Surface expression of functional IgE binding protein, an endogenous lectin, on mast cells and macrophages.
Surface expression of functional IgE binding protein, an endogenous lectin, on mast cells and macrophages.
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DOI：
10.4049/jimmunol.148.3.861
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发表时间：
1992-02
影响因子：
4.4
通讯作者：
L. Frigeri;Fuan Liu
中科院分区：
文献类型：
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作者：
L. Frigeri;Fuan Liu
IgE结合蛋白（IgE binding protein，IgE BP）是一种半乳糖苷特异性凝集素，含有一个S型糖识别结构域。它最初在大鼠嗜碱性白血病细胞中鉴定，现在已知与巨噬细胞表面Ag、Mac-2和命名为CBP 35/L-34/RL-29的凝集素相同。它也与从小鼠巨噬细胞分离的非整合素层粘连蛋白结合蛋白有关。在这份报告中，我们已经表明：在几种肥大细胞系中，BMPs以可变的量存在，并且BMPs在这些细胞系中的表面表达是相当可变的，并且与细胞中BMPs的总量无关。BBP以乳糖可逆的方式展示在细胞表面，最有可能是通过附着到尚未鉴定的糖缀合物上。细胞表面上的推定的CIPBP结合位点可以通过使用放射性标记的CIPBP容易地证明，并且这些位点在各种细胞系中以相当的量存在。细胞表面上的CD 3BP的表达可以被调节;最显著的例子是通过IgE免疫复合物通过高亲和力IgE受体激活的RBL细胞上的表面CD 3BP的上调。细胞表面BMPs是功能性的，如通过其促进胰蛋白酶化的兔红细胞与肥大细胞和巨噬细胞粘附的能力所测量的。基于这些结果和相关凝集素的报道性质，我们提出，以BMPBP为代表的凝集素是一类新的细胞粘附蛋白。
IgE-binding protein (epsilon BP) is a galactoside-specific lectin containing an S-type carbohydrate-recognition domain. It was originally identified in rat basophilic leukemia cells and is now known to be identical to a macrophage surface Ag, Mac-2, and lectins designated as CBP 35/L-34/RL-29. It has also been related to a nonintegrin laminin-binding protein isolated from mouse macrophages. In this report we have shown the following: epsilon BP is present in variable amounts in several mast cell lines, and the surface expression of epsilon BP in these cell lines is quite variable and does not correlate with the total amount of epsilon BP in the cell. epsilon BP is displayed on the cell surface in a manner that is reversible by lactose, most likely through attachment to yet unidentified glycoconjugates. The putative epsilon BP binding sites on the cell surface can be readily demonstrated by using radiolabeled epsilon BP, and the sites are present in comparable amounts in various cell lines. Expression of epsilon BP on the cell surface can be regulated; the most notable example is the upregulation of surface epsilon BP on RBL cells activated through the high-affinity IgE receptor by IgE immune complexes. Cell-surface epsilon BP is functional as measured by its ability to promote adhesion of trypsinized rabbit erythrocytes to mast cells and macrophages. On the basis of these results and reported properties of related lectins, we propose that the lectin represented by epsilon BP is a new class of cell-adhesion protein.