CSF1R antagonism results in increased supraspinal infiltration in EAE

Area of Science:

• Immunology
• Neuroscience
• Pharmacology

Background:

• Colony stimulating factor 1 receptor (CSF1R) signaling is vital for myeloid cell function.
• CSF1R antagonism has shown potential in mitigating experimental autoimmune encephalomyelitis (EAE) severity.
• Mechanisms underlying CSF1R antagonism in EAE remain incompletely understood.

Purpose of the Study:

• To investigate the effects of CSF1R signaling inhibition on immune cell populations in steady-state and EAE conditions.
• To analyze the impact of CSF1R antagonism on central nervous system (CNS) infiltration and demyelination in EAE.

Main Methods:

• Utilized the CSF1R antagonist PLX5622 in a mouse model of EAE.
• Analyzed immune cells from peripheral organs and CNS using flow cytometry.
• Assessed demyelination via immunohistochemistry and analyzed neuroinflammation-related gene transcripts.

Main Results:

• PLX5622 treatment depleted microglia, dendritic cells, and macrophages in peripheral organs and CNS.
• CSF1R antagonism modulated T effector cell frequencies and reduced overall neurological symptom severity in EAE.
• Observed altered CNS infiltration patterns, with increased peripheral immune cells in the cerebellum of treated mice, leading to localized demyelination.

Conclusions:

• CSF1R activity critically influences immune cell composition in both periphery and CNS.
• CSF1R antagonism impacts immune cell infiltration sites and lesion localization during early EAE.
• Findings highlight CSF1R as a potential therapeutic target for modulating neuroinflammation in EAE.