Influenza A virus hemagglutinin (H7)

Influenza A virus hemagglutinin (HA) is the most abundant glycoprotein on the surface of influenza virions and plays a central role in viral entry into host cells. The H7 subtype refers to one of several antigenically distinct forms of HA found in influenza A viruses. HA exists as a homotrimer, with each monomer composed of two subunits: HA1 and HA2. HA1 contains the receptor-binding site, while HA2 harbors the fusion machinery. HA binds sialic acid-containing receptors on host cell surfaces, initiating endocytosis. After endocytosis, conformational changes in HA trigger fusion between viral and host membranes, releasing viral RNA into the cytoplasm. As the principal antigenic determinant, changes in H7 can lead to immune escape. Antibodies targeting H7 can inhibit infection by blocking receptor binding or interfering with membrane fusion.

Other names

HA(H7)H7 hemagglutinin

Neutralization of viral entry via receptor binding inhibition or fusion interference