The complement cascade and its by-products contribute to which of the following immune responses?

• A. Inhibition of phagocytosis
• B. Direct production of antibodies
• C. Suppression of inflammation
• D. Opsonization of pathogens

Answer: (D)

Verified step by step guidance

1. Understand the role of the complement system in the immune response. The complement cascade is a series of protein activations that help defend against pathogens.
2. Recognize that the complement system enhances phagocytosis by marking pathogens for destruction, a process known as opsonization.
3. Recall that the complement system does not directly produce antibodies; antibody production is the function of B cells in adaptive immunity.
4. Note that the complement system generally promotes inflammation rather than suppressing it, by releasing molecules that attract immune cells to the site of infection.
5. Conclude that the complement cascade and its by-products primarily contribute to opsonization of pathogens, facilitating their recognition and ingestion by phagocytes.