Fig. 5. A. muciniphila supports T_regs in vivo expansion.

(A) 16S ribosomal RNA analysis of microbiomes from TCR^miniCNS1^k/o and TCR^mini mice. Data were confirmed by RT-qPCR (shown below legend). Reads were first normalized to UniF340/UniR514 and then to CNS1^+/+ A. muciniphila signal. (B) Inoculation of GF TCR^miniFoxp3^GFP mice with A. muciniphila expands colonic T_regs. (C) A. muciniphila induces pT_regs and expands tT_regs. Naïve CD4⁺CD44^lowFoxp3⁻ cells from congenic TCR^mini mice were adoptively transferred into CNS1^k/oTCR^mini hosts, and half of the recipients received A. muciniphila. Graphs show frequencies (left) and total number (right) of Foxp3⁺ cells gated according to their origin. (D) TCR^miniCNS1^k/o mice were colonized with A. muciniphila, and 8 weeks later, their colonic tT_regs were analyzed. Graphs show percentage (left) and numbers (right) of CD4⁺Foxp3⁺ cells. (E) tT_regs up-regulate the CD71 proliferation marker in response to A. muciniphila. Summary and typical dot plots are shown. For (B) to (D), each symbol represents individual animals, and data were obtained in at least two independent experiments. Paired t test; *P < 0.05, **P < 0.01.