Microbiota, and the plethora of signalling molecules that they generate, are a major driving force that underlies a striking range of inter-individual physioanatomic and behavioural consequences for the host organism. Among the bacterial effectors, one finds peptidoglycan, the major constituent of the bacterial cell surface. In the steady-state, fragments of peptidoglycan are constitutively liberated from bacterial members of the gut microbiota, cross the gut epithelial barrier and enter the host system. The fate of these peptidoglycan fragments, and the outcome for the host, depends on the molecular nature of the peptidoglycan, as well the cellular profile of the recipient tissue, mechanism of cell entry, the expression of specific processing and recognition mechanisms by the cell, and the local immune context. At the target level, physiological processes modulated by peptidoglycan are extremely diverse, ranging from immune activation to small molecule metabolism, autophagy and apoptosis. In this review, we bring together a fragmented body of literature on the kinetics and dynamics of peptidoglycan interactions with the mammalian host, explaining how peptidoglycan functions as a signaling molecule in the host under physiological conditions, how it disseminates within the host, and the cellular responses to peptidoglycan.

中文翻译：

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哺乳动物宿主对肽聚糖的摄取、识别和反应。

微生物群以及它们产生的大量信号分子是主要驱动力，是宿主生物体的一系列显着的个体间生理解剖学和行为后果的基础。在细菌效应器中，有人发现了肽聚糖，它是细菌细胞表面的主要成分。在稳态下，肽聚糖片段从肠道微生物群的细菌成员中组成性地释放，穿过肠道上皮屏障并进入宿主系统。这些肽聚糖片段的命运和宿主的结果取决于肽聚糖的分子性质，以及受体组织的细胞特征、细胞进入机制、细胞特定加工和识别机制的表达，和局部免疫环境。在目标层面，由肽聚糖调节的生理过程极其多样，从免疫激活到小分子代谢、自噬和细胞凋亡。在这篇综述中，我们汇集了关于肽聚糖与哺乳动物宿主相互作用的动力学和动力学的零散文献，解释了肽聚糖如何在生理条件下作为宿主中的信号分子起作用，它如何在宿主内传播，以及细胞对肽聚糖的反应。