Roles of interleukin-5 receptors on eosinophilic differentiation

包括哮喘和特应性皮炎在内的慢性过敏性炎症很难治疗，患有此类疾病的患者数量正在增加，这可能反映了环境对生活方式的变化。嗜酸性粒细胞是在变态反应性疾病发病机制中起关键作用的细胞之一。在哮喘中，嗜酸性粒细胞在骨髓和外周血中数量增多，并在各种细胞因子和化学介质的作用下聚集在炎症部位。研究证实了嗜酸性粒细胞延长存活期、渗入炎症部位和释放颗粒蛋白的机制。然而，CD34^+细胞等干细胞分化为成熟嗜酸性粒细胞的机制尚不清楚。如果要了解白细胞，特别是髓系细胞的生成和成熟，阐明这一机制是重要的，并可能有助于开发治疗过敏性炎症的新型药物。抑制向嗜酸性粒细胞分化可能有助于控制变态反应性炎症作为一种预防措施。本研究鉴定了两个新的IL-5R受体，分别命名为变异体7和变异体8。

Chronic allergic inflammation including bronchial asthma and atopic dermatitis is difficult to treat and the number of patients suffering from such diseases is increasing, probably reflecting environmental changes to life style. Eosinophils are one of the cells that play a critical role in the pathogenesis of allergic diseases. In bronchial asthma, eosinophils increase in number in bone marrow and peripheral blood, and accumulate at inflammatory sites in response to various kinds of cytokines and chemical mediators. Studies have demonstrated the mechanism by which eosinophils prolong their survival, infiltrate inflammatory sites and release granule proteins. However, the mechanism behind the differentiation of stem cells such as CD34^+ cells into mature eosinophils has not been clarified. Clarification of this mechanism is important if one is to understand the generation and maturation of white blood cells, especially myeloid lineages, and may contribute to the development of novel medications for allergic inflammation. Inhibition of the differentiation toward the eosinophil lineage might be useful for the control of allergic inflammation as a preventive measure. In this study, two novel receptors for IL-5R are identified, and named as variant 7 and variant 8.