Mononuclear phagocytes in autoimmune neuroinflammation.

Area of Science:

• Neuroimmunology
• Central Nervous System (CNS) Immunity
• Innate and Adaptive Immunity

Background:

• The healthy mammalian CNS contains diverse leukocytes, including the mononuclear phagocyte system (MPS), crucial for homeostasis.
• Neuroinflammation involves leukocyte infiltration from the periphery into the CNS.
• The MPS comprises CNS-resident macrophages, monocytes, and dendritic cells (DCs), each with unique functions.

Purpose of the Study:

• To review the newly discovered roles of the MPS in autoimmune neuroinflammation.
• To elucidate the specific contributions of different MPS subsets to CNS immune responses.
• To differentiate the functions of CNS-resident macrophages, infiltrating monocytes, and DCs in neuroinflammatory conditions.

Main Methods:

• Literature review focusing on recent findings in neuroimmunology and MPS functions.
• Analysis of studies investigating encephalitogenic T cell-induced autoimmune neuroinflammation.
• Synthesis of data on leukocyte infiltration and cellular interactions within the CNS.

Main Results:

• CNS-associated DCs function as gatekeepers and antigen-presenting cells, directing adaptive immune responses.
• Bone marrow (BM)-derived monocytes contribute to immunopathology and CNS tissue damage.
• CNS-resident macrophages are critical for supporting tissue function and promoting CNS repair and maintenance.

Conclusions:

• The MPS exhibits functional heterogeneity within the CNS during autoimmune neuroinflammation.
• Distinct MPS subsets differentially impact disease pathogenesis and resolution.
• Understanding these roles is key for developing targeted immunotherapies for CNS autoimmune diseases.