ドロソフィラの抗ウイルス免疫には,全身的なRNA干渉による拡散が必要である
Maria-Carla Saleh1, Michel Tassetto, Ronald P van Rij
1Department of Microbiology and Immunology, University of California, San Francisco 94122-2280, USA.
Nature
|February 11, 2009
まとめ
ハエは,有効な抗ウイルス免疫のために,二重鎖RNA (dsRNA) 吸収経路を必要とします. この経路は,組織的なRNA干渉 (RNAi) 反応を可能にするが,これはウイルス感染症を全体で抵抗する上で極めて重要です.
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.
- ウイルス学 ウイルス学 ウイルス学
背景:
- 多細胞生物は,病原菌に対する洗練された防御システムを備えています.
- 昆虫の抗ウイルス免疫,特にRNA干渉 (RNAi) は,以前は局所的で細胞自律的なプロセスと考えられていた.
- 免疫系が局所的にもシステム的にも反応する能力は,重要な特徴です.
研究 の 目的:
- ドロソフィラ・メラノガスターの抗ウイルス免疫における二重鎖RNA (dsRNA) 吸収経路の役割を調査する.
- ハエのRNAi媒介抗ウイルス防御が全身反応を生成できるかどうかを判断する.
主な方法:
- ミュータントハエの生成は,dsRNA吸収経路に欠陥がある.
- 野生型および突然変異のハエにドロソフィラCウイルスとシンディスウイルスを感染させる.
- ウイルスタイターとRNAレベルを測定する.
- 免疫反応を評価するために,裸のdsRNAで接種するハエ.
- 緑色光タンパク質 (GFP) にタグ付けされたSindbisウイルスを使って,全身的な影響を追跡する.
主要な成果:
- dsRNA吸収経路が欠けていた変異したハエは,ウイルス感染症に対する過敏性を示した.
- dsRNA吸収欠陥のあるハエは,ウイルスの負荷が著しく増加した (100-〜10〜5倍) ことを示しました.
- 外因的なdsRNA投与は,吸収経路に依存する配列特異の抗ウイルス反応を誘発した.
- ウイルスの感染は,遠隔部位で宿主にコードされたGFPの抑制につながり,全身的なシグナル伝達を示しています.
結論:
- dsRNA吸収経路は,成人ハエの有効な抗ウイルスRNA干渉免疫に不可欠です.
- dsRNAの全身的拡散は,包括的な抗ウイルス防御を確立するために非常に重要です.
- ハエの抗ウイルスRNAiは,脊椎動物のタンパク質ベースの免疫と同様に,免疫信号の全身的拡散に依存しています.
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