Pharmacological Cyclophilin Inhibitors Prevent Intoxication of Mammalian Cells with Bordetella pertussis Toxin
Pharmacological Cyclophilin Inhibitors Prevent Intoxication of Mammalian Cells with Bordetella pertussis Toxin
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DOI：
10.3390/toxins10050181
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发表时间：
2018-05-01
期刊：
影响因子：
4.2
通讯作者：
Barth, Holger
中科院分区：
文献类型：
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作者：
Ernst, Katharina;Eberhardt, Nina;Barth, Holger
百日咳杆菌毒素（PT）是导致严重儿童疾病百日咳的一个重要毒力因子，2013年，百日咳仍导致全球约63，000名儿童死亡。PT由PTS 1、酶活性（A）亚基和非共价连接的五聚体结合/转运（B）亚基组成。内吞作用后，PT逆行进入内质网（ER），在内质网中，PTS 1被释放到胞质溶胶中。在胞质溶胶中，PTS 1 ADP-核糖基化三聚体GTP结合蛋白（Gi）的抑制性α亚基，导致cAMP水平增加和信号传导紊乱。在这里，我们表明，亲环素（Cyp）亚型CypA和Cyp 40直接相互作用与PTS 1在体外和Cyp抑制剂环孢素A（CsA）和其定制的非免疫抑制衍生物VK 112都抑制中毒的CHO-K1细胞与PT，在基于形态学的分析。此外，在CsA存在下用PT处理的细胞中，与仅用PT处理的细胞相比，ADP-核糖基化Gi的量显著减少，并且在胞质溶胶中检测到较少的PTS 1。结果表明，PTS 1进入胞质溶胶的摄取需要Cyps。因此，CsA/VK 112代表了在毒素水平上起作用的新治疗策略的有希望的候选物，以预防由PT引起的严重的、危及生命的症状。
The Bordetella pertussis toxin (PT) is one important virulence factor causing the severe childhood disease whooping cough which still accounted for approximately 63,000 deaths worldwide in children in 2013. PT consists of PTS1, the enzymatically active (A) subunit and a non-covalently linked pentameric binding/transport (B) subunit. After endocytosis, PT takes a retrograde route to the endoplasmic reticulum (ER), where PTS1 is released into the cytosol. In the cytosol, PTS1 ADP-ribosylates inhibitory alpha subunits of trimeric GTP-binding proteins (Gi) leading to increased cAMP levels and disturbed signalling. Here, we show that the cyclophilin (Cyp) isoforms CypA and Cyp40 directly interact with PTS1 in vitro and that Cyp inhibitors cyclosporine A (CsA) and its tailored non-immunosuppressive derivative VK112 both inhibit intoxication of CHO-K1 cells with PT, as analysed in a morphology-based assay. Moreover, in cells treated with PT in the presence of CsA, the amount of ADP-ribosylated Gi was significantly reduced and less PTS1 was detected in the cytosol compared to cells treated with PT only. The results suggest that the uptake of PTS1 into the cytosol requires Cyps. Therefore, CsA/VK112 represent promising candidates for novel therapeutic strategies acting on the toxin level to prevent the severe, life-threatening symptoms caused by PT.