[PDF][PDF] Dectin-1 limits autoimmune neuroinflammation and promotes myeloid cell-astrocyte crosstalk via Card9-independent expression of Oncostatin M

ME Deerhake, K Danzaki, M Inoue, ED Cardakli… - Immunity, 2021 - cell.com
ME Deerhake, K Danzaki, M Inoue, ED Cardakli, T Nonaka, N Aggarwal, WE Barclay, RR Ji
Immunity, 2021cell.com
Pathologic roles of innate immunity in neurologic disorders are well described, but their
beneficial aspects are less understood. Dectin-1, a C-type lectin receptor (CLR), is largely
known to induce inflammation. Here, we report that Dectin-1 limited experimental
autoimmune encephalomyelitis (EAE), while its downstream signaling molecule, Card9,
promoted the disease. Myeloid cells mediated the pro-resolution function of Dectin-1 in EAE
with enhanced gene expression of the neuroprotective molecule, Oncostatin M (Osm) …
Summary
Pathologic roles of innate immunity in neurologic disorders are well described, but their beneficial aspects are less understood. Dectin-1, a C-type lectin receptor (CLR), is largely known to induce inflammation. Here, we report that Dectin-1 limited experimental autoimmune encephalomyelitis (EAE), while its downstream signaling molecule, Card9, promoted the disease. Myeloid cells mediated the pro-resolution function of Dectin-1 in EAE with enhanced gene expression of the neuroprotective molecule, Oncostatin M (Osm), through a Card9-independent pathway, mediated by the transcription factor NFAT. Furthermore, we find that the Osm receptor (OsmR) functioned specifically in astrocytes to reduce EAE severity. Notably, Dectin-1 did not respond to heat-killed Mycobacteria, an adjuvant to induce EAE. Instead, endogenous Dectin-1 ligands, including galectin-9, in the central nervous system (CNS) were involved to limit EAE. Our study reveals a mechanism of beneficial myeloid cell-astrocyte crosstalk regulated by a Dectin-1 pathway and identifies potential therapeutic targets for autoimmune neuroinflammation.
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