Potentiating and suppressive IgE-binding factors are expressed by a single cloned gene.
Potentiating and suppressive IgE-binding factors are expressed by a single cloned gene.
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增强和抑制性 IgE 结合因子由单个克隆基因表达。
DOI：
10.1073/pnas.84.3.809
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发表时间：
1987
影响因子：
11.1
通讯作者：
Moore,KW
中科院分区：
文献类型：
--
作者：
Martens,CL;Jardieu,P;Trounstine,ML;Stuart,SG;Ishizaka,K;Moore,KW
我们研究了IgE结合因子（IgE-BF）cDNA在COS-7猴肾细胞和中国仓鼠卵巢细胞中的表达。瞬时表达的IgE-BF克隆在任一种细胞类型产生的IgE-BF，这增强了体外IgE反应，并有一个小扁豆凝集素的亲和力。相比之下，当在衣霉素存在下进行瞬时表达实验时，这些因子不再与扁豆凝集素结合。此外，在这些条件下表达的IgE-BF抑制体外IgE反应。IgE-BF缺乏对小扁豆凝集素的亲和力并抑制IgE反应也是由于IgE-BF基因在糖基化抑制因子（磷脂酶抑制蛋白）存在下的瞬时表达。因此，增强或抑制IgE反应的IgE-BF可以从单个克隆基因表达;生物活性的差异似乎主要由共同多肽链的糖基化类型决定。先前的工作表明，IgE-BF带有抗Ia单克隆抗体OX 3识别的抗原决定簇。衣霉素的存在下产生的IgE-BF，和IgE-BF表达的突变体cDNA缺乏两个碳水化合物附着位点之一，缺乏OX 3决定簇。因此，IgE-BF上的OX 3决定簇似乎与N-连接糖基化位点相关。
We have investigated expression of an IgE-binding factor (IgE-BF) cDNA in both COS-7 monkey kidney cells and Chinese hamster ovary cells. Transient expression of the IgE-BF clone in either cell type yielded IgE-BF, which potentiated an in vitro IgE response and had an affinity for lentil lectin. In contrast, when the transient expression experiments were carried out in the presence of tunicamycin, the factors no longer bound to lentil lectin. Moreover, IgE-BF expressed under these conditions suppressed an in vitro IgE response. IgE-BF lacking affinity for lentil lectin and suppressing the IgE response also resulted from transient expression of the IgE-BF gene in the presence of glycosylation inhibiting factor, a phospholipase inhibitory protein. Thus, IgE-BF that either potentiate or suppress the IgE response can be expressed from a single cloned gene; the difference in biological activities appears to be determined principally by the type of glycosylation of the common polypeptide chain. Previous work showed that IgE-BF bears an antigenic determinant recognized by the anti-Ia monoclonal antibody OX3. IgE-BF produced in the presence of tunicamycin, and IgE-BF expressed from a mutant cDNA lacking one of two carbohydrate-attachment sites, lacked the OX3 determinant. Thus, the OX3 determinant on IgE-BF appears to be associated with a site of N-linked glycosylation.