Background: Annually, the influenza virus causes 500,000 deaths worldwide. Influenza -associated mortality and morbidity is especially high amongst the elderly, children and patients with chronic diseases. While there are antivirals available against influenza such as neuraminidase inhibitors and adamantanes, there is growing resistance against these drugs and there are no good drugs against influenza. Thus, there is a need for novel antivirals for resistant influenza strains. Host-directed therapies are a potential strategy for influenza as host processes are conserved and are less prone mutations as compared to virus-directed therapies.
Methods: A Pubmed search was performed for papers that performed NS1-interaction screens and the Reactome pathway database was used for the bioinformatics analysis. DAVID analysis, STRING interaction analysis was performed. YeastMine was used to determine yeast homologs. PR8 NS1 and NS1-GFP was cloned into a constitutive yeast expression vector and the Lithium Acetate method was used to transform yeast. Fluorescent microscopy was performed to visualize the colocalization in yeast. A549 cells treated with R848, a TLR7 agonist, followed by qPCR analysis.
Results: Bioinformatic analysis of NS1 interactome papers and the Interactome pathway has found that there were 167 proteins that had known yeast homologs. Of which, Sec13 was found to have one of the highest homology (66.2%) between mammalian cells and yeast. When NS1-GFP was expressed in yeast, it was found that NS1-GFP colocalized with Sec13. This is also observed in NS1 expressing stably transfected A549 cells. In A549 cells, Sec13 was found to be increased at mRNA level after 24 hours of R848 treatment.
Conclusion: Sec13 may be a key host protein in the influenza life cycle and in cytokine production.