The Effects of EX Vivo Expansion on the Differentiation of Umbilical Cord Blood-Derived CD34+ Cells (pp. 301-308)
Authors: Korashon L. Watts, Roger Tran-Son-Taya and Vijay S. Reddy
Clinical trials are ongoing involving transplantation of ex vivo expanded hematopoietic stem cells. This study was carried out in order to better understand the effects of ex vivo expansion on the differentiation of umbilical cord blood-derived stem cells. Methods: Progenitor cultures were initiated using fresh umbilical cord blood CD34+ cells and umbilical cord blood CD34+ cells that were pre-cultured for 1 week. Colony forming unit – granulocyte/macrophage (CFU-GM) and burst forming unit - erythroid (BFU-E) were enumerated after 14 days of culture in methylcellulose media, and results were analyzed to determine if pre-cultured cells differed from fresh cells in terms of differentiation potential.
As compared to fresh cells, pre-cultured cells generated a significantly higher number of CFU-GM (89.2±10.1 colonies as compared to 62.8±4.4 colonies generated from fresh cells, p=0.04) and a significantly lower number of BFU-E (65.4±11.3 colonies as compared to 98.8±11.2 colonies generated from fresh cells, p=0.004).
Culturing umbilical cord blood cells prior to transplantation may help alleviate delayed neutrophil engraftment associated with cord blood transplantation. However, the apparent polarization of cultured cells toward the myeloid lineage may result in delayed red cell engraftment.