Oxysterols regulate encephalitogenic CD4(+) T cell trafficking during central nervous system autoimmunity

Area of Science:

• Immunology
• Neuroscience
• Endocrinology

Background:

• Steroid pathway disruptions are linked to inflammation and chronic diseases.
• Oxysterols, cholesterol metabolites, influence immune responses and are potential biomarkers for neurological diseases like multiple sclerosis.
• The role of oxysterols in adaptive immunity and autoimmunity is largely unknown.

Purpose of the Study:

• To investigate the role of oxysterols in autoimmune diseases.
• To elucidate the mechanism by which oxysterols modulate adaptive immunity.
• To explore oxysterols as potential therapeutic targets for autoimmune conditions.

Main Methods:

• Utilized a murine model of multiple sclerosis (experimental autoimmune encephalomyelitis - EAE).
• Generated mice deficient in cholesterol 25 hydroxylase (Ch25h), the enzyme producing 7α,25-dihydroxycholesterol (7α,25-OHC).
• Analyzed immune cell trafficking, specifically CD4(+) T lymphocytes, to the central nervous system (CNS).

Main Results:

• Ch25h deletion significantly attenuated EAE disease severity.
• Oxysterols were found to be crucial for recruiting leukocytes to inflamed tissues.
• 7α,25-OHC was shown to promote the migration of activated CD4(+) T cells via the EBI2 receptor.

Conclusions:

• Oxysterols play a pro-inflammatory role in autoimmune diseases like EAE.
• Oxysterols, particularly 7α,25-OHC, facilitate pathogenic T cell migration to the CNS.
• Targeting oxysterol synthesis or action presents a potential therapeutic avenue for autoimmune diseases.