Centre de Recherche en Transplantation et Immunologie UMR1064, INSERM, Université de Nantes, Nantes, France; Faculté de Médecine, Université de Nantes, Nantes, France.
Centre de Recherche en Transplantation et Immunologie UMR1064, INSERM, Université de Nantes, Nantes, France; Institut de Transplantation Urologie Néphrologie (ITUN), CHU Nantes, Nantes, France.
J Autoimmun. 2018 Mar;88:61-74. doi: 10.1016/j.jaut.2017.10.005. Epub 2017 Oct 18.
Several lines of evidence support a key role for CD8 T cells in central nervous system tissue damage of patients with multiple sclerosis. However, the precise phenotype of the circulating CD8 T cells that may be recruited from the peripheral blood to invade the CNS remains largely undefined to date. It has been suggested that IL-17 secreting CD8 (Tc17) T cells may be involved, and in humans these cells are characterized by the expression of CD161. We focused our study on a unique and recently described subset of CD8 T cells characterized by an intermediate expression of CD161 as its role in neuroinflammation has not been investigated to date. The frequency, phenotype, and function of CD8 T cells with an intermediate CD161 expression level were characterized ex-vivo, in vitro, and in situ using RNAseq, RT-PCR, flow cytometry, TCR sequencing, and immunohistofluorescence of cells derived from healthy volunteers (n = 61), MS subjects (n = 90), as well as inflammatory (n = 15) and non-inflammatory controls (n = 6). We report here that CD8CD161 T cells present characteristics of effector cells, up-regulate cell-adhesion molecules and have an increased ability to cross the blood-brain barrier and to secrete IL-17, IFNγ, GM-CSF, and IL-22. We further demonstrate that these cells are recruited and enriched in the CNS of MS subjects where they produce IL-17. In the peripheral blood, RNAseq, RT-PCR, high-throughput TCR repertoire analyses, and flow cytometry confirmed an increased effector and transmigration pattern of these cells in MS patients, with the presence of supernumerary clones compared to healthy controls. Our data demonstrate that intermediate levels of CD161 expression identifies activated and effector CD8 T cells with pathogenic properties that are recruited to MS lesions. This suggests that CD161 may represent a biomarker and a valid target for the treatment of neuroinflammation.
有几条证据表明，CD8 T 细胞在多发性硬化症患者的中枢神经系统组织损伤中起着关键作用。然而，迄今为止，从外周血募集并侵入中枢神经系统的循环 CD8 T 细胞的确切表型在很大程度上仍未确定。有人提出，IL-17 分泌的 CD8（Tc17）T 细胞可能参与其中，在人类中，这些细胞的特征是表达 CD161。我们的研究集中在一种独特的、最近描述的 CD8 T 细胞亚群上，其特征是 CD161 的表达中等，因为其在神经炎症中的作用尚未得到研究。我们使用 RNAseq、RT-PCR、流式细胞术、TCR 测序和源自健康志愿者（n=61）、MS 患者（n=90）以及炎症（n=15）和非炎症对照（n=6）的细胞的免疫荧光，对具有中等 CD161 表达水平的 CD8 T 细胞的频率、表型和功能进行了体外和原位研究。我们在此报告，CD8CD161 T 细胞具有效应细胞的特征，上调细胞黏附分子，并有增加的穿过血脑屏障和分泌 IL-17、IFNγ、GM-CSF 和 IL-22 的能力。我们进一步证明，这些细胞在 MS 患者的中枢神经系统中被募集和富集，在那里它们产生 IL-17。在外周血中，RNAseq、RT-PCR、高通量 TCR 库分析和流式细胞术证实，与健康对照组相比，这些细胞在 MS 患者中具有增加的效应和迁移模式，存在多余的克隆。我们的数据表明，中等水平的 CD161 表达可识别具有致病性的激活和效应 CD8 T 细胞，这些细胞被募集到 MS 病变部位。这表明 CD161 可能代表神经炎症治疗的生物标志物和有效靶点。
