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Shigella flexneriは,感染したマクロファージでアポトーシスを誘発する

A Zychlinsky¹, M C Prevost, P J Sansonetti

¹Unité de Pathogénie Microbienne Moléculaire, INSERM U199, Institut Pasteur, Paris, France.

|July 9, 1992

まとめ

痢疾の病原体であるシゲッラ・フレックスネリは,宿主マクロファージのプログラム細胞死 (アポトーシス) を誘発する. この細菌が誘発する宿主細胞の自殺は,その侵入と病原性にとって極めて重要です.

科学分野:

微生物学微生物学とは
細胞生物学細胞生物学
パトジェネシス (病原生)

背景:

Shigella flexneriは,大腸の粘膜に侵入することで痢疾を引き起こす.
病原体は腸細胞に侵入し,細胞質に入り,隣接する細胞に広がります.
シーゲッラは,ファゴサイトと遭遇し,それを殺すラミナ・プロピアに到達し,の形成につながります.

研究の目的:

Shigella flexneriがマクロファージに対して使用する細胞毒性のメカニズムを解明する.
細菌の侵入がプログラム細胞死の誘導と関連しているかどうかを判断する.

主な方法:

4つの異なるシゲッラ・フレックスネリ菌株の細胞死を誘発する能力をテストする.
侵襲性菌株と,その非侵襲性,プラズミドで治した同位菌株を比較する.
ipaB (侵入タンパク質抗原) の変異体と,Escherichia coliのヘモリシンオペロンを発現する菌株を分析した.

主要な成果:

侵襲的なShigella flexneri菌株は,マクロファージのプログラム細胞死 (アポトーシス) を誘導した.
非侵襲的であり,プラズミドで治癒した菌株とipaB変異体は毒性がありませんでした.
E. coliを表現する非侵襲性菌株は,アポトーシスではなく,ヘモリシン誘発性死滅を引き起こす.

結論:

Shigella flexneriは,細胞毒性のメカニズムとして宿主マクロファージにおけるアポトーシスを積極的に誘発する.
これは,侵入性細菌病原体が宿主細胞の自殺を誘発する最初の証拠です.
バクテリアの侵入と特定の毒性の要因は,アポトーシスを誘発するために重要である.

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