Verloes An, Van de Velde Hilde, LeMaoult Joel, Mateizel Ileana, Cauffman Greet, Horn Peter A, Carosella Edgardo D, Devroey Paul, De Waele Marc, Rebmann Vera, Vercammen Martine
Department of Hematology, University Hospital Brussels, 1090 Brussels, Belgium.
J Immunol. 2011 Feb 15;186(4):2663-71. doi: 10.4049/jimmunol.1001081. Epub 2011 Jan 19.
Human leukocyte Ag-G, a tolerogenic molecule that acts on cells of both innate and adaptive immunity, plays an important role in tumor progression, transplantation, placentation, as well as the protection of the allogeneic fetus from the maternal immune system. We investigated HLA-G mRNA and protein expression in human embryonic stem cells (hESC) derived from the inner cell mass (ICM) of blastocysts. hESC self-renew indefinitely in culture while maintaining pluripotency, providing an unlimited source of cells for therapy. HLA-G mRNA was present in early and late passage hESC, as assessed by real time RT-PCR. Protein expression was demonstrated by flow cytometry, immunocytochemistry, and ELISA on an hESC extract. Binding of HLA-G with its ILT2 receptor demonstrated the functional active status. To verify this finding in a physiologically relevant setting, HLA-G protein expression was investigated during preimplantation development. We demonstrated HLA-G protein expression in oocytes, cleavage stage embryos, and blastocysts, where we find it in trophectoderms but also in ICM cells. During blastocyst development, a downregulation of HLA-G in the ICM cells was present. This data might be important for cell therapy and transplantation because undifferentiated hESC can contaminate the transplant of differentiated stem cells and develop into malignant cancer cells.
人类白细胞抗原G（Human leukocyte Ag-G）是一种作用于先天免疫和适应性免疫细胞的致耐受性分子，在肿瘤进展、移植、胎盘形成以及保护同种异体胎儿免受母体免疫系统攻击方面发挥着重要作用。我们研究了源自囊胚内细胞团（ICM）的人类胚胎干细胞（hESC）中HLA-G mRNA和蛋白的表达情况。hESC在培养中可无限自我更新并维持多能性，为治疗提供了无限的细胞来源。通过实时RT-PCR评估发现，早期和晚期传代的hESC中均存在HLA-G mRNA。通过流式细胞术、免疫细胞化学以及对hESC提取物进行ELISA检测证实了蛋白表达情况。HLA-G与其ILT2受体的结合表明其处于功能活性状态。为了在生理相关环境中验证这一发现，我们研究了植入前发育过程中HLA-G蛋白的表达情况。我们在卵母细胞、卵裂期胚胎和囊胚中均检测到了HLA-G蛋白表达，在滋养外胚层细胞以及ICM细胞中都能发现它。在囊胚发育过程中，ICM细胞中的HLA-G表达出现了下调。这些数据对于细胞治疗和移植可能具有重要意义，因为未分化的hESC可能会污染分化干细胞移植并发展为恶性癌细胞。
