ABSTRACT
We sought to examine the regulatory effect of Meteorin-ß (Metrnß)/Meteorin like (Metrnl)/IL-41 on lung inflammation in allergic asthma. We found that Metrnß was elevated significantly in asthmatic patients and in mice with allergic asthma induced by house dust mite (HDM) extract. Upon exposure to HDM, Metrnß was secreted predominantly by airway epithelial cells and inflammatory cells, including macrophages and eosinophils. The increased Metrnß effectively blocked the development of airway hyperreactivity (AHR) and decreased inflammatory cell airway infiltration and type 2 cytokine production, which was associated with downregulated DC-mediated adaptive immune responses. Moreover, Metrnß impaired the maturation and function of bone marrow-derived dendritic cells in vitro. Asthmatic mice adoptively transferred with dendritic cells isolated from Metrnß-treated allergic mice displayed decreased AHR, airway inflammation, and lung injury. Metrnß also displayed anti-inflammatory properties in immunodeficient SCID mice with allergic asthma and in in vitro 3D ALI airway models. Moreover, blockade of Metrnß by anti-Metrnß antibody treatment promoted the development of allergic asthma. These results revealed the unappreciated protective roles of Metrnß in alleviating DC-mediated Th2 inflammation in allergic asthma, providing the novel treatment strategy of therapeutic targeting of Metrnß in allergic asthma.