The choroid plexus synergizes with immune cells during neuroinflammation

Area of Science:

• Neuroscience
• Immunology
• Cell Biology

Background:

• The choroid plexus (ChP) is a critical brain barrier and the primary producer of cerebrospinal fluid (CSF).
• Understanding ChP's role in neuroinflammation is crucial for treating brain diseases.

Purpose of the Study:

• To elucidate the mechanisms by which the choroid plexus regulates brain inflammation.
• To investigate immune cell dynamics and barrier repair at the ChP during meningitis.

Main Methods:

• Longitudinal two-photon imaging in awake mice.
• Single-cell transcriptomics.
• Intracerebroventricular lipopolysaccharide (LPS) injection model of meningitis.

Main Results:

• Neutrophils and monocytes infiltrated the ChP stroma and CSF during LPS-induced meningitis.
• Bidirectional monocyte and macrophage recruitment to the ChP facilitated neutrophil clearance and barrier repair.
• ChP epithelial cells transiently specialized to support immune cell recruitment, survival, differentiation, and tight junction regulation.

Conclusions:

• The choroid plexus actively orchestrates neuroinflammation and barrier maintenance.
• ChP epithelial cells play a dynamic role in coordinating immune responses at the brain barrier.
• This study provides a mechanistic understanding of ChP's role in brain inflammation and barrier regulation.