抗菌肽LL-37的研究进展

Advances in Antimicrobial Peptide LL-37

抗菌肽是机体天然免疫的重要组成部分，LL-37是人体内发现的唯一一种Cathelicidin类抗菌肽，其前体肽hCAP-18主要由中性粒细胞释放，经丝氨酸蛋白酶3切割产生有活性的LL-37。LL-37的表达及活性作用受到体内、体外多种因素的影响。LL-37除了直接杀菌作用外，还能调节免疫和炎症介质的释放、引起免疫细胞分化及趋化、伤口愈合、细胞因子和组氨酸释放、中和内毒京和抗肿瘤.LL-37的直接杀菌作用并不是它最重要的免疫方式，后几种作用才是LL-37参与免疫反应的主要途径。人们通过分析LL-37的结构，设计类似LL-37多肽的新型多肽，发现它们也有相似的免疫作用。

The antimicrobial peptides（AMP） are essential components of innate immunity. The cathelicidin is one of the families of AMPs, that have been indentified in several mammalian and non-mammalian species. LL-37 belongs to the cathelicidin family and is the only hathelicidin found in human being. Its precursor protein hCAP-18 is secreted by neutrophils and becomes LL-37 after being cleaved by serine proteinase 3. The expression and the activities of LL-37 are influenced by many facfors in vivo and in vitro. Besides the direct capacity to inactivate microbes, LL-37 has also been found to act as immune modulators and it can affect the release of mediators of inflammation, influencing diverse processes such as ceU division and migration, wound healing, the release of cytokines and hisamine, LPS neutralizing, and anti-tumor activities, the latter effects is the major route. The peptiedes imitating the structure of LL-37 have the Similar activities.