Fig. 4.

Lung CD24⁻CD11b⁺ DC2s promote cDC1-mediated eosinophil recruitment. a–c Mice were sensitized and challenged with OVA and culled 1.5 days after the first OVA challenge, and eosinophil counts in the lung or Balf were assessed. a WT (solid circle) and NOS₂^−/− (empty circle) mice. n = 5–7. b 1400 W (empty circle) or control-treated (solid circle) mice, protocol on the left. n = 4–7. c NOS₂^−/− and WT bone marrow chimeric mice. WT to WT (solid circle), WT to NOS₂^−/− (empty square), NOS₂^−/− to WT (solid triangle), and NOS₂^−/− to NOS₂^−/− (empty triangle) mice. n = 6–10 (Saline) or n = 10–14 (OVA). d–f Cells were sorted from mice 1.5 days after the first OVA challenge and used for assay. d NO production measured as nitrite in lung CD45⁺ cell culture supernatants. n = 4–5 per group. e mRNA expression of NOS₂ by different types of lung CD45⁺ cells, such as CD11b⁺DCs, cDC1s (SiglecF⁻CD11c⁺IA/IE⁺CD103⁺CD11b⁻), neutrophils (NEU), etc. n = 3 per group. f NOS₂ mRNA expression in lung CD24⁻CD11b⁺ DC2s isolated from OVA (solid rectangle) or saline (empty rectangle) challenged mice. mRNA expression is shown relative to the expression of NEU (e) or CD24⁺ cDC2s (f). n = 4 per group. g NO production measured in lung CD24⁻CD11b⁺ DC2 culture supernatants. n = 4 per group. h FACS analysis of NOS₂ expression on lung CD11b⁺ DCs from OVA-challenge mice. i, j Cells were purified from NOS₂^−/− or WT mice 1.5 days after the first OVA challenge. i Eosinophils recruited into the air pouches injected with pulmonary cDC1s (SiglecF⁻CD11c⁺IA/IE⁺CD103⁺CD11b⁻) (1 × 10⁴ cells), CD24⁻CD11b⁺ DC2s (1 × 10⁴ cells). n = 4–6 per group. j mRNA expression of CCL17 and CCL22 by lung cDC1s from NOS₂^−/− (solid rectangle) or WT mice (empty rectangle). n = 3–5 per group. *P < 0.05, **P < 0.01, ***P < 0.001, unpaired Student’s t test. Means ± SD are shown. Data represent two (c, e) and three (a, b, d, f–j) independent experiments