Masuda Koji, Nakamura Kiminori, Yoshioka Sawako, Fukaya Rie, Sakai Naoki, Ayabe Tokiyoshi
Innate Immunity Laboratory, Graduate School of Life Science, Department of Cell Biological Science, Faculty of Advanced Life Science, Hokkaido University, Sapporo, Hokkaido, Japan.
Adv Otorhinolaryngol. 2011;72:97-9. doi: 10.1159/000324625. Epub 2011 Aug 18.
The antimicrobial peptide is one of major effectors of the innate immunity, and is common in the entire multicellular organisms. In mammals, one family of antibacterial peptide named defensins plays a central role in host defense, especially in the epithelial surface such as oral cavity, skin and the intestine. Recently, the importance of the antimicrobial peptides has been widely recognized. The epithelium of the gut is a largest surface that is exposed to various pathogens in the environment. It is the Paneth cells that produce antimicrobial peptides, α-defensins in the small intestine. Paneth cells contribute to mucosal innate immunity by sensing bacteria and releasing microbicidal activities mostly from activated α-defensins. In mice, α-defensins, named cryptdins, consisted of six major isoforms (cryptdin-1 to cryptdin-6), and among those cryptdin-4 is the most microbicidal, suggesting that cryptdin-4 has a pivotal role in innate immunity. Paneth cell α-defensins have selective activities against commensal bacteria which may be associated with compositions of intestinal microbiota in vivo and homeostasis of the entire intestine. In addition, Paneth cell α-defensins appeared to be regulated topographically to control intestinal integrity.
抗菌肽是天然免疫的主要效应分子之一，在整个多细胞生物中普遍存在。在哺乳动物中，一类名为防御素的抗菌肽在宿主防御中发挥核心作用，尤其是在口腔、皮肤和肠道等上皮表面。最近，抗菌肽的重要性已得到广泛认可。肠道上皮是暴露于环境中各种病原体的最大表面。产生抗菌肽（小肠中的α-防御素）的是潘氏细胞。潘氏细胞通过感知细菌并主要从活化的α-防御素释放杀菌活性，从而有助于黏膜天然免疫。在小鼠中，α-防御素（称为隐窝素）由六种主要亚型（隐窝素-1至隐窝素-6）组成，其中隐窝素-4的杀菌能力最强，这表明隐窝素-4在天然免疫中起关键作用。潘氏细胞α-防御素对共生细菌具有选择性活性，这可能与体内肠道微生物群的组成以及整个肠道的稳态有关。此外，潘氏细胞α-防御素似乎受到地形学调控以控制肠道完整性。
