Fig. 5

C3a is necessary for ILC-T-cell-driven airway responses to OVA. In total, 2 × 10⁵ flow-sorted DO11.10 OVATg T cells (CD3⁺CD4⁺) were transferred with 1 × 10⁴ flow-sorted lung IL-33R⁺ ILC2 from wildtype or C3ar1^−/− mice i.v. to Rag2^−/−Il2rg^−/− recipient mice. After 24 h, mice were challenged i.t. with 40 µg OVA 323–339 peptide. Three days after OVA challenge, a airway hyperresponsiveness to nebulized methacholine was determined. Lungs were isolated for analysis of b, c frequency and d numbers of IL-13⁺CD4⁺ T cells, e IL-13 MFI in T cells, and levels of f Il13 and g Il2 mRNA. Data are means + SEM, and pooled from two independent experiments with 6–12 mice per group, *p < 0.05