van Velzen Monique, Laman Jon D, Kleinjan Alex, Poot Angelique, Osterhaus Albert D M E, Verjans Georges M G M
Department of Virology, Erasmus Medical Center, Rotterdam, The Netherlands.
J Immunol. 2009 Aug 15;183(4):2456-61. doi: 10.4049/jimmunol.0900890. Epub 2009 Jul 27.
Satellite glial cells (SGC) in sensory ganglia tightly envelop the neuronal cell body to form discrete anatomical units. This type of glial cell is considered neuroectoderm-derived and provides physical support to neuron somata. There are scattered hints in the literature suggesting that SGC have an immune-related function within sensory ganglia. In this study, we addressed the hypothesis that SGC are tissue-resident APC. The immune phenotype and function of a large series (n = 40) of human trigeminal ganglia (TG) were assessed by detailed flow cytometry, in situ analyses, and functional in vitro assays. Human TG-resident SGC (TG-SGC) uniformly expressed the common leukocyte marker CD45, albeit at lower levels compared with infiltrating T cells, and the macrophage markers CD14, CD68, and CD11b. In addition, TG-SGC expressed the myeloid dendritic cell (DC) marker CD11c, the T cell costimulatory molecules CD40, CD54, CD80, and CD86 and MHC class II. However, the mature DC marker CD83 was absent on TG-SGC. Functionally, TG-SGC phagocytosed fluorescent bacteria, but were unable to induce an allogeneic MLR. Finally, TG-infiltrating T cells expressed the T cell inhibitory molecules CD94/NKG2A and PD-1, and the interacting TG-SGC expressed the cognate ligands HLA-E and PD-L1, respectively. In conclusion, the data demonstrate that human TG-SGC have a unique leukocyte phenotype, with features of both macrophages and immature myeloid DC, indicating that they have a role as TG-resident APC with potential T cell modulatory properties.
感觉神经节中的卫星神经胶质细胞（SGC）紧密包裹神经元细胞体，形成离散的解剖学单位。这种类型的神经胶质细胞被认为起源于神经外胚层，并为神经元胞体提供物理支持。文献中有一些零散的线索表明，SGC在感觉神经节内具有免疫相关功能。在本研究中，我们探讨了SGC是组织驻留抗原呈递细胞（APC）这一假说。通过详细的流式细胞术、原位分析和体外功能测定，评估了大量（n = 40）人三叉神经节（TG）的免疫表型和功能。人TG驻留SGC（TG-SGC）均一性表达常见白细胞标志物CD45，尽管与浸润性T细胞相比表达水平较低，同时还表达巨噬细胞标志物CD14、CD68和CD11b。此外，TG-SGC表达髓样树突状细胞（DC）标志物CD11c、T细胞共刺激分子CD40、CD54、CD80和CD86以及MHC II类分子。然而，TG-SGC上不存在成熟DC标志物CD83。在功能上，TG-SGC吞噬荧光细菌，但无法诱导同种异体混合淋巴细胞反应（MLR）。最后，TG浸润性T细胞表达T细胞抑制分子CD94/NKG2A和PD-1，与之相互作用的TG-SGC分别表达同源配体HLA-E和PD-L1。总之，数据表明人TG-SGC具有独特的白细胞表型，兼具巨噬细胞和未成熟髓样DC的特征，表明它们作为TG驻留APC具有潜在的T细胞调节特性。
