文献类型： 外文期刊

作者： Duan, Qiangde ¹ ; Pang, Shengmei ¹ ; Feng, Lili ⁴ ; Li, Baoliang ¹ ; Lv, Linfen ¹ ; Liang, Yuxuan ¹ ; Zhu, Guoqiang ¹ ;

作者机构： 1.Yangzhou Univ, Coll Vet Med, Dept Vet Microbiol, Yangzhou 225009, Peoples R China

2.Minist Educ, Jiangsu Coinnovat Ctr Prevent & Control Important, Joint Lab Int Cooperat Agr & Agr Prod Safety, Yangzhou 225009, Peoples R China

3.Jiangsu Joint Lab Int Cooperat Prevent & Control I, Yangzhou 225009, Peoples R China

4.Henan Acad Agr Sci, Inst Agr Econ & Informat, Zhengzhou 450002, Peoples R China

关键词： heat-labile enterotoxin; LTA subunit; LTB subunit; enterotoxigenic Escherichia coli; bacterial adherence

期刊名称：INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES （ 影响因子：5.6； 五年影响因子：6.2 ）

ISSN：

年卷期： 2023 年 24 卷 2 期

页码：

收录情况： SCI

摘要： There is increasing evidence indicating that the production of heat-labile enterotoxin (LT) enhances bacterial adherence within in vitro and in vivo models. However, which subunit plays the main role, and the precise regulatory mechanisms remain unclear. To further elucidate the contribution of the A subunit of LT (LTA) and the B subunit of LT (LTB) in LT-enhanced bacterial adherence, we generated several LT mutants where their ADP-ribosylation activity or GM1 binding ability was impaired and evaluated their abilities to enhance the two LT-deficient E. coli strains (1836-2 and EcNc) adherence. Our results showed that the two LT-deficient strains, expressing either the native LT or LT derivatives, had a significantly greater number of adhesions to host cells than the parent strains. The adherence abilities of strains expressing the LT mutants were significantly reduced compared with the strains expressing the native LT. Moreover, E. coli 1836-2 and EcNc strains when exogenously supplied with cyclic AMP (cAMP) highly up-regulated the adhesion molecules expression and improved their adherence abilities. Ganglioside GM1, the receptor for LTB subunit, is enriched in lipid rafts. The results showed that deletion of cholesterol from cells also significantly decreased the ability of LT to enhance bacterial adherence. Overall, our data indicated that both subunits are equally responsible for LT-enhanced bacterial adherence, the LTA subunit contributes to this process mainly by increasing bacterial adhesion molecules expression, while LTB subunit mainly by mediating the initial interaction with the GM1 receptors of host cells.