When the animals were deeply anaesthetized blood was obtained by cardiac puncture of the right ventricle. Bronchoalveolar lavage (BAL) was performed by instilling 0·25 ml PBS through the tracheal cannula, followed by gentle aspiration and repeated with 0·2 ml PBS. Finally, one femur was cut at the epiphysis and the BM cells were flushed with 2 ml PBS. Bronchoalveolar lavage fluid and bone marrow.  Samples of BALF and BM were centrifuged at 300 g for 10 min at 4°. The BAL supernatant

was saved for eotaxin-2 measurement and stored at − 80° until analysis. The cells were resuspended with 0·03% BSA in PBS. The total cell numbers in BAL and BM were determined using standard haematological procedures. Cytospins GSK-3 beta pathway of BAL and BM were prepared and stained with May–Grünwald–Giemsa for differential cell counts by counting 300–500 cells using a light microscope (Zeiss Axioplan 2; Carl Zeiss, Jena, Germany). The cells were identified using standard morphological criteria, and BM mature and immature eosinophils were determined by nuclear morphology, check details cell size and cytoplasmic granulation.23 Lung tissue cells.  The pulmonary circulation was perfused with ice-cold PBS and lungs were removed from the thoracic cavity. The lung tissue was thinly sliced and suspended

RPMI-1640 (Sigma-Aldrich) complemented with 10% fetal calf serum (FCS), collagenase (5·25 mg/ml) and DNAse (3 mg/ml; Roche). After 90 min incubation in a shaking water bath (37°), any remaining intact tissue was disrupted by repeated passage through a wide-bore Pasteur pipette and filtered through a 40-μm nylon mesh (BD Biosciences, Erembodegem, Belgium). The parenchyma lung cells were diluted in Percoll (density 1·03 g/ml; Amersham Bioscience, Uppsala, Sweden) and layered on a discontinuous gradient,

centrifuged at 400 g for 20 min. The cells in the top layer, mainly macrophages, dead cells and debris, were discarded. Cells at the Percoll interfaces were collected and washed in PBS complemented with 10% FCS. Total cell numbers were determined using standard haematological procedures. Antibodies.  Fluorescein isothiocyanate (FITC) -labelled anti-mouse CD34 (clone RAM 34; BD Bioscience), phycoerythrin (PE) or FITC-labelled anti-mouse CCR3 (clone 83101; R&D systems, Oxymatrine Abington, UK), biotinylated anti-mouse stem cell antigen-1 (Sca-1)/Ly6 (clone 177228; R&D Systems) followed by peridinin chlorophyll protein (PerCP) -labelled streptavidin, PE-labelled anti-mouse IL-5Rα (Clone 558488; BD Bioscience), PercP-labelled anti-mouse CD45 (clone 557235; BD Bioscience), FITC-labelled BrdU (BD Bioscience) and rabbit anti-mouse major basic protein (MBP) polyclonal antibody in combination with goat anti-rabbit PE or with biotinylated swine anti-rabbit followed by streptavidin-FITC were used. Animals were sensitized and exposed to OVA or PBS as described above.