Data_Sheet_1_Lipoproteins Contribute to the Anti-inflammatory Capacity of Lactobacillus plantarum WCFS1.pdf

Bacterial lipoproteins are well-recognized microorganism-associated molecular patterns, which interact with Toll-like receptor (TLR) 2, an important pattern recognition receptor of the host innate immune system. Lipoproteins are conjugated with two- or three-acyl chains (di- or tri-acyl), which is essential for appropriate anchoring in the cell membrane as well as for the interaction with TLR2. Lipoproteins have mostly been studied in pathogens and have established roles in various biological processes, such as nutrient import, cell wall cross-linking and remodeling, and host-cell interaction. By contrast, information on the role of lipoproteins in the physiology and host interaction of probiotic bacteria is scarce. By deletion of lgt, encoding prolipoprotein diacylglyceryl transferase, responsible for lipidation of lipoprotein precursors, we investigated the roles of the collective group of lipoproteins in the physiology of the probiotic model strain Lactobacillus plantarum WCFS1 using proteomic analysis of secreted proteins. To investigate the consequences of the lgt mutation in host-cell interaction, the capacity of mutant and wild-type bacteria to stimulate TLR2 signaling and inflammatory responses was compared using (reporter-) cell-based models. These experiments exemplified the critical contribution of the acyl chains of lipoproteins in immunomodulation. To the best of our knowledge, this is the first study that investigated collective lipoprotein functions in a model strain for probiotic lactobacilli, and we show that the lipoproteins in L. plantarum WCFS1 are critical drivers of anti-inflammatory host responses toward this strain.

细菌脂蛋白是广为人知的微生物相关分子模式，它们与Toll样受体2（TLR2）相互作用，而TLR2是宿主先天免疫系统中一种重要的模式识别受体。脂蛋白通过连接两个或三个酰基链（二酰基或三酰基）进行共价结合，这对于脂蛋白前体的脂化以及脂蛋白在细胞膜上的适当锚定和与TLR2的相互作用至关重要。脂蛋白主要在病原体中进行了研究，并在多种生物过程中确立了其作用，如营养物质的摄取、细胞壁交联和重塑以及宿主细胞相互作用。相比之下，关于脂蛋白在益生菌生理学和宿主相互作用中的角色信息极为匮乏。通过删除编码前体脂蛋白二酰基甘油转移酶（负责脂蛋白前体脂化）的lgt基因，我们利用分泌蛋白的蛋白质组学分析，研究了脂蛋白集合体在益生菌模式菌株Lactobacillus plantarum WCFS1生理学中的作用。为了研究lgt突变对宿主细胞相互作用的影响，我们通过基于（报告型）细胞模型比较突变型和野生型细菌刺激TLR2信号传导和炎症反应的能力，从而探讨了这一突变的影响。这些实验展示了脂蛋白酰基链在免疫调节中的关键作用。据我们所知，这是首次研究益生菌乳杆菌模式菌株中脂蛋白集合体功能的研究，我们证明了L. plantarum WCFS1中的脂蛋白是该菌株抗炎宿主反应的关键驱动力。