多能干细胞（PSC）定向分化为造血干细胞（HSC）的研究瓶颈在于分化效率低下、靶细胞成熟障碍与功能缺陷，调控机制不明等问题。最近研究发现外源性促炎信号蛋白在HSC生成中发挥了重要的作用。我们的前期研究发现肿瘤坏死因子(TNFa)基因多态性对白血病发生发展有重要作用。因此我们假设，除了内源性调控网络之外，TNFa等外源性促炎信号蛋白对造血定向分化起了至关重要的作用。本项目拟采用三维诱导分化策略与流式细胞检测技术探索TNFa对造血逐级分化效率的影响；并通过体外集落形成分析、免疫缺陷小鼠体内移植实验等明确TNFa信号通路对PSC来源的HSC的体内外自我更新能力和多向分化潜能的作用；最后运用TNFa、TNFR1、TNFR2敲降技术研究其对Notch-NFκB信号通路的调控，进一步探讨HSC命运决定的微环境调控网络和分子机制，为PSC来源的HSC临床转化应用奠定基础。

The generation of hematopoietic stem cells (HSC) from human pluripotent stem cells (PSC) in vitro holds great potential for providing alternative sources of donor cells for clinical HSC transplantation. However, the low efficiency of current protocols for generating blood lineages and the dysfunction identified in hPSC-derived hematopoietic cells limit their use for full hematopoietic reconstitution in clinics. Until now, we have very limited knowledge on embryonic hematopoiesis and didn’t know the key points of HSC generation well. The latest works have show that inflammatory signaling regulates hematopoietic stem and progenitor cell emergence in vertebrates and mouse through TNFa-Notch-NFκB signaling pathway,however,the role in human system is to be questioned. To elucidate the key stromal niche signals that differentially regulate the definitive HSC phase of hematopoiesis, could play a critical role in finally achieving the goal of generating and expanding HSPCs from ESCs and iPSCs for therapeutic purposes.