New work from the laboratories of Shahin Rafii, M.D., and Jason Butler, Ph.D., at Weill Cornell Medical College shows that co-culturing human umbilical cord blood (UCB) cells with human endothelial cells leads to an increase in the number of functional UCB stem and progenitor cells. This research from was recently published in Blood. Human UCB is a source of hematopoietic stem and progenitor cells (HSPCs) for use in transplant medicine. HSPCs give rise to blood and immune cells. However, UCB contains these important stem cells in limited quantities only, such that cells from multiple UCB donors are required to successfully transfuse an adult. Traditional methods rely on cytokines, signaling molecules, to expand HSPCs, yielding a seven-fold increase in HSPC number. Dr. Rafii’s and Dr. Butler’s research reveals that co-culturing UCB with human endothelial cells (flat cells in image) in xenobiotic-free conditions produces a 23-fold increase in HSPC number. Further, the co-cultured HSPCs (round, bright cells in image) engraft into immune compromised mice at higher rates and had higher long-term engraftment potential. The co-culture method also expanded the numbers of committed hematopoietic progenitor cells that give rise to platelets, red blood cells and immune cells, suggesting this method could provide other hematopoietic cell types of use in clinical applications. One transformative aspect of this study is the engineering of human endothelial cells grown without animal products and serum (xenobiotic-free), which commonly confound the expansion of hematopoietic cells. This innovation enables manufacturing clinical grade human endothelial cells that could be used to expand HSPC for transplantation. This work was supported by NYSTEM awards C024180, C026438, C026878.
Butler JM, Gars EJ, James DJ, Nolan DJ, Scandura JM, Rafii S. Development of a vascular platform for expansion of repopulating human cord blood stem and progenitor cells. Blood. 2012 Jun 18.