移植物抗宿主病和移植物抗白血病相关细胞因子的研究进展

异基因造血干细胞移植（allogeneic hemotoic stem cell transplantation,allo-HSCT）是治疗血液系统恶性肿瘤的有效方法,治疗效果主要依赖于移植物抗白血病效应（graft-versus-leukemia,GVL）,可以清除残存肿瘤细胞,达到完全治愈恶性血液病的目的。然而,GVL与allo-HSCT的并发症移植物抗宿主病（graft-versus-host disease,GVHD）紧密相连。通过合理调节一些细胞因子的作用可以达到降低GVHD、保留GVL的目的。该文就GVHD与GVL发生机制中相关细胞因子作用的研究进展做一综述。     

全身放疗在造血干细胞移植中的研究进展

全身照射疗法(TBI)是一种姑息治疗,该方法已经成功地应用在慢性淋巴细胞白血病或滤泡性淋巴瘤等无干细胞支持的放射敏感的疾病中。目前,在血液系统恶性疾病中造血干细胞移植是较为有效的治疗手段之一,其中全身放射治疗与大剂量化疗是造血干细胞移植疗法的经典预处理方案。TBI方法主要应用在造血移植环境中,具有较强的周期非特异性抗肿瘤效应和免疫抑制效能。TBI给予干细胞移植病人超过正常骨髓的辐射耐受量,通过重建病人的造血和免疫来达到治疗目的。     

CD4^＋CD25^＋Foxp3^＋调节性T细胞的体外扩增及其在移植物抗宿主病中的应用

同种异基因造血干细胞移植是急、慢性白血病及其他恶性血液病重要的治疗方法,但急慢性移植物抗宿主病（graft—versus-host disease,GVHD）作为异基因造血干细胞移植的主要并发症严重影响移植患者的存活率,阻碍移植的临床推广。很多研究发现,高表达Foxp3的CD4^＋CD25^＋调节性T细胞（regulatory T cells,Treg）不仅能控制急慢性GVHD的发生,而且不影响移植物抗白血病效应（graft-versusleukemia,GVL）,在急慢性GVHD发生发展及治疗方面有重要的作用。但Treg细胞在体内的数量很少,不能满足临床应用需求。目前应用外源的IL-2联合TCR、CD28信号通路共同刺激以及运用树突状细胞（dendritic cell,DC）刺激均能达到体外有效扩增Treg细胞的目的。这些扩增的Treg细胞在控制造血干细胞移植过程中急慢性GVHD的发生及防治自身免疫性疾病和移植排斥等方面具有明显作用,在疾病控制和临床应用中具有广阔前景。     

异基因免疫治疗中控制GVHD发生的研究进展

目前,异基因造血干细胞移植(allo-HSCT)已成为治疗某些恶性血液病的有效手段之一,然而伴随其而来的移植物抗宿主病(GVHD)是导致移植后患者死亡的重要并发症之一。因此,如何诱导移植后免疫耐受来控制GVHD,尤其是控制急性移植物抗宿主病(a GVHD)的发生及已成为研究的重要内容。GVHD的发生机制非常复杂,但最终为供者骨髓内的成熟T淋巴细胞识别受者体内的细胞表面的MHC-I和MHC-II及所递呈的多肽而导致供者的T细胞的激活、增殖并浸润到GVHD的靶器官如皮肤、小肠及肝脏并导致靶器官的损伤[1]。临床移植学和移植免疫学主要攻克的内容之一就是如何控制GVHD的发生发展。其预防和治疗是决定着同种异基因造血干细胞移植(allo-HSCT)是否成功的关键所在,移植个体是否长期存活的主要因素之一。本文章就导致GVHD现象的原因及最新进展做一总结。     

胚胎干细胞衍生的视网膜色素上皮细胞移植治疗眼病

Schwartz等报告的用从人胚胎干细胞分化成的视网膜色素上皮细胞（RPE）移植治疗视网膜病,已观察4月,尚属成功。这是首次用从人胚胎干细胞（hESC）定向分化而成的细胞移植至患者取得成功。本文复习RPE移植的历史与现况;hESC分化而成的RPE（hESC-RPE）的实验研究以及临床移植的意义、方法、效果及存在问题,并展望了应用干细胞分化的RPE移植的前景。     

干细胞移植患者口腔粘膜上皮细胞基因型观察

目的观察异基因外周血干细胞移植患者口腔上皮细胞基因型的变化,判断干细胞生长情况。方法采用PCR-STR分型技术对31例外周血干细胞移植患者血液、口腔拭子及部分患者毛根进行基因分型。结果31例患者移植后血液均为供体基因型;25例患者口腔上皮细胞基因型为受体与供体嵌合体型,4例为受体原有基因型,2例转为供体基因型;11例检测了毛根基因型,均为受体的原有基因型。结论移植后外周血干细胞可以转变为口腔粘膜上皮细胞,这种转变有望成为判断患者干细胞生长情况及移植后治疗效果的一项新指标。这对干细胞治疗各种血液恶性疾病及法医学应用具有较高的参考价值。     

脐带血移植的应用进展及脐带血库建设

脐带血(umbilical cord blood)作为公认的造血干细胞重要来源之一,已经被广泛地用于治疗儿童和成人的良恶性血液系统疾病以及中枢神经系统疾病、实体瘤、缺血性下肢血管病和组织再生等。相对于骨髓移植和外周血来源的造血干细胞移植,脐带血移植(UCBT)在细胞收集使用、干细胞增殖能力以及移植物抗宿主反应等方面都具有明显的优势。目前的数据显示,因为HLA配型等原因而无法进行骨髓移植的患者应该尽早进行UCBT。此外,UCBT的增多促进了脐带血库的快速建设。本文针对UCBT和脐带血库的最新进展进行了综述。     

小鼠脐血移植模型研究进展

脐血中含有丰富的原始造血干细胞,由于免疫细胞发育不成熟,抗原表达和功能活性低下,移植物抗宿主疾病发生率低。脐血来源丰富、不易受病毒及残留肿瘤细胞的污染,越来越多地作为造血干细胞的优质来源在临床上广泛应用。通过建立小鼠脐血移植模型,对临床多种疾病尤其是对恶性血液病的造血干细胞移植研究提供有效途径,可以对脐血的生物学功能、植入过程、移植疗效做进一步研究,不断优化的小鼠移植模型对我们解读人类疾病的发病机理、疾病进程起到推动作用,本文将从小鼠种属的选择、移植模型的构建及脐血移植模型新进展等方面对进行综述。     

造血干细胞及其应用研究进展

造血干细胞(hematopoietic stem cells, HSCs)是一类多能干细胞,位于特殊的造血微环境,主要存在于骨髓中。其能自我更新和多向分化为各种功能的血细胞,维持血液系统的建立和动态平衡。造血干细胞的这些重要特性以及造血干细胞移植在临床上的广泛应用,结合基因治疗和基因编辑技术的进步,使得基于造血干细胞治疗多种血液疾病和免疫疾病的基因治疗研究在近年来取得了很大的进展。该文将从造血干细胞生物学特征、来源、造血干细胞微环境的基础研究,以及造血干细胞基因治疗、自体造血干细胞移植治疗β-地中海贫血等方面的临床研究和应用进展进行综述。     

人脐带血来源造血干细胞体外扩增的研究进展

造血干细胞（HSCs）是血液系统中的一类成体干细胞群,具有自我更新和多谱系分化两个基本特征。造血干细胞移植（HSCT）可以治疗退行性疾病和多种血液系统疾病。脐带血来源造血干细胞（CB HSCs）是降低HLA配型要求的突破点,但单份脐带血中HSCs数量不能满足使用要求,为了获得足够数量的CB HSCs,体外扩增是一种可行的方法。近几年,学者们探索了多种体外扩增方法,包括优化细胞生长因子混合物、与基质细胞共培养及加入小分子化合物（SMCs）激动剂等。目前应用细胞因子联合小分子的扩增方法在多个临床试验中获得成功。本文对目前体外扩增CB HSCs的研究进展做一综述。     

Evaluation of a clinical-grade,cryopreserved, ex vivo-expanded stem cell product from cryopreserved primary umbilical cord blood demonstrates multilineage hematopoietic engraftment in mouse xenografts

Background aimsAllogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative therapy for a wide range of malignant and genetic disorders of the hematopoietic and immune systems. Umbilical cord blood (UCB) is a readily available source of stem cells for allo-HSCT, but the small fixed number of hematopoietic stem and progenitor cells (HSPCs) found in a single unit limits its widespread use in adult recipients. The authors have previously reported that culturing UCB-CD34⁺ cells in serum-free media supplemented with a combination of cytokines and the histone deacetylase inhibitor valproic acid (VPA) led to expansion of the numbers of functional HSPCs. Such fresh expanded product has been advanced to the clinic and is currently evaluated in an ongoing clinical trial in patients with hematological malignancies undergoing allo-HSCT. Here the authors report on the cryopreservation of this cellular product under current Good Manufacturing Practice (cGMP).MethodscGMP VPA-mediated expansion was initiated with CD34⁺ cells isolated from cryopreserved primary UCB collections, and the functionality after a second cryopreservation step of the expanded product evaluted in vitro and in mouse xenografts.ResultsThe authors found that the cryopreserved VPA-expanded grafts were characterized by a high degree of viability, retention of HSPC phenotypic subtypes and maintenance of long-term multilineage repopulation capacity in immunocompromised mice. All cellular and functional parameters tested were comparable between the fresh and cryopreserved VPA-expanded cellular products.ConclusionsThe authors’ results demonstrate and support the practicality of cryopreservation of VPA-expanded stem cell grafts derived from UCB-CD34⁺ cells for clinical utilization.     

Enhancement of proliferation of human umbilical cord blood–derived CD34+ hematopoietic stem cells by a combination of hyper-interleukin-6 and small molecules

Umbilical cord blood (UCB) is an alternative source of allogeneic hematopoietic stem cells (HSCs) for transplantation to treat various hematological disorders. The major limitation to the use of UCB-derived HSCs (UCB–HSCs) in transplantation, however, is the low numbers of HSCs in a unit of cord blood. To overcome this limitation, various cytokines or small molecules have been used to expand UCB-HSCs ex vivo. In this study, we investigated a synergistic effect of the combination of HIL-6, SR1, and UM171 on UCB-HSC culture and found that this combination resulted in the highest number of CD34⁺ cells. These results suggest that the combination of SR1, UM171 and HIL-6 exerts a synergistic effect in the proliferation of HSCs from UCB and thus, SR1, UM171 and HIL-6 is the most suitable combination for obtaining HSCs from UCB for clinical transplantation.     

A 37-year-old spinal cord-injured female patient, transplanted of multipotent stem cells from human UC blood, with improved sensory perception and mobility, both functionally and morphologically: a case study

HLA-matched UC blood-derived multipotent stem cells were directly transplanted into the injured spinal cord site of a 37-year-old female patient suffering from spinal cord injury (SPI). In this case, human cord blood (UCB)-derived multipotent stem cells improved sensory perception and movement in the SPI patient's hips and thighs within 41 days of cell transplantation. CT and MRI results also showed regeneration of the spinal cord at the injured site and some of the cauda equina below it. Therefore, it is suggested that UCB multipotent stem cell transplantation could be a good treatment method for SPI patients.     

Equity, Utility, and the Marketplace: Emerging Ethical Issues of Umbilical Cord Blood Banking in Australia

Over the past decade, umbilical cord blood (UCB) has routinely been used as a source of haematopoietic stem cells for allogeneic stem cell transplants in the treatment of a range of malignant and non-malignant conditions affecting children and adults. UCB banks are a necessary part of the UCB transplant program, but their establishment has raised a number of important scientific, ethical and political issues. This paper examines the scientific and clinical evidence that has provided the basis for the establishment of UCB banks. We also discuss the major ethical issues that UCB banks raise, including ownership of cord blood, processes for obtaining consent for its collection and storage, and confidentiality. Finally, we review other concerns about commercial non-altruistic banking, including concerns about social justice, equity of access and equity of care.     

无关供者脐带血干细胞移植概况

脐带血作为造血干细胞的一大来源,已逐渐获得医学界的认可,随着临床实践的不断展开,对脐带血的使用也趋于标准化。我们通过移植物抗宿主病和治愈情况对骨髓移植与脐带血移植进行了比较,提供了移植用脐带血的择优选取办法及移植的最低细胞剂量,对双份脐带血的选择给出建议,同时对非亲缘脐血与骨髓共输注临床使用情况和嵌合体检测做了介绍与评价。可以看出,在治疗恶性血液病时,脐带血移植是一个可靠的方法。     

脐带血干细胞的基础与应用研究

作为造血干/祖细胞(hematopoieticstemcells/hematopoieticprogenitorcells,HSCs/HPCs)的另一来源,脐带血已经应用于临床治疗多种恶性和非恶性疾病。脐带血中HSCs/HPCs的质与量是决定其临床应用效果的最重要因素。同时,脐带血中还存在多种非造血的干细胞和前体细胞,如间充质干细胞(mesenchymalstemcells,MSCs)、内皮前体细胞(endothelialprogenitorcells,EPCs)和非限制性体干细胞(unrestrictedsomaticstemcells,USSCs)等,这些细胞可能会在未来的细胞治疗和再生医学中发挥重要作用。本综述还讨论了脐带血的临床应用及HSCs/HPCs的体外扩增、增加HSCs归巢和再植能力等提高其临床应用能力的相关研究。     

Human cord blood-derived viral pathogens as the potential threats to the hematopoietic stem cell transplantation safety:A mini review

Umbilical cord blood(UCB) is a valuable source of hematopoietic stem cells(HSCs) and potential alternative for bone marrow transplantation for patients who lack human leukocyte antigen(HLA)-matched donors. The main practical advantages of UCB over other HSC sources are the immediate availability, lower incidence of graft-versus-host disease, minimal risk to the donor, and lower requirement for HLA compatibility. However, the use of UCB is limited by delayed engraftment and poor immune reconstitution, leading to a high rate of infection-related mortality. Therefore, severe infectious complications, especially due to viral pathogens remain the leading cause of morbidity and mortality during the post-UCB transplantation(UCBT) period. In this context, careful screening and excluding the viral-contaminated UCB units might be an effective policy to reduce the rate of UCBT-related infection and mortality. Taken together,complete prevention of the transmission of donor-derived viral pathogens in stem cell transplantation is not possible. However, having the knowledge of the transmission route and prevalence of viruses will improve the safety of transplantation. To the best of our knowledge, there are few studies that focused on the risk of virus transmission through the UCB transplant compared to other HSC sources. This review summarizes the general aspects concerning the prevalence, characteristics, and risk factors of viral infections with a focus on the impact of viral pathogens on cord blood transplantation safety.