@article {18587, title = {Developing a co-culture system for effective megakaryo/thrombopoiesis from umbilical cord blood hematopoietic stem/progenitor cells}, journal = {Cytotherapy}, volume = {17}, year = {2015}, month = {2015-02-11 00:00:00}, pages = {428-442}, abstract = {

Platelet transfusion can be a life-saving procedure in different medical settings. Thus, there is an increasing demand for platelets, of which shelf-life is only 5 days. The efficient ex\ vivo biomanufacturing of platelets would allow overcoming the shortages of donated platelets. We exploited a two-stage culture protocol aiming to study the effect of different parameters on the megakaryo/thrombopoiesis ex\ vivo. In the expansion stage, human umbilical cord blood (UCB)-derived CD34+-enriched cells were expanded in co-culture with human bone marrow mesenchymal stromal cells (BM-MSCs). The megakaryocytic commitment and platelet generation were studied, considering the impact of exogenous addition of thrombopoietin (TPO) in the expansion stage and a cytokine cocktail (Cyt) including TPO and interleukin-3 in the differentiation stage, with the use of different culture medium formulations, and in the presence/absence of BM-MSCs (direct versus non-direct cell-cell contact). Our results suggest that an early megakaryocytic commitment, driven by TPO addition during the expansion stage, further enhanced megakaryopoiesis. Importantly, the results suggest that co-culture with BM-MSCs under serum-free conditions combined with Cyt addition, in the differentiation stage, significantly improved the efficiency yield of megakaryo/thrombopoiesis as well as increasing \%CD41, \%CD42b and polyploid content; in particular, direct contact of expanded cells with BM-MSCs, in the differentiation stage, enhanced the efficiency yield of megakaryo/thrombopoiesis, despite inhibiting their maturation. The present study established an in\ vitro model for the hematopoietic niche that combines different biological factors, namely, the presence of stromal/accessory cells and biochemical cues, which mimics the BM niche and enhances an efficient megakaryo/thrombopoiesis process ex\ vivo.

}, keywords = {cell-cell contact, hematopoietic stem/progenitor cells, megakaryocyte, platelet, serum-free medium, Umbilical cord blood}, doi = {10.1016/j.jcyt.2014.12.010}, url = {http://www.sciencedirect.com/science/article/pii/S1465324915000067}, author = {Hatami, J. and Andrade, P. Z. and Alves de Matos, A. P. and Djokovic, D. and Lilaia, C. and Frederico, F. C. and Cabral, J. M. S. and da Silva, C. L.} }