632:
Expression of the Steroidogenic Enzyme, CYP11A1, Identifies Peanut-Allergic Children at Risk for Developing Life-Threatening Anaphylaxis
Sunday, March 4, 2018: 4:30 PM
South Hall A2 (Convention Center)
Meiqin Wang, MD PhD, Bruce J. Lanser, MD, Carah B. Santos, MD, Kreso Bendelja, Jennifer Fish, PNP, Elizabeth A. Esterl, DNP RN, Jordan Abbott, MD, Erwin W. Gelfand, MD FAAAAI
RATIONALE: The steroidogenic enzyme Cyp11a1 was shown to be essential for development of peanut-induced intestinal anaphylaxis in mice. Expression of Cyp11a1 in food-allergic human T lymphocytes has not been studied. We determined expression levels of Cyp11a1 in CD4+ T lymphocytes from peanut-allergic patients and correlated them with IL-13 production.

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.