IL-4–producing basophils promote the trapping of N. brasiliensis in the skin during secondary infection, a process critical for limiting the spread of infection to the lungs.

Developmental processes of hematopoietic cells are orchestrated by transcriptional networks. GATA-1, the founding member of the GATA family of transcription factors, has been demonstrated to play crucial roles in the differentiation of erythroid cells, magakaryocytes, eosinophils, and mast cells. However, the role of GATA-1 in basophils remains elusive. Here we show that basophils abundantly express Gata1 mRNAs, and that siRNA-mediated knockdown of Gata1 resulted in impaired production of IL-4 by basophils in response to the stimulation with IgE plus antigens. ΔdblGATA mice that carry the mutated Gata1 promoter and are widely used for functional analysis of eosinophils owing to their selective loss of eosinophils showed a decreased number of basophils with reduced expression of Gata1 mRNAs. The number of basophil progenitors in bone marrow was reduced in these mice, and the generation of basophils from their bone marrow cells in culture with IL-3 or thymic stromal lymphopoietin was impaired. ΔdblGATA basophils responded poorly ex vivo to stimulation with IgE plus antigens compared with wild-type basophils as assessed by degranulation and production of IL-4 and IL-6. Moreover, ΔdblGATA mice showed impaired responses in basophil-mediated protective immunity against intestinal helminth infection. Thus, ΔdblGATA mice showed numerical and functional aberrancy in basophils in addition to the known deficiency of eosinophils. Our findings demonstrate that GATA-1 plays a key role in the generation and function of basophils and underscore the need for careful distinction of the cell lineage responsible for each phenotype observed in ΔdblGATA mice.

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Background: Idiopathic pulmonary fibrosis (IPF) is the most common form of idiopathic interstitial pneumonias (IIPs) of unknown etiology that often affects male, elderly smokers. However, it is sometimes observed in never smokers. This study aimed to clarify the clinical characteristics of IPF in never-smoking patients compared with those in smoking patients. Methods:We retrospectively reviewed medical records, pulmonary function tests, and chest highresolution computed tomography (HRCT) scan of never-smoking and smoking IPF patients from July 1, 2008 to June 30, 2013 at our hospital.Results: We identified 32 never-smoking IPF patients and 66 smoking IPF patients. Never-smoking IPF patients developed more acute exacerbation (AE) than smoking IPF patients (50% vs. 18.2%, P<0.0001). Conclusions:In conclusion, never-smoking IPF patients developed AE more often and showed poor prognosis compared with smoking IPF patients. The 1-year mMRC breathlessness scale was an important predictor of mortality at our hospital.