In vitro differentiation of a CD4/CD8 double-positive equivalent thymocyte subset in adult Xenopus.
In vitro differentiation of a CD4/CD8 double-positive equivalent thymocyte subset in adult Xenopus.
复制标题
成年非洲爪蟾 CD4/CD8 双阳性等效胸腺细胞子集的体外分化。
DOI：
10.1093/intimm/11.4.499
复制
发表时间：
1999
影响因子：
4.4
通讯作者：
Cohen,N
中科院分区：
文献类型：
--
作者：
Robert,J;Cohen,N
在哺乳动物和鸟类中，胸腺是T细胞选择和分化的主要部位。为了开始研究胸腺细胞分化的进化，我们在非洲爪蛙体内开发了一种利用皮质胸腺细胞抗原(CTX)的体外系统，CTX是一种新近发现的T细胞抗原，其表达仅限于非洲爪蛙皮质胸腺细胞。在亚适浓度佛波酯、佛波酯、肉豆蔻酸酯(PMA)和离子霉素的瞬时刺激下，Xenopusys胸腺细胞被诱导分化为循环T淋巴母细胞，主动合成和表达高水平的表面MHC I类和II类分子。T淋巴母细胞的出现与表面CTX蛋白和CTX信使核糖核酸的快速下调有关。具有未成熟表型(CTX+、CD8+、II-或IIlow和I-)的胸腺细胞亚群的特征是耗尽II+细胞或用抗CTX单抗淘洗。这个未成熟的CTX+胸腺细胞亚群与总的、II+类或CTX-胸腺细胞相比显示出有限的增殖能力，并且可以在PMA/离子霉素的诱导下分化为表达表面II类和I类分子的更成熟的T淋巴母细胞。这些结果首次在体温脊椎动物中提供了胸腺细胞分化的保守胸腺内途径的体外证据。此外，我们的数据显示，CTX可以作为未成熟胸腺细胞群体的分化表面标志，该群体似乎相当于哺乳动物的CD4/CD8双阳性亚群。
The thymus is the major site of selection and differentiation of T cells in mammals and birds. To begin to study the evolution of thymocyte differentiation, we have developed, in the frogXenopus,anin vitrosystem that takes advantage of cortical thymocyte antigen (CTX), a recently discovered T cell antigen whose expression is restricted toXenopuscortical thymocytes. Upon transient stimulation with suboptimal mitogenic concentrations of the phorbol ester phorbol myristate acetate (PMA) plus ionomycin,Xenopusthymocytes are induced to differentiate into cycling T lymphoblasts that actively synthesize and express high levels of surface MHC class I and class II molecules. This appearance of T lymphoblasts correlates with a rapid down-regulation of both surface CTX protein and CTX mRNA. A thymocyte subset with an immature phenotype (CTX+, CD8+, class II–or class IIlowand class I–) was characterized by depleting class II+cells or by panning with anti-CTX mAb. This immature CTX+thymocyte subset displays a limited proliferative capacity compared to total, class II+or to CTX–thymocytes, and can be induced, by PMA/ionomycin, to differentiate into more mature T lymphoblasts expressing surface class II and class I molecules. These results provide the firstin vitroevidence in an ectothermic vertebrate of a conserved intrathymic pathway of thymocyte differentiation. In addition, our data reveal that CTX can serve as a differentiation surface marker of a population of immature thymocytes that appears to be the equivalent of the mammalian CD4/CD8 double-positive subset.