Which cells are primarily responsible for engulfing and digesting pathogens in the immune system?

Macrophages play a crucial role in the immune system as the primary cells responsible for engulfing and digesting pathogens. These large white blood cells are part of the innate immune response and are found in various tissues throughout the body. They identify pathogens through receptors that recognize common features of these microbes, a process known as phagocytosis.

Once a pathogen is engulfed, macrophages break it down using enzymes contained within their lysosomes. This not only helps to eliminate the infection but also plays a significant role in signaling other immune cells. The digestion process involves presenting fragments of the pathogen on their surface, which is vital for the activation of T cells and the adaptive immune response.

In contrast, B cells and T cells have different functions. B cells are primarily responsible for producing antibodies that target specific antigens, while T cells have roles in regulating the immune response and directly killing infected host cells. Red blood cells do not have a role in the immune response as they are primarily responsible for transporting oxygen throughout the body and do not participate in pathogen recognition or digestion. Thus, macrophages are the key players in the process of engulfing and digesting pathogens, which makes this choice the correct one.