Influenza A virus hemagglutinin and SARS-CoV-2 spike protein glycans (IAV HA and SARS-CoV-2 S Glycans)

Influenza A virus hemagglutinin (HA) and SARS-CoV-2 spike (S) protein are the primary surface glycoproteins responsible for viral entry into host cells. In a co-infection context, these molecules may interact directly or indirectly, potentially enhancing the entry and replication of both viruses. HA facilitates binding to sialic acid receptors on the host cell surface, while the Spike protein primarily binds to angiotensin-converting enzyme 2 (ACE2). The extensive glycosylation of the Spike protein plays a crucial role in shielding the virus from the immune system and can serve as a substrate for interactions with other viral or host proteins. Research suggests that IAV infection can upregulate ACE2 expression, thereby facilitating SARS-CoV-2 entry, while the glycans on the Spike protein may be recognized by the HA of certain influenza strains. Understanding the interplay between these two proteins is vital for developing broad-spectrum antivirals or combination therapies to treat respiratory co-infections. Targeting the glycosylation patterns or the receptor-binding domains of both proteins simultaneously could mitigate the increased clinical severity often observed in co-infected patients.

Other names

HA-Spike co-infection complexInfluenza A hemagglutininSARS-CoV-2 spike glycoproteinViral surface glycoproteins in co-infectionIAV HASARS-CoV-2 S protein

Inhibition of viral attachment to host receptors (ACE2 or Sialic Acid), blockade of viral membrane fusion, and neutralization of viral entry through competitive binding to the receptor-binding domain (RBD) or glycan shields.