IL-4Rα-mediated signaling on Foxp3⁺ Treg cell is required for the accumulation of Treg cells and the control of effector T-cells.

IL-4Rα−/lox, Foxp3cre IL-4Rα−/lox, and IL-4Rα−/− mice were infected with Sm cercariae and euthanized 8 wk post infection. (A) Efficiency of il4ra deletion by qPCR. CD4+ Foxp3+ T cells were sorted 8 wk post infection from pooled spleen and MLN cells, genomic DNA was extracted, and the ratio of exon8:exon5 was calculated. (B) Flow cytometry analysis of IL-4Rα expression by CD19+ B cell and CD4+ Foxp3+ T cell in pooled spleen and MLN cells 8 wk post infection. (C) Representative flow cytometry of CD4+ Foxp3+ T cells from the liver of mice infected with Sm for 8 wk. (D) Frequency of CD4+ Foxp3+ T cells (left) and (E) Foxp3 GMFI in CD4+ Foxp3+ T cells from (C). (F) Liver cytokine production 8 wk post infection. Livers from infected mice were homogenized, and the levels of the indicated cytokines were detected by ELISA and normalized to mg of liver tissue. (G) Representative flow cytometry of CD4+ Foxp3+ T cells from the MLN of mice infected with Sm for 8 wk. (H) Frequency of CD4+ Foxp3+ T cells (left) and (I) Foxp3 GMFI in CD4+ Foxp3+ T cells from (G). (J) Representative flow cytometry of CD4+ Ki-67+ cells within CD4+ Foxp3− T-cell population in MLN 8 wk post infection. (K) Frequency of CD4+ Ki-67+ cells from (J). (L) Frequency of CD3+ CD4+ CD44+ effector T cells in MLN 8 wk post infection. (M) Frequency of cytokine-producing CD3+ CD4+ T cells, from MLN, after stimulation with PMA/Ionomycin in the presence of monensin. (N) Frequency of indicated transcription factor–expressing CD4+ T cells in the MLN 8 wk post infection. (O) Frequency of cytokine-producing CD4+ GATA3+ T cells, from MLN, after stimulation with PMA/Ionomycin in the presence of monensin. (P) Frequency of cytokine-producing CD4+ Foxp3+ T cells, from MLN, after stimulation with PMA/Ionomycin in the presence of monensin. Results are representative of two independent experiments with 6–10 mice/group. Data are expressed as mean ± S.E.M. NS, P > 0.05; * P P P t test. Underlying data can be found in S1 Data. Bcl-6, B cell lymphoma 6; CD3, cluster of differentiation 3; CD4, cluster of differentiation 4; CD19, cluster of differentiation 19; CD44, cluster of differentiation 44; Foxp3, forkhead box P3; GATA3, GATA binding protein 3; GMFI, geometric mean fluorescence intensity; IFN-γ, interferon gamma; IL-4, interleukin-4; IL-4Rα, interleukin-4 receptor alpha; IL-5, interleukin-5; IL-10, interleukin-10; IL-13, interleukin-13; IL-17, interleukin-17; MLN, mesenteric lymph node; NS, not significant; PMA, phorbol myristate acetate; qPCR, quantitative real-time PCR; RORγt, RAR-related orphan receptor gamma; Sm, S. mansoni; T-bet; T-box transcription factor; Treg, regulatory T.