Disease-modifying treatments modulate myeloid cells in multiple sclerosis patients

Area of Science:

• Neuroimmunology
• Cell Biology
• Pathogenesis of Multiple Sclerosis

Background:

• Myeloid cells play a crucial role in multiple sclerosis (MS) pathogenesis, influenced by their activation state and polarization.
• Extracellular vesicles (MVs) released by myeloid cells mediate their pathogenic effects.
• Understanding how MS treatments impact myeloid cell polarization is vital for therapeutic strategies.

Purpose of the Study:

• To investigate the effects of current multiple sclerosis (MS) treatments on myeloid cell activation and polarization.
• To assess changes in myeloid extracellular vesicle (MVs) levels and myeloid cell polarization markers over time during MS treatment.

Main Methods:

• Assessed myeloid extracellular vesicle (MVs) levels and polarization markers in MS patients at baseline and up to 6 months after initiating treatment.
• Compared MVs levels and polarization markers between MS patients and healthy controls.

Main Results:

• MS patients exhibited higher MVs levels compared to controls.
• Natalizumab treatment led to a significant increase in MVs levels over 6 months.
• Interferon β-1a decreased the pro-inflammatory marker IL1β and increased Trem2 expression.
• Interferon β-1a and fingolimod reduced the pro-inflammatory marker IL6.

Conclusions:

• Current MS treatments significantly modulate myeloid cell activity and polarization.
• Therapeutic interventions impact key pathways involved in MS pathogenesis, including inflammation and debris clearance.
• Changes in MVs and polarization markers may serve as indicators of treatment response in MS.