Fetal Cord Blood as an Alternative Source of Hematopoietic Progenitor Cells: Immunophenotype, Maternal Cell Contamination, and Ex Vivo Expansion

Abstract

The present study was performed to investigate the character of hematopoietic progenitor cells in fetal cord blood (CB). Thirty blood samples from fetuses at a median of 24 weeks of gestation (range 19-29) and 30 neonatal CB samples were analyzed for their immunophenotype by three-color flow cytometry and examined for the presence of female cells by fluorescence in situ hybridization (FISH). We tested the effects of different cytokine combinations (rhIL-1beta, rhIL-3, rhIL-6, rh erythropoietin [rhEPO], rhGM-CSF plus rhSCF, and rhSCF plus rhflt3-ligand) on the differentiation of 100 CD34+-enriched neonatal CB cells for up to 21 days. Ex vivo expansion of 32 unselected fetal blood samples cells was performed in the presence of rhSCF and rhflt3-ligand. The percentage of CD34+ cells in fetal blood was significantly higher compared with neonatal CB (1.24%+/-0.82% versus 0.33%+/-0.18%, p = 0.0001) and inversely correlated with the age of gestation. The contamination of fetal and neonatal CB with maternal cells was low (1.72%+/-0.89%, range 1.0%-4.0%). By using rhflt3-ligand we were able to expand committed progenitor cells while maintaining cells with stem cell function. The use of expanded fetal immature progenitors might have implications for in utero transplantation and autologous gene therapy.

Polychromatic flow cytometry analysis of CD34+ hematopoietic stem cells in cryopreserved early preterm human cord blood samples

“…The definition of HSC antigenic mosaic by multidimensional FCM is one of the key tools available to study stem cell biology (5,7,(16)(17)(18)(19)(20). We decided to exploit this technology to propose a polychromatic FCM characterization of HSCs from long-term cryopreserved hEPCB samples and to compare their immunophenotypic pattern with counterparts from cryopreserved full-term CB.…”

“…Although hTCB transplantation will go on growing thanks to the advances in HSC basic biology knowledge and new approaches for ex vivo expansion of hematopoietic progenitor cell populations, little is known about the possible use of human early preterm cord blood (hEPCB) for hematopoietic purposes (4,5).…”

“…Pos HSCs residing in early preterm (17-24 weeks) CB (5,6). Cervera et al (7) offered a four-color flow cytometry (FCM) analysis of HSC and lymphocyte compartments present in preterm samples with a gestational age range between 26 and 36 weeks.…”

Circulating hematopoietic progenitor cells in a fetus with alpha thalassemia: comparison with the cells circulating in normal and non-thalassemic anemia fetuses and implications for in utero transplantations

“…12,28,29 The number of progenitor cells calculated according to both definitions correlates with the number of repopulating cells in humans: the CD34 + content predicts the engraftment of adult grafts, 30 while the CFC content predicts the outcome of transplants with umbilical/cord blood grafts.…”