Goebels N, Hofstetter H, Schmidt S, Brunner C, Wekerle H, Hohlfeld R
Department of Neuroimmunology, Max Planck Institute for Neurobiology, Martinsried, Germany.
Brain. 2000 Mar;123 Pt 3:508-18. doi: 10.1093/brain/123.3.508.
Autoantigen-specific T-lymphocytes are present in patients with autoimmune disease and in normal subjects. Little is currently known about the temporal variation (dynamics) of the immune repertoire of these autoreactive T cells. We analysed the long-term variation of the immune repertoire of T cells specific for myelin basic protein (MBP) in five untreated patients with multiple sclerosis and four normal control subjects over a mean observation period of 6 years. MBP-specific CD4(+) T-cell lines were selected with purified human MBP, and their epitope specificity was mapped with overlapping synthetic peptides. Three distinct patterns of repertoire development were observed. (i) Two patients and three control subjects maintained a broad epitope response with fluctuations over time. (ii) Two patients initially showed a focused response that broadened over the course of 6 years; this finding could be described as intramolecular epitope spreading. (iii) In one patient and one control subject, a strikingly focused response, which was directed to a cluster of nested epitopes in the MBP region 83-102, persisted over time. T-cell receptor Vbeta sequence analysis allowed us to trace individual clones of MBP-specific T cells for up to 7 years in the peripheral circulation in four of the five patients and three of the four controls, suggesting that the long-term persistence of MBP-specific T-cell clones is a common feature of the T-cell repertoire not unique to multiple sclerosis. The persisting MBP-specific T-cell clones were not detectable in the blood of one of the patients by complementarity-determining region (CDR)-3 spectratyping, indicating that their frequency does not exceed 1 in 5000 T cells. The temporal characteristics of the MBP-specific T-cell repertoire described here are relevant to therapeutic strategies targeting autoantigen-specific T cells in multiple sclerosis and other autoimmune diseases.
自身抗原特异性T淋巴细胞存在于自身免疫性疾病患者和正常受试者体内。目前对于这些自身反应性T细胞免疫库的时间变化（动态变化）了解甚少。我们分析了5例未经治疗的多发性硬化症患者和4例正常对照受试者中，针对髓鞘碱性蛋白（MBP）的T细胞免疫库在平均6年观察期内的长期变化。用纯化的人MBP筛选出MBP特异性CD4(+) T细胞系，并用重叠合成肽绘制其表位特异性图谱。观察到三种不同的免疫库发展模式。（i）2例患者和3例对照受试者维持广泛的表位反应，且随时间波动。（ii）2例患者最初表现为集中反应，在6年病程中反应范围扩大；这一发现可描述为分子内表位扩展。（iii）1例患者和1例对照受试者表现出显著的集中反应，该反应针对MBP区域83 - 102中的一组嵌套表位，且随时间持续存在。T细胞受体Vβ序列分析使我们能够在5例患者中的4例以及4例对照中的3例的外周循环中追踪MBP特异性T细胞的单个克隆长达7年，这表明MBP特异性T细胞克隆的长期持续存在是T细胞免疫库的一个共同特征，并非多发性硬化症所特有。通过互补决定区（CDR）-3谱型分析在其中1例患者的血液中未检测到持续存在的MBP特异性T细胞克隆，表明其频率不超过每5000个T细胞中有1个。本文描述的MBP特异性T细胞免疫库的时间特征与针对多发性硬化症和其他自身免疫性疾病中自身抗原特异性T细胞的治疗策略相关。
