IL-17A deficiency enriches Prevotella species and promotes Tregs in HLA-DR3 transgenic mice, reducing EAE severity (microbiomejournal.biomedcentral.com)

• IL-17A deficiency in HLA-DR3 transgenic mice enriches Prevotella species in the gut.
• Enriched Prevotella enhances PPAR signaling and increases FoxP3+ Tregs and IL-10.
• These changes are associated with reduced EAE severity, transferable via cohousing.
• Administration of Prevotella copri replicates the Treg-promoting and anti-inflammatory effects.

"A study using HLA-DR3 transgenic mice shows that IL-17A deficiency enriches beneficial gut bacteria, particularly Prevotella species, which enhances PPAR signaling and increases FoxP3+ regulatory T cells (Tregs) and IL-10 production. These changes lead to reduced severity of experimental autoimmune encephalomyelitis (EAE), a model of multiple sclerosis. The protective effects were transferable via cohousing, indicating a microbiota-driven regulatory circuit. This suggests that targeting the gut microbiota, especially Prevotella species, could be a therapeutic strategy for autoimmune diseases."