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Examination of Thymic Positive and Negative Selection by Flow Cytometry
Published on: October 8, 2012
ストレスシグナルキナーゼSek1は,チモサイトをCD95およびCD3によって媒介されるアポトーシスから保護します
H Nishina1, K D Fischer, L Radvanyi
1The Amgen Institute, Ontario Cancer Institute, Toronto, Canada.
Nature
|January 23, 1997
まとめ
Sek1 (JNKK/MKK4) はT細胞の発達に不可欠である. Sek1がアポトーシスから保護されたチモサイトを削除し,T細胞成熟時の生存信号を媒介する役割を示しています.
科学分野:
- 細胞信号伝達と免疫学
- 分子生物学と遺伝学
背景:
- 信号伝達カスケードは,様々なシグナルに反応して,細胞の生存と死を制御します.
- ストレス活性化タンパク質キナーゼ (SAPKs/JNKs) は,細胞のストレスとミトゲン系因子によって活性化されます.
- Sek1 (JNKK/MKK4) はSAPKs/JNKsを直接活性化し,ストレス反応に役割を果たします.
研究 の 目的:
- 胚の発達とアポトーシスにおけるSek1の役割を調査する.
- Sek1がSAPK/JNK活性化経路に不可欠であるかどうかを判断する.
- T細胞の発達と生存におけるSek1の機能を明らかにする.
主な方法:
- 胚性幹細胞 (ES) でのsek1遺伝子の削除は,同類の再結合を用いて行われます.
- sek1(-/-) rag2(-/-) のキメリックマウスの生成.
- T細胞集団 (チモサイト,成熟T細胞) とアポトーシス誘導の分析.
主要な成果:
- sek1(-/-) rag2(-/-) キメリックマウスは正常な成熟T細胞数を示したが,未成熟CD4+CD8+チモサイトは減少した.
- sek1変異は,ES細胞とT細胞における環境ストレスへの反応として,アポトーシスの誘導を損ねなかった.
- Sek1欠乏症は,チモサイトをCD95 (Fas) とCD3媒介のアポトーシスから保護した.
結論:
- 異なる細胞のストレスは,SAPK/JNKの活性化のために異なるシグナル伝達経路を利用します.
- Sek1はストレス誘発のアポトーシスには欠かせないが,T細胞発育において重要な役割を果たしている.
- Sek1はT細胞発達の過程で重要な生存信号を媒介し,FasとCD3媒介によるアポトーシスからチモサイトを保護する.
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