[Microglia in pathophysiology of neuroimmunological disorders]

Microglia are innate immune cells in the central nervous system (CNS). They function as antigen-presenting cells (APC) and inflammatory cells to cause various neuroimmunological disorders, such as multiple sclerosis. Upon activation by either bacterial lipopolysaccharide, T cell-derived cytokines, phagocytosis of neural debris, or factors from injured neurons, microglia acquire full characteristics of APC, and produce a variety of soluble factors, including proinflammatory factors, neurotoxic factors and neurotrophic factors. These factors affect neuronal, glial and endothelial cell functions. Thus, they are believed to play a predominant role in the development of neuroimmunological disorders as APC and effector cells.