保存された細菌の毒性因子の一族は,カルシウムシグナル伝達を阻害することによって,インターフェロン反応を抑制する
Noémie Alphonse1, Joseph J Wanford2, Andrew A Voak2
1Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, UK; Immunoregulation Laboratory, Francis Crick Institute, London, UK.
Cell
|May 14, 2022
まとめ
シゲラ菌は重要なカルシウムセンサーであるカルモジュリンを標的にして,インターフェロン (IFN) 信号伝達を阻害します. OspCタンパク質を含むこのメカニズムは,免疫反応を阻害し,他の病原体でも保存されます.
科学分野:
- 微生物学
- 免疫学
- 分子生物学
背景:
- インターフェロン (IFN) は抗ウイルスおよび抗菌免疫に不可欠です.
- IFN反応のバクテリア逃避は重要な毒性戦略であるが,そのメカニズムは十分に理解されていない.
研究 の 目的:
- 細菌の病原体,特にシゲラ菌がインターフェロン信号を回避できるかどうかを調査する.
- ShigellaがIFN反応を阻害する分子メカニズムを解明する.
主な方法:
- IFN信号を遮断するシゲラOspCエフェクターの役割を調査した.
- OspC1 と OspC3 がカルモジュリン (CaM) に結合することを示すために生化学的測定法を使用した.
- IFN受容体の枯渇と否の表皮細胞の細菌増殖とネズミの感染モデルを評価した.
主要な成果:
- シゲラ OspCエフェクターは,細胞死抑制とは無関係にIFNシグナル伝達を阻害する.
- OspC1とOspC3はCaMに結合し,CaMキナーゼIIとJAK/STAT信号伝達経路を阻害する.
- OspC1とOspC3が欠けているシゲラは,IFN受容体を枯渇させることで,衰弱した成長を示した.
- 他の病原体における保存されたOspCホモログは,CaMと結合し,IFNシグナル伝達を阻害した.
結論:
- Shigellaは,CaMと下流シグナリングをターゲットにすることで,IFN応答を抑制する新しいメカニズムを採用しています.
- 細菌の病原体の中で,CaM対抗性によるIFN回避は保存された毒性戦略である.
- この研究は,バクテリアの病原性におけるCa2+シグナル伝達とIFNターゲティングの重要性を強調しています.
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