Induction of Foxp3+ Treg cells by LP eosinophils but not by PB eosinophils.

(A) CD11b+ cells were isolated from the PB and stained with anti-mouse Siglec-F and CCR3 Abs, the percentage of Siglec-F+CCR3+ eosinophils were analyzed by flow cytometry.

(B) Cells from BP were stained with a panel of Abs and the indicated surface molecules of the cells were analyzed by flow cytometry. Filled histograms are the isotype control.

(C) MACS-sorted CD4+CD62L+ T cell from the OT-II mouse were cultured under activating coditions with LP or PB eosinophils, and Foxp3 expression by CD4+ T cells was analyzed by flow cytometry after 4 d of culture.

(D) CFSE-labeled CD4+ T cells were cultured with sorted LP eosinophil-induced Treg at the indicated ratios (Teff:Treg×105) under activating conditions for 3 d. The proliferation of CD4+ T cells was analyzed by flow cytometry.