Viruses bind to specific receptors on host cell surfaces to initiate infection. Which type of receptor does the influenza virus primarily bind to during host cell entry?

• A. Sialic acid-containing glycoproteins
• B. ACE2 receptors
• C. CD4 receptors
• D. Integrin receptors

Answer: (A)

Verified step by step guidance

1. Understand that viruses initiate infection by attaching to specific receptors on the surface of host cells, which determines their host range and tissue tropism.
2. Recall that the influenza virus uses a surface protein called hemagglutinin (HA) to recognize and bind to receptors on host cells.
3. Identify the type of receptor that hemagglutinin binds to, which are glycoproteins containing sialic acid residues on the host cell membrane.
4. Compare the given receptor options: ACE2 receptors are primarily used by SARS-CoV-2, CD4 receptors are targeted by HIV, and integrin receptors are used by some other viruses but not influenza.
5. Conclude that the influenza virus primarily binds to sialic acid-containing glycoproteins to enter host cells.