Fig. 1. T1L blocks the differentiation of pT_regs and promotes T_H1 immunity to dietary antigen at inductive and effector sites of the gut.

(A) For each time point, WT mice were inoculated perorally with 10¹⁰ plaque forming units (PFU) of T1L (n = 3 mice; red circles), 10¹⁰ PFU of T3D-RV (n = 3 mice; blue circles), or phosphate-buffered saline (PBS) (sham, n = 3 mice; open circles) and euthanized 6 or 48 hours after inoculation. RNA of mLN, PP, epithelium, and Lp were isolated and analyzed by means of microarray. MST is represented on multidimensional scaling ordination. The MST traces a path of minimum weight through each vertex or node that represents the profile of differentially expressed genes for each sample state shown. The lengths of edges (or connecting paths) indicate the level of dissimilarity between samples. Each sample state and the distances between them are represented in two-dimensional space. The coordinates of each sample along each dimension are indicated by the two axes. (B) Mice were inoculated perorally with 10⁸ PFU of T1L (n = 6 mice), 10⁸ PFU of T3D-RV (n = 6 mice), or PBS (sham, n = 5 mice) for 2 days. The expression of IL-12p40 on gated MHC-II⁺ CD11c⁺ CD103⁺ CD11b⁻ CD8α⁺ mLN DCs was evaluated by means of flow cytometry. Representative dot plots and percentages of IL-12p40 in the mLN are shown in the CD103⁺ CD11b⁻ CD8α⁺ DC subset. (C and D) OT-II⁺ CD45.1⁺ CD4⁺ T cells were transferred into WT CD45.2⁺ mice. One day after transfer, mice were inoculated perorally with 10¹⁰ PFU of T1L (n = 4 to 16 mice), 10¹⁰ PFU of T3D-RV (n = 5 to 14 mice), or PBS (sham, n = 6 to 15 mice) and fed 1.5% OVA in the drinking water (filled circles) or an OVA-containing diet (open circles) for 6 days. The intracellular expression of Foxp3 and T-bet in transferred OT-II⁺ CD45.1⁺ CD4⁺ T cells in the mLN and in the Lp was evaluated by means of flow cytometry. Representative dot plots and percentages of Foxp3⁺ T-bet⁻ and T-bet⁺ Foxp3⁻ cells are shown in the mLN (C) and in Lp (D), respectively. [(B) to (D)] Graphs depict at least two independent experiments. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001; one-way analysis of variance (ANOVA)/Tukey’s multiple comparison.