9P9R

KL-H15-6H4 Fab in complex with soluble A/wedge-tailed shearwater/Western Australia/2576/1979 H15 hemagglutinin trimer

Summary for 9P9R

• Entry DOI: 10.2210/pdb9p9r/pdb
• EMDB information: 71419 71420 71421 71422 71424 71480 71481 71482
• Descriptor: Hemagglutinin HA1, Hemagglutinin HA2, KL-15-6H4 heavy chain Fv, ... (5 entities in total)
• Functional Keywords: influenza virus, hemagglutinin, avian influenza virus, antibody fab complex, glycoprotein, viral protein, viral protein-immune system complex, viral protein/immune system
• Biological source: Influenza A virus (A/shearwater/West Australia/2576/79(H15N9)); More
• Total number of polymer chains: 8
• Total formula weight: 194454.41

Authors

Leon, A.N.,Ferguson, J.A.,Han, J.H.,Ward, A.B. (deposition date: 2025-06-24, release date: 2026-07-01, Last modification date: 2026-07-15)

Primary citation

Bhavsar, D.,Leon, A.N.,Hsu, W.L.,Puente-Massaguer, E.,Ferguson, J.A.,Han, J.,Wilson, P.,Ward, A.B.,Krammer, F.
Structural and functional characterization of the antigenicity of influenza A virus hemagglutinin subtype H15.
Cell Rep, 45:116773-116773, 2026

PubMed Abstract: Avian H15 influenza viruses are closely related to H7 viruses, but only 22 H15 sequences have been reported since 1987, suggesting both rarity and minimal antigenic variation. Here, we characterized a panel of mouse monoclonal antibodies (mAbs) raised against the A/wedge-tailed shearwater/Western Australia/2576/1979 ancestral strain, and a human mAb isolated from an H7N9 vaccinee. We found differences in binding and neutralization profiles against the ancestral strain and drifted strains of H15 isolated after 2008. mAbs exhibiting hemagglutination inhibition activity against the ancestral strain do not show binding to drifted strains, hinting at antigenic differences near the receptor binding site. We show that the mAbs protect in vivo and elucidate mAb-antigen interactions using negative stain and cryo-electron microscopy. The characterization of H15 antigenicity and the mechanisms of antibody-mediated neutralization expands our knowledge of this sparsely sampled avian influenza virus subtype and informs our understanding of immune pressures on viral surface glycoproteins.

PubMed: 41485218
DOI: 10.1016/j.celrep.2025.116773

Experimental method

ELECTRON MICROSCOPY (3.14 Å)