Which substances enhance phagocytosis?

Which substances enhance phagocytosis?

• A. Chemotaxins
• B. Opsonins
• C. Complement
• D. Antibodies

Answer: (B)

Opsonization is the process that directly enhances phagocytosis. When a pathogen is coated with opsonins, phagocytes recognize those opsonins through specific receptors (Fc receptors for antibodies and complement receptors for complement fragments like C3b), making binding and engulfment by the phagocyte much more efficient. This coating essentially marks the microbe for ingestion, which is why opsonins are the substances that best promote phagocytosis. Chemotaxins, on the other hand, mainly attract phagocytes to the site of infection and don’t directly coat targets for uptake. Complement has many roles in immunity, including lysis and inflammation, and while certain complement fragments can act as opsonins, the most direct and specific term for substances that boost phagocytosis is opsonins. Antibodies are a key example of opsonins.

Opsonization is the process that directly enhances phagocytosis. When a pathogen is coated with opsonins, phagocytes recognize those opsonins through specific receptors (Fc receptors for antibodies and complement receptors for complement fragments like C3b), making binding and engulfment by the phagocyte much more efficient. This coating essentially marks the microbe for ingestion, which is why opsonins are the substances that best promote phagocytosis.

Chemotaxins, on the other hand, mainly attract phagocytes to the site of infection and don’t directly coat targets for uptake. Complement has many roles in immunity, including lysis and inflammation, and while certain complement fragments can act as opsonins, the most direct and specific term for substances that boost phagocytosis is opsonins. Antibodies are a key example of opsonins.