Kim Hyo Jae, Ban Jae-Jun, Kang Junho, Im Hye-Ryeong, Ko Sun Hi, Sung Jung-Joon, Park Sung-Hye, Park Jong-Eun, Choi Seok-Jin
Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea.
Department of Neurology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul 03080, Republic of Korea.
Brain Commun. 2024 Nov 27;6(6):fcae428. doi: 10.1093/braincomms/fcae428. eCollection 2024.
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that affects motor neurons in the brain and spinal cord. Despite the crucial role of aberrant immune responses in ALS pathogenesis, studies investigating immunological profiles in the cerebrospinal fluid (CSF) of patients with ALS have reported inconsistent findings. Herein, we explored the intrathecal adaptive immune response and features of circulating T cells between CSF and blood of patients with ALS using single-cell RNA and T-cell receptor (TCR) sequencing. This study comprised a total of 11 patients with apparently sporadic ALS and three controls with non-inflammatory diseases. We collected CSF from all participants, and for three patients with ALS, we additionally obtained paired samples of peripheral blood mononuclear cells (PBMCs). Utilizing droplet-based single-cell RNA and TCR sequencing, we analysed immunological profiles, gene expression characteristics and clonality. Furthermore, we examined T-cell characteristics in both PBMC and CSF samples, evaluating the shared T-cell clones across these compartments. In the CSF, patients with ALS exhibited a lower proportion of CD4 T cells (45.2 versus 61.2%, = 0.005) and a higher proportion of CD8 effector memory T cells (TEMs) than controls (21.7 versus 16.8%, = 0.060). Higher clonality was observed in CD8 TEMs in patients with ALS compared with controls. In addition, CSF macrophages of patients with ALS exhibited a significant increase in chemokines recruiting CD8 TEMs. Immunohistochemical analysis showed slightly higher proportions of T cells in the perivascular and parenchymal spaces in patients with ALS than in controls, and CD8 TEMs co-localized with neurons or astrocytes in the motor cortices of patients with ALS. Clonally expanded CD8 TEMs primarily comprised shared T-cell clones between CSF and PBMCs. Moreover, the shared CD8 TEMs of PBMCs exhibited gene expression profiles similar to CSF T cells. Patients with ALS showed an increase in proportion and clonality of CD8 TEMs and activated features of macrophages in CSF. The shared T-cell clone between CSF and blood was mainly composed of expanded CD8 TEMs. In conclusion, single-cell immune profiling provided novel insights into the pathogenesis of ALS, characterized by activated macrophages and clonally expanded CD8 T cells potentially communicating with the central nervous system and peripheral circulation.
肌萎缩侧索硬化症（ALS）是一种致命的神经退行性疾病，会影响大脑和脊髓中的运动神经元。尽管异常免疫反应在ALS发病机制中起着关键作用，但对ALS患者脑脊液（CSF）中的免疫特征进行研究的结果并不一致。在此，我们使用单细胞RNA和T细胞受体（TCR）测序，探索了ALS患者脑脊液与血液之间的鞘内适应性免疫反应及循环T细胞的特征。本研究共纳入了11例明显散发型ALS患者和3例非炎症性疾病对照。我们收集了所有参与者的脑脊液，对于3例ALS患者，我们还额外获取了外周血单核细胞（PBMC）的配对样本。利用基于微滴的单细胞RNA和TCR测序，我们分析了免疫特征、基因表达特征和克隆性。此外，我们检查了PBMC和脑脊液样本中的T细胞特征，评估了这些区室之间共享的T细胞克隆。在脑脊液中，与对照组相比，ALS患者的CD4 T细胞比例较低（45.2%对61.2%，P = 0.005），而CD8 效应记忆T细胞（TEM）比例较高（21.7%对16.8%，P = 0.060）。与对照组相比，ALS患者的CD8 TEM克隆性更高。此外，ALS患者的脑脊液巨噬细胞在招募CD8 TEM的趋化因子方面显著增加。免疫组织化学分析显示，与对照组相比，ALS患者血管周围和实质空间中的T细胞比例略高，且CD8 TEM在ALS患者运动皮层中与神经元或星形胶质细胞共定位。克隆性扩增的CD8 TEM主要由脑脊液和PBMC之间共享的T细胞克隆组成。此外，PBMC中共享的CD8 TEM表现出与脑脊液T细胞相似的基因表达谱。ALS患者脑脊液中CD8 TEM的比例和克隆性增加，巨噬细胞呈现激活特征。脑脊液和血液之间共享的T细胞克隆主要由扩增的CD8 TEM组成。总之，单细胞免疫分析为ALS的发病机制提供了新见解，其特征为激活的巨噬细胞和克隆性扩增的CD8 T细胞，可能与中枢神经系统和外周循环相互作用。
