Taudou G, Varin-Blank N, Jouin H, Marchand F, Weyer A, Blank U
Unité d'Immuno-Allergie, Institut Pasteur, Paris, France.
Int Arch Allergy Immunol. 1993;100(4):344-50. doi: 10.1159/000236436.
The actual dilemma in studying the binding and triggering capacity of IgE from allergic patients is the lack of cultured basophils or mast cell analogs of human origin. Human IgE binds with exquisite species specificity to the high affinity IgE receptor (Fc epsilon RI) expressed on the surface of these cells. In rodents this receptor has been characterized as a tetrameric plasma membrane protein composed of an IgE-binding alpha chain, a beta chain and two disulfide-linked gamma chains. In order to establish a cell line expressing the alpha chain of human Fc epsilon RI which can be triggered with IgE from human patients and specific allergen, we transfected the cDNA coding for the human alpha subunit into rat basophilic leukemia cells. The resulting transfectants express the human alpha chain on the cell surface in the form of a hybrid complex associated with endogenous rat gamma chains. After sensitization with human IgE from mite-specific patients, the transfectant produces a calcium response upon incubation with allergen. The established cell line can be used as a model system to study the mechanism of mast cell triggering through IgE from allergic patients.
研究过敏患者IgE的结合和触发能力时实际面临的困境是缺乏源自人类的培养嗜碱性粒细胞或肥大细胞类似物。人类IgE以极高的物种特异性与这些细胞表面表达的高亲和力IgE受体（FcεRI）结合。在啮齿动物中，该受体被鉴定为一种四聚体细胞膜蛋白，由一条IgE结合α链、一条β链和两条通过二硫键连接的γ链组成。为了建立一种能够被人类患者的IgE和特异性变应原触发的、表达人类FcεRIα链的细胞系，我们将编码人类α亚基的cDNA转染到大鼠嗜碱性白血病细胞中。产生的转染子在细胞表面以与内源性大鼠γ链相关的混合复合物形式表达人类α链。在用来自螨特异性患者的人类IgE致敏后，转染子在与变应原孵育时会产生钙反应。所建立的细胞系可作为一个模型系统，用于研究通过过敏患者的IgE触发肥大细胞的机制。
