Possible role of human lymphocyte receptor for IgE (CD23) or its soluble fragments in the in vitro synthesis of human IgE.
Possible role of human lymphocyte receptor for IgE (CD23) or its soluble fragments in the in vitro synthesis of human IgE.
复制标题
人淋巴细胞 IgE 受体 (CD23) 或其可溶性片段在人 IgE 体外合成中的可能作用。
作者：
M. Sarfati;G. Delespesse
本研究表明，人il -4能够诱导PBMC分泌IgE。在200 U/ml浓度下，正常供体PBMC的11/26培养物和过敏个体的12/15培养物中观察到IgE反应。同样的il -4刺激细胞在其培养上清中释放大量的ige结合因子（IgE-BF）。这些IgE- bf首次被证明能同时结合一些抗Fc epsilon R II的单抗（mAbER）和可溶性IgE。il -4诱导的IgE- bf分泌与IgE之间缺乏相关性表明，IgE- bf的产生或Fc epsilon R II的表达并不是il -4诱导IgE合成的唯一因素。然而，观察到mAbER抑制ril -4诱导的IgE合成强烈表明，Fc epsilon R II或IgE- bf对于IgE应答是必要的。最后，从特应性供体中分离的富集B细胞制备的自发体外合成IgE以同型特异性的方式被相同的mAbER或其F（ab’）2片段抑制。这些观察结果表明，体内预激活的B细胞正在进行的IgE合成也受到IgE- bf或Fc epsilon R II的调节。综上所述，Fc epsilon R II或IgE- bf在诱导正常B细胞合成IgE和体内激活的过敏供体B细胞持续合成IgE中发挥重要作用。
The present study demonstrates that human rIL-4 is capable of inducing the secretion of IgE by PBMC. At a concentration of 200 U/ml, an IgE response was observed in 11/26 cultures of PBMC from normal donors and in 12/15 cultures from allergic individuals. The same rIL-4-stimulated cells released significant amounts of IgE-binding factors (IgE-BF) in their culture supernatant. These IgE-BF were shown for the first time to bind simultaneously to some mAb against Fc epsilon R II (mAbER) and to soluble IgE. The lack of correlation between the rIL-4-induced secretion of IgE-BF and IgE indicates that the production of IgE-BF or the expression of Fc epsilon R II is not the only factor involved in the induction of IgE synthesis by rIL-4. However, the observation that mAbER suppressed the rIL-4-induced IgE synthesis strongly suggests that either Fc epsilon R II or IgE-BF are necessary for an IgE response. Finally, the spontaneous in vitro synthesis of IgE by enriched B cell preparations isolated from atopic donors was suppressed in an isotype-specific manner by the same mAbER or by their F(ab')2 fragments. These observations suggest that the ongoing IgE synthesis by in vivo pre-activated B cells is also regulated by IgE-BF or Fc epsilon R II. It is concluded that Fc epsilon R II or IgE-BF play an essential role both in the induction of IgE synthesis by normal B cells and in the ongoing IgE synthesis by in vivo activated B cells from allergic donors.