Background

Development of a diverse T-cell receptor β (TRB) repertoire is associated with immune recovery following hematopoietic cell transplantation (HCT) for severe combined immunodeficiency (SCID). High-throughput sequencing of the TRB repertoire allows evaluation of clonotype dynamics during immune reconstitution.

Objectives

We investigated whether longitudinal analysis of the TRB repertoire would accurately describe T-cell receptor diversity and illustrate the quality of T-cell reconstitution following HCT or gene therapy for SCID.

Methods

We used high-throughput sequencing to study composition and diversity of the TRB repertoire in 27 infants with SCID at 3, 6, and 12 months and yearly posttreatment(s). Total RNA from peripheral blood was used as template to amplify TRB rearrangements.

Results

TRB sequence analysis showed poor diversity at 3 months, followed by significant improvement by 6 months after cellular therapies. Kinetics of development of TRB diversity were similar in patients with a range of underlying gene defects. However, in patients with RAG and DCLRE1C defects, HCT with no conditioning or immune suppression only resulted in lower diversity than did HCT with conditioning. HCT from a matched donor correlated with higher diversity than did HCT from a mismatched donor. Naive CD4⁺ T-cell count at 6 months post-HCT correlated with higher TRB diversity. A Shannon index of diversity of 5.2 or lower 3 months after HCT predicted a need for a second intervention.

Conclusions

TRB repertoire after hematopoietic cell therapies for SCID provides a quantitative and qualitative measure of diversity of T-cell reconstitution and permits early identification of patients who may require a second intervention.

中文翻译：

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严重联合免疫缺陷移植后早期 T 细胞受体 β 库多样性差预示免疫重建失败

背景

多种 T 细胞受体 β ( TRB ) 库的发展与严重联合免疫缺陷 (SCID) 的造血细胞移植 (HCT) 后的免疫恢复有关。TRB库的高通量测序允许评估免疫重建过程中的克隆型动力学。

目标

我们调查了TRB库的纵向分析是否能准确描述 T 细胞受体多样性，并说明 HCT 或 SCID 基因治疗后 T 细胞重建的质量。

方法

我们使用高通量测序来研究27 名 SCID 婴儿在 3、6 和 12 个月以及每年治疗后的TRB库的组成和多样性。来自外周血的总 RNA 用作模板以扩增TRB重排。

结果

TRB序列分析显示在 3 个月时多样性较差，随后在细胞治疗后 6 个月显着改善。在具有一系列潜在基因缺陷的患者中， TRB多样性的发展动力学相似。然而，在患有RAG和DCLRE1C缺陷的患者中，没有调节或免疫抑制的 HCT 仅导致比有调节的 HCT 更低的多样性。来自匹配供体的 HCT 与来自不匹配供体的 HCT 相比具有更高的多样性。HCT 后 6 个月的初始 CD4 ⁺ T 细胞计数与更高的TRB多样性相关。HCT 后 3 个月的 Shannon 多样性指数为 5.2 或更低，预测需要进行第二次干预。

结论

SCID 的造血细胞疗法后的TRB曲目提供了对 T 细胞重建多样性的定量和定性测量，并允许早期识别可能需要第二次干预的患者。