Receptor-mediated transcytosis of botulinum neurotoxin A through intestinal cell monolayers
Receptor-mediated transcytosis of botulinum neurotoxin A through intestinal cell monolayers
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DOI：
10.1111/j.1462-5822.2007.01051.x
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发表时间：
2008-02-01
影响因子：
3.4
通讯作者：
Popoff, Michel R.
中科院分区：
文献类型：
--
作者：
Couesnon, Aurelie;Pereira, Yannick;Popoff, Michel R.
肉毒杆菌中毒主要通过口服途径获得，肉毒杆菌神经毒素（BoNT）通过在进入神经末梢之前穿过消化上皮屏障而逃离胃肠道。在这里，我们表明，生物活性BoNT/A通过受体介导的转胞吞作用穿过肠细胞单层，包括在4 ℃下的转运抑制和在37 ℃下在30-60分钟内以可饱和的方式通过。BoNT/A通过肠隐窝细胞系m-ICcl 2的通过率比通过癌Caco-2或T84细胞的效率高约10倍，而当BoNT/A与无毒蛋白（肉毒杆菌复合物）结合时，则不增加。与神经元细胞一样，BoNT/A与肠细胞的结合是由半个C-末端结构域介导的，如通过荧光激活的细胞计量术和胞吞转运竞争测定所测试的。提出了BoNT/A与GD（1b）和GT（1b）系列神经节苷脂以及SV 2蛋白相互作用的“双受体模型”。GD（1b）和GT（1b）系列的神经节苷脂和重组囊泡内SV 2-C结构域部分损害BoNT/A的转胞吞作用，表明神经节苷脂和SV 2或相关蛋白在BoNT/A通过Caco-2和m-ICcl 2细胞的转胞吞作用中的假定作用。
Botulism is mainly acquired by the oral route, and botulinum neurotoxin (BoNT) escapes the gastrointestinal tract by crossing the digestive epithelial barrier prior to gaining access to the nerve endings. Here, we show that biologically active BoNT/A crosses intestinal cell monolayers via a receptor-mediated transcytosis, including a transport inhibition at 4 degrees C and a passage at 37 degrees C in a saturable manner within 30-60 min. BoNT/A passage rate was about 10-fold more efficient through the intestinal crypt cell line m-ICcl2, than through the carcinoma Caco-2 or T84 cells, and was not increased when BoNT/A was associated with the non-toxic proteins (botulinum complex). Like for neuronal cells, BoNT/A binding to intestinal cells was mediated by the half C-terminal domain as tested by fluorescence-activated cytometry and by transcytosis competition assay. A 'double receptor model' has been proposed in which BoNT/A interacts with gangliosides of GD(1b) and GT(1b) series as well as SV2 protein. Gangliosides of GD(1b) and GT(1b) series and recombinant intravesicular SV2-C domain partially impaired BoNT/A transcytosis, suggesting a putative role of gangliosides and SV2 or a related protein in BoNT/A transcytosis through Caco-2 and m-ICcl2 cells.