An overview of complement systems in teleosts. (December 2022)

• Record Type: Journal Article
• Authors: Li, Mo-fei; Zhang, Hong-qiang
• Is Part Of: Developmental and comparative immunology. Volume 137(2022)
• Publication Date: 2022-12
• Subjects: Teleost -- Complement system -- Immunity -- Regulator -- Pathogen; MBL mannose-binding lectin -- MASP MBL-associated serine protease -- MAC membrane attack complex -- C3aR C3a receptor -- C5aR C5a receptor -- CFI complement factor I -- CFH complement factor H -- C1INH C1 inhibitor -- DAF decay accelerating factor -- DC dendritic cell -- CR complement receptor -- MCP membrane cofactor protein -- CFB complement factor B -- CFD complement factor D -- C4BP C4 binding protein; Immunology -- Periodicals; Developmental immunology -- Periodicals; 616.079
• DOI: 10.1016/j.dci.2022.104520
• Languages: English
• ISSNs: 0145-305X

Abstract

Abstract: Complement plays an important role in the innate immune system, and it comprises about 35 individual proteins. In mammals, complement is activated via three different pathways, the classical pathway, the alternative pathway, and the lectin pathway. All three activation pathways produce C3-convertase in different forms. C3-convertase cleaves C3 to C3a and C3b and initiates a cascade of cleavage and activation, eventually resulting in the formation of the membrane attack complex. Complement activation results in the generation of activated fragments that are involved in microbial killing, phagocytosis, inflammatory reactions, immune complex clearance, and antibody production. Although the complement system has been studied extensively in mammals, complement is less well understood in teleosts. This review summarizes the current knowledge of the teleost complement components involved in phagocytosis, chemotaxis, and cell lysis. We report the characterized complement components in various teleost species. In addition, we provide a comprehensive compilation of complement regulators, and this information is used to analyze the role of complement regulators in pathogen infection. The influence of complement receptors on the immune responses of teleosts is reviewed. Finally, we propose directions for future study of the molecular evolution, structure, and function of complement components in teleosts. This review provides new insights into the complement system of recognition and defense, and such knowledge is essential for the development of new immune strategies in aquaculture. Highlights: This review summarizes current research progress of teleosts complement systems. The homologue of mammalian complement components are identified in teleosts. Complement of teleosts plays an important role in immune system. Regulators of complement activation are studied in teleosts. Complement receptors may involve in the immune responses of teleosts.