Endothelial cell-derived oxysterol ablation attenuates experimental autoimmune encephalomyelitis

Florian Ruiz, Benjamin Peter, Jessica Rebeaud, Solenne Vigne, Valentine Bressoud, Martin Roumain, Tania Wyss, Yannick Yersin, Ingrid Wagner, Mario Kreutzfeldt, Marisa Pimentel Mendes, Camille Kowalski, Gael Boivin, Leonard Roth, Markus Schwaninger, Doron Merkler, Giulio G. Muccioli, Stephanie Hugues, Tatiana V. Petrova, Caroline Pot*

*Corresponding author for this work

Abstract

The vasculature is a key regulator of leukocyte trafficking into the central nervous system (CNS) during inflammatory diseases including multiple sclerosis (MS). However, the impact of endothelial-derived factors on CNS immune responses remains unknown. Bioactive lipids, in particular oxysterols downstream of Cholesterol-25-hydroxylase (Ch25h), promote neuroinflammation but their functions in the CNS are not well-understood. Using floxed-reporter Ch25h knock-in mice, we trace Ch25h expression to CNS endothelial cells (ECs) and myeloid cells and demonstrate that Ch25h ablation specifically from ECs attenuates experimental autoimmune encephalomyelitis (EAE). Mechanistically, inflamed Ch25h-deficient CNS ECs display altered lipid metabolism favoring polymorphonuclear myeloid-derived suppressor cell (PMN-MDSC) expansion, which suppresses encephalitogenic T lymphocyte proliferation. Additionally, endothelial Ch25h-deficiency combined with immature neutrophil mobilization into the blood circulation nearly completely protects mice from EAE. Our findings reveal a central role for CNS endothelial Ch25h in promoting neuroinflammation by inhibiting the expansion of immunosuppressive myeloid cell populations.

Original languageEnglish
Article numbere55328
JournalEMBO Reports
Volume24
Issue number3
Pages (from-to)e55328
ISSN1469-221X
DOIs
Publication statusPublished - 06.2023

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