Human CD4 + /CD8α + regulatory T cells induced by Faecalibacterium prausnitzii protect against intestinal inflammation

This is the authors' abstract. We don't add key points for this paper.

Faecalibacterium prausnitzii (F. prausnitzii) , a dominant bacterium of the human microbiota, is decreased in patients with inflammatory bowel diseases (IBD) and exhibits anti-inflammatory effects. In human, colonic lamina propria contains IL-10-positive, Foxp3-negative regulatory T cells (Treg) characterized by a double expression of CD4 and CD8α (DP8α) and a specificity for F. prausnitzii . This Treg subset is decreased in IBD. The in vivo effect of DP8α cells has not been evaluated yet. Here, using a humanized model of NOD. Prkcscid IL2rγ -/- (NSG) immunodeficient mouse strain that expresses human leucocyte antigen D-related 4 (HLA-DR4) but not murine class II (NSG-Ab° DR4), we demonstrated a protective effect of DP8α Tregs combined with F. prausnitzii administration in a colitis model. In a cohort of patients with IBD, we showed an independent association between the frequency of circulating DP8α cells and disease activity. Finally, we pointed out a positive correlation between F. prausnitzii -specific DP8α Tregs and the amount of F. prausnitzii in fecal microbiota in healthy individuals and patients with ileal Crohn’s disease.