The rotavirus surface protein VP8 modulates the gate and fence function of tight junctions in epithelial cells
The rotavirus surface protein VP8 modulates the gate and fence function of tight junctions in epithelial cells
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DOI：
10.1242/jcs.01425
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发表时间：
2004-11-01
影响因子：
4
通讯作者：
González-Mariscal, L
中科院分区：
文献类型：
--
作者：
Nava, P;López, S;González-Mariscal, L
轮状病毒是幼年哺乳动物腹泻的主要原因。轮状病毒利用不同的整联蛋白;作为细胞受体，因此在它们到达肠腔时，它们的整联蛋白受体将隐藏在基底外侧膜上的紧密连接（TJ）下方。在这里，我们研究了轮状病毒外壳蛋白是否能够打开由TJ密封的细胞旁空间。从轮状病毒蛋白质的最外层，投射出60个由蛋白质VP 4形成的刺突。VP 4对于病毒-细胞相互作用是必需的，并且被胰蛋白酶切割成肽VP 5和VP 8。在此，我们发现，当这些肽被添加到汇合的上皮单层（Madin-Darby犬肾细胞）中时，VP 8能够以剂量依赖性和可逆的方式减小跨上皮电阻。VP 5不起作用。VP 8还可以在Ca开关测定中抑制新形成的TJ的发展。用VP 8处理增强了非离子示踪剂的细胞旁通道，允许荧光脂质探针和顶端表面蛋白GP 135从腔膜扩散到侧膜，并触发基底外侧蛋白Na+K+-ATP酶、α（v）β（3）整联蛋白和β（1）整联蛋白亚基向顶端表面的移动。VP 8产生的冷冻断裂模式，其特征在于松散的端丝的外观，这与几个TJ蛋白的分布改变。口服给予糖尿病大鼠的VP 8允许肠内给予胰岛素，从而表明其可用于调节上皮通透性。
Rotaviruses constitute a major cause of diarrhea in young mammals. Rotaviruses utilize different integrins; as cell receptors, therefore upon their arrival to the intestinal lumen their integrin receptors will be hidden below the tight junction (TJ), on the basolateral membrane. Here we have studied whether the rotavirus outer capsid proteins are capable of opening the paracellular space sealed by the TJ. From the outermost layer of proteins of the rotavirus, 60 spikes formed of protein VP4 are projected. VP4 is essential for virus-cell interactions and is cleaved by trypsin into peptides VP5 and VP8. Here we found that when these peptides are added to confluent epithelial monolayers (Madin-Darby canine kidney cells), VP8 is capable of diminishing in a dose dependent and reversible manner the transepithelial electrical resistance. VP5 exerted no effect. VP8 can also inhibit the development of newly formed TJs in a Ca-switch assay. Treatment with VP8 augments the paracellular passage of non-ionic tracers, allows the diffusion of a fluorescent lipid probe and the apical surface protein GP135, from the luminal to the lateral membrane, and triggers the movement of the basolateral proteins Na+K+-ATPase, alpha(v)beta(3) integrin and beta(1) integrin subunit, to the apical surface. VP8 generates a freeze-fracture pattern of Us characterized by the appearance of loose end filaments, that correlates with an altered distribution of several TJ proteins. VP8 given orally to diabetic rats allows the enteral administration of insulin, thus indicating that it can be employed to modulate epithelial permeability.