Patients with DOCK8 deficiency are at increased susceptibility to develop allergic diseases such as food allergy and asthma. Here, we aimed to analyze the pathogenesis of asthma in DOCK8-deficient patients. In our mouse model, DOCKS-knockout (KO) mice sensitized with low-dose OVA were challenged with 1.5% OVA to induce allergic asthma. As compared to that in WT mice, remarkable airway hyper-responsiveness was observed in KO mice. Increased inflammatory cells and eosinophils infiltrated in airway lumen in KO mice especially around bronchi. KO mice showed higher levels of serum IgE and OVA-specific IgE and significantly elevated IgE-producing B cells in blood and in spleen. Surprisingly, nasal administration with rmlL-21 significantly reduced the airway hyperresponsiveness, inflammatory infiltration, as well as the serum IgE and IgE-producing B cells. DOCKS-knockout mice are susceptible to low-dose OVA induced allergic airway inflammation and airway hyperresponsiveness. Supplementary nasal administration of rmlL-21 alleviates allergic asthma in this mouse model. (C) 2018 Elsevier Inc. All rights reserved.