Source Of Donor Cells Research Articles

Follicular cell suspension: A new surgical modality for the treatment of vitiligo

Follicular cell suspension is a recently described technique of cellular suspension for treatment of stable vitiligo. Its uniqueness lies in the fact that hair-follicle melanocytes from the outer root sheath are utilized as a source of melanocytes unlike traditional methods, which use epidermal melanocytes. Few distinctive properties of these hair-follicle melanocytes make them an attractive source of donor cells over epidermal melanocytes. In this article, we briefly discuss the theoretical basis, procedure and advantages of this novel technique.

Reduced-intensity conditioning hematopoietic stem cell transplantation: looking forward to an international consensus.

The treatment for hematological malignancies has excelled over the past decade. A vast number of hematological malignancies are now amenable to cure with hematopoietic stem cell transplants (HSCTs) [1]. Older patients with comorbidities are poor candidates for standard myeloablative conditioning (MAC). While myeloablative therapy remains the standard curative conditioning regimen in the treatment of malignant disorders such as acute myeloid leukemia, its use is limited to patients in the younger age group, and to those in good physical health. Therefore, the older population is generally unsuited to this form of treatment, even though most hematological malignancies are often diagnosed at the age of 70-80 years. The advent of reduced-intensity conditioning (RIC) has provided these patients with a viable treatment option. Prior to undergoing HSCT, patients are treated with a conditioning regimen. This not only decreases the tumor burden, but also maximizes the capability of the donor cells to engraft successfully by suppressing the patient's immune system. Conditioning regimens vary in the amount of agent used. These compounds are often used at highly toxic dosage levels that are required to induce an immunocompromised state through a cytoreductive effect [2]. Over the past decade, conditioning regimens have considerably evolved with the development of RIC. These regimens are composed of reduced doses of cytotoxic agents in addition to a T-cell depleting agent [3]. The most commonly used regimens include fludarabine in combination with low-dose total body irradiation, or an alkylating agent such as busulfan, cyclophosphamide, or melphalan [3]. This treatment modality relies on a graft-versus-leukemia effect and has minimal associated toxicity. It is difficult to define RIC as it falls into an intermediate category between the MAC and the non-myeloablative regimens, since it does result in prolonged pancytopenia. Sources of donor cells include peripheral blood stem cells, bone marrow, and umbilical cord blood. Peripheral blood stem cells are more commonly used owing to the decreased engraftment time associated with their use [4]. Umbilical cord blood stem cells are a promising alternative source of stem cells with an associated 1-year survival rate of up to 40%, and a 9% incidence of grade III-IV acute graftversus-host disease (GVHD). However, studies have also reported a transplant-related mortality (TRM) rate of 39-48% associated with use of umbilical cord blood stem cells [5,6]. Studies assessing the influence of age on the outcomes of RIC treatment have not shown any significant association between the two. Patients in the age group >65 years have a reported non-relapse mortality (NRM) rate of 30% and 34% at 1 and 2 years respectively; whereas in the younger age group (40-54 years), the reported corresponding rates are 21% and 50% respectively [7]. A meta-analysis of results from 13 studies conducted by Zeng et al. [8] found no significant difference between MAC and RIC in terms of overall survival rate, event-free survival, and NRM. Furthermore, the incidence of GVHD was significantly lower with RIC. GVHD is an important cause of mortality associated with the MAC regimen due to the highly toxic doses of agents that are often necessary to eradicate diseased host cells from the bone marrow. The leading causes of death in patients treated with a MAC regimen are GVHD and toxicity. Thus, these findings call for extensive research on RIC regimens. The reported risk of TRM associated with MAC is 20%-60%, whereas RIC is known to be associated with higher overall survival and lower TRM at the same time [9]. A retrospective study on patients with MDS and AML treated with different conditioning regimens revealed a lower NRM in patients treated with RIC; however, there was also an increased risk of relapse in the first 12 months in these patients [10]. Although disease relapse continues to be a complication associated with both treatment regimens, RIC has a relatively higher incidence of relapse. This may be attributable to the additional host factors including, but not limited to, cytogenetics and disease status at the time of allogeneic HSCT. The use of RIC has opened up new channels to treat malignant hematological disorders in the elderly and patients with multiple comorbidities. With reduction in GVHD, in conjunction with decreased TRM, RIC provides a treatment option for patients who were previously unsuited for standard conditioning regimens. However, the RIC regimens may vary from one center to another and therefore it is conceivable that the differences in outcomes may be related to different procedures and/or different criteria used for decision making by individual physicians. This indicates the need for further studies, particularly in developing countries, so that an international consensus on protocols and guidelines for RIC may be reached.

28 EFFECTS OF RECLONING ON THE PRODUCTION OF PIGS OVEREXPRESSING 11 β-HYDROXYSTEROID DEHYDROGENASE TYPE 1 (11β-HSD1)

The incidence of metabolic syndrome is increasing globally, as the prevalence of obesity continues to rise. However, the basic mechanisms of metabolic syndrome are not completely known yet. Therefore, animal disease models are required for the study of metabolic syndrome. The overexpression of 11 β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) in mice leads to metabolic syndrome; thus, we attempted to produce pigs with overexpression of 11β-HSD1 gene by somatic cell nuclear transfer (SCNT). However, low transgenic (TG) efficiency has been an obstacle to the production of TG pigs. A SCNT method in which somatic cells derived from TG pig are used as the nuclear donor (re-cloning method) is an effective technique for TG pig production. In this study, we attempted to increase TG efficiency by the re-cloning method. Pregnancy efficiency, production efficiency, and TG efficiency were compared with sources of donor cells (transfected TG fetal fibroblast v. TG fibroblast derived from newborn TG cloned pig). A total of 1382 and 881 TG SCNT embryos were produced from fetal fibroblast v. cloned fibroblast, and then transferred to 13 and 10 recipients. The pregnancy rate was not significantly different (30.8% v. 20.0%). Seventeen live piglets and 5 stillborn piglets were born from 4 recipients in the fetal fibroblast group, and 8 live piglets, 2 stillborn piglets, and 3 mummies were born from 2 recipients in the cloned fibroblast group. There were no significant differences in the production efficiency (3.7% v. 5.0%). All of the 13 re-cloned piglets showed reporter and target gene integration. But, of 22 fetal fibroblast-cloned piglets, reporter gene integration was confirmed in 9, but only 3 clone piglets showed reporter gene integration. Efficiency of TG was significantly increased in re-cloning group (13.6% v. 100.0%). In this study, TG efficiency of 11β-HSD1 overexpressed pigs was improved by re-cloning method. These results indicate that re-cloning is an efficient method for production of TG cloned pigs.This work was supported by a grant from the Next-Generation Bio Green 21 Program (No. PJ009563032014), Rural Development Administration, Republic of Korea.

29 SCRIPTAID IMPROVES SOMATIC NUCLEAR TRANSFER EFFICIENCY DURING IN VITRO CULTURE OF PORCINE EMBRYOS DERIVED FROM INBRED MINIATURE PIG FETAL FIBROBLASTS

Porcine somatic cell nuclear transfer (SCNT) is limited to the same or next day surgical embryo transfer due to poor culture conditions in vitro. In this study, we aimed to overcome this problem by treating SCNT embryos with scriptaid, an inhibitor of histone deacetylase (HDACi) that helps with epigenetic reprogramming of the somatic nuclei. Scriptaid was chosen over other HDACi because it has been shown to improve histone acetylation in the same pattern as that of IVF embryos as well as its low toxicity characteristic (Zhao et al. 2009 Biol. Reprod. 81, 525–530; Zhao et al. 2010 Cell Reprogram. 12, 75–78). An inbred miniature pig fetal fibroblast cell line that is known to give low blastocyst rate in culture was used as a source of donor cells transferred into enucleated oocytes. Traditional SCNT was performed; embryos were fused and chemically activated in 10 µM ionomycin for 5 min and 2 mM DMAP for 3 to 4 h before being transferred into scriptaid. Embryos were treated with 500 nM scriptaid (Zhao et al. 2010) for 18 h and the untreated group was used as control. A total of 806 oocytes were used in 8 replicates. The constructed embryos were cultured in modified porcine zygote medium 5 (mPZM-5) for 7 days at 39°C in 5% O2, 5% CO2, 90% N2 atmosphere. Cleavage rates were assessed at 2.5 days and blastocyst rates at Day 7 after activation. Data were analysed by ANOVA using GLM, and percentages were transformed using arcsin square root using Statistix 10 software (Tallahassee, FL, USA). There were no differences in cleavage rates for control group v. scriptaid (55.3 v. 49.9%; P > 0.1; Table 1). The blastocyst rate per construct showed remarkable increase in the scriptaid treated group compared with the control group (12.8 v. 2.2%; P < 0.01; Table 1). Similarly, a significant effect was observed for blastocyst per embryos cleaved where scriptaid had higher rates compared with control (25.8 v. 5.8%; P < 0.01). These results indicated that improving nuclear reprogramming of miniature porcine SCNT clones by scriptaid treatment enhanced blastocyst production during the in vitro culture of porcine embryos. Table 1.Mean (± s.e.m.) measures of embryonic development of SCNT embryos

Differentiation of pluripotent stem cells into striatal projection neurons: a pure MSN fate may not be sufficient.

Huntington’s disease (HD) is an autosomal dominant inherited disorder leading to the loss inter alia of DARPP-32 positive medium spiny projection neurons (“MSNs”) in the striatum. There is no known cure for HD but the relative specificity of cell loss early in the disease has made cell replacement by neural transplantation an attractive therapeutic possibility. Transplantation of human fetal striatal precursor cells has shown “proof-of-principle” in clinical trials; however, the practical and ethical difficulties associated with sourcing fetal tissues have stimulated the need to identify alternative source(s) of donor cells that are more readily available and more suitable for standardization. We now have available the first generation of protocols to generate DARPP-32 positive MSN-like neurons from pluripotent stem cells and these have been successfully grafted into animal models of HD. However, whether these grafts can provide stable functional recovery to the level that can regularly be achieved with primary fetal striatal grafts remains to be demonstrated. Of particular concern, primary fetal striatal grafts are not homogenous; they contain not only the MSN subpopulation of striatal projection neurons but also include all the different cell types that make up the mature striatum, such as the multiple populations of striatal interneurons and striatal glia, and which certainly contribute to normal striatal function. By contrast, present protocols for pluripotent stem cell differentiation are almost entirely targeted at specifying just neurons of an MSN lineage. So far, evidence for the functionality and integration of stem-cell derived grafts is correspondingly limited. Indeed, consideration of the features of full striatal reconstruction that is achieved with primary fetal striatal grafts suggests that optimal success of the next generations of stem cell-derived replacement therapy in HD will require that graft protocols be developed to allow inclusion of multiple striatal cell types, such as interneurons and/or glia. Almost certainly, therefore, more sophisticated differentiation protocols will be necessary, over and above replacement of a specific population of MSNs. A rational solution to this technical challenge requires that we re-address the underlying question—what constitutes a functional striatal graft?

Potential Barriers to Human Hepatocyte Transplantation in MUP–uPAtg(+/+)Rag2-/-γC-/-Mice

Primary human fetal and adult hepatocytes have been considered feasible donor cell sources for cell transplantation. We compared the engraftment efficiencies between adult human, fetal human, and adult porcine hepatocytes after transplantation into MUP-uPA(tg(+/+))Rag2(-/-)γC(-/-)mice. Transplantation of adult human hepatocytes yielded a 1,000-fold higher serum albumin level compared to transplantation of fetal human hepatocytes, while transplantation of adult porcine hepatocytes resulted in a 100-fold higher serum albumin level than adult human hepatocytes. These results suggest that adult liver cells are superior to fetal liver cells for transplantation, and caution should be applied if porcine hepatocytes are used for preclinical studies as a proof of concept for human hepatocytes.

Regeneration of uterine horns in rats using collagen scaffolds loaded with human embryonic stem cell-derived endometrium-like cells.

A variety of diseases may lead to hysterectomies or uterine injuries, which may form a scar and lead to infertility. Due to the limitation of native materials, there are a few effective methods to treat such damages. Tissue engineering combines cell and molecular biology with materials and mechanical engineering to replace or repair damaged organs and tissues. The use of human embryonic stem cells (hESCs) as a donor cell source for the replacement therapy will require the development of simple and reliable cell differentiation protocols. This study aimed at efficiently generating endometrium-like cells from the hESCs and at using these cells with collagen scaffold to repair uterine damage. The hESCs were induced by co-culturing with endometrial stromal cells, and simultaneously added cytokines: epidermal growth factor (EGF), platelet-derived growth factor-b (PDGF-b), and E2. Expression of cell specific markers was analyzed by immunofluorescence and reverse trascription-polymerase chain reaction to monitor the progression toward an endometrium-like cell fate. After differentiation, the majority of cells (>80%) were positive for cytokeratin-7, and the expression of key transcription factors related to endometrial development, such as Wnt4, Wnt7a, Wnt5a, Hoxa11, and factors associated with endometrial epithelial cell function: Hoxa10, Intergrinβ3, LIF, ER, and PR were also detected. Then, we established the uterine full-thickness-injury rat models to test cell function in vivo. hESC-derived cells were dropped onto collagen scaffolds and transplanted into the animal model. Twelve weeks after transplantation, we discovered that the hESC-derived cells could survive and recover the structure and function of uterine horns in a rat model of severe uterine damage. The experimental system presented here provides a reliable protocol to produce endometrium-like cells from hESCs. Our results encourage the use of hESCs in cell-replacement therapy for severe uterine damage in future.

Stem cells for cell replacement therapy: a therapeutic strategy for HD?

Much interest has been expressed over the last couple of decades in the potential application of stem cells to medicine, both for research and diagnostic tools and as a source of donor cells for therapeutic purposes. Potential therapeutic applications include replacement of cells in many body organs where the capacity for intrinsic repair is limited, including the pancreas, heart, and brain. A key challenge is to generate the relevant donor cell types, and this is particularly challenging in the brain where the number of different neuronal subtypes is so great. Although dopamine neuron replacement in Parkinson's disease has been the focus of most clinical studies, great interest has been shown in this approach for other disorders, including Huntington's disease. Replacing complete neural circuits in the adult brain is clearly challenging, and there are many other complexities with regard to both donor cells and host. This article presents the pros and cons of taking a cell therapy approach in Huntington's disease. It considers the implantation both of cells that are already of the same neural subtype as those lost in the disease process (ie, primary fetal cells derived from the developing striatum) and those derived from stem cells, which require "directing" toward that phenotype.

Effect of Human Donor Cell Source on Differentiation and Function of Cardiac Induced Pluripotent Stem Cells

BackgroundHuman-induced pluripotent stem cells (iPSCs) are a potentially unlimited source for generation of cardiomyocytes (iPSC-CMs). However, current protocols for iPSC-CM derivation face several challenges, including variability in somatic cell sources and inconsistencies in cardiac differentiation efficiency. ObjectivesThis study aimed to assess the effect of epigenetic memory on differentiation and function of iPSC-CMs generated from somatic cell sources of cardiac versus noncardiac origins. MethodsCardiac progenitor cells (CPCs) and skin fibroblasts from the same donors were reprogrammed into iPSCs and differentiated into iPSC-CMs via embryoid body and monolayer-based differentiation protocols. ResultsDifferentiation efficiency was found to be higher in CPC-derived iPSC-CMs (CPC-iPSC-CMs) than in fibroblast-derived iPSC-CMs (Fib-iPSC-CMs). Gene expression analysis during cardiac differentiation demonstrated up-regulation of cardiac transcription factors in CPC-iPSC-CMs, including NKX2-5, MESP1, ISL1, HAND2, MYOCD, MEF2C, and GATA4. Epigenetic assessment revealed higher methylation in the promoter region of NKX2-5 in Fib-iPSC-CMs compared with CPC-iPSC-CMs. Epigenetic differences were found to dissipate with increased cell passaging, and a battery of in vitro assays revealed no significant differences in their morphological and electrophysiological properties at early passage. Finally, cell delivery into a small animal myocardial infarction model indicated that CPC-iPSC-CMs and Fib-iPSC-CMs possess comparable therapeutic capabilities in improving functional recovery in vivo. ConclusionsThis is the first study to compare differentiation of iPSC-CMs from human CPCs versus human fibroblasts from the same donors. The authors demonstrate that although epigenetic memory improves differentiation efficiency of cardiac versus noncardiac somatic cell sources in vitro, it does not contribute to improved functional outcome in vivo.

Late-Onset Colitis after Cord Blood Transplantation Is Consistent with Graft-Versus-Host Disease: Results of a Blinded Histopathological Review

Cord colitis syndrome after umbilical cord blood transplantation (UCBT) involves late-onset diarrhea, absence of infection or GVHD, chronic active colitis, and granulomatous inflammation that responds to antibiotics. We tested the hypothesis that Seattle recipients of UCBT had late-occurring colitis distinct from GVHD and colitis in other allograft recipients. We conducted a blinded histological review of 153 colon biopsy specimens from 45 UCBT recipients and 45 matched allografted controls obtained between day +70 and day +365 post-transplantation. Diarrhea was the primary indication for biopsy in 10 UCBT recipients and 11 controls. No histological differences were seen between UCBT recipients and controls with diarrhea or between the entire cohort of UCBT recipients and their controls. Distorted mucosal architecture and apoptotic crypt cells typical of GVHD were common in both groups; Paneth cell metaplasia and granulomas were rare findings. Chronic active colitis was present in 58% of the UCBT recipients and in 62% of controls. No UCBT recipient with diarrhea was treated with antibiotics, and all recipients responded to systemic corticosteroids. Colitis occurring after day +70 in allografted controls was related to acute GVHD, independent of the source of donor cells. We could not identify a histologically distinct cord colitis syndrome in either the UCBT or the non–cord blood allograft recipients.

Design of a cost–effectiveness analysis alongside a randomized trial of transplantation using umbilical cord blood versus HLA-haploidentical related bone marrow in advanced hematologic cancer

BMT CTN 1101 is a Phase III randomized controlled trial evaluating the comparative effectiveness of double unrelated umbilical cord blood (dUCB) versus HLA-haploidentical related donor bone marrow (haplo-BM) donor cell sources for blood or bone marrow transplantation (BMT) in patients with hematologic malignancies. Herein, we present the rationale, design and methods of the first cost-effectiveness analysis to be conducted alongside a BMT trial. Consenting patients will provide health insurance information to allow calculation of direct medical costs from reimbursement records, and will provide out-of-pocket costs, time costs and health-related quality of life measures through an online survey. These outcomes will inform a cost-effectiveness analysis comparing dUCB and haplo-BM donor cell sources from patient, payer and societal perspectives. Novel approaches may significantly change the cost, outcomes or availability of BMT. The results of this analysis will be the first to provide a comprehensive evaluation of the comparative effectiveness of these approaches from multiple perspectives.

24 IMPROVEMENT OF PORCINE CLONED EMBRYONIC STEM-LIKE CELLS DERIVATION BY ZONA-MEDIATED EMBRYO AGGREGATION

Porcine embryonic stem cells (ESC) have become an important model for therapeutic cloning using embryonic stem cells derived by somatic cell nuclear transfer (SCNT). However, embryo quality and blastocyst formation have been major limitations for derivation of cloned embryonic stem-like cells. In this study, we tried to overcome these problems by treating with histone deacetylase inhibitors (HDACi) and aggregating porcine embryos. A porcine embryonic fibroblast (PEF) cell line was used as the source of donor cells injected into the enucleated oocytes. First, to confirm the effect of HDACi in cloned embryo quality, cloned embryos were treated with Scriptaid (histone deacetylase inhibitor). The Scriptaid-treated blastocysts (n = 26) showed significantly increased total cell number (29.50 ± 2.10; P < 0.05) than nontreated blastocysts (n = 21; 22.29 ± 1.50). Then, the cloned embryo quality and blastocyst formation were analyzed in aggregates. Three zona-free reconstructed 4-cell stage SCNT embryos were injected into empty zonae from hatched parthenogenic blastocysts. The blastocyst formation and total cell number of cloned blastocysts was significantly elevated for all the aggregates (76.3% and 83.18 ± 8.33 cells/blastocyst) compared with nonaggregated (31.0%, and 27.11 ± 1.67 cells/blastocyst; P < 0.05). Finally, aggregated blastocysts were cultured on a feeder layer to examine the efficiency of porcine embryonic stem-like cells derivation. Aggregated blastocyst showed higher primary colony formation percentage than nonaggregated cloned blastocysts (20.0 ± 12.3% v. 2.2 ± 1.35%, respectively; P < 0.05). In conclusion, the aggregation of pig SCNT embryos at the 4-cell stage could be a useful technique for improving the development rate and quality of cloned pig blastocyst and derivation efficiency of cloned embryonic stem-like cells.

Norepinephrine Improves The Generation Of Hematopoietic Cells From Human Pluripotent Stem Cells With Increased Functional Properties

The possibility of differentiating human pluripotent stem cells (hPSCs) to hematopoietic stem cells (HSCs) could provide an unlimited source of donor cells for the treatment of hematological disorders and malignancies where HSC transplantation is required. Recently, signaling from the developing peripheral nervous system (PNS) has been implicated in the generation of HSCs in the aorta gonad mesonephros (AGM) of mouse embryos. Our own observations of AGM and urogenital ridge (UR) explants from a 6 weeks old human embryo show neurogenic potential. Since the AGM and UR are active sites of hematopoietic emergence, we hypothesize that migrating neural crest (NC) cells, precursors of the PNS, play an active role in HSC generation and maturation. Given that, at the time of HSC emergence, NC cells start expressing enzymes required for catecholamine production, we added norepinephrine (NE) to our optimized hPSC differentiation system and assessed for hematopoietic progenitor cell output. We observed approximately 50% increase of cells with an HSC immunophenotype (CD43+CD34+CD38-CD90+CD45RA-) compared to control settings (1.56 ± 0.25 fold increase, n=5 independent experiments, p=0.007). We identified this phenotype as an early progenitor cell with lymphoid and myeloid differentiation potential as well as highest colony forming unit (CFU) content. Importantly, the increase was specific to this cell fraction, since the proportion of more mature progenitors (CD43+CD34+ cells) and of total blood (CD43+) did not display a significant increase in the presence of NE (respectively, 1.053 ± 0.09 fold increase p=0.2104, and 0.97 ± 0.46 fold increase p=0.880, n=5 independent experiments). Continuing the differentiation culture for 5 additional days did not show additional increase in the frequency of these early progenitors. This indicates that higher proportion of early progenitors in the presence of NE is due to increased emergence from hemogenic endothelium rather than to maintenance of the early progenitors in culture. Improved generation of early progenitors was also consistent with an increase of colonies in the CFU assay (1.84 ± 0.29 fold increase in colony numbers n=4 independent experiments, p=0.010). The increased output of early hematopoietic progenitors was reversed when the Adrenergic Receptor β2 specific inhibitor ICI 118,551 was added together with NE, showing that the effect of NE is mediated by the activation of this receptor. Our preliminary results of transplantation in NSG mice show CD43+ human chimerism at week 6 post-transplantation 11 fold higher in mice transplanted with hematopoietic cells generated in the presence of NE compared to their counterparts transplanted with cells generated in standard conditions [2.33 ± 1.25% (n=3) vs 0.21 ± 0.02% (n=2), p=0.006]. However, since the detected human cells are predominantly of myeloid lineage (CD33+/CD15+) and the chimerism levels decrease back to levels comparable to PBS transplanted negative control at week 8-10 post-transplantation, this suggests that NE increases the homing and short term repopulation ability of pluripotent stem cell derived early hematopoietic progenitors. Disclosures:No relevant conflicts of interest to declare.

Generation of neural progenitors from induced Bama miniature pig pluripotent cells

Pig pluripotent cells may represent an advantageous experimental tool for developing therapeutic application in the human biomedical field. However, it has previously been proven to be difficult to establish from the early embryo and its pluripotency has not been distinctly documented. In recent years, induced pluripotent stem (iPS) cell technology provides a new method of reprogramming somatic cells to pluripotent state. The generation of iPS cells together with or without certain small molecules has become a routine technique. However, the generation of iPS cells from pig embryonic tissues using viral infections together with small molecules has not been reported. Here, we reported the generation of induced pig pluripotent cells (iPPCs) using the iPS technology in combination with valproic acid (VPA). VPA treatment significantly increased the expression of pluripotent genes and played an important role in early reprogramming. We showed that iPPCs resembled pig epiblast cells in their morphology and pluripotent markers, such as OCT4, NANOG, and SSEA1. It had a normal karyotype and could form embryoid bodies, which express three germ layer markers in vitro. In addition, the iPPCs might directly differentiate into neural progenitors after being induced with the retinoic acid and extracellular matrix. Our study established a reasonable method to generate pig pluripotent cells, which might be a new donor cell source for human neural disease therapy.

Comparable outcomes of partially matched related and matched related allogeneic hematopoietic cell transplantation following reduced-intensity conditioning in adult patients with Philadelphia chromosome-negative acute lymphoblastic leukemia

Reports from multiple centers have shown that reduced-intensity allogeneic hematopoietic cell transplantation (RIC-HCT) is able to benefit some adult patients suffering from Philadelphia chromosome-negative acute lymphoblastic leukemia (ALL). However, the relationship between donor cell source and outcome of RIC-HCT in (Ph-)ALL patients has not been elucidated. In this study, we present the outcome of 57 (Ph-)ALL patients treated with reduced-intensity conditioning (RIC) followed by HCT from HLA-matched related (MRD, n = 34) or HLA partially matched related (PMRD, n = 23) donors from a multicenter cohort. Neutrophil recovery at day 100 occurred in 91.3 % of the PMRD group and 97.1 % of the MRD group (P = 0.84). One hundred days after treatment, the cumulative incidence of grade II-IV acute graft-versus-host disease (GVHD) was 30.4 % (95 % confidence interval [CI], 13.0-53.0 %) in patients who received PMRD grafts, and 27.3 % (95 % CI, 15.0-48.0 %) for those who received MRD grafts (P = 0.76). The cumulative risk of developing chronic GVHD was 59.4 % (95 % CI, 31.0-72.0 %) in the MRD group and 23.4 % (95 % CI, 4.0-43.0 %) in the PMRD group (P = 0.03). The cumulative incidence of relapse in patients who received PMRD grafts was 18.8 % (95 % CI, 3.0-34.0 %), while for those who received MRD grafts it was 37.2 % (95 % CI, 15.0-48.0 %) (P = 0.32). Overall treatment-related mortality was 41.6 % (95 % CI, 20.0-62.0 %) in the PMRD group and 19.9 % (95 % CI, 7.0-35.0 %) in the MRD group (P = 0.08). Relapse was the most common cause of mortality in the MRD group, while infection contributed to the majority of deaths in the PMRD group. The 3-year probability of disease-free survival did not differ significantly between the two groups (55.5 % for the PMRD group vs. 48.4 % for the MRD group; P = 0.81). These data strongly suggest that RIC-HCT performed with PMRD may represent an alternative treatment option for adult patients with (Ph-)ALL.

Epigenetic Changes of Lentiviral Transgenes in Porcine Stem Cells Derived from Embryonic Origin

Because of the physiological and immunological similarities that exist between pigs and humans, porcine pluripotent cell lines have been identified as important candidates for preliminary studies on human disease as well as a source for generating transgenic animals. Therefore, the establishment and characterization of porcine embryonic stem cells (pESCs), along with the generation of stable transgenic cell lines, is essential. In this study, we attempted to efficiently introduce transgenes into Epiblast stem cell (EpiSC)-like pESCs. Consequently, a pluripotent cell line could be derived from a porcine-hatched blastocyst. Enhanced green fluorescent protein (EGFP) was successfully introduced into the cells via lentiviral vectors under various multiplicities of infection, with pluripotency and differentiation potential unaffected after transfection. However, EGFP expression gradually declined during extended culture. This silencing effect was recovered by in vitro differentiation and treatment with 5-azadeoxycytidine. This phenomenon was related to DNA methylation as determined by bisulfite sequencing. In conclusion, we were able to successfully derive EpiSC-like pESCs and introduce transgenes into these cells using lentiviral vectors. This cell line could potentially be used as a donor cell source for transgenic pigs and may be a useful tool for studies involving EpiSC-like pESCs as well as aid in the understanding of the epigenetic regulation of transgenes.

A Transgenic Tri-Modality Reporter Mouse

Transgenic mouse with a stably integrated reporter gene(s) can be a valuable resource for obtaining uniformly labeled stem cells, tissues, and organs for various applications. We have generated a transgenic mouse model that ubiquitously expresses a tri-fusion reporter gene (fluc2-tdTomato-ttk) driven by a constitutive chicken β-actin promoter. This “Tri-Modality Reporter Mouse” system allows one to isolate most cells from this donor mouse and image them for bioluminescent (fluc2), fluorescent (tdTomato), and positron emission tomography (PET) (ttk) modalities. Transgenic colonies with different levels of tri-fusion reporter gene expression showed a linear correlation between all three-reporter proteins (R2=0.89 for TdTomato vs Fluc, R2=0.94 for Fluc vs TTK, R2=0.89 for TdTomato vs TTK) in vitro from tissue lysates and in vivo by optical and PET imaging. Mesenchymal stem cells (MSCs) isolated from this transgenics showed high level of reporter gene expression, which linearly correlated with the cell numbers (R2=0.99 for bioluminescence imaging (BLI)). Both BLI (R2=0.93) and micro-PET (R2=0.94) imaging of the subcutaneous implants of Tri-Modality Reporter Mouse derived MSCs in nude mice showed linear correlation with the cell numbers and across different imaging modalities (R2=0.97). Serial imaging of MSCs transplanted to mice with acute myocardial infarction (MI) by intramyocardial injection exhibited significantly higher signals in MI heart at days 2, 3, 4, and 7 (p<0.01). MSCs transplanted to the ischemic hindlimb of nude mice showed significantly higher BLI and PET signals in the first 2 weeks that dropped by 4th week due to poor cell survival. However, laser Doppler perfusion imaging revealed that blood circulation in the ischemic limb was significantly improved in the MSCs transplantation group compared with the control group. In summary, this mouse can be used as a source of donor cells and organs in various research areas such as stem cell research, tissue engineering research, and organ transplantation.

Norepinephrine improves the generation of hematopoietic cells from human pluripotent stem cells

The possibility of differentiating human pluripotent stem cells (hPSCs) to hematopoietic stem cells (HSCs) could provide an unlimited source of donor cells for the treatment of hematological disorders and malignancies where HSC transplantation is required. Recently, signaling from the developing peripheral nervous system (PNS) has been implicated in the generation of HSCs in the aorta gonad mesonephros (AGM) of mouse embryos. Our own observations of explants of AGM and urogenital ridge (UR) explants from 6 weeks old human embryos show neurogenic potential.

Facile and Efficient Reprogramming of Ciliary Body Epithelial Cells into Induced Pluripotent Stem Cells

Induced pluripotent stem (iPS) cells are attractive for cell replacement therapy, because they overcome ethical and immune rejection issues that are associated with embryonic stem cells. iPS cells have been derived from autonomous fibroblasts at low efficiency using multiple ectopic transcription factors. Recent evidence suggests that the epigenome of donor cell sources plays an important role in the reprogramming and differentiation characteristics of iPS cells. Thus, identification of somatic cell types that are easily accessible and are more amenable for cellular reprogramming is critical for regenerative medicine applications. Here, we identify ciliary body epithelial cells (CECs) as a new cell type for iPS cell generation that has higher reprogramming efficiency compared with fibroblasts. The ciliary body is composed of epithelial cells that are located in the anterior portion of the eye at the level of the lens and is readily surgically accessible. CECs also have a reduced reprogramming requirement, as we demonstrate that ectopic Sox2 and c-Myc are dispensable. Enhanced reprogramming efficiency may be due to increased basal levels of Sox2 in CECs. In addition, we are the first to report a cellular reprogramming haploinsufficiency observed when reprogramming with fewer factors (Oct4 and Klf4) in Sox2 hemizygous cells. Taken together, endogenous Sox2 levels are critical for the enhanced efficiency and reduced exogenous requirement that permit facile cellular reprogramming of CECs.

Factors influencing the efficiency of generating genetically engineered pigs by nuclear transfer: multi-factorial analysis of a large data set.

BackgroundSomatic cell nuclear transfer (SCNT) using genetically engineered donor cells is currently the most widely used strategy to generate tailored pig models for biomedical research. Although this approach facilitates a similar spectrum of genetic modifications as in rodent models, the outcome in terms of live cloned piglets is quite variable. In this study, we aimed at a comprehensive analysis of environmental and experimental factors that are substantially influencing the efficiency of generating genetically engineered pigs. Based on a considerably large data set from 274 SCNT experiments (in total 18,649 reconstructed embryos transferred into 193 recipients), performed over a period of three years, we assessed the relative contribution of season, type of genetic modification, donor cell source, number of cloning rounds, and pre-selection of cloned embryos for early development to the cloning efficiency.Results109 (56%) recipients became pregnant and 85 (78%) of them gave birth to offspring. Out of 318 cloned piglets, 243 (76%) were alive, but only 97 (40%) were clinically healthy and showed normal development. The proportion of stillborn piglets was 24% (75/318), and another 31% (100/318) of the cloned piglets died soon after birth. The overall cloning efficiency, defined as the number of offspring born per SCNT embryos transferred, including only recipients that delivered, was 3.95%. SCNT experiments performed during winter using fetal fibroblasts or kidney cells after additive gene transfer resulted in the highest number of live and healthy offspring, while two or more rounds of cloning and nuclear transfer experiments performed during summer decreased the number of healthy offspring.ConclusionAlthough the effects of individual factors may be different between various laboratories, our results and analysis strategy will help to identify and optimize the factors, which are most critical to cloning success in programs aiming at the generation of genetically engineered pig models.