Sex differences in EAE reveal common and distinct cellular and molecular components

Area of Science:

• Neuroimmunology
• Immunology
• Animal Models

Background:

• Experimental autoimmune encephalomyelitis (EAE) models multiple sclerosis (MS), but adjuvant effects complicate interpretation.
• Understanding sex-based immune responses is crucial for EAE and MS research.

Purpose of the Study:

• To investigate sex differences in immune cell and chemokine responses in EAE and adjuvant-only models.
• To correlate peripheral immune changes with central nervous system (CNS) pathology and clinical EAE severity.

Main Methods:

• C57BL/6 mice (male vs. female) were induced with EAE (m)MOG-35-55/CFA/Ptx, CFA/Ptx alone, or left untreated.
• Clinical, histological, spleen cellularity, and CNS chemokine profiles were analyzed.
• Sophisticated statistical methods were used to analyze response curves.

Main Results:

• Male mice exhibited heightened pro-inflammatory immune cell and cytokine/chemokine responses compared to females.
• Males also showed increased regulatory T cells, B cells, and macrophages, partially counterbalancing inflammation.
• Sex differences in peripheral immunity correlated with reduced CNS infiltration and demyelination in males, despite similar clinical EAE severity.

Conclusions:

• Sex-based immune cell profiles significantly impact EAE pathogenesis and CNS pathology.
• EAE severity is modulated by the balance between pro-inflammatory and regulatory immune components.
• These findings highlight the importance of considering sex as a biological variable in EAE and MS research.