遺伝子と微生物の相互作用は,炎症性腸疾患の病原化に寄与する
Hiutung Chu1, Arya Khosravi2, Indah P Kusumawardhani2
1Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA. hiuchu@caltech.edu sarkis@caltech.edu.
まとめ
炎症性腸疾患 (IBD) の遺伝的リスク変異は,有益な腸内細菌の信号を感知する免疫システムの能力を低下させます. この欠陥はT細胞 (Tregs) の活性化を阻害し,IBDの発症に寄与する.
科学分野:
- 微生物学
- 免疫学
- 遺伝学
背景:
- 炎症性腸疾患 (IBD) は遺伝的リスク変異と腸内微生物群不活性化に関連しています.
- これらの要因とIBDの病原性を結びつける統一的な原則は欠けている.
- Bacteroides fragilisのような共生性細菌は,外膜膀 (OMV) を介して宿主免疫細胞と通信する.
研究 の 目的:
- IBDに関連した遺伝子であるATG16L1とNOD2が,宿主の微生物 OMVに対する反応における役割を調査する.
- IBDの遺伝的変異が腸内微生物群によって免疫耐性をどのように影響するかを理解する.
- IBD 感受性の文脈で免疫細胞が微生物信号を感知するメカニズムを解明する.
主な方法:
- 大腸炎とヒト免疫細胞の マウスモデルを用いた
- Bacteroides fragilis OMVsとデンドリット細胞の相互作用を調査した.
- OMVに対するT細胞 (Tregs) の誘導を評価した.
- IBDリスク遺伝子のATG16L1とNOD2のOMVセンシングとTreg活性化の機能を調べました.
- ATG16L1リスクの変種を持つヒトの免疫細胞を分析した.
主要な成果:
- OMVはIBDに関連する遺伝子であるATG16L1とNOD2を必要とし,大腸炎に対する保護のために非正規のオートファジー経路を活性化させる.
- ATG16L1欠乏した dendritic 細胞は,粘膜の炎症を抑制する Tregs を誘導することができません.
- ATG16L1リスク変異を持つヒトの免疫細胞は,OMVに対するTreg反応が低下している.
結論:
- ATG16L1のようなIBD感受性遺伝子の遺伝的多形化は,保護的な微生物信号を感知する欠陥につながる可能性があります.
- 微生物の信号感知におけるこれらの欠陥は,T細胞の調節反応を阻害し,IBDの病原化に寄与する.
- ホストの遺伝子と微生物群のシグナル伝達を含む重要な遺伝子環境の相互作用がIBDの主要な病因として提案されています.
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