Hematopoietic reconstitution in a patient with Fanconi's anemia by means of umbilical-cord blood from an HLA-identical sibling

The Effect of Mesenchymal Stem Cell-Derived Extracellular Vesicles on Hematopoietic Stem Cells Fate

Hematopoietic stem cells (HSCs) are multipotent stem cells, with self-renewal ability as well as ability to generate all blood cells. Mesenchymal stem cells (MSCs) are multipotent stem cells, with self-renewal ability, and capable of differentiating into a variety of cell types. MSCs have supporting effects on hematopoiesis; through direct intercellular communications as well as secreting cytokines, chemokines, and extracellular vesicles (EVs). Recent investigations demonstrated that some biological functions and effects of MSCs are mediated by their EVs. MSC-EVs are the cell membrane and endosomal membrane compartments, which are important mediators in the intercellular communications. MSC-EVs contain some of the molecules such as proteins, mRNA, siRNA, and miRNA from their parental cells. MSC-EVs are able to inhibit tumor, repair damaged tissue, and modulate immune system responses. MSC-EVs compared to their parental cells, may have the specific safety advantages such as the lower potential to trigger immune system responses and limited side effects. Recently some studies demonstrated the effect of MSC-EVs on the expansion, differentiation, and clinical applications of HSCs such as improvement of hematopoietic stem cell transplantation (HSCT) and inhibition of graft versus host disease (GVHD). HSCT may be the only therapeutic choice for patients who suffer from malignant and non-malignant hematological disorders. However, there are several severe side effects such GVHD that restricts the successfulness of HSCT. In this review, we will discuss the most important effects of MSCs and MSC-EVs on the improvement of HSCT, inhibition and treatment of GVHD, as well as, on the expansion of HSCs.

Associated factors of umbilical cord blood collection quality

After 30 years of hematopoietic stem cell use for various indications, umbilical cord blood is considered as an established source of cells with marrow and postmobilization peripheral blood. The limited number of cells still remains a problematic element restricting their use, especially in adults who require to be grafted with a higher cell number. Improving the quality of harvested cord blood, at least in terms of volume and amount of cells, is essential to decrease the number of discarded units. In this review, we examine several variables related to parturient, pregnancy, labor, delivery, collection, the newborn, umbilical cord, and placenta. We aim to understand the biologic mechanisms that can impact cord blood quality. This knowledge will ultimately allow targeting donors, which could provide a rich graft and improve the efficiency of the collection.

The first decade of advanced cell therapy clinical trials using perinatal cells (2005-2015)

AIM

The first review of advanced cell therapy trials with perinatal cells.

MATERIALS & METHODS

We compiled 281 clinical trials of advanced cell therapy with perinatal cells that were registered in 2005-2015.

RESULTS

The most common cell source in these trials is cord blood, but the cell type that provides the mechanism of action in the majority of trials is mesenchymal stem/stromal cells. We analyze trends among the 15 parameters we compiled for these trials.

CONCLUSION

Advanced cell therapy with perinatal cells is a new field that covers a wide range of diagnoses but where most of the trials are early Phase. Researchers in different countries tend to work with a preferred cell source and cell type.

Comparison of human umbilical cord blood processing with or without hydroxyethyl starch

BACKGROUND

Umbilical cord blood (UCB) processing with hydroxyethyl starch (HES) is the most common protocol in the cord blood banks. The quality of UCB volume reduction was guaranteed by minimum manipulation of cord blood samples in the closed system. This study aimed to analyze and compare cell recovery and viability of UCB processed using the Sepax automated system in the presence and absence of HES.

STUDY DESIGN AND METHODS

Thirty UCB bags with a total nucleated cell (TNC) count of more than 2.5 × 109 were divided in two bags with equal volume. HES solution was added to one bag and another was intact. Both bags were processed with the Sepax. To determine cell recovery, viability, and potential of colony-forming cells (CFCs), preprocessing, postprocessing, and thawing samples were analyzed.

RESULTS

The mean TNC recovery after processing and after thaw was significantly better with the HES method (p < 0.01 for the postprocessing step and p < 0.05 for the postthaw step). There were no significant differences to mononucleated cells (MNCs) and CD34+ cell recovery between the two methods after processing and after thaw. TNC and MNC viability was significantly higher without HES after processing and after thaw (p < 0.01). The results of the CFC assay were similar for both methods after processing and after thaw.

CONCLUSION

These results showed that processing of UCB using the Sepax system with the without-HES protocol due to the lower manipulation of samples could be used as an eligible protocol to reduce the volume of UCB.

A case of Chediak-Higashi syndrome presented with accelerated phase could be treated effectively by unrelated cord blood transplantation

CHS is a rare immunodeficiency syndrome with defects in the functions of cytotoxic cells and neutrophils. Approximately 85% of patients with CHS undergo an AP within the first decade, which is similar to FHLH. Chemotherapy could induce transient remission, but only allogeneic HCT could correct the underlying genetic defect and prevent relapse. We reported a case of CHS diagnosed at 19 months, who had an elder brother who had previously succumbed to the same disease. The little girl presented with severe AP manifestations including recurrent high fever, enlarged superficial lymph nodes, and extraordinary hepatosplenomegaly occupying the whole abdominal and pelvic cavity. Comprehensive therapies including HLH 2004 protocol, supportive care, and antibiotics, especially antituberculous agents, were given to her to induce remission. After remission, the patient received fully HLA-matched UCBT. The transplantation course was uneventful, except for fluctuation of donor chimerism. The patient has been alive for 36 months without infection and neurologic manifestations and is under further follow-up. Our result provides another case that UCBT can be effective for treating patients with CHS and remission before HCT is important for good prognosis.

Fundamental Principles of Stem Cell Banking

Stem cells are highly promising resources for application in cell therapy, regenerative medicine, drug discovery, toxicology and developmental biology research. Stem cell banks have been increasingly established all over the world in order to preserve their cellular characteristics, prevent contamination and deterioration, and facilitate their effective use in basic and translational research, as well as current and future clinical application. Standardization and quality control during banking procedures are essential to allow researchers from different labs to compare their results and to develop safe and effective new therapies. Furthermore, many stem cells come from once-in-a-life time tissues. Cord blood for example, thrown away in the past, can be used to treat many diseases such as blood cancers nowadays. Meanwhile, these cells stored and often banked for long periods can be immediately available for treatment when needed and early treatment can minimize disease progression. This paper provides an overview of the fundamental principles of stem cell banking, including: (i) a general introduction of the construction and architecture commonly used for stem cell banks; (ii) a detailed section on current quality management practices; (iii) a summary of questions we should consider for long-term storage, such as how long stem cells can be stored stably, how to prevent contamination during long term storage, etc.; (iv) the prospects for stem cell banking.

Human Umbilical Cord Blood Cell Transplantation in Neuroregenerative Strategies

At present there is no effective treatment of pathologies associated with the death of neurons and glial cells which take place as a result of physical trauma or ischemic lesions of the nervous system. Thus, researchers have high hopes for a treatment based on the use of stem cells (SC), which are potentially able to replace dead cells and synthesize neurotrophic factors and other molecules that stimulate neuroregeneration. We are often faced with ethical issues when selecting a source of SC. In addition to precluding these, human umbilical cord blood (hUCB) presents a number of advantages when compared with other sources of SC. In this review, we consider the key characteristics of hUCB, the results of various studies focused on the treatment of neurodegenerative diseases (Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis), ischemic (stroke) and traumatic injuries of the nervous system and the molecular mechanisms of hUCB-derived mononuclear and stem cells.

Curative approaches for sickle cell disease: A review of allogeneic and autologous strategies

Despite sickle cell disease (SCD) first being reported >100years ago and molecularly characterized >50years ago, patients continue to experience severe morbidity and early mortality. Although there have been substantial clinical advances with immunizations, penicillin prophylaxis, hydroxyurea treatment, and transfusion therapy, the only cure that can be offered is hematopoietic stem cell transplantation (HSCT). In this work, we summarize the various allogeneic curative approaches reported to date and discuss open and upcoming clinical research protocols. Then we consider gene therapy and gene editing strategies that may enable cure based on autologous HSCs.

The role of policies and networks in development of cord blood usage in China

Research regarding the use of cord blood (CB) has focused on antigen match and the number of stem cells, with policies and networks related to its use being under researched. This article is based on fieldwork in China from 2013 to 2015 and examines ways that the studied CB bank enhances CB usage in China. This article identifies that in addition to finding a match, CB use is linked to the policies and networks, release fee and public awareness that enable CB usage development.

Update on umbilical cord blood transplantation

Allogeneic hematopoietic cell transplant is a curative procedure for many patients with leukemia, lymphoma, myelodysplasia, myeloproliferative neoplasms, and genetic disorders. Umbilical cord blood transplantation is a graft source for patients who do not have a matched donor in their family or in the unrelated registry. It is particularly difficult for Black, Hispanic, and White patients of non-Western European background to find fully matched adult volunteer donors. An estimated 700,000 umbilical cord blood units have been donated for public use, and over 40,000 umbilical cord blood transplantations have been performed. Over 25,000 patients have been cured with this approach.

Directing Stem Cell Fate: The Synthetic Natural Product Connection

Stem cells possess remarkable potential for the treatment of a broad array of diseases including many that lack therapeutic options. However, the use of cell-based products derived from stem cells as therapeutics has limitations including rejection, sufficient availability, and lack of appropriate engraftment. Chemical control of stem cells provides potential solutions for overcoming many of the current limitations in cell-based therapeutics. The development of exogenous molecules to control stem cell self-renewal or differentiation has arrived at natural product-based agents as an important class of modulators. The ex vivo production of cryopreserved cellular products for use in tissue repair is a relatively new area of medicine in which the conventional hurdles to implementing chemicals to effect human health are changed. Translational challenges centered on chemistry, such as pharmacokinetics, are reduced. Importantly, in many cases the desired human tissues can be evaluated against new chemicals, and approaches to cellular regulation can be validated in the clinically applicable system. As a result linking new and existing laboratory syntheses of natural products with findings of the compounds' unique abilities to regulate stem cell fate provides opportunities for developing improved methods for tissue manufacture, accessing probe compounds, and generating new leads that yield manufactured cells with improved properties. This review provides a summary of natural products that have shown promise in controlling stem cell fate and which have also been fully synthesized thereby providing chemistry platforms for further development.

Stem cells to restore insulin production and cure diabetes

BACKGROUND

The advancement of knowledge in the field of regenerative medicine is increasing the therapeutic expectations of patients and clinicians on cell therapy approaches. Within these, stem cell therapies are often evoked as a possible therapeutic option for diabetes, already ongoing or possible in the near future.

AIM

The purpose of this document is to make a point of the situation on existing knowledge and therapies with stem cells to treat patients with diabetes by focusing on some of the aspects that most frequently raise curiosity and discussion in clinical practice and in the interaction with the patient. In fact, at present there are no clinically approved treatments based on the use of stem cells for the treatment of diabetes, but several therapeutic approaches have already been evaluated or are being evaluated in clinical trials.

DATA SYNTHESIS

It is possible to identify three large potential application fields: 1) the reconstruction of the β cell mass; 2) the immunomodulation in type 1 diabetes (T1D); 3) the treatment of complications. In this study we will limit the discussion to approaches that have the potential for clinical translation, deliberately omitting aspects of basic biology and preclinical data. Also, we intentionally omit the treatment of the complications that will be the subject of a future document. Finally, an overview of the Italian situation regarding the storage of cord blood cells for the therapy of diabetes will be given.

The effect of maternal and infant factors on cord blood yield

Umbilical cord blood (CB) can be used as an alternative hematopoietic stem cell source for transplantation in hematological malignancy and blood disorders. The success of transplantation is highly related to the levels of total nucleated cell and CD34⁺ cell counts. The evaluation of optimal conditions can decrease the rate of graft rejection due to low cell count and increases the quality of CB units (CBUs) in the blood bank and the success rate of engraftment. To this end, we review the maternal and infant parameters affecting the quality and quantity of CBUs.

Correction of Fanconi Anemia Type C Phenotypic Abnormalities Using a Clinically Suitable Retroviral Vector Infection Protocol

Fanconi anemia (FA) is a complex autosomal recessive disease with hematologic manifestations characterized by a progressive hypoplastic anemia, hypersensitivity to clastogenic agents, and an increased incidence of acute myelogenous leukemia. The cDNA that corrects one of four FA complementation subtypes, named Fanconi anemia Type C (FAC) has recently been identified. We constructed a simplified recombinant retrovirus (vMFGFAC) encoding only the FAC cDNA, and tested its ability to correct the FAC defect in a lymphocytic cell line and primary mobilized blood progenitor cells. In addition, the gene transfer efficiency using a clinically applicable gene transfer protocol into normal primitive hematopoietic progenitor cells, high proliferating potential colony forming cells (HPP-CFC), derived from CD34+ purified cord blood cells was examined. The gene transfer efficiency was significantly enhanced when cells were transduced with supernatant while adherent to a 30/35 KD fragment of fibronectin, FN30/35, and was similar to efficiency obtained by coculture with retrovirus packaging cells. Transduction of an FAC deficient lymphoid cell line with vMFGFAC supernatant resulted in an enhanced cell viability, and G-CSF mobilized peripheral blood cells from an FAC-deficient patient transduced with the vMFGFAC virus demonstrated enhanced progenitor cell colony formation. These data indicate that the vMFGFAC virus allows functional complementation of FAC in lymphoblasts and primary hematopoietic progenitors, and that primitive cord blood hematopoietic stem/progenitor cells can be transduced at an efficiency comparable to protocols using cocultivation if adherent to FN 30/35 fragment.

Sources of Human Hematopoietic Stem Cells for Transplantation–A Review

Transplantation of hematopoietic stem cells provides a means of replacing a defective hematopoietic system in patients with a wide range of malignant and nonmalignant disorders that affect the blood forming tissue. The same procedure has also allowed dose-escalation of standard chemotherapy and radiotherapy in the treatment of malignant disease of nonhematological origin. Until recently, bone marrow has been the sole source of hematopoietic stem cells, but limitations of conventional bone marrow transplantation have stimulated a search for alternative sources and uses of stem cells. Fetal tissues (especially liver) are a recognized source of transplantable stem cells and offer the great advantage of reduced immunogenicity, potentially removing the problems of tissue type matching. Umbilical cord blood is also a rich source of stem cells and, although it contains alloreactive cells, it is readily available without special ethical constraints. Both fetal tissue and cord blood suffer the disadvantages of limited numbers of stem cells per donation, and there is much interest in the development of technologies for the safe and reliable expansion and/or pooling of stem and progenitor cells. The observation that small numbers of stem cells are found in the peripheral blood of adults has led to the exploitation of the blood as a further source of stem cells. The ability to mobilize these cells from the medullary compartment into the periphery by the use of chemotherapy and/or recombinant hematopoietic growth factors has enabled the collection of sufficient numbers of cells for transplantation purposes. All of these advances are increasing the options and the range of choices available to clinicians and patients in the arena of hematopoietic stem cell transplantation.

CD34+++ Stem/Progenitor Cells Purified from Cryopreserved Normal Cord Blood can be Transduced with High Efficiency by a Retroviral Vector and Expanded Ex Vivo with Stable Integration and Expression of Fanconi Anemia Complementation C Gene

A future possibility for treatment of genetic diseases may be gene therapy using autologous cord blood (CB) stem/progenitor cells. This might require cryopreservation of CB stem/progenitor cells prior to purification, gene transduction, and ex vivo expansion of cells. To address this possibility, nonadherent low density T-lymphocyte depleted (NALT-) cells from fresh or cryopreserved cord blood were sorted for CD34+++ phenotype, transduced with a recombinant retroviral vector encoding Fanconi anemia complementation C (FACC) gene, and cells expanded ex vivo in suspension culture for 7 days with growth factors. The results demonstrate: 1) high recovery of viable cells after thawing; 2) high efficiency purification of CD34+++ cells from NALT- cells prior to and after cryopreservation; 3) high degree of expansion of nucleated cells and immature progenitors from CD34+++ cells before and after cryopreservation; 4) efficient transduction with stable integration and expression of newly introduced genes in cryopreserved and then sorted stem/progenitor cells, as detected prior to and after ex vivo expansion; and 5) high efficiency transduction of single isolated CD34+++ cells obtained from cryopreserved NALT- CB. This information should be of value for future studies evaluating the use of cryopreserved cord blood for gene transfer/gene therapy.

The influence of temperature treatment before cryopreservation on the viability and potency of cryopreserved and thawed CD34+ and CD45+ cord blood cells

BACKGROUND

Hematopoietic stem cell (HSC) viability and potency is crucial for qualified cord blood (CB) transplants. This study analyzes time and temperature condition before cryopreservation for the viability of CD34⁺/CD45⁺ cells after cryopreservation.

METHODS

Cell viabilities were determined by antibody co-staining with 7-aminoactinomycin D detecting necrotic cells, and subsequent flow cytometric analysis. Additionally, Annexin V staining for determination of apoptotic cells and colony-forming unit (CFU) assays for testing functional potency of HSCs were performed.

RESULTS

For all cell types assessed (CD45⁺/CD34⁺ cells, lymphocytes and granulocytes), the highest viabilities were obtained for CB maintained at 4°C or room temperature (RT; 22 ± 4°C) and cryopreserved directly after collection. Starting material were CB units with an age of 24.7 ± 3.5 h after birth. Post-thaw CD34⁺ cell results were > 90% after temperature treatment of t = 24 h (48 h total age) and > 70% after t = 48 h (72 h total age) at 4°C (48 h, 91.4 ± 5.5%; 72 h, 75.0 ± 12.0%) and RT (48 h, 84.2 ± 9.7%; 72 h, 72.6 ± 0.6%). Viabilities for 30°C samples were < 80% after t = 24 h (48 h total age, 79.8 ± 3.1%) and < 50% after t = 48 h of treatment (72 h total age, 46.8 ± 14.3%). Regarding CFU recovery of pre-freeze (without volume reduction) and thawed CB, a trend toward the highest recoveries was observed at 4°C/RT. The difference between 4°C (77.5 ± 12.0%) and 30°C samples (53.9 ± 4.8%) was shown to be significant in post-thaw samples after t = 24 h treatment (48 h total age; P = 0.0341).

DISCUSSION

Delays between collection and cryopreservation should be minimized because increasing time reduces numbers of viable cells and CFUs before/after cryopreservation. CB units should be maintained at 4°C/RT to retain the highest possible potency of the cells after thawing.

Donor Selection for Allogenic Hemopoietic Stem Cell Transplantation: Clinical and Ethical Considerations

Allogenic hematopoietic progenitor cell transplantation (allo-HSCT) is an established treatment for many diseases. Stem cells may be obtained from different sources: mobilized peripheral blood stem cells, bone marrow, and umbilical cord blood. The progress in transplantation procedures, the establishment of experienced transplant centres, and the creation of unrelated adult donor registries and cord blood banks gave those without an human leucocyte antigen- (HLA-) identical sibling donor the opportunity to find a donor and cord blood units worldwide. HSCT imposes operative cautions so that the entire donation/transplantation procedure is safe for both donors and recipients; it carries with it significant clinical, moral, and ethical concerns, mostly when donors are minors. The following points have been stressed: the donation should be excluded when excessive risks for the donor are reasonable, donors must receive an accurate information regarding eventual adverse events and health burden for the donors themselves, a valid consent is required, and the recipient's risks must be outweighed by the expected benefits. The issue of conflict of interest, when the same physician has the responsibility for both donor selection and recipient care, is highlighted as well as the need of an adequate insurance protection for all the parties involved.

A Novel Method for Isolation of Pluripotent Stem Cells from Human Umbilical Cord Blood

Very small embryonic-like cells (VSELs) are a population of very rare pluripotent stem cells isolated in adult murine bone marrow and many other tissues and organs, including umbilical cord blood (UCB). VSEL existence is still not universally accepted by the scientific community, so for this purpose, we sought to investigate whether presumptive VSELs (pVSELs) could be isolated from human UCB with an improved protocol based on the isolation of enriched progenitor cells by depletion of nonprogenitor cells with magnetic separation. Progenitor cells, likely including VSELs, cultured with retinoic acid were able to form dense colonies and cystic embryoid bodies and to differentiate toward the ecto-meso-endoderm lineages as shown by the positivity to specific markers. VSEL differentiative potential toward mesodermal lineage was further demonstrated in vitro upon exposure to an established inductive protocol, which induced the acquisition of renal progenitor cell phenotype. VSEL-derived renal progenitors showed regenerative potential in a cisplatin model of acute kidney injury by restoring renal function and tubular structure through induction of proliferation of endogenous renal cells. The data presented here foster the great debate that surrounds VSELs and, more in general, the existence of cells endowed with pluripotent features in adult tissues. In fact, the possibility to find and isolate subpopulations of cells that fully fit all the criteria utilized to define pluripotency remains, nowadays, almost unproven. Thus, efforts to better characterize the phenotype of these intriguing cells are crucial to understand their possible applications for regenerative and precision medicine purposes.

Alternative Donor Graft Sources for Adults with Hematologic Malignancies: A Donor for All Patients in 2017!

Hematopoietic stem cell transplant (HSCT) is potentially curative for a wide variety of malignant diseases, including acute and leukemias, lymphoma, and myelodysplasia. Choice of a stem cell donor is dependent on donor availability, donor compatibility and health, recipient disease type, and recipient condition. Current sources of stem cell donation for HSCT are matched sibling donors (MSDs), matched unrelated donors (MUDs), 1-antigen mismatched unrelated donors (MMUDs), haploidentical donors (haplo), and umbilical cord blood (UCB) units. Historically, preferred donors for HSCT have been human leukocyte antigen (HLA)-matched sibling donors; however, only about 30% of U.S. patients will have a MSD available. The majority of patients referred for HSCT will require an alternative donor graft: MUD, MMUD, UCB, or haplo. The likelihood of finding a MUD varies depending on the ethnicity of the recipient. White Caucasians of European descent have the greatest chance of finding a MUD. Chances of finding a MUD are significantly less for African-American or Hispanic recipients due to HLA polymorphisms. Therefore, MMUD, UCB, and haplo donor graft sources expand the donor pool for recipients who do not have a MSD or MUD available. Given the variety of different donor stem cell sources available today, nearly every patient who needs an allogeneic HSCT has a potential donor in 2017. All transplant-eligible patients with hematologic malignancies should be evaluated by a transplant center to determine if HSCT is a viable treatment option for their underlying disease process.

IMPLICATIONS FOR PRACTICE

The goal of this review is to increase the awareness of oncology practitioners to the availability of alternative donor stem cell transplants for patients with hematologic malignancies. Despite new agents, stem cell transplant remains the only curative therapy for many patients with acute and chronic leukemia, myelodysplasia, and lymphoma. Given the variety of different donor stem cell sources available today, nearly every patient who needs an allogeneic stem cell transplant will have a donor.

Steric Hindrance Assay for Secreted Factors in Stem Cell Culture

The ex vivo expansion of hematopoietic stem cells is significantly inhibited by secreted proteins that induce negative feedback loops. The ability to effectively monitor these factors is critical for their real-time regulation and control and, by extension, enhancing stem cell expansion. Here, we describe a novel monitoring strategy for the detection of soluble signaling factors in stem cell cultures using a DNA-based sensing mechanism on a chip-based nanostructured microelectrode platform. We combine DNA hybridization engineering with antibody-capturing chemistry in an amplified steric hindrance hybridization assay. This method enables the quantification of important secreted proteins, showcased by the detection of 10 pg·mL^-1 level concentrations of three proteins in stem cell culture samples. This approach is the first universal nonsandwich technique that permits pg·mL^-1 level quantification of small proteins in stem cell culture media without signal loss.

A cost analysis of public cord blood banks belonging to the Italian Cord Blood Network

BACKGROUND

Public cord blood banking is currently managed in Italy by a network of 19 regional cord blood banks coordinated by the National Blood Centre and the National Transplant Centre. A cost analysis was carried out within the Italian network to determine the relationship between cost of cord blood collection and banking and size of the bank inventory, which ranged from 106 to 9,341 units on December 31^st, 2012.

MATERIALS AND METHODS

The 19 banks were invited to report costs incurred in 2012 related to cord blood unit collection, transportation, biological validation, characterisation, manipulation, cryopreservation, storage, data management, and general costs. Missing information on selected items was replaced with standardised costs represented by average data obtained from the reporting banks. Eight banks (52%) participated in the study. Average costs were determined in the three banks with inventories of >3,000 units vs the three banks with inventories of <1,000 units.

RESULTS

Both cord blood collection and cord blood banking costs per unit were lower in the larger banks than in the smaller banks (average collection costs: € 119.25 and € 151.31, respectively; average banking costs: € 3,614.15 and € 8,158.37, respectively).

DISCUSSION

The study outlined an inverse relationship between the costs of cord blood collection and banking and the size of the bank inventory, suggesting that scale economies could be obtained through centralisation of banking activities.

Advances in umbilical cord blood cell therapy: the present and the future

INTRODUCTION

Umbilical cord blood (UCB), previously seen as medical waste, is increasingly recognized as a valuable source of cells for therapeutic use. The best-known application is in hematopoietic stem cell transplantation (HSCT), where UCB has become an increasingly important graft source in the 28 years since the first umbilical cord blood transplantation (UCBT) was performed. Recently, UCB has been increasingly investigated as a putative source for adoptive cell therapy. Areas covered: This review covers the advances in umbilical cord blood transplantation (UCBT) to overcome the limitation regarding cellular dose, immunological naivety and additional cell doses such as DLI. It also provides an overview regarding the progress in adoptive cellular therapy using UCB. Expert opinion: UCB has been established as an important source of stem cells for HSCT. Successful strategies to overcome the limitations of UCBT, such as the limited cell numbers and naivety of the cells, are being developed, including novel methods to perform in vitro expansion of progenitor cells, and to improve their homing to the bone marrow. Promising early clinical trials of adoptive therapies with UCB cells, including non-immunological cells, are currently performed for viral infections, malignant diseases and in regenerative medicine.

Assessment of Drug Sensitivity in Hematopoietic Stem and Progenitor Cells from Acute Myelogenous Leukemia and Myelodysplastic Syndrome Ex Vivo

Current understanding suggests that malignant stem and progenitor cells must be reduced or eliminated for prolonged remissions in myeloid neoplasms such as acute myelogenous leukemia (AML) or myelodysplastic syndrome (MDS). Multicolor flow cytometry has been widely used to distinguish stem and myeloid progenitor cells from other populations in normal and malignant bone marrow. In this study, we present a method for assessing drug sensitivity in MDS and AML patient hematopoietic stem and myeloid progenitor cell populations ex vivo using the investigational Nedd8‐activating enzyme inhibitor MLN4924 and standard‐of‐care agent cytarabine as examples. Utilizing a multicolor flow cytometry antibody panel for identification of hematopoietic stem cells, multipotent progenitors, common myeloid progenitors, granulocyte‐monocyte progenitors, and megakaryocyte‐erythroid progenitors present in mononuclear cell fractions isolated from bone marrow aspirates, we compare stem and progenitor cell counts after treatment for 24 hours with drug versus diluent. We demonstrate that MLN4924 exerts a cytotoxic effect on MDS and AML stem and progenitor cell populations, whereas cytarabine has more limited effects. Further application of this method for evaluating drug effects on these populations ex vivo and in vivo may inform rational design and selection of therapies in the clinical setting. Stem Cells Translational Medicine2017;6:840–850

Long-Term Quality Control Program Plan for Cord Blood Banks in Korea: A Pilot Study for Cryopreservation Stability

Background

Maintaining the quality of cryopreserved cord blood is crucial. In this pilot study, we describe the results of the internal quality control program for a cord blood bank thus far.

Methods

Donated cord blood units unsuitable for transplantation were selected for internal quality control once a month. One unit of cord blood, aliquoted into 21 capillaries, was cryopreserved and thawed annually to analyze the total nucleated cell count, CD34⁺ cell count, cell viability test, and colony-forming units assay.

Results

No significant differences in the variables (total nucleated cell count, cell viability, CD34⁺ cell count) were observed between samples cryopreserved for one and two years. Upon comparing the variables before cryopreservation and post thawing with the capillaries of one year of storage, cell viability and CD34⁺ cell counts decreased significantly. The use of cord blood samples in capillaries, which can be easily stored for a long period, was similar to the methods used for testing segments attached to the cord blood unit.

Conclusions

The results of this study may be useful for determining the period during which the quality of cryopreserved cord blood units used for transplantation is maintained.

Stem cell therapy: An emerging modality in glomerular diseases

The kidney has been considered a highly terminally differentiated organ with low proliferative potential and thus unlikely to undergo regeneration. Glomerular disease progresses to end-stage renal disease (ESRD), which requires dialysis or renal transplantation for better quality of life for patients with ESRD. Because of the shortage of implantable kidneys and complications such as immune rejection, septicemia and toxicity of immunosuppression, kidney transplantation remains a challenge. Therapeutic options available for glomerular disease include symptomatic treatment and strategies to delay progression. In an attempt to develop innovative treatments by promoting the limited capability of regeneration and repair after kidney injury and overcome the progressive pathological process that is uncontrolled with conventional treatment modalities, stem cell-based therapy has emerged as novel intervention due to its ability to inhibit inflammation and promote regeneration. Recent developments in cell therapy have demonstrated promising therapeutic outcomes in terms of restoration of renal structure and function. This review focuses on stem cell therapy approaches for the treatment of glomerular disease, including the various cell sources used and recent advances in preclinical and clinical studies.

Alternative Donor/Unrelated Donor Transplants for the β-Thalassemia and Sickle Cell Disease

Considerable progress with respect to donor source has been achieved in allogeneic stem cell transplant for patients with hemoglobin disorders, with matched sibling donors in the 1980s, matched unrelated donors and cord blood sources in the 1990s, and haploidentical donors in the 2000s. Many studies have solidified hematopoietic progenitors from matched sibling marrow, cord blood, or mobilized peripheral blood as the best source-with the lowest graft rejection and graft versus host disease (GvHD), and highest disease-free survival rates. For patients without HLA-matched sibling donors, but who are otherwise eligible for transplant, fully allelic matched unrelated donor (8/8 HLA-A, B, C, DRB1) appears to be the next best option, though an ongoing study in patients with sickle cell disease will provide data that are currently lacking. There are high GvHD rates and low engraftment rates in some of the unrelated cord transplant studies. Haploidentical donors have emerged in the last decade to have less GvHD; however, improvements are needed to increase the engraftment rate. Thus the decision to use unrelated cord blood units or haploidentical donors may depend on the institutional expertise; there is no clear preferred choice over the other. Active research is ongoing in expanding cord blood progenitor cells to overcome the limitation of cell dose, including the options of small molecule inhibitor compounds added to ex vivo culture or co-culture with supportive cell lines. There are inconsistent data from using 7/8 or lower matched unrelated donors. Before routine use of these less matched donor sources, work is needed to improve patient selection, conditioning regimen, GvHD prophylaxis, and/or other strategies.

The Impact of High-resolution HLA-A, HLA-B, HLA-C, and HLA-DRB1 on Transplant-related Outcomes in Single-unit Umbilical Cord Blood Transplantation in Pediatric Patients

Current practice for selecting donor units for umbilical cord blood transplant (UCBT) involves matching at HLA-A and HLA-B by low-resolution typing and the HLA-DRB1 allele by high-resolution (HR) typing. We retrospectively studied the impact of HR allele matching at HLA-A, HLA-B, HLA-C, and HLA-DRB1 on transplant-related outcomes in 60 single-unit UCBTs in pediatric patients with malignant and nonmalignant conditions. Five-year overall survival of our cohort was 71% (95% confidence interval, 58-81); 27% experienced primary graft failure. Applying HR typing, donor-recipient mismatch variability increased ranging from 1/8 to 8/8, however, no impact on primary graft failure, graft-versus-host disease or posttransplant infection was observed. UCBTs with ≥6/8 HR matches did have a better overall survival (P=0.04) and decreased transplant-related mortality (P=0.02) compared with <6/8 HR matches. Using standard HLA typing, we showed an increased incidence of acute graft-versus-host disease (grade II to IV) and decreased transplant-related mortality in comparing the matched (6/6) versus ≤5/6 group (P=0.05 and 0.05, respectively). These data support the use of current guidelines for umbilical cord blood selection and encourage utilization of HR typing to select umbilical cord blood units matched at ≥6/8 especially when appropriate ≥5/6 units are available.

Analysis of Cap-binding Proteins in Human Cells Exposed to Physiological Oxygen Conditions

Translational control is a focal point of gene regulation, especially during periods of cellular stress. Cap-dependent translation via the eIF4F complex is by far the most common pathway to initiate protein synthesis in eukaryotic cells, but stress-specific variations of this complex are now emerging. Purifying cap-binding proteins with an affinity resin composed of Agarose-linked m⁷GTP (a 5' mRNA cap analog) is a useful tool to identify factors involved in the regulation of translation initiation. Hypoxia (low oxygen) is a cellular stress encountered during fetal development and tumor progression, and is highly dependent on translation regulation. Furthermore, it was recently reported that human adult organs have a lower oxygen content (physioxia 1-9% oxygen) that is closer to hypoxia than the ambient air where cells are routinely cultured. With the ongoing characterization of a hypoxic eIF4F complex (eIF4F^H), there is increasing interest in understanding oxygen-dependent translation initiation through the 5' mRNA cap. We have recently developed a human cell culture method to analyze cap-binding proteins that are regulated by oxygen availability. This protocol emphasizes that cell culture and lysis be performed in a hypoxia workstation to eliminate exposure to oxygen. Cells must be incubated for at least 24 hr for the liquid media to equilibrate with the atmosphere within the workstation. To avoid this limitation, pre-conditioned media (de-oxygenated) can be added to cells if shorter time points are required. Certain cap-binding proteins require interactions with a second base or can hydrolyze the m⁷GTP, therefore some cap interactors may be missed in the purification process. Agarose-linked to enzymatically resistant cap analogs may be substituted in this protocol. This method allows the user to identify novel oxygen-regulated translation factors involved in cap-dependent translation.

Expansion of Human Tregs from Cryopreserved Umbilical Cord Blood for GMP-Compliant Autologous Adoptive Cell Transfer Therapy

Umbilical cord blood is a traditional and convenient source of cells for hematopoietic stem cell transplantation. Thymic regulatory T cells (Tregs) are also present in cord blood, and there is growing interest in the use of autologous Tregs to provide a low-risk, fully human leukocyte antigen (HLA)-matched cell product for treating autoimmune diseases, such as type 1 diabetes. Here, we describe a good manufacturing practice (GMP)-compatible Treg expansion protocol using fluorescence-activated cell sorting, resulting in a mean 2,092-fold expansion of Tregs over a 16-day culture for a median yield of 1.26 × 10⁹ Tregs from single-donor cryopreserved units. The resulting Tregs passed prior clinical trial release criteria for Treg purity and sterility, including additional rigorous assessments of FOXP3 and Helios expression and epigenetic analysis of the FOXP3 Treg-specific demethylated region (TSDR). Compared with expanded adult peripheral blood Tregs, expanded cord blood Tregs remained more naive, as assessed by continued expression of CD45RA, produced reduced IFN-γ following activation, and effectively inhibited responder T cell proliferation. Immunosequencing of the T cell receptor revealed a remarkably diverse receptor repertoire within cord blood Tregs that was maintained following in vitro expansion. These data support the feasibility of generating GMP-compliant Tregs from cord blood for adoptive cell transfer therapies and highlight potential advantages in terms of safety, phenotypic stability, autoantigen specificity, and tissue distribution.

Clinical Studies of Ex Vivo Expansion to Accelerate Engraftment After Umbilical Cord Blood Transplantation: A Systematic Review

Cell dose limits greater use of umbilical cord blood (UCB) in hematopoietic cell transplantation. The clinical benefits of ex vivo expansion need clarity to understand its potential impact. A systematic search of studies addressing UCB ex vivo expansion was conducted. Fifteen clinical studies (349 transplanted patients) and 13 registered trials were identified. The co-infusion of an expanded unit and a second unmanipulated unit (8 studies), the fractional expansion of 12% to 60% of a single unit (5 studies), and the infusion of a single expanded unit (2 studies) were reported. More recently, published studies and 12 of 13 ongoing trials involve the use of novel small molecules in addition to traditional cytokine cocktails. Higher total cell number was closely associated with faster neutrophil engraftment. Compared with historical controls, neutrophil engraftment was significantly accelerated in more recent studies using small molecules or mesenchymal stromal cells (MSC) co-culture, and in some cases, platelet recovery was also statistically improved. Recent studies using nicotinamide and StemRegenin-1 reported long-term chimerism of the expanded unit. No significant improvement in survival or other transplant-related outcomes was demonstrated for any of the strategies. Ex vivo expansion of UCB can accelerate initial neutrophil engraftment after transplant. More recent studies suggest that long-term engraftment of ex vivo expanded cord blood units is achievable. Results of larger randomized controlled trials are needed to understand the impact on patient outcomes and health care costs.

Cord blood transplantation: rewind to fast forward

The utilization of cord blood as a source of stem cells for transplantation has decreased in recent years. Although cord blood transplantation (CBT) is an established practice for the treatment of adult and pediatric patients with hematological malignancies, the high acquisition cost of CB units along with high transplant-related mortality due to delayed hematopoietic recovery and immune reconstitution have contributed to the slowing in widespread adoption of CBT. Strategies aimed to enhance speed of engraftment and ongoing clinical trials are investigating ways to make CBT more widely available. Meanwhile, the recent clinical data suggest that the choice of CBT might be preferable for patients with pre-transplant minimal residual disease. We review here the background data on the utilization of CB for the treatment of hematological malignancies, and discuss the current challenges and future directions in the field of CBT.

Milestones of Hematopoietic Stem Cell Transplantation - From First Human Studies to Current Developments

Since the early beginnings, in the 1950s, hematopoietic stem cell transplantation (HSCT) has become an established curative treatment for an increasing number of patients with life-threatening hematological, oncological, hereditary, and immunological diseases. This has become possible due to worldwide efforts of preclinical and clinical research focusing on issues of transplant immunology, reduction of transplant-associated morbidity, and mortality and efficient malignant disease eradication. The latter has been accomplished by potent graft-versus-leukemia (GvL) effector cells contained in the stem cell graft. Exciting insights into the genetics of the human leukocyte antigen (HLA) system allowed improved donor selection, including HLA-identical related and unrelated donors. Besides bone marrow, other stem cell sources like granulocyte-colony stimulating-mobilized peripheral blood stem cells and cord blood stem cells have been established in clinical routine. Use of reduced-intensity or non-myeloablative conditioning regimens has been associated with a marked reduction of non-hematological toxicities and eventually, non-relapse mortality allowing older patients and individuals with comorbidities to undergo allogeneic HSCT and to benefit from GvL or antitumor effects. Whereas in the early years, malignant disease eradication by high-dose chemotherapy or radiotherapy was the ultimate goal; nowadays, allogeneic HSCT has been recognized as cellular immunotherapy relying prominently on immune mechanisms and to a lesser extent on non-specific direct cellular toxicity. This chapter will summarize the key milestones of HSCT and introduce current developments.

Impact of CTLA4 genotype and other immune response gene polymorphisms on outcomes after single umbilical cord blood transplantation

We evaluated the impact of recipient and cord blood unit (CBU) genetic polymorphisms related to immune response on outcomes after unrelated cord blood transplantations (CBTs). Pretransplant DNA samples from 696 CBUs with malignant diseases were genotyped for NLRP1, NLRP2, NLRP3, TIRAP/Mal, IL10, REL, TNFRSF1B, and CTLA4. HLA compatibility was 6 of 6 in 10%, 5 of 6 in 39%, and ≥4 of 6 in 51% of transplants. Myeloablative conditioning was used in 80%, and in vivo T-cell depletion in 81%, of cases. The median number of total nucleated cells infused was 3.4 × 10⁷/kg. In multivariable analysis, patients receiving CBUs with GG-CTLA4 genotype had poorer neutrophil recovery (hazard ratio [HR], 1.33; P = .02), increased nonrelapse mortality (NRM) (HR, 1.50; P < .01), and inferior disease-free survival (HR, 1.41; P = .02). We performed the same analysis in a more homogeneous subset of cohort 1 (cohort 2, n = 305) of patients who received transplants for acute leukemia, all given a myeloablative conditioning regimen, and with available allele HLA typing (HLA-A, -B, -C, and -DRB1). In this more homogeneous but smaller cohort, we were able to demonstrate that GG-CTLA4-CBU was associated with increased NRM (HR, 1.85; P = .01). Use of GG-CTLA4-CBU was associated with higher mortality after CBT, which may be a useful criterion for CBU selection, when multiple CBUs are available.

Impact of Graft-Recipient ABO Compatibility on Outcomes after Umbilical Cord Blood Transplant for Nonmalignant Disease

Existing literature shows mixed conclusions regarding the impact of ABO incompatibility on outcomes after hematopoietic stem cell transplantation. Because the future for umbilical cord blood (UCB) expansion technologies is bright, we assessed whether this typically overlooked graft characteristic impacted various outcomes after UCB transplantation (UCBT) for nonmalignant disorders (NMDs). A prospectively maintained institutional blood and marrow transplant program database was queried for all patients undergoing first UCBT for NMDs. UCB and recipient ABO compatibility was considered as matched, major mismatched, minor mismatched, or bidirectional mismatched. The impact of ABO incompatibility was assessed on overall survival, graft failure, acute and chronic graft-versus-host disease (GVHD), time to neutrophil and platelet recovery, day 0 to day 100 RBC transfusion burden, and donor hematopoietic chimerism. Through December 2014, 270 patients have undergone first UCBT for various NMDs. In both univariable and multivariable analyses, ABO compatibility status did not appear to impact any outcomes assessed, although a trend toward increased grades III to IV acute GVHD was seen in recipients of major mismatched units. When considering UCBT for treatment of NMDs, ABO compatibility between the donor unit and intended recipient does not appear to be an important consideration in the UCB unit choice.

Increasing injection frequency enhances the survival of injected bone marrow derived mesenchymal stem cells in a critical limb ischemia animal model

Critical limb ischemia (CLI) is one of the most severe forms of peripheral artery diseases, but current treatment strategies do not guarantee complete recovery of vascular blood flow or reduce the risk of mortality. Recently, human bone marrow derived mesenchymal stem cells (MSCs) have been reported to have a paracrine influence on angiogenesis in several ischemic diseases. However, little evidence is available regarding optimal cell doses and injection frequencies. Thus, the authors undertook this study to investigate the effects of cell dose and injection frequency on cell survival and paracrine effects. MSCs were injected at 10⁶ or 10⁵ per injection (high and low doses) either once (single injection) or once in two consecutive weeks (double injection) into ischemic legs. Mice were sacrificed 4 weeks after first injection. Angiogenic effects were confirmed in vitro and in vivo, and M2 macrophage infiltration into ischemic tissues and rates of limb salvage were documented. MSCs were found to induce angiogenesis through a paracrine effect in vitro, and were found to survive in ischemic muscle for up to 4 weeks dependent on cell dose and injection frequency. In addition, double high dose and low dose of MSC injections increased vessel formation, and decreased fibrosis volumes and apoptotic cell numbers, whereas a single high dose did not. Our results showed MSCs protect against ischemic injury in a paracrine manner, and suggest that increasing injection frequency is more important than MSC dosage for the treatment CLI.

Endothelial progenitor cells promote efficient ex vivo expansion of cord blood-derived hematopoietic stem/progenitor cells

BACKGROUND AIMS

Cord blood (CB) hematopoietic stem cell transplantation has often been limited by the scarcity of stem cells. Therefore, the number of CB hematopoietic stem/progenitor cells (HSPCs) should be increased while maintaining the stem cell characteristics.

METHODS

We designed an ex vivo culture system using endothelial progenitor cells (EPCs) as stroma to determine the capacity of expanding CB-HSPCs in a defined medium, the effect on engraftment of the expanded cells in a mouse model and the underlying mechanism.

RESULTS

After 7 days of culture, compared with those cultured with cytokines alone (3.25 ± 0.59), CD34+ cells under contact and non-contact co-culture with EPCs were expanded by 5.38 ± 0.61 (P = 0.003) and 4.06 ± 0.43 (P = 0.025)-fold, respectively. Direct cell-to-cell contact co-culture with EPCs resulted in more primitive CD34+ CD38- cells than stroma-free culture (156.17 ± 21.32 versus 79.12 ± 19.77-fold; P = 0.010). Comparable engraftment of day 7 co-cultured HSPCs with respect to HSPCs at day 0 in nonobese diabetic-severe combined immunodeficiency disease (NOD/SCID) mice was measured as a percentage of chimerism (13.3% ± 11.0% versus 16.0% ± 14.3%; P = 0.750). EPCs highly expressed interleukin 6 (IL6) and angiopoietin 1 (ANGPT1), the hematopoietic- related cytokines. A higher transcriptional level of WNT5A genes in EPCs and co-cultured HSPCs suggests that the activation of Wnt signaling pathway may play a role in HSPCs' expansion ex vivo.

DISCUSSION

These data demonstrated that EPCs improve the CD34+ population but do not compromise the repopulating efficacy of the amplified HSPCs, possibly via cytokine secretion and Wnt signaling pathway activation.