GENERATION OF NORMAL LYMPHOCYTE POPULATIONS BY RB-DEFICIENT EMBRYONIC STEM-CELLS
GENERATION OF NORMAL LYMPHOCYTE POPULATIONS BY RB-DEFICIENT EMBRYONIC STEM-CELLS
复制标题
DOI：
10.1016/0960-9822(93)90347-q
复制
发表时间：
1993-07-01
期刊：
影响因子：
9.2
通讯作者：
ALT, FW
中科院分区：
文献类型：
--
作者：
CHEN, JZ;GORMAN, JR;ALT, FW
背景：重组激活基因 2 (RAG 2) 发生功能丧失突变的纯合小鼠不产生成熟的 B 和 T 淋巴细胞，而重组激活基因 2 (RAG 2) 是抗原受体基因重排所必需的。但是，将正常胚胎干（ES）细胞注射到RAG2缺陷小鼠的囊胚中而产生的嵌合小鼠，会发育出正常的成熟淋巴细胞群，所有这些细胞都源自注射的ES细胞；我们将此过程称为 RAG 2 缺陷囊胚互补。使用具有纯合突变的 ES 细胞，RAG 2 缺陷型囊胚互补可以提供一种生理测定法，用于确定几乎任何基因在淋巴细胞发育和/或功能中的潜在作用。为了测试该系统的通用性，我们用它来测试 ES 细胞的分化潜力，这些细胞具有视网膜母细胞瘤易感性 (Rb) 基因位点的纯合功能丧失突变。我们选择 Rb 进行这项分析，是因为它在控制细胞周期和细胞分化方面具有广泛的功能，Rb 纯合种系突变对胎儿肝脏造血的不利影响，以及将纯合 Rb 突变引入种系时导致的胚胎致死性。 结果：纯合 Rb 突变型 ES 细胞在 RAG2 缺陷的背景下可以发育为表型正常、成熟的 B 和 T 淋巴细胞。引人注目的是，Rb 缺陷型 B 细胞和 T 细胞在激活或功能方面均不存在重大缺陷。结论：我们已经证明了 RAG2 缺陷型囊胚互补系统在评估关键基因在淋巴细胞发育中的作用方面的功效。我们的结果表明，尽管淋巴细胞中 Rb 的表达水平通常很高，但 B 细胞或 T 细胞功能本质上并不需要 Rb 表达。
Background: Mice homozygous for a loss-of-function mutation of the recombination-activating gene-2 (RAG 2), which is required for the rearrangement of antigen receptor genes, do not produce mature B and T lymphocytes. But chimeric mice that result from injection of normal embryonic stem (ES) cells into blastocysts from RAG2-deficient mice develop normal mature lymphocyte populations, all of which are derived from the injected ES cells; we have called this process RAG 2-deficient blastocyst complementation. Using ES cells with homozygous mutations, RAG 2-deficient blastocyst complementation could provide a physiological assay with which to determine the potential role of almost any gene in the development and/or function of lymphocytes. To test the general utility of this system, we have used it to test the differentiation-potential of ES cells that harbor homozygous loss-of function mutations of their retinoblastoma susceptibility (Rb) gene loci. We chose Rb for this analysis because of its widespread function in the control of the cell cycle and cell differentiation, the adverse effect of homozygous germline mutations of Rb on hematopoiesis in fetal liver, and the embryonic lethality that results when the homozygous Rb mutation is introduced into the germline.Results: Homozygous Rb-mutant ES cells can develop into phenotypically normal, mature B and T lymphocytes in the RAG2-deficient background. Strikingly, Rb-deficient B and T cells do not have major defects in either activation or function.Conclusion: We have demonstrated the efficacy of the RAG2-deficient blastocyst complementation system for evaluating the role of critical genes in lymphocyte development. Our results indicate that Rb expression is not intrinsically required for B-cell or T-cell function, despite the normally high levels of Rb expressed in lymphoid cells.