Functional Analysis of Lactobacillus rhamnosus GG Pili in Relation to Adhesion and Immunomodulatory Interactions with Intestinal Epithelial Cells
Functional Analysis of Lactobacillus rhamnosus GG Pili in Relation to Adhesion and Immunomodulatory Interactions with Intestinal Epithelial Cells
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DOI：
10.1128/aem.06192-11
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发表时间：
2012-01-01
影响因子：
4.4
通讯作者：
Vanderleyden, Jos
中科院分区：
文献类型：
--
作者：
Lebeer, Sarah;Claes, Ingmar;Vanderleyden, Jos
鼠李糖乳杆菌GG是一种在人体肠道内具有良好生存能力的益生菌，具有良好的粘附性和健康效应。最近，在其细胞表面发现了spaCBA编码的菌毛，可以与人的肠道粘液结合。在这里，我们报告了一个spaCBA菌毛基因敲除突变体的表型分析，并与野生型和其他粘附素突变体进行了比较。鼠李糖GG的SpaCBA菌毛是Caco-2肠上皮细胞(IEC)有效黏附和生物膜形成的关键。此外，与野生型相比，spaCBA突变体诱导Caco-2细胞中IL-8的mRNA水平升高，可能涉及脂磷壁酸与Toll样受体2的相互作用。相反，没有胞外多糖但菌毛暴露增加的L.rhamnosus GG突变体导致IL-8的表达降低。使用Trswells将细菌从Caco-2细胞中分离出来，无论是使用野生型还是突变的L.rhamnosus GG细胞，IL-8的诱导都被完全阻断。综上所述，我们的数据表明，Lhamnosus GG SpaCBA菌毛在促进与IECS的强烈黏附相互作用的同时，在平衡脂磷壁酸等表面分子诱导的IL-8mRNA表达方面具有功能作用。
Lactobacillus rhamnosus GG, a probiotic with good survival capacity in the human gut, has well-documented adhesion properties and health effects. Recently, spaCBA-encoded pili that bind to human intestinal mucus were identified on its cell surface. Here, we report on the phenotypic analysis of a spaCBA pilus knockout mutant in comparison with the wild type and other adhesin mutants. The SpaCBA pilus of L. rhamnosus GG showed to be key for efficient adherence to the Caco-2 intestinal epithelial cell (IEC) line and biofilm formation. Moreover, the spaCBA mutant induces an elevated level of interleukin-8 (IL-8) mRNA in Caco-2 cells compared to the wild type, possibly involving an interaction of lipoteichoic acid with Toll-like receptor 2. In contrast, an L. rhamnosus GG mutant without exopolysaccharides but with an increased exposure of pili leads to the reduced expression of IL-8. Using Transwells to partition bacteria from Caco-2 cells, IL-8 induction is blocked completely regardless of whether wild-type or mutant L. rhamnosus GG cells are used. Taken together, our data suggest that L. rhamnosus GG SpaCBA pili, while promoting strong adhesive interactions with IECs, have a functional role in balancing IL-8 mRNA expression induced by surface molecules such as lipoteichoic acid.