在细胞间传播过程中,Shigella flexneri需要一个具有转移能力的孔隙才能从双膜真空中逃脱出来
Julie E Raab1, Tucker B Harju1, Jody D Toperzer1
1Department of Immunology and Microbiology, University of Colorado-Anschutz Medical Campus, Aurora, Colorado, USA.
mBio
|August 11, 2025
概括
石格拉柔性菌利用其3型分泌系统 (T3SS) 在结肠细胞之间传播. T3SS 蛋白 IpaC 形成毛孔以提供毒性因子,使细菌能够在传播过程中逃脱双膜真空.
科学领域:
- 微生物学 微生物学
- 细胞生物学 细胞生物学
- 传染性疾病 传染性疾病
背景情况:
- 3型分泌系统 (T3SSs) 是许多细菌病原体的关键毒性因子,促进了效应蛋白向宿主细胞的输送.
- 石格拉柔性菌利用T3SS对宿主细胞进行入侵和细胞间传播,这一过程涉及形成并随后从双膜真空中 (DMV) 逃逸.
- 细菌逃离DMV的确切机制尚未完全理解,尽管已知T3SS转位孔蛋白IpaC是必不可少的.
研究的目的:
- 研究IpaC在Shigella flexneri细胞间传播过程中转移T3SS效应物的作用.
- 阐明IpaC介导的孔形成和功能在DMV逃生中的机制.
- 要了解与入侵相比,细菌传播期间T3SS的独特调节.
主要方法:
- 影响毛孔形成和转位的IpaC突变的遗传分析.
- 在体外测试以评估IpaC插入宿主的血膜.
- 显微镜技术观察细菌与宿主细胞相互作用和DMV动态.
主要成果:
- 在细胞间传播过程中,IpaC在宿主血中形成功能性毛孔.
- 依赖IpaC的孔隙转移了Shigella flexneri逃离DMV所需的必不可少的效应器.
- 在扩散期间的T3SS激活与入侵期间的激活不同,并且不需要孔隙形成.
- IpaC促进了DMV膜的顺序分解.
结论:
- 在Shigella flexneri细胞间传播期间,IpaC在T3SS介导的效应因子跨宿主膜转移中发挥着关键作用.
- 在扩散过程中明确的T3SS调节允许有针对性的效应器传递,促进DMV逃跑.
- 这项研究为细菌发病机制和T3SS在细胞间传播中的功能提供了新的见解.
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