MAPK and PI3K pathways are involved in eosinophil degranulation.

<p>AnnexinV⁻ eosinophils (A) and NK cells (B), cultured alone or together at the 10∶1 NK:Eos ratio, were stained with anti-ERK or anti-phosphorylated ERK (pERK) antibodies. Eosinophils and NK cells were identified on the basis of their size difference (FSC) and granularity (SSC). Live eosinophils were defined as AnnexinV⁻ cells. Gray full lines and black dotted lines represent control antibody staining for each cell type alone or in co-culture, respectively. Gray plain histograms and black full lines represent staining with antibody of interest for each cell type alone or in co-culture, respectively. One representative experiment out of three is shown. (C) Eosinophils were pre-incubated with DMSO as control or with inhibitors of signaling pathways for 5 min at 37°C: PD 98059 25 μM an inhibitor of ERK pathway, SB 203580 1 μM an inhibitor of P38 MAPK, SP 600125 20 μM an inhibitor of JNK pathway and LY 294002 10 μM an inhibitor of PI3K pathway for the NK:Eos ratio 10∶1. Results show percentage of CD63⁺ eosinophils for each donor and mean is indicated with the black line. One-way Anova (Friedman) tests were performed, followed by Dunn’s post tests. *p<0.05, **p<0.01.