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Nottingham, United Kingdom

Naing M.W.,Loughborough University | Gibson D.A.,Anthony Nolan Cell Therapy Center | Hourd P.,Loughborough University | Gomez S.G.,Anthony Nolan Cell Therapy Center | And 3 more authors.
Cytotherapy | Year: 2015

Background aims: With the rising use of umbilical cord blood (UCB) as an alternative source of hematopoietic stem cells, storage inventories of UCB have grown, giving rise to genetically diverse inventories globally. In the absence of reliable markers such as CD34 or counts of colony-forming units, total nucleated cell (TNC) counts are often used as an indicator of potency, and transplant centers worldwide often select units with the largest counts of TNC. As a result, cord blood banks are driven to increase the quality of stored inventories by increasing the TNC count of products stored. However, these banks face challenges in recovering consistent levels of TNC with the use of the standard protocols of automated umbilical cord processing systems, particularly in the presence of input variation both of cord blood volume and TNC count, in which it is currently not possible to process larger but useable UCB units with consequent losses in TNC. Methods: This report addresses the challenge of recovering consistently high TNC yields in volume reduction by proposing and validating an alternative protocol capable of processing a larger range of units more reliably. Results: This work demonstrates improvements in plastic ware and tubing sets and in the recovery process protocol with consequent productivity gains in TNC yield and a reduction in standard deviation. Conclusions: This work could pave the way for cord blood banks to improve UCB processing and increase efficiency through higher yields and lower costs. © 2015 International Society for Cellular Therapy.

New S.E.P.,University College London | Alvarez-Gonzalez C.,Anthony Nolan Research Institute | Alvarez-Gonzalez C.,University College London | Vagaska B.,University College London | And 5 more authors.
Stem Cell Research | Year: 2015

Human somatic stem cells with neural differentiation potential can be valuable for developing cell-based therapies, including treatment of birth-related defects, while avoiding issues associated with cell reprogramming. Precisely defining the "identity" and differentiation potential of somatic stem cells from different sources, has proven difficult, given differences in sets of specific markers, protocols used and lack of side-by-side characterization of these cells in different studies. Therefore, we set to compare expression of mesenchymal and neural markers in human umbilical cord-derived mesenchymal stem cells (UC-MSCs), pediatric adipose-derived stem cells (p-ADSCs) in parallel with human neural stem cells (NSCs). We show that UC-MSCs at a basal level express mesenchymal and so-called "neural" markers, similar to that we previously reported for the p-ADSCs. All somatic stem cell populations studied, independently from tissue and patient of origin, displayed a remarkably similar expression of surface markers, with the main difference being the restricted expression of CD133 and CD34 to NSCs. Expression of certain surface and neural markers was affected by the expansion medium used. As predicted, UC-MSCs and p-ADSCs demonstrated tri-mesenchymal lineage differentiation potential, though p-ADSCs display superior chondrogenic differentiation capability. UC-MSCs and p-ADSCs responded also to neurogenic induction by up-regulating neuronal markers, but crucially they appeared morphologically immature when compared with differentiated NSCs. This highlights the need for further investigation into the use of these cells for neural therapies. Crucially, this study demonstrates the lack of simple means to distinguish between different cell types and the effect of culture conditions on their phenotype, and indicates that a more extensive set of markers should be used for somatic stem cell characterization, especially when developing therapeutic approaches. © 2015.

Alvarez-Gonzalez C.,Anthony Nolan Research Institute | Alvarez-Gonzalez C.,University College London | Duggleby R.,Anthony Nolan Research Institute | Vagaska B.,University College London | And 5 more authors.
PLoS ONE | Year: 2013

Human umbilical cord blood (hUCB) has been proposed to contain not only haematopoietic stem cells, but also a rare pluripotent embryonic-like stem cell (ELSc) population that is negative for hematopoietic markers (Lin-CD45-) and expresses markers typical of pluripotent cells. The aim of this work was to isolate, characterise and expand this ELSc fraction from hUCB, as it may provide a valuable cell source for regenerative medicine applications. We found that we could indeed isolate a Lin-CD45- population of small cells (3-10 μm diameter) with a high nucleus to cytoplasm ratio that expressed the stem cell markers CD34 and CXCR4. However, in contrast to some previous reports, this fraction was not positive for CD133. Furthermore, although these cells expressed transcripts typical of pluripotent cells, such as SOX2, OCT3/4, and NANOG, they were not able to proliferate in any of the culture media known to support stem cell growth that we tested. Further analysis of the Lin-CD45- population by flow cytometry showed the presence of a Lin-CD45-Nestin+ population that were also positive for CD34 (20%) but negative for CXCR4. These data suggest that the Lin-CD45- stem cell fraction present in the cord blood represents a small heterogeneous population with phenotypic characteristics of stem cells, including a Lin-CD45-Nestin+ population not previously described. This study also suggests that heterogeneity within the Lin-CD45- cell fraction is the likely explanation for differences in the hUCB cell populations described by different groups that were isolated using different methods. These populations have been widely called "embryonic-like stem cell" on the basis of their phenotypical similarity to embryonic stem cells. However, the fact they do not seem to be able to self-renew casts some doubt on their identity, and warns against defining them as "embryonic-like stem cell" at this stage. © 2013 Alvarez Gonzalez et al.

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