Gateways for myeloid cell entry into the central nervous system

Area of Science:

• Neuroimmunology
• Central Nervous System (CNS) Immunity
• Myeloid Cell Biology

Background:

• Resident myeloid cells are key immune components in the healthy CNS, established early in development.
• They play vital roles in neuronal network formation and physiological maintenance.
• The CNS has specialized structures for immune cell trafficking, particularly myeloid cells.

Purpose of the Study:

• To summarize current knowledge on myeloid cell trafficking into the healthy CNS.
• To highlight novel routes for immune cell entry into the CNS.
• To emphasize the importance of understanding myeloid gateways for therapeutic development.

Main Methods:

• Review of existing literature on CNS myeloid cell trafficking.
• Analysis of anatomical and molecular properties of myeloid gateways.
• Synthesis of findings from embryogenesis to physiological aging.

Main Results:

• Myeloid cells seed the CNS prenatally and persist lifelong.
• Specific CNS structures facilitate postnatal myeloid cell entry, termed myeloid gateways.
• These gateways are activated by physiological needs, aging, or pathologies, influencing CNS compartment accessibility.

Conclusions:

• Understanding myeloid cell trafficking routes and gateways is critical for CNS health.
• Novel routes for myeloid cell entry into the CNS have been discovered.
• Targeting myeloid gateways offers potential for cell therapies in CNS disorders.