Although it had been known for more than a decade that influenza viruses with partial deletions in NS1 proteins were attenuated, all but one NS1 truncation variants of influenza A viruses were generated by in vitro mutagenesis. Wang et al. later demonstrated that the naturally truncated variant had propensity to generate new variants when passaged in ovo. Remarkably, the new variants were excellent live-attenuated influenza vaccine candidates . The ability to attenuate influenza viruses by truncation of the NS1 protein presents a novel approach in design and development of the next generation live-attenuated influenza vaccines for both poultry and humans.