Robinson D S, Damia R, Zeibecoglou K, Molet S, North J, Yamada T, Kay A B, Hamid Q
Allergy and Clinical Immunology, Imperial College School of Medicine, National Heart and Lung Institute, London, United Kingdom.
Am J Respir Cell Mol Biol. 1999 Jan;20(1):9-13. doi: 10.1165/ajrcmb.20.1.3449.
Eosinophil differentiation is thought to occur by the action of interleukin (IL)-5 on CD34(+) progenitor cells. The allergen-induced increase in eosinophil numbers in isolated airway preparations in vitro, and detection of increased numbers of circulating CD34(+) cells in atopic subjects, led us to the hypothesis that the eosinophil infiltration of the airway in asthma may result from local mucosal differentiation, in addition to recruitment from the bone marrow. We examined CD34(+) cell numbers by immunohistochemistry and IL-5 receptor alpha (IL-5Ralpha) messenger RNA (mRNA) expression by in situ hybridization in bronchial biopsies from atopic asthmatic patients, and from atopic and nonatopic control subjects. CD34(+) cell numbers were increased in the airway in atopic asthmatic and atopic nonasthmatic subjects. In contrast, CD34(+)/ IL-5Ralpha mRNA+ cells were increased in asthmatic subjects when compared with both atopic and nonatopic control subjects. Airway numbers of CD34(+)/IL-5Ralpha mRNA+ cells were correlated to airway caliber in asthmatic subjects and to eosinophil numbers. These findings support the concept that eosinophils may differentiate locally in the airway in asthma.
嗜酸性粒细胞的分化被认为是由白细胞介素（IL）-5作用于CD34(+)祖细胞而发生的。体外分离气道制剂中变应原诱导的嗜酸性粒细胞数量增加，以及特应性受试者循环CD34(+)细胞数量增加，使我们提出这样的假设：哮喘患者气道中的嗜酸性粒细胞浸润除了源于骨髓募集外，还可能是局部黏膜分化的结果。我们通过免疫组织化学检查特应性哮喘患者、特应性和非特应性对照受试者支气管活检组织中的CD34(+)细胞数量，并通过原位杂交检测白细胞介素-5受体α（IL-5Rα）信使核糖核酸（mRNA）的表达。特应性哮喘患者和特应性非哮喘患者气道中的CD34(+)细胞数量增加。相比之下，与特应性和非特应性对照受试者相比，哮喘患者中CD34(+)/IL-5Rα mRNA+细胞增加。哮喘患者气道中CD34(+)/IL-5Rα mRNA+细胞数量与气道管径及嗜酸性粒细胞数量相关。这些发现支持了嗜酸性粒细胞可能在哮喘气道中局部分化的观点。
