74 - Superior Red Blood Cell Generation From Human Pluripotent Stem Cells via a Novel Microcarrier Based Embryoid Body Platform

Abstract

In vitro generation of red blood cells (RBCs) from human embryonic stem cells (hESC) and human induced pluripotent stem cells (hiPSC) appears to be a promising alternate approach to circumvent shortages in donor-derived blood supplies for clinical applications. Conventional methods for hematopoietic differentiation of hESC and iPSC rely on embryoid body (EB) formation and/or co-culture with xenogeneic cell-lines. However, these current methods are not amenable for scale-up and face obstacles for clinical translation due to the use of xenogeneic materials. Here we report the development of a serum-free and chemically defined platform using recombinant human Laminin-521 coated microcarriers for pluripotent stem cell expansion and hematopoietic differentiation of hESC and hiPSC. Improved survival and better quality EBs generated with the microcarrier-based method resulted in at least a 6-fold improvement in hemangioblast expansion, potentially culminating in a 80-fold improvement in the yield of RBC generation as compared to a conventional EB-based method. Using the improved microcarrier-based differentiation protocol, we demonstrated successful differentiation of O-negative (Rhesus factor D negative) RBCs from donor hiPSC generated from finger-prick blood. Universal donor RBCs (blood type O-RhD negative) could prove to be extremely useful for future cell therapy applications such as emergency blood transfusions and for treating poly-immunized patients with recurrent transfusion needs. Thus, our microcarrier-based differentiation platform could prove to be an appealing strategy for future scale-up of hESC and hiPSC culture and for hematopoietic differentiation under defined conditions for large-scale generation of universal donor RBCs.