Role of mucosal immunity and epithelial–vascular barrier in modulating gut homeostasis

作者：Antonio Di Sabatino, Giovanni Santacroce, Carlo Maria Rossi, Giacomo Broglio, Marco Vincenzo Lenti · 发表于：Internal and Emergency Medicine · 年份：2023 · DOI：10.1007/s11739-023-03329-1 · 被引用次数：110 · 研究领域：Gut microbiota and health、Dietary Effects on Health、Gastrointestinal motility and disorders

Abstract The intestinal mucosa represents the most extensive human barrier having a defense function against microbial and food antigens. This barrier is represented externally by a mucus layer, consisting mainly of mucins, antimicrobial peptides, and secretory immunoglobulin A (sIgA), which serves as the first interaction with the intestinal microbiota. Below is placed the epithelial monolayer, comprising enterocytes and specialized cells, such as goblet cells, Paneth cells, enterochromaffin cells, and others, each with a specific protective, endocrine, or immune function. This layer interacts with both the luminal environment and the underlying lamina propria , where mucosal immunity processes primarily take place. Specifically, the interaction between the microbiota and an intact mucosal barrier results in the activation of tolerogenic processes, mainly mediated by FOXP3 + regulatory T cells, underlying intestinal homeostasis. Conversely, the impairment of the mucosal barrier function, the alteration of the normal luminal microbiota composition (dysbiosis), or the imbalance between pro- and anti-inflammatory mucosal factors may result in inflammation and disease. Another crucial component of the intestinal barrier is the gut–vascular barrier, formed by endothelial cells, pericytes, and glial cells, which regulates the passage of molecules into the bloodstream. The aim of this review is to examine the various components of the intestinal barrier, assessing their interaction...