Larché M, Rencher S D, Hurwitz J L
St. Jude Children's Research Hospital, Memphis, TN.
Eur J Immunol. 1992 Oct;22(10):2733-6. doi: 10.1002/eji.1830221039.
Experiments were designed to test whether T cell progenitors are committed to particular T cell receptor (TcR) gene rearrangement and expression patterns (prior to rearrangement) or whether such patients are molded by the thymic microenvironment in which T cells develop. To this end, day 14 fetal thymocytes were removed from their normal environment and grown in organ culture (FTOC) for 5 to 12 days. RNA was extracted from organ-cultured cells, processed to cDNA, and TcR alpha sequences were amplified by the polymerase chain reaction for cloning and sequencing. By the examination of N-region additions and V-gene usage, and by the comparison of resultant patterns with those of early vs. adult stages of T cell differentiation in vivo, it was demonstrated that thymocytes in FTOC did not maintain early patterns of gene rearrangement. The thymocyte patterns were most dissimilar from those of normal, early ontogeny when interleukin-4 was added to FTOC. Taken together, results demonstrated the flexibility of T cell progenitors and that environment plays a critical role in the molding of TcR alpha rearrangement and expression patterns.
实验旨在测试T细胞祖细胞是否在特定的T细胞受体（TcR）基因重排和表达模式上具有定向性（在重排之前），或者此类患者是否受T细胞发育所处的胸腺微环境的影响。为此，从正常环境中取出第14天的胎胸腺细胞，并在器官培养（FTOC）中培养5至12天。从器官培养的细胞中提取RNA，处理成cDNA，通过聚合酶链反应扩增TcRα序列以进行克隆和测序。通过检查N区域添加和V基因使用情况，并将所得模式与体内T细胞分化早期与成年阶段的模式进行比较，结果表明FTOC中的胸腺细胞并未维持早期的基因重排模式。当向FTOC中添加白细胞介素-4时，胸腺细胞模式与正常早期个体发育的模式差异最大。综合来看，结果证明了T细胞祖细胞的灵活性，以及环境在塑造TcRα重排和表达模式中起关键作用。
