Vandenabeele S, Hochrein H, Mavaddat N, Winkel K, Shortman K
The Walter and Eliza Hall Institute of Medical Research, P.O. Royal Melbourne Hospital, 3050 Melbourne, Victoria, Australia.
Blood. 2001 Mar 15;97(6):1733-41. doi: 10.1182/blood.v97.6.1733.
In this study, 2 distinct populations of mature dendritic cells (DCs) were identified in the human thymus. The major population is CD11b-, CD11c+, and CD45RO(low) and does not express myeloid-related markers. It displays all the characteristics of mature DCs with a typical dendritic morphology, high surface levels of HLA-DR, CD40, CD83, and CD86, and expression of DC-lysosome-associated membrane glycoprotein messenger RNA (mRNA). In addition, CD11b- thymic DCs do not express macrophage inflammatory protein-1alpha (MIP-1alpha) mRNA, but express thymus-expressed chemokine (TECK) mRNA and are able to secrete bioactive interleukin 12 (IL-12) upon stimulation. In contrast, the minor and variable thymic DC population is CD11b+, CD11c(high), and CD45RO(high) and comprises CD83+CD14- mature and CD83- CD14+ immature DCs. It expresses macrophage-colony stimulating factor receptor, MIP-1alpha mRNA and high amounts of decysin mRNA after CD40 activation, but does not express TECK and is a weak bioactive IL-12 producer. Also identified were the IL-3Ralpha(high) plasmacytoid cells, which are present in the thymic cortex and medulla. Upon culture with IL-3, granulocyte/macrophage-colony stimulating factor, and CD40 ligand, the plasmacytoid cells can adopt a phenotype resembling that of freshly isolated CD11b- thymic DCs. However, these plasmacytoid-derived DCs fail to secrete bioactive IL-12; therefore, conclusions cannot be made about a direct relation between thymic plasmacytoid cells and CD11b- DCs. Whereas CD11b+ thymic DCs appear to be related to tonsillar germinal-center DCs, the major CD11b- IL-12-secreting human thymus DC population has similarities to mouse CD11b- CD8+ DCs.
在本研究中，在人类胸腺中鉴定出2种不同的成熟树突状细胞（DC）群体。主要群体为CD11b-、CD11c+和CD45RO（低表达），不表达髓系相关标志物。它具有成熟DC的所有特征，具有典型的树突形态、高表面水平的HLA-DR、CD40、CD83和CD86，以及DC-溶酶体相关膜糖蛋白信使核糖核酸（mRNA）的表达。此外，CD11b-胸腺DC不表达巨噬细胞炎性蛋白-1α（MIP-1α）mRNA，但表达胸腺表达趋化因子（TECK）mRNA，并且在受到刺激时能够分泌生物活性白细胞介素12（IL-12）。相比之下，次要且可变的胸腺DC群体为CD11b+、CD11c（高表达）和CD45RO（高表达），包括CD83+CD14-成熟DC和CD83-CD14+未成熟DC。它表达巨噬细胞集落刺激因子受体，并在CD40激活后表达MIP-1α mRNA和大量的decysin mRNA，但不表达TECK，是一种较弱的生物活性IL-12产生者。还鉴定出IL-3Rα（高表达）浆细胞样细胞，其存在于胸腺皮质和髓质中。在用IL-3、粒细胞/巨噬细胞集落刺激因子和CD40配体培养后，浆细胞样细胞可呈现类似于新鲜分离的CD11b-胸腺DC的表型。然而，这些浆细胞样来源的DC不能分泌生物活性IL-12；因此，无法得出胸腺浆细胞样细胞与CD11b-DC之间存在直接关系的结论。虽然CD11b+胸腺DC似乎与扁桃体生发中心DC相关，但主要的分泌IL-12的CD11b-人类胸腺DC群体与小鼠CD11b-CD8+DC有相似之处。
