Department of Neurosurgery, David Geffen School of Medicine at the University of California, Los Angeles, CA, United States.
Department of Medicine: Division of Digestive Diseases, David Geffen School of Medicine at the University of California, Los Angeles, CA, United States.
Front Immunol. 2021 Apr 6;12:664344. doi: 10.3389/fimmu.2021.664344. eCollection 2021.
Using a targeted transcriptomics approach, we have analyzed resected brain tissue from a cohort of 53 pediatric epilepsy surgery cases, and have found that there is a spectrum of involvement of both the innate and adaptive immune systems as evidenced by the differential expression of immune-specific genes in the affected brain tissue. The specimens with the highest expression of immune-specific genes were from two Rasmussen encephalitis cases, which is known to be a neuro-immunological disease, but also from tuberous sclerosis complex (TSC), focal cortical dysplasia, and hemimegalencephaly surgery cases. We obtained T cell receptor (TCR) Vβ chain sequence data from brain tissue and blood from patients with the highest levels of T cell transcripts. The clonality indices and the frequency of the top 50 Vβ clonotypes indicated that T cells in the brain were clonally restricted. The top 50 Vβ clonotypes comprised both public and private (patient specific) clonotypes, and the TCR Vβ chain third complementarity region (CDR3) of the most abundant public Vβ clonotype in each brain sample was strikingly similar to a CDR3 that recognizes an immunodominant epitope in either human cytomegalovirus or Epstein Barr virus, or influenza virus A. We found that the frequency of 14 of the top 50 brain Vβ clonotypes from a TSC surgery case had significantly increased in brain tissue removed to control recurrent seizures 11 months after the first surgery. Conversely, we found that the frequency in the blood of 18 of the top 50 brain clonotypes from a second TSC patient, who was seizure free, had significantly decreased 5 months after surgery indicating that T cell clones found in the brain had contracted in the periphery after removal of the brain area associated with seizure activity and inflammation. However, the frequency of a public and a private clonotype significantly increased in the brain after seizures recurred and the patient underwent a second surgery. Combined single cell gene expression and TCR sequencing of brain-infiltrating leukocytes from the second surgery showed that the two clones were CD8 effector T cells, indicating that they are likely to be pathologically relevant.
使用靶向转录组学方法，我们分析了 53 例小儿癫痫手术病例的切除脑组织，发现固有和适应性免疫系统都存在受累范围，这表现在受影响脑组织中免疫特异性基因的差异表达。免疫特异性基因表达最高的标本来自两例朗格汉斯细胞组织细胞增生症病例，已知该病是一种神经免疫性疾病，但也来自结节性硬化症、局灶性皮质发育不良和大脑半球巨脑畸形手术病例。我们从免疫转录本水平最高的患者的脑组织和血液中获得了 T 细胞受体 (TCR) Vβ 链序列数据。克隆性指数和前 50 个 Vβ克隆型的频率表明，大脑中的 T 细胞受到克隆限制。前 50 个 Vβ克隆型包括公共和私有（患者特异性）克隆型，每个脑样本中最丰富的公共 Vβ克隆型的 TCR Vβ 链第三互补区 (CDR3) 与识别人巨细胞病毒或 EBV 或流感病毒 A 中免疫优势表位的 CDR3 惊人地相似。我们发现，从一例结节性硬化症手术病例中切除的脑组织中，前 50 个大脑 Vβ克隆型中的 14 种克隆型的频率在第一次手术后 11 个月控制复发性癫痫发作时显著增加。相反，我们发现，在第二次手术中无癫痫发作的第二位结节性硬化症患者的血液中，前 50 个大脑克隆型中的 18 种克隆型的频率显著降低，这表明在与癫痫活动和炎症相关的脑区切除后，大脑中发现的 T 细胞克隆在外周收缩。然而，在癫痫复发和患者接受第二次手术后，大脑中一种公共和一种私有克隆型的频率显著增加。对第二次手术的脑浸润白细胞进行单细胞基因表达和 TCR 测序表明，这两个克隆是 CD8 效应 T 细胞，表明它们可能与疾病相关。
