天然免疫是抵御病原微生物入侵的最初免疫反应 ,而内源性抗菌肽是天然免疫的重要介质。近 2 0年来 ,已发现 1 2 0余种抗菌肽 ,防御素是其中的一大家族 ,在自然界分布广泛 ,从植物、昆虫到动物均有表达。在人类 ,防御素按结构分为α 防御素、β 防御素两种亚型 ,α -防御素主要 Natural immunity is the initial immune response against the invasion of pathogenic microorganisms, and endogenous antimicrobial peptides are important mediators of innate immunity. In the recent 20 years, more than 120 kinds of antimicrobial peptides have been found, and defensins are one of the major families, which are widely distributed in nature and expressed from plants, insects and animals. In humans, defensins are classified by structure into alpha defensins, beta defensins, and alpha-defensins