Immune Repertoire Profiling Reveals that Clonally Expanded B and T Cells Infiltrating Diseased Human Kidneys Can Also Be Tracked in Blood

Recent advances in high-throughput sequencing allow for the competitive analysis of the human B and T cell immune repertoire. In this study we compared Immunoglobulin and T cell receptor repertoires of lymphocytes found in kidney and blood samples of 10 patients with various renal diseases based on next-generation sequencing data. We used Biomed-2 primer panels and ImmunExplorer software to sequence, analyze and compare complementarity determining regions and V-(D)-J elements. While generally an individual’s renal receptor repertoire is different from the repertoire present in blood, 94% (30/32) of the lymphocytes with clonal expansion in kidney can also be traced in blood however, not all of these clonotypes are equally abundant. Summarizing the data of all analyzed patients, 68% of highly expanded T cell clonotypes and 30% of the highly expanded B cell clonotypes that have infiltrated the kidney can be found amongst the five most abundant clonotypes in blood. In addition, complementarity determining region 3 sequences of the immunoglobulin heavy chains are on average more diverse than T cell receptor beta chains. Immune repertoire analysis of tissue infiltrating B and T cells adds new approaches to the assessment of adaptive immune response in kidney diseases. Our data suggest that expanded clonotypes in the tissues might be traceable in blood samples in the course of treatment or the natural history of the disease.

高通量测序（high-throughput sequencing）技术的最新进展，使得人类B细胞与T细胞免疫组库（immune repertoire）的对比分析成为可能。本研究基于下一代测序（next-generation sequencing）数据，对10名罹患不同肾脏疾病患者的肾脏与血液样本中的淋巴细胞免疫球蛋白（immunoglobulin）组库及T细胞受体（T cell receptor, TCR）组库进行了比较分析。本研究采用Biomed-2引物组合（primer panels）与ImmunExplorer软件，对互补决定区（complementarity determining regions, CDR）及V-(D)-J基因元件进行测序、分析与比对。尽管通常而言个体的肾脏受体组库与血液中的受体组库存在差异，但肾脏中发生克隆扩增（clonal expansion）的淋巴细胞中有94%（30/32）也可在血液中被溯源；不过这些克隆型（clonotype）的丰度并不完全一致。综合所有分析患者的数据，浸润肾脏的高扩增T细胞克隆型中有68%、高扩增B细胞克隆型中有30%，可在血液中丰度排名前五的克隆型中被检出。此外，免疫球蛋白重链的互补决定区3（complementarity determining region 3, CDR3）序列平均多样性高于T细胞受体β链。对组织浸润性B、T细胞开展免疫组库分析，为肾脏疾病适应性免疫应答（adaptive immune response）的评估提供了全新的研究方法。本研究数据显示，在疾病治疗过程或自然病程中，组织内扩增的克隆型可在血液样本中被溯源。