通过Shigella效应物抑制宿主防御的GBPs的化和降解
Peng Li1,2, Wei Jiang2, Qin Yu2
1Peking University-Tsinghua University-National Institute of Biological Sciences Joint Graduate Program, National Institute of Biological Sciences, Beijing, 102206, China.
Nature
|November 17, 2017
概括
通过使用IpaH9.8效应器降解酸结合蛋白 (GBPs),Shigella flexneri细菌逃避免疫防御. 破坏这一过程使GBPs能够抑制细菌生长,揭示了宿主-病原体相互作用的关键机制.
科学领域:
- 免疫学
- 微生物学
- 细胞生物学
背景情况:
- 干扰素诱导的酸结合蛋白 (GBP) 对细胞自主抗菌免疫非常重要.
- 石格拉柔性菌使用III型分泌系统效应剂,包括入侵等离子体抗原Hs (IpaHs),它们是细菌无酸酶,其功能尚不清楚.
研究的目的:
- 调查Shigella flexneri通过酸盐结合蛋白来规避宿主防御的机制.
- 确定感染期间负责向和降解宿主GBP的特定细菌因素.
主要方法:
- 在S. flexneri中进行了转子子选,以确定对hGBP1降解有抵抗力的突变物.
- 使用生物化学测定来证明IpaH9.8的hGBP1与Lys48结合的泛化和蛋白质体降解.
- 评估了野生型和突变S. flexneri的小鼠模型中的细菌复制和宿主存活率,以及不同GBP缺陷的小鼠.
主要成果:
- 鉴定出S. flexneri效应物IpaH9.8负责人类酸结合蛋白-1 (hGBP1) 的快速蛋白体降解.
- 证明IpaH9.8针对细胞质中的多个GBP,促进S. flexneri的复制并导致宿主死亡.
- 表明IpaH9.8功能或GBP结合的破坏允许GBPs转移到细胞内细菌,抑制复制并改善宿主存活.
结论:
- 通过降解关键宿主防御蛋白质,S. flexneri效应器IpaH9.8积极破坏GBP介导的免疫力.
- 在控制细胞内细菌感染方面,GBP起着至关重要的作用,而细菌因子对它们的逃避对于病原体的生存和毒性至关重要.
- IpaH9.8-GBP相互作用为研究抗菌免疫中的GBP功能提供了一个新系统.
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