What is the function of the complement system in immunity?

The function of the complement system in immunity is primarily to enhance the ability of antibodies and phagocytic cells to clear pathogens. This system consists of a series of proteins that circulate in the blood and become activated in response to infection. When triggered, the complement proteins can opsonize pathogens, meaning they coat the pathogen surfaces, which increases their visibility to phagocytic cells such as macrophages and neutrophils. This opsonization process facilitates the recognition and ingestion of pathogens by these immune cells.

Additionally, the complement system can lead to the formation of membrane attack complexes that create pores in the membranes of pathogens, ultimately leading to cell lysis. However, the primary role that is often emphasized in the context of immunity is its capacity to enhance the opsonization process and promote inflammation, which aids in the recruitment and activation of various immune responses.

The other options do not accurately represent the primary role of the complement system. While killing pathogens directly can be a part of its function, it is not its sole or primary role. Producing antibodies is a function of B cells, not the complement system. Regulating body temperature is more related to systemic responses to infection, rather than a function of the complement proteins. Thus, the correct answer