IL-25 deficiency reduced eosinophil chemotaxis after HDM
sensitization in lung and BALF
Previous studies have identified eosinophils process antigen to promote
Th2 cells expansion25-27. Since the antigen-presenting
role occurs during the sensitization phase, we wondered whether IL-25
affects eosinophils during the sensitization phase. Sensitized dose of
HDM was administrated intranasally into WT mice and we explored lung
eosinophils chemotaxis from day 0 to day 5 (Figure 5A) and found that on
the third day eosinophils were significantly increased after HDM
sensitization, suggesting it may exert an antigen-presenting role at
this time (Figure 5B,5C). To determine whether IL-25 contributes to the
role of eosinophils in sensitization response, we analyzed eosinophils
chemotaxis in IL-25-/- mice 3 days after HDM
sensitization (Figure 5D). IL-25-/- mice exhibited
reduced eosinophils compared with WT mice, both in lung and BALF (Figure
5E~H), which demonstrated the effect of IL-25 in
promoting eosinophils chemotaxis to airway to exert its role in the
sensitization phase, before the onset of effector stage.