Collectins and Its Roles in the Fungal Infections

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.