Developmental failure of chimeric embryos expressing high levels of H-2Dd transplantation antigens.
Developmental failure of chimeric embryos expressing high levels of H-2Dd transplantation antigens.
复制标题
表达高水平 H-2Dd 移植抗原的嵌合胚胎发育失败。
DOI：
10.1073/pnas.89.13.5927
复制
发表时间：
1992
影响因子：
11.1
通讯作者：
Bikoff,EK
中科院分区：
文献类型：
--
作者：
Jaffe,L;Robertson,EJ;Bikoff,EK
在发育早期缺乏主要组织相容性复合体的I类产物的表达被认为在母体对同种异体胎儿移植的耐受性中起着关键作用。为了测试这一点，我们开发了一种策略，允许我们描述H-2DD移植抗原在发育中的胚胎中过度表达的后果。将含有人β-肌动蛋白启动子控制的H-2DD基因的载体导入多能胚胎干细胞。特别是在这种情况下，由于主要组织相容性复合体I类基因产物的过度表达可能深刻地影响胚胎发育，因此ES细胞系统的一个重要优势是能够在体外分析基因表达和研究对细胞生长和分化的影响。ES细胞不表达β2-微球蛋白。与此一致的是，ES细胞转化子表达的H-2DD H链不与β2-微球蛋白结合，也不转运到细胞表面。在体外分化过程中，β2-微球蛋白和H-2DD膜糖蛋白的表达水平显著升高。导入H-2DD基因的ES细胞可分化为多种类型的细胞，没有证据表明导入的H-2DD基因的表达影响ES细胞的体外分化能力。当将H-2DD转基因的ES细胞引入囊胚后，可广泛促进胚胎和胚外组织的发育，但这会导致胚胎中期嵌合妊娠的失败。考虑到转基因嵌合体不能通过转移到同基因寄养雌性体内来挽救，似乎非免疫机制对这些产前死亡负有责任。
The absence of expression of class I products of the major histocompatibility complex at early stages of development is thought to play a key role in maternal tolerance of the fetal allograft. To test this, we developed a strategy that would allow us to describe the consequences of overexpression of the H-2Dd transplantation antigen in the developing embryo. A construct containing the H-2Dd gene under control of the human beta-actin promoter was transfected into pluripotent embryonic stem (ES) cells. Particularly in this case, since overexpression of major histocompatibility complex class I gene products may profoundly affect embryonic development, an important advantage of the ES cell system is the ability to analyze gene expression and study effects on cell growth and differentiation in vitro. ES cells do not constitutively express beta 2-microglobulin. Consistent with this, H-2Dd H chains expressed by ES cell transformants were not associated with beta 2-microglobulin or transported to the cell surface. Significant levels of beta 2-microglobulin and H-2Dd membrane glycoproteins were expressed following differentiation in vitro. H-2Dd-transfected ES cells gave rise to a wide range of differentiated cell types, and there was no evidence to suggest that expression of the introduced H-2Dd gene affects the differentiation abilities of ES cells in vitro. When introduced into blastocysts, H-2Dd-transfected ES cells extensively contribute to embryonic and extraembryonic tissues, but this results in the failure of chimeric conceptuses at midgestation. Considering that transgenic chimeras cannot be rescued by transfer into syngeneic foster females, it seems likely that nonimmunological mechanisms are responsible for these prenatal lethalities.