胶凝素及其在真菌感染中的作用

Collectins and Its Roles in the Fungal Infections

胶凝素是一组具有以胶原蛋白和凝集素区结构为特征的蛋白,包括甘露糖结合凝集素、肺表面活性物质脱辅基蛋白A和D、CL-L1、CL-46、胶固素等,是脊椎动物天然免疫中的重要因子。胶凝素选择性地识别病原微生物表面糖基,使胶凝素具有识别自我和异己的能力。胶凝素与病原微生物结合,通过活化补体及补体C3沉积而对病原微生物发挥调理作用;或直接凝集微生物,增强吞噬细胞的吞噬作用而达到杀死微生物的目的。

The collectins, including mannan-binding lectin （MBL）, surfactant protein A and D （ SP-A and SP-D）, CL-L1, CL-46 and conglutinin, are oligomeric proteins composed of agglutinin-like domains （CRDs） and collagenous regions. The collectins play an important role in the innate immunity of the vertebrates. Collectins selectively recognize the carbohydrate structures on the surface of the microorganisms and thus have an ability to distinguish self from nonself. Collectins binding to the microorganisms could lead to either opsonization of microorganisms via complement activation and deposition of C3 or agglutination of microorganisms and upregulation of the phagocytosis by the phagocytes.In this review, we focus on the structures and biologic characteristics of collectins and their functions in the defenses on the fungal infections.