炎症性カスパスは,細胞内LPSの先天的な免疫受容体である
Jianjin Shi1, Yue Zhao2, Yupeng Wang3
11] Peking University-Tsinghua University-National Institute of Biological Sciences Joint Graduate Program, National Institute of Biological Sciences, Beijing 102206, China [2] National Institute of Biological Sciences, Beijing 102206, China [3].
Nature
|August 15, 2014
まとめ
人間のカスパゼ4とカスパゼ5とマウスカスパゼ11は,直接リポポリサッカリド (LPS) に結合し,細胞死経路を誘発する. この発見は,免疫パターン認識とカスパース活性化のための新しいメカニズムを明らかにします.
科学分野:
- 免疫学 免疫学とは
- 細胞生物学 細胞生物学
- 分子生物学は分子生物学である.
背景:
- マウリンカスパース11を含む非正規の炎症ゾームは,細菌感染に反応する.
- Caspase-11の活性化は,細胞質のリポポリサッカリド (LPS) センシングを介して,ピロプトーシスとエンド毒性ショックにつながるが,受容体は不明のままである.
研究 の 目的:
- 細胞性LPS感知のメカニズムを解明し,LPS誘発細胞死の原因となるパターン認識受容体を特定する.
主な方法:
- 人体細胞 (単細胞,上皮細胞,ケラチノ細胞) の細胞質伝達時にLPS誘発の細胞毒性を調査した.
- ヒトのカスパース-4とネズミのカスパース-11の間の機能的補完分析を用いた.
- カスパース (カスパース-4/11,カスパース-5) をLPSと脂質A.に直接結合させるアッセイを行った.
- 精製された昆虫細胞カスペスを用いて,LPS結合に対するカスペーゼオリゴメリゼーションとアクティベーションを試験した.
- LPS電解および細菌感染モデルで結合欠乏CARDドメインのポイントミュータントを生成および試験した.
主要な成果:
- 人間の細胞は,ヒトのカスパース-4によって媒介される細胞質のLPS配送時にネクロシスを経験し,これは機能的にネズミのカスパース-11を補完する.
- 人間のカスパゼ-4/11とカスパゼ-5は,LPSと脂質Aに直接結合し,高い親和性を示しています.
- LPS結合は,CARDドメインに依存するプロセスであるカスパース-4/11のオリゴメリゼーションと活性化を誘導する.
- アンデラサイレートされたLPS変種は,カスパース活性化を誘導できず,特異性を示す.
- CARDドメインの突然変異者は,オリゴメリ化,活性化,および熱死を引き起こす能力を失った.
結論:
- 人間のカスパゼ-4/11とカスパゼ-5は,直接的なLPSセンサーとして作用し,ピロプトーシスとネクロシスを媒介する.
- これは,免疫における新しいパターン認識メカニズムと,カスパース活性化のための新しい経路を表しています.
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