ミコバクテリアのタンパク質の宿主介のユビキチン化は免疫を抑制する
Lin Wang1, Juehui Wu1,2, Jun Li3
1Shanghai Key Laboratory of Tuberculosis, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China.
Nature
|January 17, 2020
まとめ
Mycobacterium tuberculosisはホストのANAPC2タンパク質を使って,そのRv0222タンパク質にユビキチンを結合させ,ホストの免疫反応を抑制する. この相互作用はM. tuberculosisの毒性にとって極めて重要であり,免疫調節剤にとって新しい標的となる.
科学分野:
- 免疫学
- 微生物学
- 分子生物学
背景:
- 結核菌 (Mycobacterium tuberculosis) は宿主の免疫信号を操作する細胞内病原体である.
- バクテリアの病原体はしばしば病原性のために宿主ユビキチネーションシステムを利用する.
- M. 結核のタンパク質調節における宿主ユビキチン化の役割は,以前は知られていなかった.
研究 の 目的:
- ホストのユビキチン化が M. tuberculosis のタンパク質を調節するかどうかを調査する.
- 結核菌が宿主の免疫信号に干渉するメカニズムを解明する.
- M. 結核に対する新しい免疫調節剤の潜在的な標的を特定する.
主な方法:
- ホストとバクテリアのタンパク質の相互作用を検出する共免疫プレシピテーション
- ユビキチン連鎖のタイプを特定するためのユビキチン化測定法.
- ホストの遺伝子発現を抑制する短いヘアピンRNA (shRNA)
- 特定のユビキチネーション部位の役割を研究するための部位指向型変異.
- マウスの感染モデルで 毒性を評価する
主要な成果:
- ホストのE3ユビキチンリガゼANAPC2は,M. tuberculosisのタンパク質Rv0222と相互作用する.
- ANAPC2はリシン11結合ユビキチン鎖をRv0222に結合し,炎症性サイトカイン発現を抑制する.
- ANAPC2の抑制またはRv0222のユビキチン化部位の変異は,この抑制を無効化し,毒性を減少させます.
- Rv0222のユビキチネーションは,SHP1のTRAF6へのリクルートを促進し,TRAF6の活性化を阻害する.
結論:
- M. tuberculosisは宿主の免疫を抑制するために,宿主のANAPC2媒介によるRv0222のユビキチン化を利用する.
- このメカニズムは,SHP1によるTRAF6活性化の抑制を伴う.
- 結核に対する新たな免疫回避戦略と 潜在的な治療標的を明らかにした.
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