MyD88から独立したTIR信号のキートランスデューサーとしてのLps2の識別
1Department of Immunology, IMM-31, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
Nature
|July 23, 2003
まとめ
研究者らは,トール/インターリューキン-1受容体/抵抗 (TIR) アダプタタンパク質Trifの変異を特定し,トール型受容体4 (TLR4) 経路から2つの重要なシグナル伝達経路を明らかにした. この発見は,細菌のエンドトキシンとウイルス感染症に対する免疫システムの反応に光を当てています.
科学分野:
- 免疫学 免疫学とは
- 分子生物学は分子生物学である.
- 遺伝学 遺伝学とは
背景:
- トール型受容体 (TLRs) は,先天的免疫において決定的な役割を果たし,微生物の成分を認識し,シトカイン生成を通じて炎症反応を誘発する.
- 現存する知識によると,TLRはアダプタータンパク質を使って信号を伝達するが,TLR4のような特定のTLRの正確な経路はまだ研究中である.
研究 の 目的:
- 二重鎖RNAとリポポリサッカリド (LPS) に対するサイトカイン反応に影響を与えるLps2変異の遺伝的基礎を特定する.
- トール型受容体4 (TLR4) 経路の下流の信号伝達経路,特にTrifアダプタタンパク質を含む信号伝達経路の解明.
主な方法:
- 化学的変異性 (N-エチル-N-ニトロス尿素) を用いて,マウスの生殖線変異を誘発する.
- LPSとウイルスチャレンジ (マウスサイトメガロウイルス) に対するサイトカイン応答アッセイを含む変異性マウスのフェノタイプ分析.
- Trif (Ticam-1) 遺伝子の特定の突然変異を特定するための遺伝子マッピングとシーケンシング.
主要な成果:
- Lps2変異は,Trifアダプタータンパク質のフレームシフトとして特定され,Trif ((Lps2) と命名されました.
- Trif (((Lps2) ホモジゴトは,LPSの毒性に対する耐性を発揮し,I型インターフェロン産生障害によるマウス細胞メガロウイルスに対する感受性が高まります.
- TrifとMyD88の組み合わせた変異は,LPS受容体からの2つの主要なシグナル伝達経路を示し,すべてのLPS応答を廃止します.
- Trif-独立,MyD88-依存の経路がマクロファージのサブセットで特定され,免疫専門性を示唆しました.
結論:
- Trifアダプタータンパク質は,LPSに対するTLR4媒介反応と抗ウイルス免疫に不可欠です.
- 主な2つの信号伝達経路,一つはTrifに依存し,もう一つはMyD88に依存する経路 (アダプタX) がLPS受容体から発生します.
- 代替的な経路の存在は,免疫応答のためのマクロファージ集団内の機能的専門化を暗示しています.
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