What type of immunity do macrophages contribute to when they eliminate pathogens?

Macrophages are a critical component of the body's first line of defense, which is characterized as innate immunity. This type of immunity is non-specific; it acts quickly and does not require prior exposure to a pathogen to recognize and eliminate it.

Macrophages function by engulfing and digesting pathogens such as bacteria and viruses through a process called phagocytosis. They can also secrete cytokines to recruit other immune cells, enhancing the immune response. Since this action is immediate and not tailored to a specific pathogen, it exemplifies innate immunity.

In contrast, adaptive immunity involves a more complex response that relies on the recognition of specific antigens and requires previous exposure to pathogens, resulting in a memory that enhances future responses. Cell-mediated immunity, which is part of adaptive immunity, primarily involves T-cells. Humoral immunity, also part of the adaptive response, involves B-cells and the production of antibodies. Thus, while these other forms of immunity are essential for targeted responses, they do not pertain to the function of macrophages in their role in the innate immune system.