子宫内膜再生细胞在抑制抗体介导免疫排斥反应中的作用机理研究

Organ transplantation is the therapy of choice for end-stage organ failure or congenital organ abnormalities, and offers an excellent opportunity for allowing patients to resume their normal lifestyles. Antibody-mediated rejection (AMR) is emerging as the leading cause of allograft rejection and graft loss in presensitized patients, however novel immunotherapies directly against AMR are still lacking. The endometrial regenerative cell (ERC) is a mesenchymal-like stem cell derived from menstrual blood that is believed to be associated with endometrial angiogenesis. ERCs can be non-invasively obtained from an abundant resource of menstrual blood; furthermore, the process permits an alternative use for bodily waste and is easily expandable to a large scale with no tendency to induce tumorigenesis. These unique features of ERCs make them a promising therapeutic tool in the inhibition of AMR. Our preliminary data demonstrated for the first time - to our knowledge - that ERCs were capable of stimulating endothelial cell proliferation, modulating immune cell reaction, preventing critical limb ischemic injury in mice and, more importantly, prolonging heart allograft survival, and in combination with rapamycin, effectively prevented AMR and achieved long-term graft survival in presensitized recipients. Currently, the mechanisms whereby ERCs mediate their immunomodulatory functions in vivo remain to be elucidated. In this proposed study, we will use cellular/molecular biology and imaging techniques to track ERC migration and localization in presensitized recipients of heart allografts, and to determine if ERCs are (a) inhibitors of dendritic cell (DC) maturation, T and B cell activation, and (b) capable of inducing cardiac allograft prolongation and potentiating tolerance through: (i) induction of immature DCs, (ii) attenuation of B-cell maturation and differentiation, and (iii) direct conversion of T and B cells to regulatory cells (Tregs and Bregs). We will also demonstrate that Bregs are essential for the induction of Tregs. Through this series of proposed experiments, we hope to expand our understanding of the mechanisms underlying the ability of ERCs to inhibit AMR and ultimately induce indefinite cardiac allograft survival in presensitized transplant recipients. This study aims to demonstrate the multi-potency of ERCs as an immunomodulator; the data generated will establish a framework for the development of clinically applicable therapy that will enable the use of ERCs to prevent and treat AMR following transplantation.

抗体介导免疫排斥反应(AMR)对移植物的损害被国际移植界广泛关注，尚无理想治疗方案。育龄妇女月经血子宫内膜再生细胞(ERC)的应用具有独特优势，即机体废弃物再利用，无限来源，无创收集，无诱导肿瘤倾向。ERC在免疫调节和组织损伤修复中的新发现令人鼓舞，但机理尚待阐明。申请人前期发表成果证实ERC可促进血管内皮细胞增殖、防止组织缺血损伤、调节免疫细胞反应、有效抑制预致敏小鼠移植心脏AMR发生。本项目采用细胞分子生物学及影像学技术，利用预致敏小鼠心脏移植模型对ERC抑制AMR的作用机理进行系列研究。明确ERC治疗对树突状细胞、T和B细胞的相关免疫调控机理；研究ERC抑制B细胞作用的关键信号通路及促进调节性T和B细胞增殖的作用机理。阐明ERC抑制移植物AMR发生并诱导抗原特异性免疫耐受形成的作用机制。本研究结果有望成为治疗AMR的突破性新方法，为ERC诱导移植免疫耐受的临床转化提供理论和实践依据。

抗体介导免疫排斥反应(AMR)对移植物的损害被国际移植界广泛关注，尚无理想治疗方案。育龄妇女月经血子宫内膜再生细胞(ERC)的应用具有独特优势，即机体废弃物再利用，无限来源，无创收集，无诱导肿瘤倾向。ERC在免疫调节和组织损伤修复中的新发现令人鼓舞，但机理尚待阐明。基于申请人有关ERC可促进血管内皮细胞增殖、防止组织缺血损伤、调节免疫细胞反应、有效抑制预致敏小鼠移植心脏AMR的前期发现。本项目采用细胞分子生物学及影像学技术，利用预致敏小鼠心脏移植模型对ERC抑制AMR的作用机理进行系列研究。研究结果发现ERC在抑制B细胞活化、增殖、成熟和功能中起着关键性作用。ERC可抑制移植受体中B细胞的增殖和抗体产生，降低移植受体血清中抗供体特异性抗体的水平和抗供体特异性抗体分泌细胞的比例，减轻心脏移植物中抗体沉积。同时，结果证实ERC介导心脏移植物抗原特异性免疫耐受是通过分泌基质细胞衍生因子1（Stromal Cell-Derived Factor 1，SDF-1）来实现的。在体外培养中，SDF-1介导ERC可以促进具有免疫抑制功能的耐受性树突状细胞、调节性T和B细胞及M2型巨噬细胞的产生。进一步发现证明SDF-1介导ERC联合雷帕霉素治疗可以减轻心脏移植物中IgM及IgG的沉积和CD4+及CD8+免疫细胞浸润，减轻心脏移植物AMR、ACR的严重程度，增加受体小鼠体内Tol-DC、M2、Treg及Breg细胞比例。本研究结果有望成为治疗AMR的突破性新方法，为ERC诱导移植免疫耐受的临床转化提供理论和实践依据。