EXPLORING THE ENTRY CAPABILITIES OF H5N1 IN THE ABSENCE OF THE SIALIC ACID BINDING REGION IN HEMAGGLUTININ
Brenna Dooley, Emily Rumschlag-Booms.
Northeastern Illinois University, Chicago, IL.
With high mutation rates and increased pathogenicity, influenza has the potential to cross the species barrier, sparking a global pandemic. H5N1 avian influenza has already jumped the species barrier, and although transfer between humans is not currently viable, elevated mutation rates in the influenza envelope protein, hemagglutinin (HA), may trigger sustainable transmission among humans. The only known mechanism for influenza to attach and enter host cells is via the sialic acid (SA) binding region of HA and host cell SA receptors; however, studies suggest that other entry routes may be possible. Therefore, if H5N1 can mediate entry in the absence of the SA binding region, the virus may be using another mechanism or cofactor to enter the cell. Our research is centered on exploring the entry capabilities of H5N1 by disrupting the SA binding region and measuring viral entry. Using site directed mutagenesis, amino acid residues were substituted, altering the SA binding region of HA. Then, pseudovirus containing the mutated HA was synthesized. After infection, viral entry levels into target cells will be measured using a luciferase assay. If the viruses with the mutated HA and wild-type HA have comparable levels of entry, it suggests that H5N1 may be entering cells via another method or with the help of an unidentified cofactor. Fully understanding H5N1 entry mechanics could help direct antiviral therapeutics and treatments. Future experiments can focus on identifying potential substances, besides sialic acid, that are being used by H5N1 to mediate attachment and entry.