CD40-CD40L and ICOS-ICOSL interactions enhance the activation of eosinophils from ECRS patients
Since upregulation of CD40 and ICOSL expression on eosinophils in nasal tissue of CRS patients, we investigated whether CD40-CD40L and ICOS-ICOSL interactions involved in eosinophils dysfunction. Considering that ECRS is characterized circulating and histologically high proportion of eosinophils. To determine this, peripheral blood samples from 10 ECRS patients were stimulated by rhCD40L (5ug/mL), rhICOS (10 ug/mL), or control IgG (5ug/mL), respectively. Cells were harvested 24h post-stimulation for flow cytometry. CD45+C16- cells was defined as eosinophils and CD69 was an activation marker of eosinophils. The detailed gating strategy was shown in Fig. 7A. There were notably upregulation CD69 expression on eosinophils in response to CD40L and ICOS protein stimulation compared with that to control IgG group (Fig. 7B). These data indicated that the up-regulation of CD40 and ICOSL on eosinophils mediated their activation in ECRS patients.