硫氧还蛋白YbbN调控生物被膜形成及细胞毒性增强副溶血弧菌致病性

Thioredoxin YbbN regulates biofilm formation and cytotoxicity to enhance the pathogenicity of Vibrio parahaemolyticus

摘要:

硫氧还蛋白家族在细菌氧化应激防御和毒力调控中具有重要作用，但其成员YbbN蛋白在副溶血弧菌中的功能尚不明确。目的 揭示YbbN蛋白对副溶血弧菌生物学特性和致病性的调控作用，为开发新型抗感染策略提供潜在靶点。方法 使用同源重组技术构建副溶血弧菌SH112株的ybbN基因缺失株(ΔybbN)和互补株(CΔybbN)，比较各菌株的生长特性、运动性、生物被膜形成能力、细菌间竞争、细胞黏附、细胞毒性以及对小鼠的致病性。结果 ybbN缺失不影响细菌生长、运动性、细胞黏附和定殖能力，削弱了副溶血弧菌的关键致病特性：生物被膜形成能力降低19%-30%，对大肠杆菌的杀伤效率极显著下降(*：P<0.05；****：P<0.000 1)，对HeLa细胞的毒性减弱27%，小鼠感染存活率提升87.5%。结论 本研究阐明YbbN通过调控副溶血弧菌的生物被膜形成、细菌竞争和宿主细胞毒性等关键环节，显著影响其生物学特性和致病性。这一发现不仅拓展了对硫氧还蛋白家族蛋白功能多样性的认知，更为防控副溶血弧菌感染提供了新的分子靶标和理论依据。

Abstract:

The thioredoxin family plays crucial roles in bacterial oxidative stress defenses and virulence regulation, while the function of its member YbbN in Vibrio parahaemolyticus remains unclear.Objective To elucidate the regulatory role of YbbN in the biological characteristics and pathogenicity of Vibrio parahaemolyticus, providing potential targets for developing novel anti-infection strategies.Methods The ybbN knockout strain (ΔybbN) and complementary strain (CΔybbN) of Vibrio parahaemolyticus SH112 were constructed by homologous recombination. The strains were compared regarding the growth characteristics, motility, biofilm formation, bacterial competition, cell adhesion, cytotoxicity, and pathogenicity in mice.Results Although the knockout of ybbN showed no significant effects on bacterial growth, motility, cell adhesion, or colonization, it markedly attenuated key pathogenic traits. Specifically, it decreased the biofilm formation (by 19%-30%), killing efficiency against competitive bacteria (*: P<0.05; ****: P<0.000 1), and cytotoxicity in HeLa cells (by 27%), while increasing the survival rate of mice by 87.5%.Conclusion This study demonstrates for the first time that YbbN specifically regulates critical aspects involved in biofilm formation, bacterial competition, and cytotoxicity in host cells, significantly influencing the biological characteristics and pathogenicity of Vibrio parahaemolyticus. These findings not only expand the understanding about the functional diversity of the thioredoxin family proteins but also provide new molecular targets and a theoretical basis for preventing Vibrio parahaemolyticus infections.