Artificial thymic organoids represent a reliable tool to study T-cell differentiation in patients with severe T-cell lymphopenia
Artificial thymic organoids represent a reliable tool to study T-cell differentiation in patients with severe T-cell lymphopenia
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DOI：
10.1182/bloodadvances.2020001730
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发表时间：
2020-06-23
期刊：
影响因子：
7.5
通讯作者：
Notarangelo, Luigi D.
中科院分区：
文献类型：
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作者：
Bosticardo, Marita;Pala, Francesca;Notarangelo, Luigi D.
由于胸腺样本的有限可用性和体外t细胞分化测定的局限性，人类早期t细胞发育的研究具有挑战性。我们使用人工胸腺类器官（ATO）平台，将表达dll4的基质细胞系（MS5-hDLL4）与从骨髓或动员的外周血中分离的CD34（+）细胞聚集在一起，研究携带造血固有缺陷或胸腺缺陷（导致t细胞淋巴减少）的患者的CD34（+）细胞发育成t细胞。我们发现AK2缺陷与细胞活力下降和t细胞发育早期阻滞有关。我们在一名携带IL2RG无效突变的患者中观察到类似的缺陷。相比之下，携带错义IL2RG突变的患者的CD34（+）细胞达到了完全的t细胞成熟，尽管细胞数量明显低于对照组。携带RAG突变的患者的CD34（+）细胞能够分化为CD4-CD8+细胞，但不能分化为CD3(+)TCR α - β(+)细胞。最后，在完全性迪乔治综合征患者中观察到正常的t细胞分化，这与该缺陷的非造血性质相一致。ATO系统可以帮助确定t细胞缺乏是否反映造血或胸腺内在异常，并确定t细胞分化被阻断的确切阶段。
The study of early T-cell development in humans is challenging because of limited availability of thymic samples and the limitations of in vitro T-cell differentiation assays. We used an artificial thymic organoid (ATO) platform generated by aggregating a DLL4-expressing stromal cell line (MS5-hDLL4) with CD34(+) cells isolated from bone marrow or mobilized peripheral blood to study T-cell development from CD34(+) cells of patients carrying hematopoietic intrinsic or thymic defects that cause T-cell lymphopenia. We found that AK2 deficiency is associated with decreased cell viability and an early block in T-cell development. We observed a similar defect in a patient carrying a null IL2RG mutation. In contrast, CD34(+) cells from a patient carrying a missense IL2RG mutation reached full T-cell maturation, although cell numbers were significantly lower than in controls. CD34(+) cells from patients carrying RAG mutations were able to differentiate to CD4-CD8+ cells, but not to CD3(+)TCR alpha beta(+) cells. Finally, normal T-cell differentiation was observed in a patient with complete DiGeorge syndrome, consistent with the extra-hematopoietic nature of the defect. The ATO system may help determine whether T-cell deficiency reflects hematopoietic or thymic intrinsic abnormalities and define the exact stage at which T-cell differentiation is blocked.