Umbilical cord blood immunology: relevance to stem cell transplantation

Because of its easier accessibility and less severe graft-versus-host disease, umbilical cord blood (UCB) has been increasingly used as an alternative to bone marrow for hematopoietic stem cell transplantation. Naiveté of UCB lymphocytes, however, results in delayed immune reconstitution and infection-related mortality in transplant recipients. This review updates the phenotypic and functional deficiencies of various immune cell populations in UCB compared with their adult counterparts and discusses clinical implications and possible therapeutic strategies to improve the outcome of stem cell transplantation.     

Cord blood stem cell transplantation in primary immune deficiencies

PURPOSE OF REVIEW: Umbilical cord haematopoietic stem cell transplantation for primary immunodeficiencies is examined with other developments in treatment. Cord blood biology is reviewed, and advantages and disadvantages of umbilical cord blood stem cell transplantation for primary immunodeficiencies discussed. Clinical outcome data and future developments are reviewed. RECENT FINDINGS: Cord blood T lymphocytes become tolerant to host human leukocyte antigen antigens, but retain alloreactivity to other antigens, in part due to immaturity of cord blood T lymphocytes and dendritic cells. Although na?ve T lymphocytes can generate herpes virus specificity after transplantation, the risk of viral death is increased within the first 100 days. The clinical success of umbilical cord blood stem cell transplantation for primary immunodeficiencies is reviewed and new methods for expanding the stem cell number or encouraging engraftment with the use of third-party haematopoietic or mesenchymal stem cells examined. SUMMARY: Many advantages make umbilical cord blood an attractive source of stem cells; over 100 umbilical cord blood stem cell transplantations have been performed for primary immunodeficiencies, with low rates of significant graft vs. host disease, despite significant human leukocyte antigen mismatch. Immune reconstitution is as good as for other stem cell sources: use of nascent stem cells in young recipients may have long-term advantages. Stem cell engineering to improve engraftment will expand potential beneficiaries of umbilical cord blood stem cell transplantation to older patients.     

Concise review: Cord blood banking, transplantation and induced pluripotent stem cell: success and opportunities

Hematopoietic cell transplantation (HCT) has become a standard practice to treat a number of malignant and nonmalignant hematologic diseases. Bone marrow, mobilized peripheral blood, and umbilical cord blood can all serve as primary sources of cells for HCT. The number of cord blood units currently stored is large, although it represents only a fraction of potential collections. With much of the collection being sequestered in private banks for possible autologous use, there is a reason to expect that public banks may not be able to provide for the demand in coming years as use of cord blood for treatment of patients with diseases such as leukemia and lymphoma continues to increase. We suggest that a possible solution to encourage private banks to share their valuable units is to apply recent methodologies to generate induced pluripotent stem cells from cord cells and to optimize techniques to generate hematopoietic lineages from them. This strategy would allow us to take advantage of the units already collected under appropriate regulatory guidelines, to access a pristine cell that can be converted to a pluripotent cell at a much higher efficiency and in a shorter time period than other cells. The ability to potentially replenish a used cord unit with new cells, as well as extend the potential utility of cord blood for additional therapeutic applications, should allow banks to develop an appropriate business model for both private and public cord blood banks to flourish.     

Cord blood banking and transplantation

The availability of umbilical cord blood (UCB) as a source of haematopoietic stem cells (HSC) for transplantation has met an important niche in the field of HSC transplantation (HSCT) as patients unable to find a HLA-matched sibling or unrelated donor have been able to receive less well-matched UCB transplantation (UCBT) with equivalent outcomes. This has led to significant growth in this field resulting in more than 20 000 unrelated donor UCBTs performed to date with about 3000 more performed annually. Growth of UCBT has been further supported by the proliferation of public cord blood banks throughout the world which store UCB at no cost to the donor, making these available for patients all round the world through global search registries like the US National Marrow Donor Program (NMDP), NetCord and the Bone Marrow Donors Worldwide (BMDW). International organizations like the World Marrow Donor Association have also helped to steer these efforts through the formulation and distribution of guidelines and protocols for these cord blood banks and bone marrow registries. The US Food and Drug Administration (FDA) has also stepped in to regulate publicly banked UCB as an Investigational New Drug (IND). The key limiting factor in UCBT is in the limited number of cells for transplantation (about 10-fold less than donated bone marrow) resulting in delayed engraftment and even non-engraftment, particularly for adult patients for whom UCB cell doses may be insufficient relative to the patient’s body size. Efforts to overcome this barrier include the use of concurrent infusion of two differing cord blood units in order to raise the cumulative cell dose. Interestingly, this does not lead to mutual rejection of the CBUs, but appears to result in an additive effect on enhancing engraftment. Other efforts to overcome cell dose constraints of cord blood include direct bone marrow injection, use of homing molecules and ex vivo cord blood expansion. Cell dose is also an important consideration for cord blood banking as donated UCB that is collected with cell count <800 million nucleated cells has very low chance of utilization by many transplant centres which demand the best cell doses for their patients. As such, not all UCB collected is banked, although many of the low volume cords can still be reassigned to research. Strategies to increase the number of cells collected from each delivery include the use of ex utero devices which apply suction, perfusion or pressure to delivered placenta and umbilical cord in order to maximize HSC collection. Devices which enhance cell recovery during cord blood processing also help to minimize cell loss. Other strategies which might influence obstetric practice are not advised. As the worldwide experience in UCBT and UCB banking grows, patient outcomes have continued to improve such that UCBT now has a firm place in the HSCT spectrum of care with even greater potential for growth in the years to come. The challenge is for these advances to stay cost-effective so that the majority of patients can still have access to them.     

M-CSF levels during peripheral blood stem cell harvest and autologous stem cell transplantation

Plasma macrophage colony-stimulating factor(M-CSF) levels were determined during peripheral blood stem cell harvest and autologous stem cell transplantation(PBSCT). Plasma of 10 patients were analyzed by using ELISA system. The average peak values during PBSCT were quite higher than those during harvest(20,092 vs 1,681 pg/ml). Peak values were observed mainly around leukocyte nadir(Phase II) during harvest. On the other hand, they were detected just after pretreatment(Phase I) during PBSCT courses. Moreover, samples showing extremely high M-CSF values(Phase I) were associated with increase in serum LDH levels. These data suggest that plasma M-CSF in Phase I are mainly derived from chemotherapy-induced cellular damage during PBSCT courses, and there might be different mechanisms to raise M-CSF around the nadir of leukocytes. It is necessary to elucidate the biological meanings of M-CSF.     

Hyaluronic acid-human blood hydrogels for stem cell transplantation

Tissue engineering-based approaches have the potential to improve stem cell engraftment by increasing cell delivery to the myocardium. Our objective was to develop and characterize a naturally-derived, autologous, biodegradable hydrogel in order to improve acute stem cell retention in the myocardium. HA-blood hydrogels (HA-BL) were synthesized by mixing in a 1:1(v/v) ratio, lysed whole blood and hyaluronic acid (HA), whose carboxyl groups were functionalized with N-hydroxysuccinimide (NHS) to yield HA succinimidyl succinate (HA-NHS). We performed physical characterization and measured survival/proliferation of cardiosphere-derived cells (CDCs) encapsulated in the hydrogels. Hydrogels were injected intra-myocardially or applied epicardially in rats. NHS-activated carboxyl groups in HA react with primary amines present in blood and myocardium to form amide bonds, resulting in a 3D hydrogel bound to tissue. HA-blood hydrogels had a gelation time of 58?±?12?s, swelling ratio of 10?±?0.5, compressive and elastic modulus of 14?±?3 and 1.75?±?0.6?kPa respectively. These hydrogels were not degraded at 4wks by hydrolysis alone. CDC encapsulation promoted their survival and proliferation. Intra-myocardial injection of CDCs encapsulated in these hydrogels greatly increased acute myocardial retention (p?=?0.001). Epicardial application of HA-blood hydrogels improved left ventricular ejection fraction following myocardial infarction (p?=?0.01). HA-blood hydrogels are highly adhesive, biodegradable, promote CDC survival and increase cardiac function following epicardial application after myocardial infarction.     

临床病例讨论（step by step）——自体干细胞移植后发热、呼吸困难

 植入综合征 (ES) 系造血干细胞移植过程中严重并发症,主要发生在造血干细胞移植后中性粒细胞恢复早期。ES以发热、皮疹、非心源性肺水肿为主要特征。ES以往与高移植相关死亡率相关,多数患者死于呼吸衰竭和多器官功能不全。早期诊断并合理应用皮质激素可以显著降低移植相关死亡率。本文报道了一个年轻女性NHL患者,在自体外周血干细胞移植后粒细胞恢复早期出现发热、呼吸困难、肺水肿,早期诊断为ES并及时应用皮质激素后病情获得完全缓解。     

Late infectious complications after cord blood stem cell transplantation

The slower engraftment kinetics and impaired immune reconstitution of cord blood stem cell transplant recipients increase the risk of infectious complications. We retrospectively reviewed patients who underwent cord blood stem cell transplantation at Roswell Park Cancer Institute for hematological malignancies and who survived beyond day 100 for late infectious events. Among 15 patients who were included in the study, there were 18 episodes of bacteremia, 5 cases of bacterial pneumonia, 9 viral, 4 fungal, and 1 nontuberculous mycobacterial infection. Overall mortality was 60%, with infections contributing in 44% of cases. In conclusion, survival beyond day 100 following cord bloodstem cell transplantation is associated with a considerable risk of infections in our single center experience.     

外周血造血干细胞移植治疗3例重型β地中海贫血和1例特发性溶血性贫血

目的探讨异基因外周血造血干细胞移植(allogeneic peripheral blood stem cell transplantation,Allo-PBSCT)治疗遗传性溶血性贫血(hereditary haemolytic     

Cord blood stem cell-generated KIR+NK cells effectively target leukemia cell lines

Acute lymphoid (ALL) and myeloid leukemia (AML) are known to be invasive and highly lethal hematological malignancies. Because current treatments are insufficient and have a variety of side effects, researchers are looking for new and more effective therapeutic methods. Interestingly, ongoing efforts to find the best approach to optimize NK cell anti-leukemia potential shed light on the successful treatment of cancer. Mature KIR⁺NK cells ability to remove HLA Class-I deficient cells has been exploited in cancer immunotherapy. Here, we generated KIR⁺NK cells from cord blood stem cells using IL-2 and IL-15 cytokines. Our finding underlined the importance of KIR expression in the cytotoxic function of NK cells. Taken together, this study presented an effective in vitro method for the expansion and differentiation of KIR⁺NK cells using cytokines without any feeder cells. Furthermore, the presented culture condition could be useful for the generation of mature and pure NK cells from limited numbers of CD34⁺ cord blood cells and might be used as a novel method to improve the current state of cancer therapy.     

HLA-identical sibling peripheral blood stem cell transplantation in children and adolescents.

Allogeneic peripheral blood stem cell transplantation (PBSCT) was performed in children and adolescents for the treatment of malignant (n = 49) and nonmalignant hematological disease (n = 8). Granulocyte colony-stimulating factor (G-CSF)-mobilized PBSCs were apheresed from 57 HLA-matched siblings aged 9 months to 24 years (median, 8 years) without any serious adverse, effects. No abnormalities were found in these donors for a median follow-up of 25 months (range, 6-56 months). Patients were conditioned with a TBI-containing regimen (n = 17) or a non-TBI regimen (n = 40). GVHD prophylaxis consisted of methotrexate (MTX) plus cyclosporine A (CSP) for 23 patients, CSP plus methylprednisolone (mPDN) for 22 patients, MTX only for 7 patients, CSP only for 4 patients, and MTX plus CSP plus mPDN for 1 patient. Engraftment was prompt, with a median number of days to reach an absolute neutrophil count (ANC) above 0.5 x 10(9)/L of 13 days (range, 8-23 days), with 1 graft failure. Acute GVHD (grades II-IV) occurred in 8 (16%) of 49 evaluable patients, and chronic GVHD developed in 23 (64%) of 36 evaluable patients. Notably, two thirds of chronic GVHD was extensive. The Kaplan-Meier estimate of 3-year disease-free survival was 0% for refractory disease (n = 6), 37.2% +/- 11.8% for high-risk malignancies (n = 25), 81.4% +/- 9.7% for standard-risk malignancies (n = 18), and 100% for nonmalignant disease (n = 8). The estimated 100-day nonrelapse mortality rate was 9.9% +/- 4.2%. In conclusion, allogeneic PBSCT is feasible in a pediatric population. Although the grade of acute GVHD was set low, as in Japanese BMT studies, the incidence and severity of chronic GVHD appears to be relatively high. For nonmalignant disease, the question arises of whether the higher incidence and severity of chronic GVHD is a drawback of this procedure. For high-risk malignancies, whether or not a graft-versus-leukemia effect prevents relapse needs to be clarified in future comparative studies with BMT.     

脐血间充质干细胞移植对心肌细胞凋亡的影响

BACKGROUND: Umbilical cord blood mesenchymal stem cell transplantation can reduce myocardial apoptosis and myocardial fibrosis, thereby improving the cardiac function.     

Allogeneic stem cell transplantation with peripheral blood stem cells mobilized by pegylated G-CSF.

Mobilization of stem cells with pegylated granulocyte colony-stimulating factor (peg-G-CSF) modulates donor T- and natural killer T-cell (NKT-cell) functions, thus separating graft-versus-host from graft-versus-leukemia disease in animal models. We report a phase I/II study that analyzed the feasibility of mobilizing stem cells from normal donors with peg-G-CSF and the ability of these cells to restore hematopoiesis in allogeneic transplant recipients after myeloablative conditioning. Administration of 6 mg of peg-G-CSF resulted in suboptimal stem cell mobilization, with a peak peripheral blood CD34+ count of 29+/-5/microL. Apheresis 4 days after peg-G-CSF yielded 2.7+/-.4x10(6) CD34+ cells/kg recipient weight, and all donors required a second collection on day 5 to yield a total of 4.2+/-.5x10(6) CD34+ cells/kg recipient weight. After escalation of the dose to 12 mg, the peak CD34+ count was 99+/-11/microL and 12 of 13 donors collected sufficient stem cells for transplantation in a single apheresis (8.9+/-1.4x10(6) CD34+ cells/kg recipient weight). Late transient increases in serum hepatic transaminases were noted, but other side effects (predominantly bone pain) were otherwise similar to those seen in donors mobilized with standard G-CSF. Median neutrophil and platelet engraftments occurred on days 18 and 14, respectively, after transplantation and were identical to those seen with in recipients of grafts mobilized with standard G-CSF. With a median follow-up of 357 days, the incidence of grade II-IV acute graft-versus-host disease was 50% and there have been no relapses to date. Mobilization of stem cells with peg-G-CSF in normal donors is feasible and 12 mg results in mobilization characteristics similar to those of standard G-CSF.     

HLA-G与移植免疫

非经典HLA Ⅰ类分子(HLA-Ⅰb)HLA-G参与抗原递呈,通过相应受体调节NK细胞及T淋巴细胞功能,是一个 重要的免疫调节分子。HLA-G分子的免疫调节作用已从母胎免疫耐受扩展到肿瘤免疫、抗感染免疫和器官移植免疫等领域, 近年来在移植免疫方面取得了重要进展。     

自体外周血造血干细胞移植后淋巴细胞亚群的恢复

目的探讨自体外周血造血干细胞移植(auto-PBSCT)后免疫重建的规律。方法测定血液肿瘤患者auto-PBSCT前后淋巴细胞各亚群的绝对值。结果部分亚群在移植前低于正常。移植后各细胞亚群恢复时间不同,其中NK细胞在6个月恢复;B细胞在9个月恢复正常。T细胞总数在9个月恢复正常,其中主要为CD3 CD8 细胞。CD3 CD4 细胞在18个月恢复,而CD4 CD28 细胞在2年内仍未恢复。CD3 CD8 细胞在移植后早期有所下降,在3个月时恢复并高于正常,至9个月时逐渐下降至正常。CD3 CD8 细胞的主要部分是免疫表型呈活化的T细胞,即CD8 HLA-DR 细胞和CD8 CD38 细胞。两者分别在1个月和3个月时高于正常,在9个月时恢复正常。结论血液肿瘤患者移植前即存在淋巴细胞亚群异常的前提下,移植后NK细胞最先恢复,其次为B细胞,T细胞各亚群中CD3 CD8 细胞恢复较早,其中主要为活化T细胞。     

Nonmyeloablative blood stem cell transplantation as adoptive allogeneic immunotherapy for metastatic renal cell carcinoma

Allogeneic stem cell transplantation has emerged as a potentially curative form of immunotherapy for patients with hematological malignancies that are resistant to conventional chemo/radiotherapy. Donor T cell populations targeting allogeneic minor histocompatibility antigens expressed on the patient's malignant cells are felt to be the driving force of the graft-versus-leukemia reaction, although to date only a handful of these antigens have been fully characterized. Recent data from experimental animal models and limited clinical data in humans suggest that graft-versus-tumor effects, analogous to the graft-versus-leukemia reaction, may be generated against malignancies of epithelial origin. This article reviews the results of a pilot trial demonstrating graft-versus-renal cell carcinoma effects following nonmyeloablative stem cell transplantation, highlighting the potential of allogeneic immunotherapy for treating cancer.     

氧化压力与干细胞移植

背景：干细胞来源广泛,具有自我分化和更新的潜能,且自体干细胞更能最大程度避免移植后的免疫排斥反应,已成为组织器官移植最有前途的替代方法之一,但是受移植部位氧化压力等恶劣环境影响,现今干细胞的移植效率还较为低下。 目的：综述氧化压力对干细胞本身及移植效率的影响和机制。 方法：由第一作者检索1990至2015年PubMed数据库收录的与干细胞移植有关的文献。英文检索词为“stem cell transplantation,stem cell,oxidative  stress,molecular mechanisms”。共纳入97篇文章进行综述。 结果与结论：内源氧化压力对干细胞移植有直接且重要的影响,各类型干细胞抗氧化压力水平有差异,但高氧化水平能引起干细胞增殖停止、过早衰老、凋亡、癌变,也能引起肿瘤细胞的凋亡。干细胞可通过多条通路调节其内源性抗氧化水平,应用各种方法提高内源抗氧化压力水平可以提高干细胞的移植效率及预防氧化压力导致的干细胞癌变发生,使干细胞移植治疗能更广泛更安全的应用于临床。中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程