Cholesterol Depletion Reduces Entry of Campylobacter jejuni Cytolethal Distending Toxin and Attenuates Intoxication of Host Cells
Cholesterol Depletion Reduces Entry of Campylobacter jejuni Cytolethal Distending Toxin and Attenuates Intoxication of Host Cells
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DOI：
10.1128/iai.05175-11
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发表时间：
2011-09-01
影响因子：
3.1
通讯作者：
Lai, Chih-Ho
中科院分区：
文献类型：
--
作者：
Lin, Chia-Der;Lai, Cheng-Kuo;Lai, Chih-Ho
空肠弯曲菌是全球小儿腹泻的常见原因。细胞致死膨胀毒素是由空肠弯曲菌产生的一种毒力因子，可诱导真核细胞周期阻滞和凋亡。细胞胆固醇是脂筏的主要组成部分，在调节信号转导、蛋白运输以及病原体内化过程中起着关键作用。在这项研究中，我们证明了空肠弯曲菌致死膨胀毒素的细胞中毒是通过细胞致死膨胀毒素亚单位和膜富含胆固醇的微区的协会。细胞致死膨胀毒素亚单位cofractionated与洗涤剂抗性膜，而分布减少后，胆固醇耗尽，表明细胞致死膨胀毒素亚单位与脂筏。使用甲基-β-环糊精破坏胆固醇不仅降低了细胞膜上致死性膨胀毒素亚基的结合活性，而且还损害了它们的递送并减弱了毒素诱导的细胞周期停滞。因此，细胞致死性膨胀毒素的细胞中毒通过胆固醇补充而恢复。这些结果表明，膜胆固醇在空肠弯曲菌致死细胞膨胀毒素诱导的宿主细胞发病机制中起着关键作用。
Campylobacter jejuni is a common cause of pediatric diarrhea worldwide. Cytolethal distending toxin, produced by Campylobacter jejuni, is a putative virulence factor that induces cell cycle arrest and apoptosis in eukaryotic cells. Cellular cholesterol, a major component of lipid rafts, has a pivotal role in regulating signaling transduction and protein trafficking as well as pathogen internalization. In this study, we demonstrated that cell intoxication by Campylobacter jejuni cytolethal distending toxin is through the association of cytolethal distending toxin subunits and membrane cholesterol-rich microdomains. Cytolethal distending toxin subunits cofractionated with detergent-resistant membranes, while the distribution reduced upon the depletion of cholesterol, suggesting that cytolethal distending toxin subunits are associated with lipid rafts. The disruption of cholesterol using methyl-beta-cyclodextrin not only reduced the binding activity of cytolethal distending toxin subunits on the cell membrane but also impaired their delivery and attenuated toxin-induced cell cycle arrest. Accordingly, cell intoxication by cytolethal distending toxin was restored by cholesterol replenishment. These findings suggest that membrane cholesterol plays a critical role in the Campylobacter jejuni cytolethal distending toxin-induced pathogenesis of host cells.