Brain immune cells

Brain immune cells, primarily represented by microglia, are the resident macrophages of the central nervous system (CNS) and serve as the primary mediators of neuroinflammation and brain homeostasis (Source: Nature Reviews Immunology, 2018; PubMed: 29749548). These cells constantly survey the brain parenchyma, performing critical roles such as the phagocytosis of cellular debris and the pruning of excess synapses during neurodevelopment. In the context of disease, brain immune cells can become chronically activated, contributing to the progression of neurodegenerative conditions like Alzheimer's and Parkinson's disease through the release of pro-inflammatory cytokines (Source: NIH/NIA, 2023). While 'Brain immune cells' is a cellular category rather than a specific molecular target, drug development focuses on specific proteins expressed by these cells, such as Colony stimulating factor 1 receptor (CSF1R) and Triggering receptor expressed on myeloid cells 2 (TREM2) (Source: UniProt: Q9NZC2; P07333). Therapeutic strategies aim to either deplete dysfunctional microglia or modulate their activation state to restore a neuroprotective environment.

Other names

MicrogliaCNS-resident macrophagesPerivascular macrophagesMeningeal macrophagesCNS myeloid cells

Modulation of brain immune cells is typically achieved by targeting specific receptors on the cell surface. For instance, CSF1R inhibitors like pexidartinib cause microglial depletion or shift phenotypes, while TREM2 agonists (e.g., AL002) aim to enhance phagocytic clearance of amyloid-beta plaques and apoptotic neurons in Alzheimer's disease (Source: Nature Reviews Drug Discovery, 2021; PubMed: 34131333).