Iron is an essential nutrient in mammalian cell cultures, conventionally supplemented as iron-loaded transferrin (holotransferrin). The high cost of human transferrin represents a challenge for the large scale production of cell therapies, such as cultured red blood cells. We evaluated the use of deferiprone, a cell membrane-permeable drug for iron chelation therapy, as an iron carrier for erythroid cultures. Iron-loaded deferiprone (Def3·Fe3+) at a concentration of 52μmol/L could fully replace holotransferrin during erythroblast differentiation into reticulocytes, the erythroid differentiation stage with maximal iron requirements. Reticulocytes cultured in presence of Def3·Fe3+ or holotransferrin (1000μg/mL) were similar with respect to expression of cell-surface markers CD235a and CD49d, hemoglobin content, and oxygen association/dissociation. Def3·Fe3+ also supported expansion of the erythroid compartment in vitro, except for the first stage when hematopoietic stem cells committed to erythroblasts, in which a reduced erythroblasts yield was observed. This suggests that erythroblasts acquired the potential to process Def3·Fe3+ as iron source for biosynthesis pathways. Replacement of holotransferrin by Def3·Fe3+ was also successful in cultures of six myeloid cell lines (MOLM13, NB4, EOL1, K562, HL60, ML2). These results suggest that iron-loaded deferiprone can partially replace holotransferrin in chemically defined medium formulations for the production of cultured reticulocytes and proliferation of selected myeloid cell lines. This would lead to a significant decrease in medium cost that would improve the economic perspectives of the large scale production of red blood cells for transfusion purposes.
818. Development of Packaging Cell Lines for the Large-Scale Production of High-Titer Clinical Grade Recombinant Retroviruses
