What is the role of macrophages in the immune response?

Macrophages play a crucial dual role in the immune response by both presenting antigens and phagocytosing (engulfing and digesting) pathogens. After encountering pathogens, macrophages can engulf these foreign invaders via phagocytosis, which is essential for the elimination of pathogens and the initiation of an immune response.

Once the macrophages digest the pathogens, they process the antigenic components and present these antigens on their surface using major histocompatibility complex (MHC) molecules. This antigen presentation is vital for the activation of T cells, which are key players in the adaptive immune response. The engagement between presented antigens and T cells enables further orchestrated defense mechanisms against infections.

In summary, the ability of macrophages to phagocytose pathogens and present antigens makes them indispensable for linking the innate and adaptive immune responses, facilitating both immediate and longer-term immunity.