title: Neuron-interacting satellite glial cells in human trigeminal ganglia have an APC phenotype.
abstract: 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.
authors.affiliation: Department of Virology, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Monique
authors.initials: M
authors.lastname: van Velzen
authors.forename: Jon D
authors.initials: JD
authors.lastname: Laman
authors.forename: Alex
authors.initials: A
authors.lastname: Kleinjan
authors.forename: Angelique
authors.initials: A
authors.lastname: Poot
authors.forename: Albert D M E
authors.initials: AD
authors.lastname: Osterhaus
authors.forename: Georges M G M
authors.initials: GM
authors.lastname: Verjans
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000938:Antigen-Presenting Cells / Q000276:immunology* / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism; D004926:Escherichia coli / Q000276:immunology; D006801:Humans; D016130:Immunophenotyping; D008264:Macrophages / Q000276:immunology / Q000378:metabolism; D008875:Middle Aged; D023461:Myeloid Progenitor Cells / Q000276:immunology / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D010587:Phagocytosis / Q000276:immunology; D027161:Satellite Cells, Perineuronal / Q000276:immunology* / Q000378:metabolism; D012668:Trigeminal Ganglion / Q000166:cytology* / Q000276:immunology* / Q000378:metabolism
chemical_list: D015415:Biomarkers