Macrophages are a type of white blood cell that are essential to the immunological response of the body and play a vital part in this response.
There are two main types of macrophages: M1 and M2.
M1 macrophages are activated by cytokines and by various microbial components. M1 macrophages kill intracellular organisms and secrete cytokines.
M2 macrophages are activated by cytokines (eg, IFN-gamma, interleukin (IL)-4, IL-13)as well as by many distinct microbiological components (eg, lipopolysaccharide), they also play varied roles in amplifying or limiting the inflammatory response.
The M1 type is usually associated with a more aggressive immune response, while the M2 type is typically associated with a more muted or limited response.
Macrophages play a crucial role in the pathogenesis of autoimmune diseases. They are activated by cytokines and microbial components, which leads to the release of inflammatory mediators. These mediators can then damage tissues and contribute to the development of the disease.
Macrophages also play a role in the induction of autoimmunity. They can promote autoimmunity by presenting autoantigens to T cells, or by producing pro-inflammatory cytokines.
Therefore, macrophages play an important role in both the initiation and progression of autoimmune diseases.