Boniface S, Magnan A
Service de Pneumo-Allergologie, UPRES EA 3287, Groupe de Recherche Clinique Pathologie respiratoire liée à l'environnement, Hôpital Sainte-Marguerite, 270, boulevard de Sainte-Marguerite, BP 29, 13274 Marseille Cedex 9.
Rev Pneumol Clin. 2003 Apr;59(2 Pt 1):77-83.
The IgE-dependent reaction is a specific type of inflammatory reaction occurring in allergic persons responding to an allergen. When the allergen penetrates the airways, it is captured by the antigen presenting cells and presented to CD4+ T cells. The most important conditions of antigenic presentation are the presence of IL-4 and not IL-12 at the presentation site and the implication of certain coreceptors determining T-cell differentiation to Th2 cells, which produce IL-4, IL-3, and IL-5. Il-4 and IL-3 induce IgE production by plasmocytes and IL-5 activates eosinophils. The specific IgEs of the allergens then bid to their high-affinity receptor on the surface of mast cells (sensitivization phase). If the allergens are still present or if there is an new exposure, coaggregation of high-affinity receptors via specific IgEs induces mast cell degranulation and release of vaso- and broncho-active mediators which lead to the acute signs of rhinitis or asthma (early phase of the immediate reaction). At the same time, activated eosinophils, attracted by IL-5 as well as chemokines, infiltrate the mucosa, producing basic proteins toxic for the epithelium. These cells are responsible for the late phase of the immediate allergic reaction, and during repeated or continuous exposure, are the cause of the chronic allergic disease.
IgE 依赖性反应是过敏体质者对过敏原产生的一种特异性炎症反应。当过敏原侵入气道时，被抗原呈递细胞捕获并呈递给 CD4+ T 细胞。抗原呈递的最重要条件是在呈递部位存在白细胞介素 -4 而非白细胞介素 -12，以及某些共受体的作用决定 T 细胞分化为产生白细胞介素 -4、白细胞介素 -3 和白细胞介素 -5 的 Th2 细胞。白细胞介素 -4 和白细胞介素 -3 诱导浆细胞产生 IgE，白细胞介素 -5 激活嗜酸性粒细胞。然后，过敏原的特异性 IgE 与肥大细胞表面的高亲和力受体结合（致敏阶段）。如果过敏原仍然存在或再次接触，通过特异性 IgE 导致高亲和力受体共聚集，诱导肥大细胞脱颗粒并释放血管活性和支气管活性介质，从而引发鼻炎或哮喘的急性症状（速发反应的早期阶段）。同时，被白细胞介素 -5 以及趋化因子吸引的活化嗜酸性粒细胞浸润黏膜，产生对上皮细胞有毒性的碱性蛋白。这些细胞负责速发型过敏反应的晚期阶段，在反复或持续接触过程中，是慢性过敏性疾病的病因。
