Macrophages are a type of white blood cell that plays a crucial role in the immune system. They are part of the innate immune system and are found in essentially all tissues, where they patrol for potential pathogens by amoeboid movement
. Macrophages engulf and digest pathogens, such as cancer cells, microbes, cellular debris, and foreign substances, through a process called phagocytosis
. This process acts to defend the host against infection and injury.
Macrophages also play a critical role in nonspecific defense (innate immunity) and help initiate specific defense mechanisms (adaptive immunity) by recruiting other immune cells such as lymphocytes
. They are important as antigen presenters to T cells and can stimulate the production of proinflammatory cytokine interferon gamma (IFN-γ) by natural killer (NK) cells, which serves as an important source of IFN-γ before the adaptive immune system is activated
.
Beyond increasing inflammation and stimulating the immune system, macrophages also play an important anti-inflammatory role and can decrease immune reactions through the release of cytokines
. Macrophages that encourage inflammation are called M1 macrophages, whereas those that decrease inflammation and encourage tissue repair are called M2 macrophages
.
In summary, macrophages are a vital component of the immune system, playing a key role in both innate and adaptive immunity. They are involved in the recognition and elimination of pathogens, the activation of other immune cells, and the regulation of inflammation
. Macrophages engulf and digest pathogens, such as cancer cells, microbes, cellular debris, and foreign substances, through a process called phagocytosis
. This process acts to defend the host against infection and injury.
Macrophages also play a critical role in nonspecific defense (innate immunity) and help initiate specific defense mechanisms (adaptive immunity) by recruiting other immune cells such as lymphocytes
. They are important as antigen presenters to T cells and can stimulate the production of proinflammatory cytokine interferon gamma (IFN-γ) by natural killer (NK) cells, which serves as an important source of IFN-γ before the adaptive immune system is activated
.
Beyond increasing inflammation and stimulating the immune system, macrophages also play an important anti-inflammatory role and can decrease immune reactions through the release of cytokines
. Macrophages that encourage inflammation are called M1 macrophages, whereas those that decrease inflammation and encourage tissue repair are called M2 macrophages
.
In summary, macrophages are a vital component of the immune system, playing a key role in both innate and adaptive immunity. They are involved in the recognition and elimination of pathogens, the activation of other immune cells, and the regulation of inflammation
