Large-Scale Ex Vivo Generation of Human Red Blood Cells from Cord Blood CD34+ Cells

Abstract

The ex vivo generation of human red blood cells on a large scale from hematopoietic stem and progenitor cells has been considered as a potential method to overcome blood supply shortages. Here, we report that functional human erythrocytes can be efficiently produced from cord blood (CB) CD34+ cells using a bottle turning device culture system. Safety and efficiency studies were performed in murine and nonhuman primate (NHP) models. With the selected optimized culture conditions, one human CB CD34+ cell could be induced ex vivo to produce up to 200 million erythrocytes with a purity of 90.1% ± 6.2% and 50% ± 5.7% (mean ± SD) for CD235a+ cells and enucleated cells, respectively. The yield of erythrocytes from one CB unit (5 million CD34+ cells) could be, in theory, equivalent to 500 blood transfusion units in clinical application. Moreover, induced human erythrocytes had normal hemoglobin content and could continue to undergo terminal maturation in the murine xenotransplantation model. In NHP model, xenotransplantation of induced human erythrocytes enhanced hematological recovery and ameliorated the hypoxia situation in the primates with hemorrhagic anemia. These findings suggested that the ex vivo‐generated erythrocytes could be an alternative blood source for traditional transfusion products in the clinic. Stem Cells Translational Medicine 2017;6:1698–1709

The opposing roles of the mTOR signaling pathway in different phases of human umbilical cord blood-derived CD34+ cell erythropoiesis

“…In the past decades, numerous studies have successfully produced reticulocytes from adult hematopoietic stem and progenitor cells in vitro and demonstrated the feasibility of using in vitro cultured erythrocytes for blood transfusion 5,30,31 . However, their clinical application has been hampered by the use of animal serum and/or feeder cells of murine or human origin in the culture medium 7,30,31 .…”

“…Erythropoiesis in mammals is an intricately regulated, complex, and multiphase process, during which hematopoietic stem cells undergo a series of dramatic morphological changes to generate highly specialized and enucleated erythrocytes. Although significant progress has been made in past few decades, in vitro‐generated RBCs are still not clinically available because of several major technical hurdles including limited yield, poor enucleation rate, low level of adult globin expression, and cost‐effectiveness 5‐7 . In particular, the erythroid terminal maturation efficiency is a critical rate‐limiting step of in vitro RBC production.…”

Metabolite patterns in human myeloid hematopoiesis result from lineage-dependent active metabolic pathways

“…35 These results indicate that differentiation of primitive progenitors occurs during expansion, lack of most lineage markers, however, indicate a multi-lineage potential in the expanded population. We, therefore, continued differentiation of the progenitor population into erythroid 36 , megakaryocytic 37 and natural killer T cell lineages 38 . Erythroid differentiation could be confirmed ( Figure S1b) while, lineage markers for megakaryocytic and natural killer T cell lineages remained negative ( Figure S1c,d).…”

Transforming growth factor β1 accelerates and enhances in vitro red blood cell formation from hematopoietic stem cells by stimulating mitophagy

“…Considering its importance and eventual application in transfusion medicine, efforts are being made to produce RBCs on a large scale by using feeder layers or suspension cultures [1][2][3][4][5][6][7]. However, in spite of these efforts in vitro generation of RBCs from HSCs continues to take about 21 days [1,2,5,6,8]. Acceleration of this process may make the large-scale production of RBCs affordable by reducing the high cost associated with growth factors, media, etc.…”