Fig. 3.

The microbiota is dispensable for pTreg induction in mLNs. Four- to eight-week-old GF and SPF-housed mice received CPDviolet-labeled naive CD4⁺ T cells from Foxp3^hCD2xRag2^−/−xDO11.10 mice. One day later, recipients were immunized via repetitive i.v. injection with Ova_323-339 peptide on two consecutive days and analyzed on day 3 after the first immunization. a Example dot plots depict de novo pTreg induction in the indicated LNs of either GF- or SPF-housed mice gated on adoptively transferred OvaTCR⁺CD4⁺ T cells. b Scatterplot displaying the frequencies of de novo induced Foxp3⁺ pTregs among transferred OvaTCR⁺CD4⁺ T cells in the indicated LNs of either GF- or SPF-housed mice. Data pooled from two independent experiments, with bars indicating the mean ± SD (n = 15-19). GF, germ-free; i.v., intravenous; mLNs, mesenteric lymph nodes; Ova, ovalbumin; pLN, peripheral lymph node; pTregs, peripherally induced regulatory T cells; SPF, specific pathogen-free; TCR, T cell receptor