The HOX Code as a “biological fingerprint” to distinguish functionally distinct stem cell populations derived from cord blood

AbstractMesenchymal stem cells (MSC) have been isolated from almost every adult tissue. In cord blood (CB), different non-hematopoietic CD45-, CD34− adherent cell populations can be generated: the cord blood derived MSC (CB-MSC), that behave almost like MSC from bone marrow (BM-MSC), and unrestricted somatic stem cells (USSC) which show a distinct differentiation potential into all three germ layers. However, distinguishing these populations easily by molecular markers is still a concern. In this study we were able to present the HOX expression pattern of USSC, CB-MSC and BM-MSC, which in fact allows a discrimination of these populations.Briefly, RT-PCR analysis of the HOX code revealed a high similarity between BM-MSC and CB-MSC, which are both HOX-positive, whereas USSC resembled H9 embryonic stem cells HOX-negative.Especially HOXA9, HOXB7, HOXC10 and HOXD8 are good candidate markers to discriminate MSC from USSC. Thus, our data suggest that the "biological fingerprint" based on the HOX code can be used to distinguish functionally distinct MSC populations derived from bone marrow and cord blood

Efficient In Vitro Generation of IL-22-Secreting ILC3 From CD34+ Hematopoietic Progenitors in a Human Mesenchymal Stem Cell Niche

Innate lymphoid cells (ILCs) and in particular ILC3s have been described to be vital for mucosal barrier functions and homeostasis within the gastrointestinal (GI) tract. Importantly, IL-22-secreting ILC3 have been implicated in the control of inflammatory bowel disease (IBD) and were shown to reduce the incidence of graft-versus-host disease (GvHD) as well as the risk of transplant rejection. Unfortunately, IL-22-secreting ILC3 are primarily located in mucosal tissues and are not found within the circulation, making access to them in humans challenging. On this account, there is a growing desire for clinically applicable protocols for in vitro generation of effector ILC3. Here, we present an approach for faithful generation of functionally competent human ILC3s from cord blood-derived CD34+ hematopoietic progenitors on layers of human mesenchymal stem cells (MSCs) generated in good manufacturing practice (GMP) quality. The in vitro-generated ILC3s phenotypically, functionally, and transcriptionally resemble bona fide tissue ILC3 with high expression of the transcription factors (TF) RorγT, AHR, and ID2, as well as the surface receptors CD117, CD56, and NKp44. Importantly, the majority of ILC3 belonged to the desired effector subtype with high IL-22 and low IL-17 production. The protocol thus combines the advantages of avoiding xenogeneic components, which were necessary in previous protocols, with a high propensity for generation of IL-22-producing ILC3. The present approach is suitable for the generation of large amounts of ILC3 in an all-human system, which could facilitate development of clinical strategies for ILC3-based therapy in inflammatory diseases and cancer

A New Human Somatic Stem Cell from Placental Cord Blood with Intrinsic Pluripotent Differentiation Potential

Here a new, intrinsically pluripotent, CD45-negative population from human cord blood, termed unrestricted somatic stem cells (USSCs) is described. This rare population grows adherently and can be expanded to 1015 cells without losing pluripotency. In vitro USSCs showed homogeneous differentiation into osteoblasts, chondroblasts, adipocytes, and hematopoietic and neural cells including astrocytes and neurons that express neurofilament, sodium channel protein, and various neurotransmitter phenotypes. Stereotactic implantation of USSCs into intact adult rat brain revealed that human Tau-positive cells persisted for up to 3 mo and showed migratory activity and a typical neuron-like morphology. In vivo differentiation of USSCs along mesodermal and endodermal pathways was demonstrated in animal models. Bony reconstitution was observed after transplantation of USSC-loaded calcium phosphate cylinders in nude rat femurs. Chondrogenesis occurred after transplanting cell-loaded gelfoam sponges into nude mice. Transplantation of USSCs in a noninjury model, the preimmune fetal sheep, resulted in up to 5% human hematopoietic engraftment. More than 20% albumin-producing human parenchymal hepatic cells with absence of cell fusion and substantial numbers of human cardiomyocytes in both atria and ventricles of the sheep heart were detected many months after USSC transplantation. No tumor formation was observed in any of these animals

Transplanted human cord blood-derived unrestricted somatic stem cells preserve high-energy reserves at the site of acute myocardial infarction

It has been demonstrated that transplantation of human cord blood-derived unrestricted somatic stem cells (USSC) in a porcine model of acute myocardial infarction (MI) significantly improved left ventricular (LV) function and prevented scar formation as well as LV dilation. Differentiation, apoptosis and macrophage mobilization at the infarct site could be excluded as the underlying mechanisms. The paracrine effect of the cells is most likely to be observed as the cause for the USSC treatment. The aim of our study was to examine the cardiomyocyte metabolism and the role of high-energy phosphates at the marginal infarct. USSC were transplanted into the myocardium of the LV, which was supplied by a ligated circumflex artery. Forty-eight hours later, the hearts were harvested and biopsies were performed from the marginal infarct zone surrounding the site of the cell injection. The concentrations of creatinine phosphate (CP), adenosine monophosphate (AMP), adenosine diphosphate (ADP) and adenosine triphosphate (ATP) were determined by chromatography. The concentration of ADP, ATP and CP in the marginal zone of the infarction was significantly higher in the USSC group. The mean global left ventricular ejection fraction (LVEF) (SD) was 64% (8%) before MI; post-MI, LVEF decreased to 35% (9%). Preservation of high-energy phosphates in the marginal infarct zone suggests that the preservation of energy reserves of surviving cardiomyocytes is a possible mechanism of action of transplanted stem cells in acutely ischemic myocardium