Hemagglutinin-stem nanoparticles generate heterosubtypic influenza protection.

The epitope residues were calculated from [PDB: 5C0R] as the antigen residues at 4Å atomic distance from the antibody. The epitope of the broadly neutralizing C179 Fab on the construct Gen3 HA SS was determined from the crystal structure of the complex, solved by molecular replacement. For the Gen HA–SS constructs, the HA head was replaced with a three-residue linker. This was followed by the insertion of a thermostable HIV-1 gp41 trimerization domain to create Gen2 HA–SS. Gen3 HA–SS complex was created by further truncation of membrane-distal HA1 and HA2 regions of the stem.