Transplantation stimulates interstitial cell migration in hydra

Migration of interstitial cells and nerve cell precursors was analyzed in Hydra magnipapillata and Hydra vulgaris (formerly Hydra attenuata). Axial grafts were made between [3H]thymidine-labeled donor and unlabeled host tissue. Migration of labeled cells into the unlabeled half was followed for 4 days. The results indicate that the rate of migration was initially high and then slowed on Days 2–4. Regrafting fresh donor tissue on Days 2–4 maintained high levels of migration. Thus, migration appears to be stimulated by the grafting procedure itself

Stem cells of Hydra magnipapillata can differentiate into somatic cells and germ line cells

We investigated whether all stem cells of Hydra can differentiate both somatic cells and gametes or if a separate germ line exists in these phylogenetically old organisms. The differentiation potential of single stem cells was analyzed by applying a statistical cloning procedure. All stem cell clones were found to differentiate somatic cells. No clone was found to contain stem cells which do not differentiate. Most of the clones could be induced to form gametes. No clone was found that produced gametes only. The results indicate that stem cells are multipotent in the sense that individual stem cells can differentiate into somatic cells as well as germ line cells

Comparison of gene expression in CD34+ cells from bone marrow and G-CSF-mobilized peripheral blood by high-density oligonucleotide array analysis - Supplemental Materials Only.

A prospective randomized trial has shown that there is a survival advantage for allogeneic transplant recipients who received granulocyte colony-stimulating factor (G-CSF)-stimulated peripheral blood mononuclear cells (GPBMC) versus those who received bone marrow (BM) as a source of stem cells. The biological basis for this advantage is not clear and may be attributable to qualitative as well as quantitative differences in the CD34 cells, T cells, and/or the monocytes transplanted. To begin to address this issue, gene expression patterns in CD34 cells isolated from these 2 stem cell sources were compared to identify functional pathways that may distinguish these 2 populations. CD34 cells were isolated to purity from the BM and peripheral blood stem cells of multiple healthy donors. (The complete data set will be available at http://parma.fhcrc.org/lgraf upon publication.) Two separate RNA preparations from pooled samples from both sources were analyzed by Affymetrix Oligonucleotide Array chips for expression of over 6400 human genes. Comparative analyses among the samples showed that a small set of 28 sequences increased and 38 sequences decreased in expression more than 3-fold in both of the GPBMC samples compared to those in BM samples. More highly expressed genes include several for nuclear proteins and transcriptional factors. Functional categorization of the genes decreased in expression indicated sequences influential in cell cycle progression, in agreement with the recognized quiescence of circulating CD34 cells. Multiple transcriptional regulators and chemokines were also found to be decreased. These data emphasize that in addition to increased numbers of CD34 cells, G-CSF mobilization also results in significant qualitative changes. Whether they impact engraftment remains to be determined

Progress in Cryopreservation of Stem Cells and Immune Cells for Cytotherapy

Cellular therapy with stem and immune cells has demonstrated significant success both in clinical treatments and the industrial market. Cryopreservation is a necessary and essential component of cellular therapy. In this chapter, first of all, some basic theories of cryoinjury and techniques in cryopreservation are reviewed. Then it focuses on the progress of cryopreservation of stem cells and immune cells, including new protocols and techniques, alternative cryoprotective agents (CPA), side effects after transplantation, and advances in reducing adverse reactions. Strategies to minimize adverse effects include medication before and after transplantation, optimizing the infusion procedure, reducing the CPA concentration or using alternative CPAs for cryopreservation, and removing CPA prior to infusion. Traditional and newly developed approaches including methods and devices for CPA removal are discussed. Future work is recommended including further optimization of cryopreservation protocols especially for lymphocytes; standardization of the optimized protocols with temperature monitoring and quality control; exploration of DMSO-free, serum-free, and even xeno-free media for cryopreservation; development of simple, reliable, and cost-effective devices for cryopreservation; and more fundamental cryobiological studies to avoid cellular injury.Keywords: cryopreservation, stem cell, immune cell, cytotherap

Putative intermediates in the nerve cell differentiation pathway in hydra have properties of multipotent stem cells

We have investigated the properties of nerve cell precursors in hydra by analyzing the differentiation and proliferation capacity of interstitial cells in the peduncle of Hydra oligactis, which is a region of active nerve cell differentiation. Our results indicate that about 50% of the interstitial cells in the peduncle can grow rapidly and also give rise to nematocyte precursors when transplanted into a gastric environment. If these cells were committed nerve cell precursors, one would not expect them to differentiate into nematocytes nor to proliferate apparently without limit. Therefore we conclude that cycling interstitial cells in peduncles are not intermediates in the nerve cell differentiation pathway but are stem cells. The remaining interstitial cells in the peduncle are in G1 and have the properties of committed nerve cell precursors (Holstein and David, 1986). Thus, the interstitial cell population in the peduncle contains both stem cells and noncycling nerve precursors. The presence of stem cells in this region makes it likely that these cells are the immediate targets of signals which give rise to nerve cells

Correlation of infused CD3+CD8+ cells with single-donor dominance after double-unit cord blood transplantation.

Single-donor dominance is observed in the majority of patients following double-unit cord blood transplantation (dCBT); however, the biological basis for this outcome is poorly understood. To investigate the possible influence of specific cell lineages on dominance in dCBT, flow cytometry assessment for CD34(+), CD14(+), CD20(+), CD3(-)CD56(+), CD3(+)CD56(+) (natural killer), and T cell subsets (CD4(+), CD8(+), memory, naïve, and regulatory) was performed on individual units. Subsets were calculated as infused viable cells per kilogram of recipient actual weight. Sixty patients who underwent dCBT were included in the final analysis. Higher CD3(+) cell dose was statistically concordant with the dominant unit in 72% of cases (P = .0006). Further T cell subset analyses showed that dominance was correlated more with the naive CD8(+) cell subset (71% concordance; P = .009) than with the naive CD4(+) cell subset (61% concordance; P = .19). These data indicate that a greater total CD3(+) cell dose, particularly of naïve CD3(+)CD8(+) T cells, may play an important role in determining single-donor dominance after dCBT

Intracellular Disposition of Fludarabine Triphosphate in Human Natural Killer Cells

Purpose. Fludarabine is a key component of several reduced-intensity conditioning regimens for hematopoietic cell transplantation (HCT). Shortly after reduced-intensity conditioning, the percent of donor natural killer (NK) cells has been associated with progression-free survival. Insufficient suppression of the recipient’s NK cells by fludarabine may lead to lower donor chimerism; however, the effect of fludarabine upon NK cells is poorly understood. Thus, in purified human NK cells we evaluated the uptake and activation of fludarabine to its active metabolite, fludarabine triphosphate (F-ara-ATP), and assessed the degree of interindividual variability in F-ara-ATP accumulation. Methods. Intracellular F-ara-ATP was measured in purified NK cells isolated from healthy volunteers (n = 6) after ex vivo exposure to fludarabine. Gene expression levels of the relevant transporters and enzymes involved in fludarabine uptake and activation were also measured in these cells. Results. F-ara-ATP accumulation (mean ± s.d.) was 6.00 ± 3.67 pmol/1x106 cells/4 hours, comparable to average levels previously observed in CD4+ and CD8+ T-lymphocytes. We observed considerable variability in F-ara-ATP accumulation and mRNA expression of transporters and enzymes relevant to F-ara-ATP accumulation in NK cells from different healthy volunteers. Conclusions. Human NK cells have the ability to form F-ara-ATP intracellularly and large interindividual variability was observed in healthy volunteers. Further studies are needed to evaluate whether F-ara-ATP accumulation in NK cells are associated with apoptosis and clinical outcomes

Notch-mediated expansion of human cord blood progenitor cells capable of rapid myeloid reconstitution

Delayed myeloid engraftment after cord blood transplantation (CBT) is thought to result from inadequate numbers of progenitor cells in the graft and is associated with increased early transplant–related morbidity and mortality. New culture strategies that increase the number of cord blood progenitors capable of rapid myeloid engraftment after CBT would allow more widespread use of this stem cell source for transplantation. Here we report the development of a clinically relevant Notch-mediated ex vivo expansion system for human CD34+ cord blood progenitors that results in a marked increase in the absolute number of stem/progenitor cells, including those capable of enhanced repopulation in the marrow of immunodeficient nonobese diabetic–severe combined immunodeficient (NOD-SCID) mice. Furthermore, when cord blood progenitors expanded ex vivo in the presence of Notch ligand were infused in a clinical setting after a myeloablative preparative regimen for stem cell transplantation, the time to neutrophil recovery was substantially shortened. To our knowledge, this is the first instance of rapid engraftment derived from ex vivo expanded stem/progenitor cells in humans

Early outcomes of gastrostomy feeding in paediatric allogenic bone marrow transplantation: A retrospective cohort study

Background: Nutrition support is an essential component of care for a child undergoing bone marrow transplantation (BMT). Enteral nutrition (EN) is becoming increasingly recognised as having advantages over parenteral nutrition (PN) and recommended as first-line nutrition support. EN has traditionally been provided via nasogastric tube (NGT). Gastrostomies avoid certain complications associated with NGTs and could provide a preferential alternative. Aims: To compare nutritional and post-transplantation outcomes during admission, the primary outcome being PN use, between children who had a gastrostomy placed prophylactically prior to BMT versus those who had not. Methods: Electronic medical records of children transplanted between January 2014 and May 2018 within a single-centre were retrospectively reviewed. Outcomes between the gastrostomy group (n = 54) and non-gastrostomy group (n = 91) were compared. Results: Multivariate regression analyses showed children in the gastrostomy group were less likely to require PN (odds ratio (OR) 0.4; 95% confidence interval (CI) 0.2–0.9; P = 0.049), initiated PN later if required (hazard ratio 0.6; 95% CI 0.4–0.8; P = 0.005), more often received EN as first-line nutrition support (P < 0.001) and more frequently required EN post-discharge (OR 2.4; 95% CI 1.1–5.4; P = 0.029). No differences were found between groups on length of admission, day 100 overall survival, incidence of graft-versus-host-disease, positive blood cultures and changes in weight or albumin during admission. Conclusions: Providing EN via gastrostomy is feasible in this population and may be more acceptable to older children than NGTs. Weighing up the potential benefits against the potential risks of prophylactic gastrostomy placement in these high-risk children is a challenging decision. Further research investigating safety, longer-term outcomes and family perceptions of gastrostomy feeding is required