The development of immuno-modulation therapy by use of ES cell-derived dendritic cells

在之前的研究中，我们开发了一种从小鼠胚胎干细胞(ES-DC)中生成树突状细胞(DC)的方法。ES-DC的基因修饰可以通过将ES细胞导入并随后向DC分化来实现。在本研究期间，我们开展了以下研究项目：DC表达抗原的ES-DC免疫联合T细胞趋化因子的抗肿瘤免疫治疗比单纯抗原表达的肿瘤细胞更有效地保护肿瘤细胞。我们证明，如果ES-DC和小鼠共享一些MHC等位基因，那么ES-DC的抗肿瘤免疫治疗即使在同种异体受体小鼠中也是有效的。表达肿瘤胎儿抗原Glypcan-3的ES-DC可诱导小鼠B16-F10对高转移性黑色素瘤B16-F10的保护性免疫。我们证明双转基因ES-DC可以减轻髓鞘少突胶质细胞糖蛋白(MOG)多肽诱导的实验性自身免疫性脑脊髓炎(EAE)的严重程度，在MHC II类分子的背景下呈现髓鞘少突胶质细胞糖蛋白(MOG)多肽，同时表达肿瘤坏死因子相关的凋亡诱导配体(TRAIL)或程序性死亡1配体(PD-L1)。此外，我们还获得了一系列证据，表明调节性T细胞参与了表达TRAIL的ES-DC诱导的疾病预防作用。从灵长类ES细胞获得ES-DC为这项技术的未来临床应用提供了一种方法。在我们使用人ES细胞之前，我们建立了一种从食蟹猴ES细胞系获得ES-DC的方法，该方法在许多方面与人ES细胞相似。

In the previous study, we developed a method to generate dendritic cells (DC) from mouse embryonic stem (ES) cells (ES-DC). Genetic modification of ES-DC can readily be done by transfection of ES cells and subsequent their differentiation to DC. In this research period, we carried out the following projects.Anti-tumor immunotherapy by ES-DCImmunization with DC expressing antigen plus T cell-attracting chemokines provided protection from antigen-expressing tumor cells more potently than that with antigen only. We demonstrated that anti-tumor immunotherapy with ES-DC was effective even in the allogeneic recipient mice, if some of MHC alleles were shared by the ES-DC and the mice. ES-DC expressing Glypican-3, a recently identified oncofetal antigen, induced protective immunity against highly metastatic mouse melanoma, B16-F10.Antigen-specific down-modulation of immune response by ES-DCWe tried to establish a method for antigen-specific down-modulation of immune response by ES-DC expressing antigen along with immuno-suppressive molecules. We demonstrated that severity of myelin oligodendrocyte glycoprotein (MOG) peptide-induced experimental autoimmune encephalomyelitis (EAE) was reduced in mice treated with the double-transfectant ES-DC, presenting myelin oligodendrocyte glycoprotein (MOG) peptide in the context of MHC class II molecules and simultaneously expressing TNF-related apoptosis-inducing ligand (TRAIL) or Programmed Death-1 ligand (PD-L1). In addition, we obtained several lines of evidence showing that regulatory T cells were involved in the disease-preventive effect induced by ES-DC expressing TRAIL.Generation of ES-DC form primate ES cellsFor future clinical applications of this technology, it is necessary to develop a method to generate DC from human ES cells. Before we use human ES cells, we established a method to generate ES-DC from a cynomolgus monkey ES cell line, which is similar in many aspects to human ES cells.