Division of Gastroenterology, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL 33101, USA.
Curr Opin Gastroenterol. 2011 Mar;27(2):125-31. doi: 10.1097/MOG.0b013e3283438dea.
In this article, we provide an update of the latest findings related to the innate immunity in the small intestine. In particular, we will focus on innate immune receptors and antimicrobial strategies that keep luminal bacteria and viral pathogens under control to avoid mucosal damage. These strategies include IgA secretion and antimicrobial peptides produced by Paneth cells, and downregulation or anergy of the innate immune receptors themselves.
Pattern-recognition receptors are the main target in the study of innate immunity in the intestinal mucosa due to their involvement in the regulation of host-commensal interactions. It has been shown that TLR5-deficient mice develop metabolic syndrome and have altered intestinal microbiota. On the contrary, NOD2 has been associated with the activation of autophagy and the inhibition of TLR4. Moreover, NOD2 has been described to be essential to keep a feedback loop in the host-commensal homeostasis, through the kinase Rip-2.
Innate immunity in the small intestine is mainly characterized by IgA secretion and Paneth cell antimicrobial function. In both cases pattern-recognition receptors, Toll-like receptors and nucleotide-binding and oligomerization domain-like receptors, are involved. A better understanding of the innate immunity in the small intestine would provide valuable information to develop vaccines against pathogens.
本文就小肠固有免疫的最新研究进展进行综述。具体而言，我们将重点介绍固有免疫受体和抗菌策略，这些策略可以控制肠道腔内细菌和病毒病原体，避免黏膜损伤。这些策略包括 IgA 分泌和潘氏细胞产生的抗菌肽，以及固有免疫受体自身的下调或失能。
模式识别受体是研究肠黏膜固有免疫的主要靶点，因为它们参与宿主共生相互作用的调节。已经表明，TLR5 缺陷型小鼠会发展为代谢综合征，并伴有肠道微生物群改变。相反，NOD2 与自噬的激活和 TLR4 的抑制有关。此外，NOD2 已被描述为通过激酶 Rip-2 对宿主共生稳态的反馈环至关重要。
小肠固有免疫的主要特征是 IgA 分泌和潘氏细胞抗菌功能。在这两种情况下，都涉及到模式识别受体、Toll 样受体和核苷酸结合寡聚结构域样受体。对小肠固有免疫的深入了解将为开发针对病原体的疫苗提供有价值的信息。
