Interleukin-3 coordinates glial-peripheral immune crosstalk to incite multiple sclerosis

Area of Science:

• Neuroimmunology
• Cellular and Molecular Neuroscience
• Autoimmune Diseases

Background:

• Multiple sclerosis (MS) pathogenesis involves glial cells and infiltrating leukocytes in the central nervous system (CNS).
• The communication networks between these distinct cell populations in MS remain largely unknown.

Purpose of the Study:

• To elucidate the molecular mechanisms governing crosstalk between glial cells and infiltrating immune cells in MS.
• To identify novel therapeutic targets for mitigating immune cell infiltration and disease severity in MS.

Main Methods:

• Single-nucleus RNA sequencing (snRNA-seq) of human CNS tissue from MS patients.
• Analysis of cytokine and receptor expression in glial and myeloid cells in mouse models and human samples.
• Correlation analysis of gene expression and protein levels with clinical MS severity.

Main Results:

• CNS-resident astrocytes and T cells produce interleukin-3 (IL-3).
• Microglia and infiltrating myeloid cells express the IL-3 receptor alpha (IL-3Rɑ).
• IL-3 signaling drives myeloid cell migration and CNS immune cell infiltration, exacerbating MS.
• IL3RA expression in myeloid cells and IL-3 levels in cerebrospinal fluid correlate with disease severity.

Conclusions:

• Interleukin-3 (IL-3) and Interleukin-3 receptor alpha (IL-3Rɑ) form a critical glial-peripheral immune network.
• This network promotes immune cell recruitment to the CNS, worsening MS.
• Targeting the IL-3:IL-3Rɑ axis represents a potential therapeutic strategy for MS.