Fetal and maternal progenitor cells in co-culture respond equally to erythropoietin

To explore potentially selective growth conditions for fetal cells in cultu res from the blood of pregnant women, we investigated if fetal and adult er ythroid progenitors with different hemoglobin expression programs are diffe rentially responsive to erythropoietin (EPO). Co-cultures of clonogenic cel ls from 12-week fetal and adult peripheral blood were established, and the development of erythropoietic cells was monitored using flow cytometric pro files of correlated cellular contents of fetal and adult hemoglobin (HbF an d HbA, respectively). Adult nucleated red cells were classified as F+A-, FA+ or F-A+. All fetal cells were F+A-. The population of F+A- cells was flo w-sorted and fetal cells were identified by fluorescence in sine hybridizat ion (FISH) using chromosome-specific probes. Delayed EPO addition revealed that all types of erythroid cells entered the EPO-dependent phase With simi lar kinetics, beginning at about Day 4. The data suggest that fetal and adu lt erythroid stem/progenitor cells have the same initial maturation kinetic s in culture independent of their hemoglobin chain expression program, Feta l and adult cells with different hemoglobin profiles also showed similar EP O dose response curves. determined for different intervals during the first 2 weeks of culture. Thus, the kinetics of entry into the phase of EPO depe ndence, as well as the sensitivity to EPO at various stages of development, are essentially the same for erythropoietic progenitor cells derived from adult and early fetal blood, which rules out the possibility of using the t inting or concentration of EPO for the selective growth of fetal cells from the blood of pregnant women. Copyright (C) 2001 John Wiley & Sons, Ltd.