Rajakulasingam K, Till S, Ying S, Humbert M, Barkans J, Sullivan M, Meng Q, Corrigan C J, Bungre J, Grant J A, Kay A B, Durham S R
Upper Respiratory Medicine and Allergy and Clinical Immunology, Imperial College School of Medicine at the National Heart and Lung Institute, Dovehouse Street, London, United Kingdom.
Am J Respir Crit Care Med. 1998 Jul;158(1):233-40. doi: 10.1164/ajrccm.158.1.9708106.
FcepsilonRI receptors play an important role in allergen-induced mediator release and antigen presentation by mast cells, basophils, and monocyte/macrophages in atopic disorders. The expression of FcepsilonRI by tissue eosinophils in atopic asthma after allergen challenge has not been established. For this reason we attempted to identify mRNA and protein product + FcepsilonRIalpha eosinophils in cytospins made from bronchoalveolar lavage (BAL) from atopic asthmatics (n = 9) and nonatopic normal subjects (n = 4) 24 h after segmental challenge with allergen or diluent. Messenger RNA for FcepsilonRIalpha was determined using in situ hybridization and FcepsilonRIalpha protein expression by immunocytochemistry using a mouse monoclonal antibody 22E7. Colocalization of FcepsilonRIalpha receptors to eosinophils was performed using chromotrope 2R. When compared with a control challenge, segmental challenge with Dermatophagoides pteronyssinus induced significant BAL eosinophilia (p = 0.007). The total number of BAL FcepsilonRIalpha mRNA and protein-positive cells also increased in asthmatics, median values 2 (0.7-7.2) and 11.5 (0.6-65.0) x 10(6) cells (p = 0.02) and 0 (0-0.3 x 10(6)) and 3.1 x 10(6) (0.45 - 162.5 x 10(6)) cells (p = 0.007), respectively, for mRNA and protein. Net increases in FcepsilonRIalpha+ cells correlated with the net increases in BAL eosinophils (r = 0.98, p = 0.0001 for mRNA and r = 0.72, p = 0.02 for protein). Colocalization studies with chromotrope 2R revealed that only 4% of FcepsilonRIalpha+ cells were eosinophils after control challenge and, in contrast, 85 to 95% of FcepsilonRIalpha+ cells were eosinophils after allergen. There were no differences in the numbers of FcepsilonRIalpha+ cells or eosinophils in normal control subjects. Our results demonstrated that local endobronchial allergen provocation in atopic asthmatics results in increased synthesis and expression of FcepsilonRIalpha predominantly on BAL eosinophils.
在特应性疾病中，FcepsilonRI受体在变应原诱导的介质释放以及肥大细胞、嗜碱性粒细胞和单核细胞/巨噬细胞的抗原呈递过程中发挥重要作用。变应原激发后，特应性哮喘患者组织嗜酸性粒细胞中FcepsilonRI的表达尚未明确。因此，我们试图在24名特应性哮喘患者（n = 9）和非特应性正常受试者（n = 4）经变应原或稀释剂进行节段性激发后24小时，从支气管肺泡灌洗（BAL）制备的细胞涂片上鉴定FcepsilonRIα嗜酸性粒细胞的mRNA和蛋白质产物。使用原位杂交法测定FcepsilonRIα的信使RNA，并使用小鼠单克隆抗体22E7通过免疫细胞化学法检测FcepsilonRIα蛋白表达。使用铬变素2R对FcepsilonRIα受体与嗜酸性粒细胞进行共定位研究。与对照激发相比，用屋尘螨进行节段性激发可诱导显著的BAL嗜酸性粒细胞增多（p = 0.007）。哮喘患者BAL中FcepsilonRIα mRNA和蛋白阳性细胞总数也增加，mRNA的中位数为2（0.7 - 7.2）和11.5（0.6 - 65.0）×10⁶细胞（p = 0.02），蛋白的中位数为0（0 - 0.3×10⁶）和3.1×10⁶（0.45 - 162.5×10⁶）细胞（p = 0.007）。FcepsilonRIα⁺细胞的净增加与BAL嗜酸性粒细胞的净增加相关（mRNA的r = 0.98，p = 0.0001；蛋白的r = 0.72，p = 0.02）。用铬变素2R进行的共定位研究显示，对照激发后只有4%的FcepsilonRIα⁺细胞是嗜酸性粒细胞，相反，变应原激发后85%至95%的FcepsilonRIα⁺细胞是嗜酸性粒细胞。正常对照受试者中FcepsilonRIα⁺细胞或嗜酸性粒细胞数量无差异。我们的结果表明，特应性哮喘患者局部支气管内变应原激发导致FcepsilonRIα主要在BAL嗜酸性粒细胞上的合成和表达增加。
