Human Microglia

Microglia are a type of unique myeloid cells, reside in the parenchyma of the healthy central nervous system (CNS), account for 10–15% of all cells found within the brain. Microglia act as the first and main form of active immune defense in the CNS, constantly monitoring the microenvironment, in order to timely respond to different noxious stimuli (effector function). Microglia can express antigens in the context of MHC class II to CD-4 positive T cells.
Microglia Function
Under some circumstances, such as programmed cell death occurs or CNS is injured, microglia will work as brain macrophages to clear tissue debris, damaged cells, or microbes. Besides, microglial cells are also scavenging the CNS for plaques, damaged or unnecessary neurons and synapses, and infectious agents constantly, the processes of which are potentially dangerous. Therefore, microglia are extremely sensitive to pathological changes. These activities are important in the regulation of brain homeostasis during development and in the adult brain, both in physiological and pathology conditions.

Application
Chronic microglial activation is generally considered as a pathogenic mechanism common to several neurological disorders. Thus, microglia cells and their immortalized cells have become ideal model for physiopathology research on diseases like multiple sclerosis, Alzheimer’s disease, Parkinson’s disease, dementia, etc.