Mice were treated i.p. with anti-CCR3 in three different doses (30–300 μg/animal in 500 μl PBS) or isotype control (100 μg/animal in 500 μl PBS, rat IgG2b, clone R35-38; BD-Bioscience Europe, Erembodegem, Belgium) 1 hr before allergen exposure on the first day of exposure. Cytospin preparations from BM and BAL were stained for CD34 using a biotinylated rat anti-mouse CD34 mAb (clone

RAM34; BD Biosciences). Bound antibodies were visualized with a Vector Red Alkaline Phosphatase Substrate kit (Vector Laboratories Inc., Burlingame, CA). The slides Pembrolizumab cost were also stained with Luxol Fast Blue and counterstained with Mayer’s haematoxylin (DAKO) to identify these cells as eosinophil-lineage precursors. Five hundred cells were evaluated in random fields of view. Cytospins from BAL were stained with a rat anti-mouse CD34 mAb (clone RAM34; BD Biosciences). A rabbit anti-rat immunoglobulin

(DAKO) was used as a link antibody before incubation with alkaline phosphatase–anti-alkaline phosphatase (DAKO). Bound antibodies were visualized with the Vector Red Alkaline Phosphatase Substrate kit. Slides were then treated with a biotin blocking system (DAKO) and incubated overnight at 4° with a biotinylated rat anti-mouse Sca-1/Ly6 mAb (Clone 177228; R&D Systems). Next day, the slides were washed and incubated with streptavidin-β-galactosidase and X-Gal substrate (β-Gal Selleck Palbociclib staining set; Roche) and counterstained with Mayer’s haematoxylin. Four hundred cells were counted in random fields of view. All data are expressed as mean ± SEM. Statistical analysis was carried out using a non-parametric analysis of variance (Kruskal–Wallis test) to determine the

variance among more than two groups. If significant variance was found, an unpaired two-group test (Mann–Whitney U-test) was used to determine significant differences between individual groups. Wilcoxon signed rank test was used to analyse changes within the same group. P < 0·05 was considered statistically significant. Flow cytometric analysis for CD34+ CCR3+ cells in BM, blood, lung and BAL showed a significant increase of this PAK5 cell population in all three compartments of OVA-sensitized/exposed animals when compared with OVA-sensitized but saline-exposed control animals (Fig. 1a). Triple staining for CD34+ CCR3+ Sca-1+ on lung cells was performed to determine if a part of the CD34+ CCR3+ cells also expressed Sca-1. Allergen exposure induced a significant increase in the number of CD34+ CCR3+ Sca-1+ lung cells both in the SSChigh gated population (i.e. eosinophils) and in the SSClow gated cell population (i.e. eosinophil-lineage-committed progenitors) when compared with saline-exposed animals (Fig. 1b). CCR3+, Sca-1+ CCR3+ and CD34+ CCR3+ cells were also increased in the SSChigh and SSClow gated cell populations in allergen-exposed mice when compared with saline-exposed mice (Fig. 1c,d).