NOD/SCID小鼠人源化TCR Vβ亚家族T细胞分布与克隆性分析

Features of T cell receptor Vβ T cells expansion in NOD/SCID mice transplanted with human cord blood hematopoietic stem cell

目的应用脐血CD34+细胞移植NOD/SCID鼠所建立的人源化SCID模型,分析人源化TCR Vβ亚家族T淋巴细胞分布与克隆性。方法磁珠分选法分离脐血中CD34+细胞,分别经尾静脉输入亚致死剂量照射的NOD/SCID小鼠。第6周处死小鼠提取外周血、骨髓、胸腺的RNA,RT-PCR扩增人TCR Vβ亚家族基因,并用基因扫描进行T细胞克隆性分析。结果采用RT-PCR技术在模型小鼠骨髓中检测到部分人TCR Vβ亚家族基因Vβ1、2、91、3、19。经进一步基因扫描分析,发现部分TCR Vβ亚家族基因Vβ9、13、19呈寡克隆表达。结论在NOD/SCID模型可重建分化成熟的TCR Vβ亚家族T细胞。未能检测到全部人TCR VβT细胞的原因可能与免疫重建不完全或存在移植物抗宿主的反应有关。人源T淋巴细胞在模型鼠骨髓中分化成熟。

Objective To investigate the distribution and elonal expansion of T cell receptor （TCR） Vβ subfamily T cells in Hu-SRCNOD/SCID mice transplanted with human cord blood hematopoietic stem cell. Methods NOD/SCID mice irradiated with sublethal dose of ^60Co （300 cGy） were transplanted intravenously with CB. CD34^＋ cells were sorted by MACS. After 6 weeks, RNA was obtained from peripheral blood, bone marrow and thymus of the mice. The gene expression and clonality of TCR Vβ repertoires were detected by RT-PCR and GeneScan technique, respectively. Results Some TCR Vβ subfamilies were exhibited in the bone marrow of mice, which including TCR Vβ 1, 2, 9, 13, and 19. Furthermore, oligoclonal expressions of TCR Vβ 9, 13, and 19 were detected by GeneScan technique. Conclusion Maturation of some TCR Vβ subfamily T cells could be reconstituted in NOD/SCID mice, but the whole TCR Vβ subfamily of T cells could not be detected because of incomplete immune reconstitution or graft-versus-host response. The maturation of T lymphocytes could be happened in bone marrow of mouse model.