METHODS: Human PBMCs from peanut-allergic children and healthy controls were isolated and stimulated with anti-human CD3/anti-CD28 for 48 hours. Cyp11a1 expression levels were monitored by real-time PCR and protein expression in cells was detected by flow cytometry and immunocytochemistry staining. Cytokine levels were determined by ELISA and intracellular staining. All patients underwent double-blind, placebo-controlled oral food challenges to peanut protein. Levels of serum total IgE and peanut-specific IgE were measured.
RESULTS: Cyp11a1 protein and mRNA levels were significantly increased in PBMCs and CD4+ T cells from peanut-allergic children compared to controls. In parallel, activated PBMCs from peanut-allergic children produced significantly increased levels of IL-13 compared to controls; IFNg levels were not different between groups. In these patients, there was a significant correlation between Cyp11a1 mRNA expression levels and IL-13 mRNA and protein levels.
CONCLUSIONS: The Cyp11a1-IL-13 axis may be an essential pathway in the development of peanut allergy. Cyp11a1 may serve as a novel target in the regulation and treatment of food allergy.