ペプチドが,生きている細胞のクラスIIのMHC分子と不可逆的に結合する
A Lanzavecchia1, P A Reid, C Watts
1Basel Institute for Immunology, Switzerland.
Nature
|May 21, 1992
まとめ
クラスIIメジャーヒストコンパティビリティコンプレックス (MHC) 分子は,ヒト細胞でペプチドを不可逆的に結合する. この長期結合,または分子記憶は,抗原を提示する細胞とのT細胞の相互作用を高めます.
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.
- 細胞生物学 細胞生物学
背景:
- クラスIIメジャーヒストコンパティビリティコンプレックス (MHC) 分子は,生物合成中に処理されたペプチドを結合します.
- In vivoペプチド/MHCクラスII複合体は,in vitro複合体よりも安定性が低いと考えられており,ペプチド交換メカニズムの可能性を示唆しています.
- ペプチド交換は抗原結合能力を高めるが,提示された抗原の有効性を低下させる可能性がある.
研究 の 目的:
- ペプチド/クラスII複合体の安定性と半減期をヒトの活体抗原呈現細胞で測定する.
- ペプチドの交換が生理学的条件下でin vivoで起こるかどうかを調査する.
- T細胞-抗原を提示する細胞相互作用に対するペプチド結合安定性の意味を理解する.
主な方法:
- ペプチド/IIクラス複合体の半減期をヒトの抗原呈現細胞で測定する.
- ペプチド/クラスII複合体の半減期とクラスII分子そのものの半減期の比較.
主要な成果:
- ペプチド/クラスII複合体の半減期は,クラスIIの分子の半減期と非常に似ています.
- ペプチドは,生理学的条件下で,IIクラスMHC分子に不可逆的に結合する.
- この不可逆的結合は,ペプチド情報の長期保存を示している.
結論:
- クラスIIのMHC分子はペプチドをin vivoで不可逆的に結合する.
- この不可逆的な結合により,II級MHCは,過去の抗原との接触に関する長期の"記憶"を保持することができます.
- 安定したペプチド結合は,T細胞/抗原を提示する細胞の相互作用の機会を最大化し,免疫監視を強化します.
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