Hemagglutinin protein (H7N9 influenza virus) (H7 HA)

The Hemagglutinin (HA) protein of the H7N9 influenza virus is a critical surface glycoprotein that mediates viral entry into host cells. It functions as a homotrimeric class I fusion protein, where the HA1 subunit facilitates binding to sialic acid receptors on the host cell surface and the HA2 subunit mediates the fusion of the viral envelope with the endosomal membrane [1, 10]. In the context of H7N9, this protein is a primary driver of zoonotic transmission from birds to humans and possesses significant pandemic potential due to its ability to adapt to human-type receptors [9, 12]. HA is the principal target for neutralizing antibodies and the primary component of influenza vaccines [8, 13]. Therapeutic strategies targeting H7 HA include monoclonal antibodies that bind to the conserved stalk region to prevent membrane fusion and small molecule inhibitors that block the receptor-binding site or stabilize the prefusion conformation [2, 3]. However, the protein's high rate of antigenic drift and the relatively low immunogenicity of the H7 subtype present ongoing challenges for vaccine efficacy and drug development [7, 17].

Other names

H7N9 HAHemagglutinin (H7)HA proteinH7 glycoprotein

Inhibition of viral attachment to host cells and prevention of membrane fusion between the viral envelope and host endosomal membrane.