Generation of the human erythroblast-derived iPSC line UBTi001-A.

We performed reprogramming of human erythroblasts derived from CD34+ hematopoietic stem / progenitor cells of a healthy donor. CD34+ cells were differentiated in-vitro into a pure population of CD36 erythroblasts and nucleofected with four episomal plasmids expressing SOX2, OCT3/4, KLF4, LIN28, L-MYC and TP53-shRNA. The established iPSC line showed normal karyotype.

Biomechanical properties of native and cultured red blood cells-Interplay of shape, structure and biomechanics.

Modern medicine increases the demand for safe blood products. cultured red blood cells (cRBC) are eagerly awaited as a standardized, safe source of RBC. Established culture models still lack the terminal cytoskeletal remodeling from reticulocyte to erythrocyte with changes in the biomechanical properties and interacts with membrane stiffness, viscosity of the cytoplasm and the cytoskeletal network.

Membrane Properties of Human Induced Pluripotent Stem Cell-Derived Cultured Red Blood Cells.

Cultured red blood cells from human induced pluripotent stem cells (cRBC_iPSCs) are a promising source for future concepts in transfusion medicine. Before cRBC_iPSCs will have entrance into clinical or laboratory use, their functional properties and safety have to be carefully validated. Due to the limitations of established culture systems, such studies are still missing.

Biomechanics of Ex Vivo-Generated Red Blood Cells Investigated by Optical Tweezers and Digital Holographic Microscopy.

Ex vivo-generated red blood cells are a promising resource for future safe blood products, manufactured independently of voluntary blood donations. The physiological process of terminal maturation from spheroid reticulocytes to biconcave erythrocytes has not been accomplished yet. A better biomechanical characterization of cultured red blood cells (cRBCs) will be of utmost interest for manufacturer approval and therapeutic application.

Membrane Rearrangements in the Maturation of Circulating Human Reticulocytes.

Red blood cells (RBCs) begin their circulatory life as reticulocytes (Retics) after their egress from the bone marrow where, as R1 Retics, they undergo significant rearrangements in their membrane and intracellular components, via autophagic, proteolytic, and vesicle-based mechanisms. Circulating, R2 Retics must complete this maturational process, which involves additional loss of significant amounts of membrane and selected membrane proteins. Little is known about the mechanism(s) at the basis of this terminal differentiation in the circulation, which culminates with the production of a stable biconcave discocyte.

Cholesterol Deficiency Causes Impaired Osmotic Stability of Cultured Red Blood Cells.

generation of red blood cells (cRBCs) is an attractive tool in basic research and for replacing blood components donated by volunteers. As a prerequisite for the survival of cRBCs during storage as well as in the circulation, the quality of the membrane is of utmost importance. Besides the cytoskeleton and embedded proteins, the lipid bilayer is critical for membrane integrity.

Enhanced Ex Vivo Generation of Erythroid Cells from Human Induced Pluripotent Stem Cells in a Simplified Cell Culture System with Low Cytokine Support.

Red blood cell (RBC) differentiation from human induced pluripotent stem cells (hiPSCs) offers great potential for developmental studies and innovative therapies. However, ex vivo erythropoiesis from hiPSCs is currently limited by low efficiency and unphysiological conditions of common culture systems. Especially, the absence of a physiological niche may impair cell growth and lineage-specific differentiation.

Emergence of CD43-Expressing Hematopoietic Progenitors from Human Induced Pluripotent Stem Cells.

Background: The ex vivo generation of human hematopoietic stem cells (HSCs) with long-term repopulating capacity and multi-lineage differentiation potential represents the holy grail of hematopoiesis research. In principle, human induced pluripotent stem cells (hiPSCs) provide the tool for both studying molecular mechanisms of hematopoietic development and the ex vivo production of 'true' HSCs for transplantation purposes and lineage-specific cells, e.g.

Shiga toxin of enterohaemorrhagic Escherichia coli directly injures developing human erythrocytes.

Haemolytic anaemia is one of the characteristics of life-threatening extraintestinal complications in humans during infection with enterohaemorrhagic Escherichia coli (EHEC). Shiga toxins (Stxs) of EHEC preferentially damage microvascular endothelial cells of the kidney and the brain, whereby occluded small blood vessels may elicit anaemia through mechanical erythrocyte disruption. Here we show for the first time that Stx2a, the major virulence factor of EHEC, is also capable of direct targeting developing human erythrocytes.

Erythroid differentiation of human induced pluripotent stem cells is independent of donor cell type of origin.

Epigenetic memory in induced pluripotent stem cells, which is related to the somatic cell type of origin of the stem cells, might lead to variations in the differentiation capacities of the pluripotent stem cells. In this context, induced pluripotent stem cells from human CD34(+) hematopoietic stem cells might be more suitable for hematopoietic differentiation than the commonly used fibroblast-derived induced pluripotent stem cells. To investigate the influence of an epigenetic memory on the ex vivo expansion of induced pluripotent stem cells into erythroid cells, we compared induced pluripotent stem cells from human neural stem cells and human cord blood-derived CD34(+) hematopoietic stem cells and evaluated their potential for differentiation into hematopoietic progenitor and mature red blood cells.

Prolonged anemia in an intrauterine-transfused neonate with Rh-hemolytic disease: no evidence for anti-D-related suppression of erythropoiesis in vitro.

Background: Rh-hemolytic disease may be complicated in some cases by a prolonged postnatal anemia with an extended need for postnatal red blood cell (RBC) transfusion. Besides ongoing hemolysis, marrow suppression and erythropoietin (EPO) deficiency are discussed as underlying mechanisms of this so-called "late hyporegenerative anemia."

Case Report: We present a case of a newborn with Rh-hemolytic disease caused by anti-D who received several intrauterine RBC transfusions.

Acquired von Willebrand syndrome in a 10-year-old girl with acute lymphoblastic leukaemia.

Unlabelled: Following diagnosis of acute lymphoblastic leukaemia (ALL) in a 10-year-old girl, routine coagulation screening including von Willebrand factor antigen (VWF:Ag), ristocetin cofactor activity (VWF:RCo) and factor VIIIC (FVIII:C) detected no pathological findings. After the first HR2' element of the high-risk group of the ALL-BFM 2000 protocol, the patient demonstrated extensive bleeding symptoms and acquired von Willebrand syndrome was diagnosed. VWF:Ag (13%), VWF:RCo (13%) and FVIII:C (27%) were decreased.

In vitro proliferation and differentiation of human CD34+ cells from peripheral blood into mature red blood cells with two different cell culture systems.

Background: An in vitro erythropoiesis assay is a powerful tool for investigating red blood cell (RBC) development and diseases of the erythroid lineage. Most assays, however, failed in either proliferation or terminal differentiation. Here two liquid cultures (LCs) for in vitro generation of RBCs from peripheral blood CD34+ cells were compared.

Interferon-alpha stimulation of liver cells enhances hepatitis delta virus RNA editing in early infection.

Background/aims: RNA editing controls the formation of hepatitis-delta-antigen-S and -L and therefore plays a central role in the hepatitis-delta-virus (HDV) life-cycle. Editing is catalyzed by the enzyme Adenosine-deaminase-acting-on-RNA1 (ADAR1) of which two different forms, ADAR1-L and ADAR1-S, exist. As ADAR1-L is induced by interferon (IFN)-alpha, we examined the influence of IFN-alpha-stimulation of host cells on HDV-RNA editing.

Recommendations for optimized settings of the Amicus Crescendo cell separator for the collection of CD34+ progenitor cells.

Background: CD34+ PBPCs for autologous transplantation purposes are collected by leukapheresis procedures on automated cell separators. In this study, the influence of different parameters on collection efficiency (CE) of the Amicus Crescendo cell separator (Baxter) was investigated.

Study Design And Methods: A total of 146 PBPC collections with Amicus cell separators were performed in 56 patients with either settings recommended by the manufacturer or modified settings to identify variables that have a significant and important impact on CE.

Lamina propria plasma cells in inflammatory bowel disease: intracellular detection of immunoglobulins using flow cytometry.

This is the first application of flow cytometry for the detection of lamina propria plasma cells and their intracellular immunoglobulins in patients with inflammatory bowel disease compared to healthy controls. The study has been focused on the distribution of IgA, IgG, IgM and the four IgG subclasses. Plasma cells were detected as high CD38 positive cells.