Proietto Anna I, Lahoud Mireille H, Wu Li
Immunology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.
Immunol Cell Biol. 2008 Nov-Dec;86(8):700-8. doi: 10.1038/icb.2008.63. Epub 2008 Sep 9.
Dendritic cells (DC) are antigen-presenting cells that activate naive T cells. Murine DC are a heterogeneous population and can be subdivided into distinct subsets with different immune regulatory functions, namely the conventional DC (cDC), which include the CD8(+)Sirpalpha(-) and CD8(-)Sirpalpha(+) DC, and the plasmacytoid DC (pDC). In this study, the phenotype and function of DC subsets in both the thymus and spleen were compared. Significant differences between the thymic and splenic DC were observed in the expression of genes encoding chemokine receptors (CCRs), toll-like receptors (TLRs) and chemokines. Thymic DC expressed high levels of genes encoding a unique set of chemokines (CCL17 and CCL22) known to be important for T-cell development. Moreover, the capacity of the DC from the two organs to produce IL-6, IFN-alpha and IL-12p70 in response to the TLR 9 agonist CpG differed markedly, indicating intrinsic functional differences between subsets with similar surface phenotype. These results indicate that the microenvironment is an important factor that contributes to the functional specification of DC subsets in different lymphoid tissues.
树突状细胞（DC）是激活初始T细胞的抗原呈递细胞。小鼠DC是一个异质性群体，可细分为具有不同免疫调节功能的不同亚群，即传统DC（cDC），包括CD8(+)Sirpalpha(-)和CD8(-)Sirpalpha(+) DC，以及浆细胞样DC（pDC）。在本研究中，对胸腺和脾脏中DC亚群的表型和功能进行了比较。在编码趋化因子受体（CCR）、Toll样受体（TLR）和趋化因子的基因表达方面，观察到胸腺DC和脾脏DC之间存在显著差异。胸腺DC高水平表达一组独特的编码趋化因子（CCL17和CCL22）的基因，已知这些趋化因子对T细胞发育很重要。此外，来自这两个器官的DC对TLR 9激动剂CpG产生IL-6、IFN-α和IL-12p70的能力明显不同，表明具有相似表面表型的亚群之间存在内在功能差异。这些结果表明，微环境是促成不同淋巴组织中DC亚群功能特化的一个重要因素。
