Effect of IL-37 on Allergic Airway Inflammation

Rationale: The new cytokine IL-37 has been described as a negative regulator of innate immunity. It reduces activation of dendritic cells and the production of proinflammatory mediators in murine and human immune cells. Although recent results from the CLARA childhood asthma cohort suggested an impact of IL-37 on human asthma pathogenesis, the receptor for IL-37 and its implication in adaptive immune responses have not been determined.Objectives: This study aimed to clarify whether IL-37 also provides antiinflammatory effects on adaptive immune responses and through which receptor it exerts its effects.Methods: IL-37 levels in supernatants of restimulated peripheral blood mononuclear cells isolated from children with asthma and healthy children were determined. Mice (wild-type, IL-18Rα−/−, and SIGIRR/IL-1R8−/−) were sensitized to ovalbumin (OVA) and challenged with OVA aerosol to induce acute allergic experimental asthma, and IL-37 was applied intranasally during OVA challenge. Airway hyperresponsiveness ...