Functional analysis of putative adhesion factors in Lactobacillus acidophilus NCFM
Functional analysis of putative adhesion factors in Lactobacillus acidophilus NCFM
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DOI：
10.1128/aem.71.12.8344-8351.2005
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发表时间：
2005-12-01
影响因子：
4.4
通讯作者：
Klaenhammer, TR
中科院分区：
文献类型：
--
作者：
Buck, BL;Altermann, E;Klaenhammer, TR
乳酸菌是胃肠道正常菌群的主要居民，一些精选的物种已被广泛用作益生菌培养物。这些生物的一个潜在的重要特性是它们与肠道上皮细胞相互作用的能力，这可能促进滞留和宿主-细菌交流。然而，它们附着于肠上皮细胞的机制尚不清楚。本研究的目的是研究嗜酸乳杆菌的细胞表面蛋白可能促进肠道组织的附着。利用基因组序列数据，在已知蛋白质和蛋白质基序数据库中搜索预测的开放阅读框，以确定四种可能参与上皮细胞粘附的蛋白质。利用同源重组构建了编码黏液结合蛋白、纤维连接蛋白结合蛋白、表面层蛋白和两种链球菌R28同源基因的等基因突变。然后在体外评估突变体粘附肠上皮细胞的能力。每个菌株在Caco-2细胞上进行筛选，Caco-2细胞分化和表达正常小肠细胞特征的标记物。在纤维连接蛋白结合蛋白突变体（76%）和粘蛋白结合蛋白突变体（65%）中观察到粘附性显著降低。表面层蛋白突变也显示出粘附能力的降低（84%），但这种突变的影响可能是由于可能嵌入在s层中的多个表面蛋白的丢失。该研究表明，嗜酸乳杆菌NCFM中的多种细胞表面蛋白可以单独促进该生物在体外附着于肠细胞的能力。
Lactobacilli are major inhabitants of the normal microflora of the gastrointestinal tract, and some select species have been used extensively as probiotic cultures. One potentially important property of these organisms is their ability to interact with epithelial cells in the intestinal tract, which may promote retention and host-bacterial communication. However, the mechanisms by which they attach to intestinal epithelial cells are unknown. The objective of this study was to investigate cell surface proteins in Lactobacillus acidophilus that may promote attachment to intestinal tissues. Using genome sequence data, predicted open reading frames were searched against known protein and protein motif databases to identify four proteins potentially involved in adhesion to epithelial cells. Homologous recombination was used to construct isogenic mutations in genes encoding a mucin-binding protein, a fibronectin-binding protein, a surface layer protein, and two streptococcal R28 homologs. The abilities of the mutants to adhere to intestinal epithelial cells were then evaluated in vitro. Each strain was screened on Caco-2 cells, which differentiate and express markers characteristic of normal small-intestine cells. A significant decrease in adhesion was observed in the fibronectin-binding protein mutant (76%) and the mucin-binding protein mutant (65%). A surface layer protein mutant also showed reduction in adhesion ability (84%), but the effect of this mutation is likely due to the loss of multiple surface proteins that may be embedded in the S-layer. This study demonstrated that multiple cell surface proteins in L. acidophilus NCFM can individually contribute to the organism's ability to attach to intestinal cells in vitro.