Shanahan F
Department of Medicine, National University of Ireland, Cork, Ireland.
Adv Exp Med Biol. 1999;473:1-9. doi: 10.1007/978-1-4615-4143-1_1.
The close anatomic juxtaposition of epithelial cells with lymphocytes lining the intestinal tract facilitates communication between the two cell types. This intercellular dialogue is important for mucosal development and has a conditioning effect on mucosal structure, function, and response to tissue injury. Lymphoepithelial communication is bi-directional, and mediated in large part, by shared ligands and receptors. The chemical messengers involved include cytokines, growth factors, local hormones, and products of arachidonate metabolism. The interdependency between the epithelium and adjacent lymphoid cells is such that the epithelium is considered to have a central role in the mucosal immune system and is an active participant in both the afferent and efferent limbs of the mucosal immune response. The molecular crosstalk between the epithelium and adjacent lymphocytes is just one aspect of a more complex network of intercellular signalling within the intestinal mucosa and upon which the integrity of the mucosa is dependent. Thus, there are extensive interactions between nerve and immune cells and between the enteric flora and the epithelium and amongst intestinal mesenchymal cells including fibroblasts and vascular endothelial cells. Disruption of any aspect of the mucosal microenvironment, as has been achieved with selective genetically engineered murine models, is associated with impaired mucosal defence and inflammation.
上皮细胞与肠道内淋巴细胞在解剖学上紧密相邻，这有利于两种细胞类型之间的交流。这种细胞间对话对黏膜发育很重要，对黏膜结构、功能及对组织损伤的反应具有调节作用。淋巴细胞与上皮细胞的交流是双向的，在很大程度上由共享的配体和受体介导。所涉及的化学信使包括细胞因子、生长因子、局部激素以及花生四烯酸代谢产物。上皮细胞与相邻淋巴细胞之间相互依存，以至于上皮细胞被认为在黏膜免疫系统中起核心作用，并且是黏膜免疫反应传入和传出环节的积极参与者。上皮细胞与相邻淋巴细胞之间的分子串扰只是肠黏膜内更复杂的细胞间信号网络的一个方面，而黏膜的完整性依赖于此网络。因此，神经细胞与免疫细胞之间、肠道菌群与上皮细胞之间以及包括成纤维细胞和血管内皮细胞在内的肠道间充质细胞之间存在广泛的相互作用。正如通过选择性基因工程小鼠模型所实现的那样，黏膜微环境任何方面的破坏都与黏膜防御受损和炎症相关。
