Recent studies have shown that basophils contribute to the initiation of Th2 cytokine–mediated inflammation. However, the underlying mechanism by which protease allergens triggering basophils to produce Th2 cytokine remains unclear.
Objectives
The objective of this study is to demonstrate the role of the mitogen activated kinase (MAPK) family in mouse bone marrow-derived basophils (BMBs) when treated with cysteine protease allergen Der f 1.
Methods BMBs were selected as DX5+FceRI+c-Kit– by flow cytometry of the mouse bone marrow culture. Sorted BMBs were stimulated with proteolytically active recombinant Der f 1 expressed in the yeast Pichia pastoris. The expression levels of Th2 cytokines, IL-4 and IL-13, were examined by real time PCR and ELISA. The activities of various intracellular MAPK signaling components were assessed by FACS.
Results
Production of both IL-4 and IL-13 in mouse basophils was induced by the treatment of enzymatically active Der f 1, whereas inactive Der f 1 did not. Extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinases (JNK) were phosphorylated upon treatment of active Der f 1 on BMBs. Additionally, treatment of pharmacological inhibitors PD098059 (ERK inhibitor) and SP600125 (JNK inhibitor) were able to inhibit IL-4 and IL-13 secretion. However, p38 MAPK was not inhibited by its inhibitor (SB203580).
Conclusions
These data suggest involvement of ERK, and JNK MAPKs in signal pathway for the production of Th2 cytokines such as IL-4 and IL-13 in BMBs when treated with a cysteine protease allergen rDer f 1.