树突状细胞(dendritic cell,DC)是免疫系统中一类强有力的抗原提呈细胞,在始动机体免疫反应中起着至关重要的作用,可刺激B细胞及T细胞发生免疫反应。DC于1973年首次由Steinman发现,因其表面有众多树状突起而得名。DC源于骨髓多能干细胞,进入血液,形成前体细胞,随血液迁移,广泛分布于各组织中。DC在外周血中数量极少,加入某些细胞因子,可使其扩增,如GM-CSF和IL-3可诱导不成熟DC前体细胞的分化与增殖;而TNF-2和CD_(40)配基可促进DC前体细胞的增生及诱导成熟DC的分化。GM-CSF及IL-4的联合刺激能增强DC表面免疫分子的表达,从而增强DC的免疫功能。DC的功能与其不同的成熟阶段有关。正常状态下绝大多数体内DC处于非成 Dendritic cells (DCs) are potent antigen-presenting cells in the immune system and play a crucial role in initiating the immune response of the body. They can stimulate the immune response of B cells and T cells. DC was first discovered by Steinman in 1973 and named for its numerous dendrites. DC derived from bone marrow pluripotent stem cells, into the blood, the formation of precursor cells, with the blood migration, widely distributed in various tissues. DCs in peripheral blood in a very small number, by adding certain cytokines, can make its expansion, such as GM-CSF and IL-3 can induce immature DC precursor cell differentiation and proliferation; and TNF-2 and CD40 ) Ligands can promote the proliferation of DC precursor cells and induce the differentiation of mature DCs. The combined stimulation of GM-CSF and IL-4 can enhance the expression of immune molecules on the surface of DC and enhance the immune function of DC. The function of DC is related to its different stages of maturity. Under normal conditions most of the in vivo DC in non-into