コレラ毒素は病原体の宿主由来栄養素の吸収を促進する
Fabian Rivera-Chávez1, John J Mekalanos2
1Department of Microbiology, Harvard Medical School, Boston, MA, USA.
Nature
|August 2, 2019
まとめ
Vibrio choleraeによって生成されるコレラ毒素 (CTX) は,鉄が不足した腸内環境を生み出します. このニッチは,細菌が栄養のために宿主由来のヘムと脂肪酸を利用できるようにすることで,病原体の成長を促進します.
科学分野:
- 微生物学
- 感染症
- バクテリア病原性
背景:
- Vibrio choleraeは 重度の下痢性疾患であるコレラを引き起こします
- コレラ毒素 (CTX) は重度の病気と病原体の伝播に不可欠です.
- V. コレラが腸内高濃度に達するメカニズムは完全に理解されていません.
研究 の 目的:
- 感染時に腸内でのV.コレラ菌の高濃度を 調べる
- V.コレラの腸内植民と成長におけるコレラ毒素 (CTX) の役割を解明する.
- ホストの腸環境におけるV. choleraeの代謝適応を特定する.
主な方法:
- 感染中のV.コレラのトランスクリプトミックの分析
- V. コレラが鉄を吸収する経路 (ヘムとビブリオバクチン) の遺伝子解析
- CTX誘発のイレアル病変と代謝産物および栄養素の可用性との相関.
主要な成果:
- CTXはトランスクリプトミックのサインを誘発し 鉄が不足した腸のニッチを示唆します
- ヘムとビブリオバクチンの鉄の獲得のための遺伝子は,CTXが生成されたときにのみ成長の利点を授与します.
- CTX誘発のイレアル詰まりは,血液の生物利用性を高め,血液中のメタボリート (脂肪酸,L- 乳酸) を変化させる.
- 病原体の成長は,CTXを生成する株におけるヘムと脂肪酸の吸収に依存する.
結論:
- CTX誘発の病気は 腸内の鉄欠乏した代謝ニッチを生み出します
- このニッチは,宿主由来ヘムと脂肪酸の獲得を通じて,選択的にV.コレラエの成長を促します.
- このメカニズムを理解することは コレラの病原性を制御する鍵です
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