Figure 2. Tcf7^−/− Mice Lack Functional ILC2 in the Lung.

(A and B) Tcf7^+/+ and Tcf7^−/− mice were intranasally challenged with papain (10 μg in 40 μl of PBS) every 24 hr on day 0, day 1, and day 2. Mice were sacrificed 12 hr after the last challenge. Lung hematopoietic cells were isolated and stimulated with PMA (50 ng/ml) and ionomycin (500 ng/ml) in the presence of monensin for 3 hr. Cells were stained for ILC2 followed by intracellular staining of IL-5 and IL-13.

(C) IL-5 and IL-13 concentrations in the BAL fluid from papain-treated mice were measured by ELISA. Data are from four mice (error bars are SEM). **p < 0.05.

(D and E) Eosinophils in BAL and lungs were examined by flow cytometry analysis. Flow plots were gated on CD45⁺ cells. We used the combination of CD11c and Siglec-F to distinguish airway macrophages and eosinophils as described (Dyer et al., 2011). The CD11c⁻Siglec-F⁺ cells were further confirmed to be SSC^high cells (data not shown). Data are from three to five mice per group (error bars are SEM).

(F) We intravenously transferred 10⁵ WT ILC2 into Tcf7^−/− mice 8 hr before the first challenge with papain. The restoration of lung ILC2 was examined by flow cytometry analysis 12 hr after the final challenge. Flow plots were gated on Lin− cells.

(G) The number of eosinophils in papain challenged Tcf7^+/+ mice, Tcf7^−/− mice, and Tcf7^−/− mice with adoptive transfer of WT ILC2 is shown. Data are from three to four mice per group (error bars are SEM). **p < 0.05. See also Figure S2.