Publications by authors named "Suzanne M Watt"

65 Publications

The stem cell revolution: on the role of CD164 as a human stem cell marker.

NPJ Regen Med 2021 Jun 8;6(1):33. Epub 2021 Jun 8.

Myeloma Research Laboratory, Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, Australia.

Accurately defining hierarchical relationships between human stem cells and their progeny, and using this knowledge for new cellular therapies, will undoubtedly lead to further successful treatments for life threatening and chronic diseases, which represent substantial burdens on patient quality of life and to healthcare systems globally. Clinical translation relies in part on appropriate biomarker, in vitro manipulation and transplantation strategies. CD164 has recently been cited as an important biomarker for enriching both human haematopoietic and skeletal stem cells, yet a thorough description of extant human CD164 monoclonal antibody (Mab) characteristics, which are critical for identifying and purifying these stem cells, was not discussed in these articles. Here, we highlight earlier but crucial research describing these relevant characteristics, including the differing human CD164 Mab avidities and their binding sites on the human CD164 sialomucin, which importantly may affect subsequent stem cell function and fate.
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http://dx.doi.org/10.1038/s41536-021-00143-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8187384PMC
June 2021

Development of LT-HSC-Reconstituted Non-Irradiated NBSGW Mice for the Study of Human Hematopoiesis .

Front Immunol 2021 25;12:642198. Epub 2021 Mar 25.

Transplantation Research and Immunology Group, John Radcliffe Hospital, Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom.

Humanized immune system (HIS) mouse models are useful tools for the investigation of human hematopoiesis. However, the majority of HIS models currently in use are biased towards lymphocyte development and fail to support long-term multilineage leucocytes and erythrocytes. Those that achieve successful multilineage reconstitution often require preconditioning steps which are expensive, cause animal morbidity, are technically demanding, and poorly reproducible. In this study, we address this challenge by using HSPC-NBSGW mice, in which NOD,B6.SCID IL-2r Kit (NBSGW) mice are engrafted with human CD133 hematopoietic stem and progenitor cells (HSPCs) without the need for preconditioning by sublethal irradiation. These HSPCs are enriched in long-term hematopoietic stem cells (LT-HSCs), while NBSGW mice are permissive to human hematopoietic stem cell (HSC) engraftment, thus reducing the cell number required for successful HIS development. B cells reconstitute with the greatest efficiency, including mature B cells capable of class-switching following allogeneic stimulation and, within lymphoid organs and peripheral blood, T cells at a spectrum of stages of maturation. In the thymus, human thymocytes are identified at all major stages of development. Phenotypically distinct subsets of myeloid cells, including dendritic cells and mature monocytes, engraft to a variable degree in the bone marrow and spleen, and circulate in peripheral blood. Finally, we observe human erythrocytes which persist in the periphery at high levels following macrophage clearance. The HSPC-NBSGW model therefore provides a useful platform for the study of human hematological and immunological processes and pathologies.
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http://dx.doi.org/10.3389/fimmu.2021.642198DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8044770PMC
March 2021

The BET inhibitor CPI203 promotes ex vivo expansion of cord blood long-term repopulating HSCs and megakaryocytes.

Blood 2020 11;136(21):2410-2415

Nuffield Division of Clinical Laboratory Medicine, Radcliffe Department of Medicine, University of Oxford.

Although cytokine-mediated expansion of human hematopoietic stem cells (HSCs) can result in high yields of hematopoietic progenitor cells, this generally occurs at the expense of reduced bone marrow HSC repopulating ability, thereby limiting potential therapeutic applications. Because bromodomain-containing proteins (BCPs) have been demonstrated to regulate mouse HSC self-renewal and stemness, we screened small molecules targeting various BCPs as potential agents for ex vivo expansion of human HSCs. Of 10 compounds tested, only the bromodomain and extra-terminal motif inhibitor CPI203 enhanced the expansion of human cord blood HSCs without losing cell viability in vitro. The expanded cells also demonstrated improved engraftment and repopulation in serial transplantation assays. Transcriptomic and functional studies showed that the expansion of long-term repopulating HSCs was accompanied by synchronized expansion and maturation of megakaryocytes consistent with CPI203-mediated reprogramming of cord blood hematopoietic stem and progenitor cells. This approach may therefore prove beneficial for ex vivo gene editing, for enhanced platelet production, and for the improved usage of cord blood for transplantation research and therapy.
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http://dx.doi.org/10.1182/blood.2020005357DOI Listing
November 2020

P-Related Protein Accelerates Human Mesenchymal Stromal Cell Migration by Modulating VLA-5 Interactions with Fibronectin.

Cells 2020 04 29;9(5). Epub 2020 Apr 29.

Stem Cell Research, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9BQ, UK.

P-related protein (PZR), a Noonan and Leopard syndrome target, is a member of the transmembrane Immunoglobulin superfamily. Its cytoplasmic tail contains two immune-receptor tyrosine-based inhibitory motifs (ITIMs), implicated in adhesion-dependent signaling and regulating cell adhesion and motility. PZR promotes cell migration on the extracellular matrix (ECM) molecule, fibronectin, by interacting with SHP-2 (Src homology-2 domain-containing protein tyrosine phosphatase-2), a molecule essential for skeletal development and often mutated in Noonan and Leopard syndrome patients sharing overlapping musculoskeletal abnormalities and cardiac defects. To further explore the role of PZR, we assessed the expression of PZR and its ITIM-less isoform, PZRb, in human bone marrow mesenchymal stromal cells (hBM MSC), and its ability to facilitate adhesion to and spreading and migration on various ECM molecules. Furthermore, using siRNA knockdown, confocal microscopy, and immunoprecipitation assays, we assessed PZR and PZRb interactions with β1 integrins. PZR was the predominant isoform in hBM MSC. Migrating hBM MSCs interacted most effectively with fibronectin and required the association of PZR, but not PZRb, with the integrin, VLA-5(α5β1), leading to modulation of focal adhesion kinase phosphorylation and vinculin levels. This raises the possibility that dysregulation of PZR function may modify hBM MSC migratory behavior, potentially contributing to skeletal abnormalities.
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http://dx.doi.org/10.3390/cells9051100DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7290418PMC
April 2020

A modified CD34+ hematopoietic stem and progenitor cell isolation strategy from cryopreserved human umbilical cord blood.

Transfusion 2019 12 25;59(12):3560-3569. Epub 2019 Nov 25.

Stem Cell Research, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.

Background: Umbilical cord blood (UCB) is a source of hematopoietic stem cells for transplantation, offering an alternative for patients unable to find a matched adult donor. UCB is also a versatile source of hematopoietic stem and progenitor cells (hCD34 + HSPCs) for research into hematologic diseases, in vitro expansion, ex vivo gene therapy, and adoptive immunotherapy. For these studies, there is a need to isolate hCD34 + HSPCs from cryopreserved units, and protocols developed for isolation from fresh cord blood are unsuitable.

Study Design: This study describes a modified method for isolating hCD34 + HSPCs from cryopreserved UCB. It uses the Plasmatherm system for thawing, followed by CD34 microbead magnetic-activated cell sorting isolation with a cell separation kit (Whole Blood Columns, Miltenyi Biotec). hCD34 + HSPC phenotypes and functionality were assessed in vitro and hematologic reconstitution determined in vivo in immunodeficient mice.

Results: Total nucleated cell recovery after thawing and washing was 44.7 ± 11.7%. Recovery of hCD34 + HSPCs after application of thawed cells to Whole Blood Columns was 77.5 ± 22.6%. When assessed in two independent laboratories, the hCD34+ cell purities were 71.7 ± 10.7% and 87.8 ± 2.4%. Transplantation of the enriched hCD34 + HSPCs into NSG mice revealed the presence of repopulating hematopoietic stem cells (estimated frequency of 0.07%) and multilineage engraftment.

Conclusion: This provides a simplified protocol for isolating high-purity human CD34 + HSPCs from banked UCB adaptable to current Good Manufacturing Practice. This protocol reduces the number of steps and associated risks and thus total production costs. Importantly, the isolated CD34 + HSPCs possess in vivo repopulating activity in immunodeficient mice, making them a suitable starting population for ex vivo culture and gene editing.
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http://dx.doi.org/10.1111/trf.15597DOI Listing
December 2019

Discovery of a CD10-negative B-progenitor in human fetal life identifies unique ontogeny-related developmental programs.

Blood 2019 09 5;134(13):1059-1071. Epub 2019 Aug 5.

Department of Paediatrics and.

Human lymphopoiesis is a dynamic lifelong process that starts in utero 6 weeks postconception. Although fetal B-lymphopoiesis remains poorly defined, it is key to understanding leukemia initiation in early life. Here, we provide a comprehensive analysis of the human fetal B-cell developmental hierarchy. We report the presence in fetal tissues of 2 distinct CD19 B-progenitors, an adult-type CD10+ve ProB-progenitor and a new CD10-ve PreProB-progenitor, and describe their molecular and functional characteristics. PreProB-progenitors and ProB-progenitors appear early in the first trimester in embryonic liver, followed by a sustained second wave of B-progenitor development in fetal bone marrow (BM), where together they form >40% of the total hematopoietic stem cell/progenitor pool. Almost one-third of fetal B-progenitors are CD10-ve PreProB-progenitors, whereas, by contrast, PreProB-progenitors are almost undetectable (0.53% ± 0.24%) in adult BM. Single-cell transcriptomics and functional assays place fetal PreProB-progenitors upstream of ProB-progenitors, identifying them as the first B-lymphoid-restricted progenitor in human fetal life. Although fetal BM PreProB-progenitors and ProB-progenitors both give rise solely to B-lineage cells, they are transcriptionally distinct. As with their fetal counterparts, adult BM PreProB-progenitors give rise only to B-lineage cells in vitro and express the expected B-lineage gene expression program. However, fetal PreProB-progenitors display a distinct, ontogeny-related gene expression pattern that is not seen in adult PreProB-progenitors, and they share transcriptomic signatures with CD10-ve B-progenitor infant acute lymphoblastic leukemia blast cells. These data identify PreProB-progenitors as the earliest B-lymphoid-restricted progenitor in human fetal life and suggest that this fetal-restricted committed B-progenitor might provide a permissive cellular context for prenatal B-progenitor leukemia initiation.
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http://dx.doi.org/10.1182/blood.2019001289DOI Listing
September 2019

Single-cell assessment of transcriptome alterations induced by Scriptaid in early differentiated human haematopoietic progenitors during ex vivo expansion.

Sci Rep 2019 03 28;9(1):5300. Epub 2019 Mar 28.

Stem Cell Research, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, and NHS Blood and Transplant, John Radcliffe Hospital, Oxford, OX3 9BQ, UK.

Priming haematopoietic stem/progenitor cells (HSPCs) in vitro with specific chromatin modifying agents and cytokines under serum-free-conditions significantly enhances engraftable HSC numbers. We extend these studies by culturing human CD133+ HSPCs on nanofibre scaffolds to mimic the niche for 5-days with the HDAC inhibitor Scriptaid and cytokines. Scriptaid increases absolute Lin-CD34+CD38-CD45RA-CD90+CD49f+ HSPC numbers, while concomitantly decreasing the Lin-CD38-CD34+CD45RA-CD90- subset. Hypothesising that Scriptaid plus cytokines expands the CD90+ subset without differentiation and upregulates CD90 on CD90- cells, we sorted, then cultured Lin-CD34+CD38-CD45RA-CD90- cells with Scriptaid and cytokines. Within 2-days and for at least 5-days, most CD90- cells became CD90+. There was no significant difference in the transcriptomic profile, by RNAsequencing, between cytokine-expanded and purified Lin-CD34+CD38-CD45RA-CD49f+CD90+ cells in the presence or absence of Scriptaid, suggesting that Scriptaid maintains stem cell gene expression programs despite expansion in HSC numbers. Supporting this, 50 genes were significantly differentially expressed between CD90+ and CD90- Lin-CD34+CD38-CD45RA-CD49f+ subsets in Scriptaid-cytokine- and cytokine only-expansion conditions. Thus, Scriptaid treatment of CD133+ cells may be a useful approach to expanding the absolute number of CD90+ HSC, without losing their stem cell characteristics, both through direct effects on HSC and potentially also conversion of their immediate CD90- progeny into CD90+ HSC.
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http://dx.doi.org/10.1038/s41598-019-41803-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6438964PMC
March 2019

An Innovative Standard Operation Procedure for Isolating GMP-Grade CD4CD25 T Cells from Non-Mobilized Leukapheresis.

Methods Mol Biol 2019 ;1899:67-83

Nuffield Division of Laboratory Sciences, University of Oxford, Oxford, UK.

This SOP describes a closed system for isolating GMP-grade CD4CD25 T cells from non-mobilized leukapheresis collections (nMLCs), independent of a clean room in a certified GMP premises, by using CliniMACS format GMP grade reagents (CD25-labeled magnetic beads with/without pre-depletion of CD8 T cells and CD19 B cells), a GMP grade-A laminar hood and CliniMACS cell processing system.
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http://dx.doi.org/10.1007/978-1-4939-8938-6_6DOI Listing
June 2019

Does osteogenic potential of clonal human bone marrow mesenchymal stem/stromal cells correlate with their vascular supportive ability?

Stem Cell Res Ther 2018 12 19;9(1):351. Epub 2018 Dec 19.

Stem Cell Research, Nuffield Division of Clinical Laboratory Medicine, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, OX3 9BQ, UK.

Background: Human bone marrow-derived mesenchymal stem/stromal cells (hBM MSCs) have multiple functions, critical for skeletal formation and function. Their functional heterogeneity, however, represents a major challenge for their isolation and in developing potency and release assays to predict their functionality prior to transplantation. Additionally, potency, biomarker profiles and defining mechanisms of action in a particular clinical setting are increasing requirements of Regulatory Agencies for release of hBM MSCs as Advanced Therapy Medicinal Products for cellular therapies. Since the healing of bone fractures depends on the coupling of new blood vessel formation with osteogenesis, we hypothesised that a correlation between the osteogenic and vascular supportive potential of individual hBM MSC-derived CFU-F (colony forming unit-fibroblastoid) clones might exist.

Methods: We tested this by assessing the lineage (i.e. adipogenic (A), osteogenic (O) and/or chondrogenic (C)) potential of individual hBM MSC-derived CFU-F clones and determining if their osteogenic (O) potential correlated with their vascular supportive profile in vitro using lineage differentiation assays, endothelial-hBM MSC vascular co-culture assays and transcriptomic (RNAseq) analyses.

Results: Our results demonstrate that the majority of CFU-F (95%) possessed tri-lineage, bi-lineage or uni-lineage osteogenic capacity, with 64% of the CFU-F exhibiting tri-lineage AOC potential. We found a correlation between the osteogenic and vascular tubule supportive activity of CFU-F clones, with the strength of this association being donor dependent. RNAseq of individual clones defined gene fingerprints relevant to this correlation.

Conclusions: This study identified a donor-dependent correlation between osteogenic and vascular supportive potential of hBM MSCs and important gene signatures that support these functions that are relevant to their bone regenerative properties.
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http://dx.doi.org/10.1186/s13287-018-1095-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6300038PMC
December 2018

Neonatal Micro-RNA Profile Determines Endothelial Function in Offspring of Hypertensive Pregnancies.

Hypertension 2018 10 20;72(4):937-945. Epub 2018 Aug 20.

Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.

Offspring of hypertensive pregnancies are at increased risk of developing hypertension in adulthood. In the neonatal period they display endothelial cell dysfunction and altered microvascular development. MicroRNAs, as important endothelial cellular regulators, may play a role in this early endothelial dysfunction. Therefore we identified differential microRNA patterns in endothelial cells from offspring of hypertensive pregnancies and determined their role in postnatal vascular cell function. Studies were performed on human umbilical vein endothelial cell (HUVECs) samples from 57 pregnancies. Unbiased RNA-sequencing identified 30 endothelial-related microRNAs differentially expressed in HUVECs from hypertensive compared to normotensive pregnancies. Quantitative reverse transcription PCR (RT-qPCR) confirmed a significant higher expression level of the top candidate, miR-146a. Combined miR-146a targeted gene expression and pathway analysis revealed significant alterations in genes involved in inflammation, angiogenesis and immune response in the same HUVECs. Elevated miR-146a expression level at birth identified cells with reduced ability for vascular tube formation, which was rescued by miR-146a inhibition. In contrast, miR-146a overexpression significantly reduced vascular tube formation in HUVECs from normotensive pregnancies. Finally, we confirmed that mir146a levels at birth predicted microvascular development during the first three postnatal months. Offspring of hypertensive pregnancy have a distinct endothelial regulatory microRNA profile at birth, which is related to altered endothelial cell behaviour, and predicts patterns of microvascular development during the first three months of life. Modification of this microRNA profile can restore impaired vascular cell function.
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http://dx.doi.org/10.1161/HYPERTENSIONAHA.118.11343DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6166786PMC
October 2018

Stem cells, niches and scaffolds: Applications to burns and wound care.

Adv Drug Deliv Rev 2018 01 26;123:82-106. Epub 2017 Oct 26.

Department of Plastic and Reconstructive Surgery, North Bristol NHS Trust and University of Bristol, Westbury on Trym, Bristol BS9 3TZ, UK. Electronic address:

The importance of skin to survival, and the devastating physical and psychological consequences of scarring following reparative healing of extensive or difficult to heal human wounds, cannot be disputed. We discuss the significant challenges faced by patients and healthcare providers alike in treating these wounds. New state of the art technologies have provided remarkable insights into the role of skin stem and progenitor cells and their niches in maintaining skin homeostasis and in reparative wound healing. Based on this knowledge, we examine different approaches to repair extensive burn injury and chronic wounds, including full and split thickness skin grafts, temporising matrices and scaffolds, and composite cultured skin products. Notable developments include next generation skin substitutes to replace split thickness skin autografts and next generation gene editing coupled with cell therapies to treat genodermatoses. Further refinements are predicted with the advent of bioprinting technologies, and newly defined biomaterials and autologous cell sources that can be engineered to more accurately replicate human skin architecture, function and cosmesis. These advances will undoubtedly improve quality of life for patients with extensive burns and difficult to heal wounds.
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http://dx.doi.org/10.1016/j.addr.2017.10.012DOI Listing
January 2018

miR-193a-3p interaction with HMGB1 downregulates human endothelial cell proliferation and migration.

Sci Rep 2017 03 9;7:44137. Epub 2017 Mar 9.

Stem Cell Research, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9BQ, UK.

Circulating endothelial colony forming cells (ECFCs) contribute to vascular repair where they are a target for therapy. Since ECFC proliferative potential is increased in cord versus peripheral blood and to define regulatory factors controlling this proliferation, we compared the miRNA profiles of cord blood and peripheral blood ECFC-derived cells. Of the top 25 differentially regulated miRNAs selected, 22 were more highly expressed in peripheral blood ECFC-derived cells. After validating candidate miRNAs by q-RT-PCR, we selected miR-193a-3p for further investigation. The miR-193a-3p mimic reduced cord blood ECFC-derived cell proliferation, migration and vascular tubule formation, while the miR-193a-3p inhibitor significantly enhanced these parameters in peripheral blood ECFC-derived cells. Using in silico miRNA target database analyses combined with proteome arrays and luciferase reporter assays of miR-193a-3p mimic treated cord blood ECFC-derived cells, we identified 2 novel miR-193a-3p targets, the high mobility group box-1 (HMGB1) and the hypoxia upregulated-1 (HYOU1) gene products. HMGB1 silencing in cord blood ECFC-derived cells confirmed its role in regulating vascular function. Thus, we show, for the first time, that miR-193a-3p negatively regulates human ECFC vasculo/angiogenesis and propose that antagonising miR-193a-3p in less proliferative and less angiogenic ECFC-derived cells will enhance their vasculo/angiogenic function.
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http://dx.doi.org/10.1038/srep44137DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5343468PMC
March 2017

Potency of Human Cardiosphere-Derived Cells from Patients with Ischemic Heart Disease Is Associated with Robust Vascular Supportive Ability.

Stem Cells Transl Med 2017 05 16;6(5):1399-1411. Epub 2017 Feb 16.

Radcliffe Department of Medicine.

Cardiosphere-derived cell (CDC) infusion into damaged myocardium has shown some reparative effect; this could be improved by better selection of patients and cell subtype. CDCs isolated from patients with ischemic heart disease are able to support vessel formation in vitro but this ability varies between patients. The primary aim of our study was to investigate whether the vascular supportive function of CDCs impacts on their therapeutic potential, with the goal of improving patient stratification. A subgroup of patients produced CDCs which did not efficiently support vessel formation (poor supporter CDCs), had reduced levels of proliferation and increased senescence, despite them being isolated in the same manner and having a similar immunophenotype to CDCs able to support vessel formation. In a rodent model of myocardial infarction, poor supporter CDCs had a limited reparative effect when compared to CDCs which had efficiently supported vessel formation in vitro. This work suggests that not all patients provide cells which are suitable for cell therapy. Assessing the vascular supportive function of cells could be used to stratify which patients will truly benefit from cell therapy and those who would be better suited to an allogeneic transplant or regenerative preconditioning of their cells in a precision medicine fashion. This could reduce costs, culture times and improve clinical outcomes and patient prognosis. Stem Cells Translational Medicine 2017;6:1399-1411.
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http://dx.doi.org/10.1002/sctm.16-0229DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5442720PMC
May 2017

A Novel High-Throughput Screening Platform Reveals an Optimized Cytokine Formulation for Human Hematopoietic Progenitor Cell Expansion.

Stem Cells Dev 2016 11 30;25(22):1709-1720. Epub 2016 Sep 30.

2 Stem Cell Research, Nuffield Division of Clinical Laboratory Medicine, Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford , Oxford, United Kingdom .

The main limitations of hematopoietic cord blood (CB) transplantation, viz, low cell dosage and delayed reconstitution, can be overcome by ex vivo expansion. CB expansion under conventional culture causes rapid cell differentiation and depletion of hematopoietic stem and progenitor cells (HSPCs) responsible for engraftment. In this study, we use combinatorial cell culture technology (CombiCult) to identify medium formulations that promote CD133 CB HSPC proliferation while maintaining their phenotypic characteristics. We employed second-generation CombiCult screens that use electrospraying technology to encapsulate CB cells in alginate beads. Our results suggest that not only the combination but also the order of addition of individual components has a profound influence on expansion of specific HSPC populations. Top protocols identified by the CombiCult screen were used to culture human CD133 CB HSPCs on nanofiber scaffolds and validate the expansion of the phenotypically defined CD34CD38CD45RACD90CD49f population of hematopoietic stem cells and their differentiation into defined progeny.
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http://dx.doi.org/10.1089/scd.2016.0216DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5105341PMC
November 2016

Association of Maternal Antiangiogenic Profile at Birth With Early Postnatal Loss of Microvascular Density in Offspring of Hypertensive Pregnancies.

Hypertension 2016 09 25;68(3):749-59. Epub 2016 Jul 25.

From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine (G.Z.Y., C.Y.L.A., A.J.L., E.F.D., L.N., A.A.H.Z., L.J.S., K.O'B., T.K., K.M.C., P.L.), Stem Cell Research, Radcliffe Department of Medicine, Nuffield Division of Clinical Laboratory Sciences and National Health Service Blood and Transplant (G.Z.Y., C.P.K., L.N., C.T.Y., L.J.S., D.A.C., S.M.W.), Nuffield Department of Obstetrics and Gynaecology, Medical Sciences Division (C.Y.L.A., I.G.), and Wellcome Trust Centre for Human Genetics (A.A.H.Z., T.K.), University of Oxford, United Kingdom; and Peninsula Schools of Medicine and Dentistry, Plymouth University, United Kingdom (K.O'B.).

Offspring of hypertensive pregnancies are more likely to have microvascular rarefaction and increased blood pressure in later life. We tested the hypothesis that maternal angiogenic profile during a hypertensive pregnancy is associated with fetal vasculogenic capacity and abnormal postnatal microvascular remodeling. Infants (n=255) born after either hypertensive or normotensive pregnancies were recruited for quantification of postnatal dermal microvascular structure at birth and 3 months of age. Vasculogenic cell potential was assessed in umbilical vein endothelial cells from 55 offspring based on in vitro microvessel tube formation and proliferation assays. Maternal angiogenic profile (soluble fms-like tyrosine kinase-1, soluble endoglin, vascular endothelial growth factor, and placental growth factor) was measured from postpartum plasma samples to characterize severity of pregnancy disorder. At birth, offspring born after hypertensive pregnancy had similar microvessel density to those born after a normotensive pregnancy, but during the first 3 postnatal months, they had an almost 2-fold greater reduction in total vessel density (-17.7±16.4% versus -9.9±18.7%; P=0.002). This postnatal loss varied according to the vasculogenic capacity of the endothelial cells of the infant at birth (r=0.49; P=0.02). The degree of reduction in both in vitro and postnatal in vivo vascular development was proportional to levels of antiangiogenic factors in the maternal circulation. In conclusion, our data indicate that offspring born to hypertensive pregnancies have reduced vasculogenic capacity at birth that predicts microvessel density loss over the first 3 postnatal months. Degree of postnatal microvessel reduction is proportional to levels of antiangiogenic factors in the maternal circulation at birth.
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http://dx.doi.org/10.1161/HYPERTENSIONAHA.116.07586DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4978605PMC
September 2016

Junctional Adhesion Molecule-A Is Highly Expressed on Human Hematopoietic Repopulating Cells and Associates with the Key Hematopoietic Chemokine Receptor CXCR4.

Stem Cells 2016 06 15;34(6):1664-78. Epub 2016 Mar 15.

Nuffield Division of Clinical Laboratory Medicine, Radcliffe Department of Medicine, Stem Cell Research, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom.

Hematopoietic stem/progenitor cells (HSPCs) reside in specialized bone marrow microenvironmental niches, with vascular elements (endothelial/mesenchymal stromal cells) and CXCR4-CXCL12 interactions playing particularly important roles for HSPC entry, retention, and maintenance. The functional effects of CXCL12 are dependent on its local concentration and rely on complex HSPC-niche interactions. Two Junctional Adhesion Molecule family proteins, Junctional Adhesion Molecule-B (JAM)-B and JAM-C, are reported to mediate HSPC-stromal cell interactions, which in turn regulate CXCL12 production by mesenchymal stromal cells (MSCs). Here, we demonstrate that another JAM family member, JAM-A, is most highly expressed on human hematopoietic stem cells with in vivo repopulating activity (p < .01 for JAM-A(high) compared to JAM-A(Int or Low) cord blood CD34(+) cells). JAM-A blockade, silencing, and overexpression show that JAM-A contributes significantly (p < .05) to the adhesion of human HSPCs to IL-1β activated human bone marrow sinusoidal endothelium. Further studies highlight a novel association of JAM-A with CXCR4, with these molecules moving to the leading edge of the cell upon presentation with CXCL12 (p < .05 compared to no CXCL12). Therefore, we hypothesize that JAM family members differentially regulate CXCR4 function and CXCL12 secretion in the bone marrow niche. Stem Cells 2016;34:1664-1678.
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http://dx.doi.org/10.1002/stem.2340DOI Listing
June 2016

Human bone marrow processing using a new continuous-flow cell separation device.

Transfusion 2016 Apr 12;56(4):899-904. Epub 2015 Dec 12.

Stem Cell Research, Nuffield Division of Clinical Laboratory Medicine, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford.

Background: Processing of bone marrow (BM) is often required to remove incompatible red blood cells (RBCs) or to reduce the volume before transplantation or cryopreservation. We have evaluated the Spectra Optia apheresis system to determine its effectiveness in volume reduction and RBC depletion of human BM before transplantation.

Study Design And Methods: BM from 30 donations (28 allogeneic and two autologous) were processed using the Spectra Optia over a 12-month period. The mean BM collection volume was 1094 ± 337 mL and RBC volume was 374 ± 148 mL. Processing using the Spectra Optia was as described by the manufacturer.

Results: Volume reduction achieved was 93.0 ± 1.2%; RBC depletion was 98.8 ± 0.4%; and mononuclear, CD34+, and CD3+ cell recoveries were 79.12 ± 14.03, 88.36 ± 13.76, and 79.84 ± 16.27%, respectively. In total 26 of 28 processed allografts were transplanted; 24 achieved neutrophil engraftment in 20.7 ± 5.9 days and 18 achieved platelet engraftment in 19.6 ± 8.9 days. Time in transit significantly affected the Spectra Optia's ability to recover mononuclear, CD34+, and CD3+ cells, and the overall age of the BM at the time of processing significantly affected the recovery of mononuclear and CD3+ cells, but not CD34+ cells. Time in storage at 2 to 6°C had no adverse effect on processing.

Conclusion: This study demonstrates that the Spectra Optia can effectively volume reduce and RBC deplete human BM before transplantation. Time in transit should be as short as possible but may be extended up to 24 hours if the donation is refrigerated during transit.
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http://dx.doi.org/10.1111/trf.13438DOI Listing
April 2016

Direct Comparison of Wharton's Jelly and Bone Marrow-Derived Mesenchymal Stromal Cells to Enhance Engraftment of Cord Blood CD34(+) Transplants.

Stem Cells Dev 2015 Nov 8;24(22):2649-59. Epub 2015 Oct 8.

1 Jon J van Rood Center for Clinical Transfusion Research , Sanquin Blood Supply Foundation, Leiden, the Netherlands .

Cotransplantation of CD34(+) hematopoietic stem and progenitor cells (HSPCs) with mesenchymal stromal cells (MSCs) enhances HSPC engraftment. For these applications, MSCs are mostly obtained from bone marrow (BM). However, MSCs can also be isolated from the Wharton's jelly (WJ) of the human umbilical cord. This source, regarded to be a waste product, enables a relatively low-cost MSC acquisition without any burden to the donor. In this study, we evaluated the ability of WJ MSCs to enhance HSPC engraftment. First, we compared cultured human WJ MSCs with human BM-derived MSCs (BM MSCs) for in vitro marker expression, immunomodulatory capacity, and differentiation into three mesenchymal lineages. Although we confirmed that WJ MSCs have a more restricted differentiation capacity, both WJ MSCs and BM MSCs expressed similar levels of surface markers and exhibited similar immune inhibitory capacities. Most importantly, cotransplantation of either WJ MSCs or BM MSCs with CB CD34(+) cells into NOD SCID mice showed similar enhanced recovery of human platelets and CD45(+) cells in the peripheral blood and a 3-fold higher engraftment in the BM, blood, and spleen 6 weeks after transplantation when compared to transplantation of CD34(+) cells alone. Upon coincubation, both MSC sources increased the expression of adhesion molecules on CD34(+) cells, although stromal cell-derived factor-1 (SDF-1)-induced migration of CD34(+) cells remained unaltered. Interestingly, there was an increase in CFU-GEMM when CB CD34(+) cells were cultured on monolayers of WJ MSCs in the presence of exogenous thrombopoietin, and an increase in BFU-E when BM MSCs replaced WJ MSCs in such cultures. Our results suggest that WJ MSC is likely to be a practical alternative for BM MSC to enhance CB CD34(+) cell engraftment.
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http://dx.doi.org/10.1089/scd.2015.0138DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4652197PMC
November 2015

An innovative method to generate a Good Manufacturing Practice-ready regulatory T-cell product from non-mobilized leukapheresis donors.

Cytotherapy 2015 Sep;17(9):1268-79

Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, Oxford, United Kingdom; NHS Blood and Transplant Oxford Centre, John Radcliffe Hospital, Oxford, United Kingdom; Cancer and Haematology Centre, Churchill Hospital, Oxford, United Kingdom.

Background Aims: There is real and sustained interest in preparing T-regulatory cells from leukapheresis collections for cellular therapy through the use of simple, effective and reliable methods conforming to Good Manufacturing Practice (GMP). We describe a GMP-ready isolation procedure for CD25(+) products with the use of a sterile docking device, pigtail sampling, a laminar flow hood and the CliniMACS system that uses leukapheresis collections made by two apheresis machines.

Methods: We used CD8/CD19 depletion followed by CD25-positive selection. The median number of CD4(+) cells recovered was 72.5 ± 32.6 × 10(6), of which 60.5% ± 17.8% were CD25(+)FOXP3(+) cells. Suppression of autologous CD25(-) cell proliferation by the cryopreserved CD25(+) products was 51.3% ± 4.4%, 49.0% ± 3.7% and 39.0% ± 3.6% at CD25(+):CD25(-) ratios of 1:1, 1:2 and 1:4 (n = 6), respectively, comparable to suppression by fresh CD25(+) products (53% ± 6.2%, 51% ± 3.3% and 39% ± 7.1%).

Results: We found Leukapheresis collections by Cobe Spectra contained more lymphocytes and platelets than collections by Spectra Optia apheresis machine (median, 9.2 × 10(9) versus 6.7 × 10(9); P = 0.04) and platelets (median, 610 × 10(9) versus 170 × 10(9); P = 0.04). The frequency of CD4(+)CD25(+)FOXP3(+) was significantly higher in the leukapheresis (4.85%; 95% confidence interval, 1.95% to 5.38%) than in peripheral blood (3.9%; 95% confidence interval, 2.63% to 6.45%) (P = 0.02). The CD8- and CD19-negative depletion step was associated with significant loss of total CD4(+) T cells (P = 0.001).

Conclusions: Results suggest that functional CD25(+) products can be isolated with a GMP-ready method, and good recovery can be obtained with the use of an optimized cryopreservation protocol. These data and methods show the potential, possibilities and future work needed to isolate target cell populations in a reproducible, time-efficient and cost-efficient manner for clinical applications.
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http://dx.doi.org/10.1016/j.jcyt.2015.05.015DOI Listing
September 2015

CXCR2 modulates bone marrow vascular repair and haematopoietic recovery post-transplant.

Br J Haematol 2015 May 9;169(4):552-64. Epub 2015 Mar 9.

Stem Cell Research Laboratory, NHS Blood and Transplant, John Radcliffe Hospital, Oxford, UK; Nuffield Division of Clinical and Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK.

Murine models of bone marrow transplantation show that pre-conditioning regimens affect the integrity of the bone marrow endothelium and that the repair of this vascular niche is an essential pre-requisite for successful haematopoietic stem and progenitor cell engraftment. Little is known about the angiogenic pathways that play a role in the repair of the human bone marrow vascular niche. We therefore established an in vitro humanized model, composed of bone marrow stromal and endothelial cells and have identified several pro-angiogenic factors, VEGFA, ANGPT1, CXCL8 and CXCL16, produced by the stromal component of this niche. We demonstrate for the first time that addition of CXCL8 or inhibition of its receptor, CXCR2, modulates blood vessel formation in our bone marrow endothelial niche model. Compared to wild type, Cxcr2(-/-) mice displayed a reduction in bone marrow cellularity and delayed platelet and leucocyte recovery following myeloablation and bone marrow transplantation. The delay in bone marrow recovery correlated with impaired bone marrow vascular repair. Taken together, our data demonstrate that CXCR2 regulates bone marrow blood vessel repair/regeneration and haematopoietic recovery, and clinically may be a therapeutic target for improving bone marrow transplantation.
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http://dx.doi.org/10.1111/bjh.13335DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4654909PMC
May 2015

Human induced pluripotent stem cell-derived B lymphocytes express sIgM and can be generated via a hemogenic endothelium intermediate.

Stem Cells Dev 2015 May 25;24(9):1082-95. Epub 2015 Feb 25.

1 Stem Cell Research Laboratory, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, and National Health Service Blood and Transplant, University of Oxford , John Radcliffe Hospital, Oxford, United Kingdom .

The differentiation of human pluripotent stem cells to the B-cell lymphoid lineage has important clinical applications that include in vitro modeling of developmental lymphogenesis in health and disease. Here, we first demonstrate the capacity of human induced pluripotent stem cells (hiPSCs) to differentiate into CD144(+)CD73(-)CD43/CD235a(-) cells, characterized as hemogenic endothelium, and show that this population is capable of differentiating to CD10(+)CD19(+) B lymphocytes. We also demonstrate that B lymphocytes generated from hiPSCs are able to undergo full VDJ rearrangement and express surface IgM (sIgM(+)), thus representing an immature B-cell subset. Efficiency of sIgM expression on the hiPSC-derived B lymphocytes (∼ 5% of CD19(+) cells) was comparable with B lymphocytes generated from human umbilical cord blood (UCB) hematopoietic progenitor cells. Importantly, when assessed by global transcriptional profiling, hiPSC-derived B-cells show a very high level of similarity when compared with their UCB-derived counterparts, such that from more than 47,000 different transcripts, only 45 were significantly different (with a criteria adjusted P value P<0.05, log FC >1.5 or 2.8-fold). This represents a unique in vitro model to delineate critical events during lymphogeneisis in development and lymphoid diseases such as acute lymphocytic leukemia.
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http://dx.doi.org/10.1089/scd.2014.0318DOI Listing
May 2015

Thrombopoietin treatment of one graft in a double cord blood transplant provides early platelet recovery while contributing to long-term engraftment in NSG mice.

Stem Cells Dev 2015 Jan;24(1):67-76

1 Jon J. van Rood Center for Clinical Transfusion Research , Sanquin Blood Supply Foundation, Leiden, The Netherlands .

Human cord blood (CB) hematopoietic stem cell (HSC) transplants demonstrate delayed early neutrophil and platelet recovery and delayed longer term immune reconstitution compared to bone marrow and mobilized peripheral blood transplants. Despite advances in enhancing early neutrophil engraftment, platelet recovery after CB transplantation is not significantly altered when compared to contemporaneous controls. Recent studies have identified a platelet-biased murine HSC subset, maintained by thrombopoietin (TPO), which has enhanced capacity for short- and long-term platelet reconstitution, can self-renew, and can give rise to myeloid- and lymphoid-biased HSCs. In previous studies, we have shown that transplantation of human CB CD34(+) cells precultured in TPO as a single graft accelerates early platelet recovery as well as yielding long-term repopulation in immune-deficient mice. In this study, using a double CB murine transplant model, we investigated whether TPO cultured human CB CD34(+) cells have a competitive advantage or disadvantage over untreated human CB CD34(+) cells in terms of (1) short-term and longer term platelet recovery and (2) longer term hematological recovery. Our studies demonstrate that the TPO treated graft shows accelerated early platelet recovery without impairing the platelet engraftment of untreated CD34(+) cells. Notably, this was followed by a dominant contribution to platelet production through the untreated CD34(+) cell graft over the intermediate to longer term. Furthermore, although the contribution of the TPO treated graft to long-term hematological engraftment was reduced, the TPO treated and untreated grafts both contributed significantly to long-term chimerism in vivo.
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http://dx.doi.org/10.1089/scd.2014.0294DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4273186PMC
January 2015

The hematopoietic chemokine CXCL12 promotes integration of human endothelial colony forming cell-derived cells into immature vessel networks.

Stem Cells Dev 2014 Nov 25;23(22):2730-43. Epub 2014 Jul 25.

1 Stem Cell Research Laboratory , Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, and NHS Blood and Transplant, John Radcliffe Hospital, Oxford, United Kingdom .

Proangiogenic factors, vascular endothelial growth factor (VEGF), and fibroblast growth factor-2 (FGF-2) prime endothelial cells to respond to "hematopoietic" chemokines and cytokines by inducing/upregulating expression of the respective chemokine/cytokine receptors. Coculture of human endothelial colony forming cell (ECFC)-derived cells with human stromal cells in the presence of VEGF and FGF-2 for 14 days resulted in upregulation of the "hematopoietic" chemokine CXCL12 and its CXCR4 receptor by day 3 of coculture. Chronic exposure to the CXCR4 antagonist AMD3100 in this vasculo/angiogenesis assay significantly reduced vascular tubule formation, an observation recapitulated by delayed AMD3100 addition. While AMD3100 did not affect ECFC-derived cell proliferation, it did demonstrate a dual action. First, over the later stages of the 14-day cocultures, AMD3100 delayed tubule organization into maturing vessel networks, resulting in enhanced endothelial cell retraction and loss of complexity as defined by live cell imaging. Second, at earlier stages of cocultures, we observed that AMD3100 significantly inhibited the integration of exogenous ECFC-derived cells into established, but immature, vascular networks. Comparative proteome profiler array analyses of ECFC-derived cells treated with AMD3100 identified changes in expression of potential candidate molecules involved in adhesion and/or migration. Blocking antibodies to CD31, but not CD146 or CD166, reduced the ECFC-derived cell integration into these extant vascular networks. Thus, CXCL12 plays a key role not only in endothelial cell sensing and guidance, but also in promoting the integration of ECFC-derived cells into developing vascular networks.
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http://dx.doi.org/10.1089/scd.2014.0005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4216481PMC
November 2014

Human induced pluripotent stem cell derived erythroblasts can undergo definitive erythropoiesis and co-express gamma and beta globins.

Br J Haematol 2014 Aug 16;166(3):435-48. Epub 2014 May 16.

Blood Research Laboratory, Radcliffe Department of Medicine, NHS Blood and Transplant and Nuffield Division of Clinical Laboratory Medicine, John Radcliffe Hospital, University of Oxford, Oxford, UK; Stem Cell Research Laboratory, Radcliffe Department of Medicine, NHS Blood and Transplant and Nuffield Division of Clinical Laboratory Medicine, John Radcliffe Hospital, University of Oxford, Oxford, UK.

Human induced pluripotent stem cells (hiPSCs), like embryonic stem cells, are under intense investigation for novel approaches to model disease and for regenerative therapies. Here, we describe the derivation and characterization of hiPSCs from a variety of sources and show that, irrespective of origin or method of reprogramming, hiPSCs can be differentiated on OP9 stroma towards a multi-lineage haemo-endothelial progenitor that can contribute to CD144(+) endothelium, CD235a(+) erythrocytes (myeloid lineage) and CD19(+) B lymphocytes (lymphoid lineage). Within the erythroblast lineage, we were able to demonstrate by single cell analysis (flow cytometry), that hiPSC-derived erythroblasts express alpha globin as previously described, and that a sub-population of these erythroblasts also express haemoglobin F (HbF), indicative of fetal definitive erythropoiesis. More notably however, we were able to demonstrate that a small sub-fraction of HbF positive erythroblasts co-expressed HbA in a highly heterogeneous manner, but analogous to cord blood-derived erythroblasts when cultured using similar methods. Moreover, the HbA expressing erythroblast population could be greatly enhanced (44·0 ± 6·04%) when a defined serum-free approach was employed to isolate a CD31(+) CD45(+) erythro-myeloid progenitor. These findings demonstrate that hiPSCs may represent a useful alternative to standard sources of erythrocytes (RBCs) for future applications in transfusion medicine.
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http://dx.doi.org/10.1111/bjh.12910DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4375519PMC
August 2014

Scarring, stem cells, scaffolds and skin repair.

J Tissue Eng Regen Med 2015 Jun 29;9(6):649-68. Epub 2013 Oct 29.

Stem Cell Research Laboratory, NHS Blood and Transplant, Oxford, UK.

The treatment of full thickness skin loss, which can be extensive in the case of large burns, continues to represent a challenging clinical entity. This is due to an on-going inability to produce a suitable tissue engineered substrate that can satisfactorily replicate the epidermal and dermal in vivo niches to fulfil both aesthetic and functional demands. The current gold standard treatment of autologous skin grafting is inadequate because of poor textural durability, scarring and associated contracture, and because of a paucity of donor sites in larger burns. Tissue engineering has seen exponential growth in recent years with a number of 'off-the-shelf' dermal and epidermal substitutes now available. Each has its own limitations. In this review, we examine normal wound repair in relation to stem/progenitor cells that are intimately involved in this process within the dermal niche. Endothelial precursors, in particular, are examined closely and their phenotype, morphology and enrichment from multiple sources are described in an attempt to provide some clarity regarding the controversy surrounding their classification and role in vasculogenesis. We also review the role of the next generation of cellularized scaffolds and smart biomaterials that attempt to improve the revascularisation of artificial grafts, the rate of wound healing and the final cosmetic and functional outcome.
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http://dx.doi.org/10.1002/term.1841DOI Listing
June 2015

Storage time affects umbilical cord blood viability.

Transfusion 2014 May 14;54(5):1278-85. Epub 2013 Nov 14.

NHS Blood and Transplant, Bristol, UK.

Background: Cryopreserved umbilical cord blood (CB) is increasingly used as a cell source to reconstitute marrow in hematopoietic stem cell transplant patients. Delays in cryopreservation may adversely affect cell viability, thereby reducing their potential for engraftment after transplantation.

Study Design And Methods: The impact of delayed cryopreservation for up to 3 days on the viability of both CD45+ and CD34+ cell populations in 28 CB donations with volumes of 58.40 ± 15.4 mL (range, 39.4-107.4 mL) was investigated to establish whether precryopreservation storage time could be extended from our current time of 24 to 48 hours in line with other CB banks. Viability was assessed on 3 consecutive days, both before and after cryopreservation, by flow cytometry using 7-aminoactinomycin D (7-AAD) and annexin V methods.

Results: The results using 7-AAD and annexin V indicated the viability of CD34+ cells before cryopreservation remained high (>92.33 ± 4.11%) over 3 days, whereas the viability of CD45+ cells decreased from 86.36 ± 4.97% to 66.24 ± 7.78% (p < 0.0001) by Day 3. Storage time significantly affected the viability of CD34+ cells after cryopreservation. Using 7-AAD, the mean CD34+ cell viability decreased by approximately 5% per extra day in storage from 84.30 ± 6.27% on Day 1 to 79.01 ± 7.44% (p < 0.0057) on Day 2 and to 73.95 ± 7.54% (p < 0.0001) on Day 3. With annexin V staining CD34+ cell viability fell by approximately 7% per extra day in storage from 77.17 ± 8.47% on Day 1 to 69.56 ± 13.30% (p < 0.0194) on Day 2 and to 62.89 ± 15.22% (p < 0.0002) on Day 3.

Conclusion: This study demonstrates that extended precryopreservation storage adversely affects viability and should be avoided.
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http://dx.doi.org/10.1111/trf.12481DOI Listing
May 2014

Definition and application of good manufacturing process-compliant production of CEA-specific chimeric antigen receptor expressing T-cells for phase I/II clinical trial.

Cancer Immunol Immunother 2014 Feb 5;63(2):133-45. Epub 2013 Nov 5.

Cellular Therapeutics, Grafton Street, Manchester, M13 9XX, UK.

Adoptive cell therapy employing gene-modified T-cells expressing chimeric antigen receptors (CARs) has shown promising preclinical activity in a range of model systems and is now being tested in the clinical setting. The manufacture of CAR T-cells requires compliance with national and European regulations for the production of medicinal products. We established such a compliant process to produce T-cells armed with a first-generation CAR specific for carcinoembryonic antigen (CEA). CAR T-cells were successfully generated for 14 patients with advanced CEA(+) malignancy. Of note, in the majority of patients, the defined procedure generated predominantly CD4(+) CAR T-cells with the general T-cell population bearing an effector-memory phenotype and high in vitro effector function. Thus, improving the process to generate less-differentiated T-cells would be more desirable in the future for effective adoptive gene-modified T-cell therapy. However, these results confirm that CAR T-cells can be generated in a manner compliant with regulations governing medicinal products in the European Union.
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http://dx.doi.org/10.1007/s00262-013-1492-9DOI Listing
February 2014

The angiogenic properties of mesenchymal stem/stromal cells and their therapeutic potential.

Br Med Bull 2013 23;108:25-53. Epub 2013 Oct 23.

Stem Cell Research Laboratory, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK.

Background: Blood vessel formation is fundamental to development, while its dysregulation can contribute to serious disease. Expectations are that hundreds of millions of individuals will benefit from therapeutic developments in vascular biology. MSCs are central to the three main vascular repair mechanisms.

Sources Of Data: Key recent published literature and ClinicalTrials.gov.

Areas Of Agreement: MSCs are heterogeneous, containing multi-lineage stem and partly differentiated progenitor cells, and are easily expandable ex vivo. There is no single marker defining native MSCs in vivo. Their phenotype is strongly determined by their specific microenvironment. Bone marrow MSCs have skeletal stem cell properties. Having a perivascular/vascular location, they contribute to vascular formation and function and might be harnessed to regenerate a blood supply to injured tissues.

Areas Of Controversy: These include MSC origin, phenotype and location in vivo and their ability to differentiate into functional cardiomyocytes and endothelial cells or act as vascular stem cells. In addition their efficacy, safety and potency in clinical trials in relation to cell source, dose, delivery route, passage and timing of administration, but probably even more on the local preconditioning and the mechanisms by which they exert their effects.

Growing Points: Understanding the origin and the regenerative environment of MSCs, and manipulating their homing properties, proliferative ability and functionality through drug discovery and reprogramming strategies are important for their efficacy in vascular repair for regenerative medicine therapies and tissue engineering approaches.

Areas Timely For Developing Research: Characterization of MSCs' in vivo origins and biological properties in relation to their localization within tissue niches, reprogramming strategies and newer imaging/bioengineering approaches.
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http://dx.doi.org/10.1093/bmb/ldt031DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3842875PMC
July 2014
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