IRAPは,MHCクラスIのクロスプレゼンテーションに必要なエンドソーマ区画を特定します
Loredana Saveanu1, Oliver Carroll, Mirjana Weimershaus
1INSERM, U580, 75015 Paris, France; Université Paris Descartes, Faculté de Médecine René Descartes, 75015 Paris, France.
まとめ
インスリン調節アミノペプチダゼ (IRAP) は,メジャー・ヒストコンパティビリティ・コンプレックス (MHC) クラスIの分子のためにエンドソーム内のペプチドをトリミングすることによって,クロスプレゼンテーションにおいて重要な役割を果たします. この発見は,抗原プレゼンテーションに関与する細胞区間を明確にします.
科学分野:
- 免疫学 免疫学とは
- 細胞生物学 細胞生物学
- プロテオスタシス プロテオスタシス
背景:
- メジャー・ヒストコンパティビリティ・コンプレックス (MHC) クラスIの分子は,細胞性タンパク質から細胞毒性Tリンパ球にペプチドを提示する.
- クロスプレゼンテーションにより,デンドリット細胞はMHCクラスI経由で外来抗原を提示できますが,関与する細胞区画は完全に理解されていません.
研究 の 目的:
- 細胞のクロスプレゼンテーションのメカニズムにおけるペプチドトリミングの役割を調査する.
- クロスプレゼンテーション経路に関与する特定の細胞区間と酵素を特定する.
主な方法:
- 免疫光顕微鏡を用いて,ヒトのデンドリット細胞にIRAPとMHCクラスIを局所化する.
- CRISPR/Cas9遺伝子編集により,IRAP欠乏型デンドリート細胞が作られる.
- クロスプレゼンテーションの効率を評価するために,in vitroおよびin vivoアッセイ.
主要な成果:
- インスリン調節アミノペプチダゼ (IRAP) は,Rab14+内分体区間に局所され,MHCクラスI分子と相互作用しました.
- IRAP欠乏症は,in vitroおよびin vivoモデルの両方でクロスプレゼンテーションを損なう.
- MHCクラスIによる内生性ペプチド表現は,IRAP欠乏によって影響を受けませんでした.
結論:
- IRAPは効率的なクロスプレゼンテーションに不可欠であり,ペプチドの最終的なトリミングのためにエンドソーマのコンパートメントで作用します.
- プロテアソーム依存のクロスプレゼンテーションのための2つの異なる経路が提案されています:一つは,エンドソーム内のIRAPを含む,もう一つは,エンドプラズマ網膜に居住するアミノペプチダースを使用します.
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