Li Zhuan, He Wen-Yan, Li Ren, Chen Dong-Bo, Zhang Yu, Liu Bing
Laboratory of Oncology, Affiliated Hospital, Academy of Military Medical Sciences, Beijing 100071, China.
Zhongguo Shi Yan Xue Ye Xue Za Zhi. 2010 Oct;18(5):1282-5.
The anatomical location of lymphocyte ontogeny in the developing mouse embryo remains controversial. To define the site that can generate lymphocytes de novo, the intraembryonic splanchnopleura (SP) and extraembryonic yolk sac (YS) at 8.5 days postcoitum, when systemic circulation is not established, were investigated. The results indicated that in standard colony forming assay, the cells from both splanchnopleura and yolk sac formed typical myeloerythroid colonies, but their types were distinct. When cocultured with the OP9, the splanchnopleura produced B cells expressing B220, CD19 and surface IgM. Using a three-step culture protocols with the OP9 expressing Delta-like 1 as feeders, the splanchnopleura produced immature T precursor cells (CD44-/CD25+) and more mature single positive T cells (CD4+/CD8-) after 16 days of incubation. However, the yolk sac failed to generate B and T lymphocytes under identical conditions. It is concluded that prior to linked embryonic circulation, the splanchnopleura other than the yolk sac had robust lymphoid potential in vitro. In the future, more reliable evidence from novel model animals will ultimately delineate the embryonic origin of lymphocytes in vivo.
发育中小鼠胚胎中淋巴细胞个体发生的解剖位置仍存在争议。为了确定能够从头生成淋巴细胞的部位，研究了妊娠8.5天时胚胎内脏壁层（SP）和胚外卵黄囊（YS），此时全身循环尚未建立。结果表明，在标准集落形成试验中，来自脏壁层和卵黄囊的细胞均形成典型的髓系红系集落，但其类型不同。当与OP9共培养时，脏壁层产生表达B220、CD19和表面IgM的B细胞。使用以表达Delta样1的OP9为饲养层的三步培养方案，孵育16天后，脏壁层产生未成熟T前体细胞（CD44-/CD25+）和更成熟的单阳性T细胞（CD4+/CD8-）。然而，在相同条件下卵黄囊未能产生B和T淋巴细胞。得出的结论是，在胚胎循环建立之前，脏壁层而非卵黄囊在体外具有强大的淋巴生成潜力。未来，来自新型模式动物的更可靠证据最终将阐明体内淋巴细胞的胚胎起源。
