POSSIBLE INTERACTIONS BETWEEN THE FC-EPSILON RECEPTOR AND A NOVEL MAST-CELL FUNCTION-ASSOCIATED ANTIGEN
POSSIBLE INTERACTIONS BETWEEN THE FC-EPSILON RECEPTOR AND A NOVEL MAST-CELL FUNCTION-ASSOCIATED ANTIGEN
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DOI：
10.1093/intimm/3.4.333
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发表时间：
1991-04-01
影响因子：
4.4
通讯作者：
PECHT, I
中科院分区：
文献类型：
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作者：
ORTEGA, E;SCHNEIDER, H;PECHT, I
我们最近描述了一种识别肥大细胞一种新的膜成分的单抗G63。该抗原是一种表观分子质量为28-40kd的糖蛋白，存在于大鼠粘膜和浆膜肥大细胞的表面。在黏膜肥大细胞系RBL-2H3的细胞上其密度为1-2×10(4)拷贝/细胞。该膜蛋白被完整的单抗G63交联后，可显著抑制Fc-epsilon-RI介导的RBL-2H3细胞的分泌。在这里，我们表明，这种新的膜成分的交联会抑制由Fc-epsilon-RI聚集启动的生化过程，如磷脂酰肌醇的水解，钙离子的内流，以及从头形成的炎症介质的合成和释放。此外，在荧光显微镜下，我们发现Fc-epsilon-RI-IgE复合物被多价抗原交联导致G63识别的膜成分的重新分布，导致其与聚集的Fc-epsilon-RI共存。这种定位被NaN3抑制，但不被秋水仙素或细胞松弛素D所抑制。Fc-epsilon-RI交联物也促进了这种新的膜成分的内化。综上所述，这些数据提示，mAbG63识别的肥大细胞膜成分参与了Fc-epsilon-RI介导的肥大细胞刺激，因此可以认为是肥大细胞功能相关抗原(MAFA)。
We have recently described a monoclonal antibody, mAb G63, which identifies a novel membrane component of mast cells. This antigen is a glycoprotein with an apparent molecular mass of 28 - 40 kd, and is present on the surface of rat mucosal and serosal mast cells. Its density on cells of the mucosal mast cell line RBL-2H3 is 1 - 2 x 10(4) copies per cell. Crosslinking of this membrane protein by the intact mAb G63 results in a pronounced inhibition of the Fc-epsilon-RI-mediated secretion of RBL-2H3 cells. Here we show that crosslinking this novel membrane component inhibits biochemical processes initiated by Fc-epsilon-RI aggregation, such as the hydrolysis of phosphatidylinositides, the influx of Ca2+ ions, and the synthesis and release of de novo formed inflammatory mediators. Furthermore, by fluorescence microscopy, we show that crosslinking of Fc-epsilon-RI-IgE complexes by multivalent antigen results in redistribution of the membrane component recognized by G63, leading to its co-localization with the aggregated Fc-epsilon-RI. This localization is inhibited by NaN3, but not by colchicine or cytochalasin D. Fc-epsilon-RI crosslinking also promotes internalization of this novel membrane component. Taken together these data suggest that the mast cell membrane component recognized by mAb G63 is involved in the Fc-epsilon-RI-mediated stimulation of these cells, and thus can be considered a mast cell function-associated antigen (MAFA).