In vitro production of transfusable red blood cells

Abstract

Background The supply of transfusable red blood cells (RBCs) is not sufficient in many countries. If transfusable RBCs could be produced abundantly from certain resources it would be very useful. We have developed a method to produce enucleated RBCs efficiently from haematopoietic stem cells present in umbilical cord blood (Nat Biotechnol 2006; 24:1255). More recently, it was reported that enucleated RBCs could be abundantly produced from human embryonic stem (ES) cells (Blood 2008; 112:4475). The common obstacle for application of these methods is that these methods require very high cost to produce sufficient number of RBCs that are applicable in the clinic.Aims If erythroid cell lines (immortalized cell lines) able to produce transfusable RBCs in vitro were established, they would be valuable resources. However, such cell lines have not been established. To evaluate the feasibility of establishing useful erythroid cell lines, we attempted to establish such cell lines from mouse ES cells.Methods We developed a robust method to obtain differentiated cell lines following the induction of haematopoietic differentiation of mouse ES cells. Briefly, we have used feeder cells and several kinds of humoral factor so as to induce haematopoietic differentiation of mouse ES cells efficiently.Results We established five independent haematopoietic cell lines using the method. Three of these lines exhibited characteristics of erythroid cells. Although their precise characteristics varied, each of these lines could differentiate in vitro into more mature erythroid cells, including enucleated RBCs. Following transplantation of these erythroid cells into mice suffering from acute anaemia, the cells proliferated transiently, subsequently differentiated into functional RBCs, and significantly ameliorated the acute anaemia. In addition, we did not observe formation of any tumours following transplantation of these cells (PLoS ONE 2008; 3:e1544).Conclusions To the best of our knowledge, this is the first report to show the feasibility of establishing erythroid cell lines ablility to produce mature RBCs. Considering the number of human ES cell lines that have been established so far and the number of induced pluripotent stem cell lines that will be established in future, the intensive testing of a number of these lines for erythroid potential may allow the establishment of human erythroid cell lines similar to the mouse erythroid cell lines.