How do complement proteins enhance immune function?

• A. By creating barriers against infections
• B. By enhancing the clearance of pathogens
• C. By inducing fever during infections
• D. By producing reactive oxygen species

Answer: (B)

Complement proteins play a crucial role in enhancing immune function primarily through the process of opsonization and the formation of the membrane attack complex. When activated, complement proteins can bind to pathogens, marking them for enhanced recognition and phagocytosis by immune cells such as macrophages and neutrophils. This process significantly increases the clearance of pathogens from the bloodstream and tissues, facilitating a more effective immune response.

Additionally, complement activation can lead to the recruitment of inflammatory cells to the site of infection, further aiding in the clearance of these pathogens. The cascading effects of complement activation also contribute to inflammation, which helps contain the infection. Thus, the role of complement proteins in enhancing the clearance of pathogens is central to their function in the immune system.