House dust mite allergen Der f 2 drives IL-6 and GM–CSF expression in airway epithelial cells via p38 MAPK/NF-κB signaling

Objective: Der f 2, a major allergen derived from Dermatophagoides farinae, is a leading cause of allergic asthma. IL-6 and GM–CSF play essential roles in the exacerbation of asthma. However, the mechanical act by which Der f 2 mediates the expression of IL-6, IL-8, and GM–CSF in airway epithelial cells remains incompletely elucidated. Herein, we aimed to explore the effect of Der f 2 on IL-6 and GM–CSF expression in the human airway epithelial cell BEAS-2B and A549. Methods: Recombinant Der f 2 (rDf2) was acquired using Pichia pastoris. BEAS-2B and A549 cells were used as cell model. The expression of genes and proteins and the involvement of the signaling cascade were assessed using RT–PCR, quantitative real-time PCR (qPCR), Western blotting, and ELISA, respectively. Results: Our findings showed that rDf2 significantly induced mRNA expression and protein production of IL-6 and GM-CSF in BEAS-2B and A549 cells. In contrast, rDf2 did not influence IL-8 expression or production in both cells. Mechanistic studies revealed that rDf2 triggered activation of the p38 MAPK and JNK. Inhibition of p38, but not JNK, significantly attenuated rDf2-induced IL-6 and GM–CSF expression and production. Conclusion: This study demonstrates that Der f 2 promotes the expression and production of the pro-inflammatory cytokines IL-6 and GM–CSF in airway epithelial cells via activation of the p38 signaling pathway. These findings provide insights into the molecular mechanisms that Der f 2 may exacerbate airway inflammation.