Generation of a DSF-Guided Refolded Bacterially Expressed Hemagglutinin Ectodomain of Influenza Virus A/Puerto Rico/8/1934 H1N1 as a Model for Influenza Vaccine Antigens

Influenza virus infections represent an ongoing public health threat as well economic burden. Although seasonal influenza vaccines have been available for some decades, efforts are being made to generate new efficient, flexible, and cost-effective technologies be transferred into production. Our work describes the development of a model hemagglutinin antigen that is capable inducing protection against viral challenge in mice. High amounts H1 ectodomain, HA18–528, were expressed bacterial system insoluble inclusion bodies. Solubilization was followed by thorough differential scanning fluorimetry (DSF)-guided optimization refolding, which allows fast reliable screening several refolding conditions, yielding tens milligrams/L folded protein. Structural functional analysis revealed native-like folding presence mix monomers oligomers solution. Mice immunized with HA18–528 protected when exposed A opposed mice received full-length denatured Sera showed both high titers antigen-specific IgG1 IgG2a isotypes neutralization activity. These results prove feasibility recombinant expression coupled DSF-guided providing vaccine development.