ヘリコバクター・パイロリ CagAによる上皮のアピカル・ジャンクション複合体の破壊

Manuel R Amieva¹, Roger Vogelmann, Antonello Covacci

¹Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA. amieva@stanford.edu

Science (New York, N.Y.)

|May 31, 2003

まとめ

ヘリコバクター・パイロリ菌はCagAタンパク質を胃細胞に注入し,細胞の結合とバリア機能を破壊する. これにより,胃がんの発症に関連した細胞変化が起こります.

科学分野:

微生物学微生物学とは
細胞生物学細胞生物学
胃腸内科胃腸内科

背景:

ヘリコバクター・パイロリ菌感染症は,胃潰瘍疾患と胃がんの主要な原因です.
細菌のタンパク質CagAは,宿主胃の上皮細胞に転移する重要な毒性因子です.

研究の目的:

CagAが胃上皮細胞の結合と機能に影響を与える分子機構を調査する.
表皮壁の整合性と細胞形態の破壊におけるCagAの役割を明らかにする.

主な方法:

同免疫プレシピテーションアッセイは,CagA,ZO-1,および交差点粘着分子間のタンパク質-タンパク質相互作用を研究する.
緊密な接合部位の位置を視覚化するための免疫光顕微鏡.
トランセピテリア電気抵抗 (TEER) 測定を用いた上皮壁機能の評価.
ポラライズされた上皮細胞培養にCagAを長期にわたって送る長期的研究.

主要な成果:

注入されたCagAはZO-1と直接結合し,交差点の粘着分子と結合する.
CagAは,バクテリアの結合部位で緊密な結合タンパク質の子宮外集合を誘導する.
頂点-交差点複合体の組成と機能の変化が観察されました.
長期にわたるCagA曝露は,上皮膜のバリア機能を破壊し,細胞形態の不形成的変化を引き起こしました.

結論:

CagAはヘリコバクター・パイロリを標的とし,細胞の細胞間結合をホストする.
CagAは結合媒介機能を妨害し,上皮膜の障壁の欠陥を引き起こします.
CagA誘発の細胞変異は,胃がんの病原化に寄与する可能性があります.

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