树突状细胞由多种表型特征及生物学功能特性不同的亚群组成，单核细胞源性树突状细胞是其中的重要组成群体。近年来研究表明,人体内外周血单核细胞由CD14++CD16-和CD14+CD16+两个群体组成，小鼠体内则由CD115+Ly6Chigh和CD115+Ly6Clow组成；不同亚群单核细胞可发育分化成为具有不同表型特征的树突状细胞，在体内外诱导产生不同类型的免疫应答反应。小鼠体内CD115+Ly6Clow群体是机体稳定状态下外周组织器官树突状细胞的重要前体细胞， CD115+Ly6Chigh单核细胞是炎症状态下外周淋巴器官中树突状细胞的重要来源。CD115+Ly6Chigh来源的树突状细胞，一方面可以直接提呈外周摄取的抗原，另一方面还可将MHCⅠ/抗原肽复合物传递给淋巴组织中原住性树突状细胞。不同来源树突状细胞间的协同和交互作用确保机体诱发针对不同外源抗原刺激的有效免疫应答。

Dendritic cells (DCs) have different subtypes with distinct phenotypes and biological functions. Meloyiod dendritic cell subtype is one of the most important DCs subtypes. Recent studies have revealed that human monocytes were composed of CD14++CD16- and CD14+CD16+ subtypes, and mouse monocytes consisted of CD115+Ly6Chigh and CD115+Ly6Clow/ subtypes. Different monocyte subsets differentiate into different dendritic cells subsets with distinct phenotypes and induce different types of immune responses in vivo or in vitro. Under steady state, mouse CD115+Ly6Clow monocyte subtype is an important precursor of dendritic cells in peripheral organs and tissues, but in inflammatory response, CD115+Ly6Chigh monocyte subtype is the main precursor of dendritic cells in peripheral lymphoid organs. CD115+Ly6Chigh monocyte derived dendritic cells can directly present antigens that acquired in peripheral tissues after differentiating into dendritic cells, and transfer their MHCⅠ/peptide complex to residential dendritic cells as well. The cooperation and interaction of dendritic cells from different sources enable the immune system to respond to different stimuli properly.

国家自然科学基金资助项目(No.30872301)