A review of the dentritic cells research in fish

Dendritic cells (DCs) are currently the most powerful antigen-presenting cellsin vivo and the only ones that can activate the initial T lymphocyte reaction. It plays an important role in innate immunity, adaptive immunity and maintenance of autoimmune tolerance, so it has always been an important area of immunological research. This paper briefly reviews the types of DCs and its function in animals and the cellular markers of various DCs. It summarizes separation, purification method and the method of morphological observation of DCs in fish. Results show that the dendritic cells of fish have many of the hallmarks of mammalian DCs including the ability to phagocytose small particles, stimulate T cell proliferation, induce CD4⁺ T cell activation, and the expression of dendritic cell markers, activation by Toll like receptor-ligands, and the ability to migrate in vivo and stimulate a mixed lymphocyte reaction; the molecular markers of DCs in different fishes are not exactly the same; DCs in fish were found in various organs including head kidney, kidney, gill, skin, thymus, spleen and intestine. Although some progress has been made in the research of DCs in fish, there are still many important problems to be solved: ① there are currently no cellular markers for DCs in fish, so strengthening the research in this field is useful to enhance the research level of DCs’ isolation, distribution in vivo and function. ② It is necessary to intensify and improve the technique of isolation and culture of DCs in fish and to master the methods of isolation and culture of various DCs. ③ Enhancing the research of DCs in antigen-presentation in fish has important theoretical significance for further research of immune mechanism and rational design and application of vaccine.