Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
Atopy (Allergy) Research Center, Juntendo University Graduate School of Medicine, Tokyo, Japan.
Curr Pharm Des. 2018;24(10):1079-1091. doi: 10.2174/1381612824666180327113418.
Cathelicidins form one of the major families of antimicrobial peptides and have been identified in many vertebrates, including humans. LL-37, the only human member of the cathelicidin family, is detected in most sites of the human body that is normally exposed to microbes, including the epithelial lining of the skin, gastrointestinal tract, genitourinary tract and lungs. This peptide is also expressed by a variety of epithelial cells and immune cells, such as neutrophils, monocytes and mast cells. LL-37 has emerged as a key component of innate immunity due to its direct antimicrobial activity against a broad spectrum of invading pathogens. It also exhibits diverse immunomodulatory functions by activating both pro- and anti-inflammatory mediators; inducing cell migration, proliferation and differentiation; and regulating apoptosis of epithelial cells and neutrophils. Given that the phenotypic and functional properties of immune compartments are different and significantly impacted by the anatomical sites, tissue-specific factors of host origin and microbial communities play important roles in the regulation of LL-37. This review summarizes the expression and biological functions of LL-37 and discusses its significant roles in the innate immune system based on its anatomical distribution.
抗菌肽 cathelicidins 是一大类抗菌肽家族，已在许多脊椎动物中被发现，包括人类。LL-37 是抗菌肽家族中唯一的人类成员，存在于人体中大多数正常暴露于微生物的部位，包括皮肤、胃肠道、泌尿生殖道和肺部的上皮衬里。这种肽也由各种上皮细胞和免疫细胞表达，如中性粒细胞、单核细胞和肥大细胞。由于其对广泛入侵病原体的直接抗菌活性，LL-37 已成为先天免疫的关键组成部分。它还通过激活促炎和抗炎介质；诱导细胞迁移、增殖和分化；调节上皮细胞和中性粒细胞的凋亡，表现出多种免疫调节功能。鉴于免疫区室的表型和功能特性不同，并且受到解剖部位、宿主来源的组织特异性因素和微生物群落的显著影响，因此，LL-37 的表达和生物学功能及其在先天免疫系统中的重要作用基于其解剖分布进行了综述。
