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Stem Cells International
Volume 2011, Article ID 602483, 9 pages
Research Article

Phenotypic Definition of the Progenitor Cells with Erythroid Differentiation Potential Present in Human Adult Blood

1Cell Biology and Neuroscience, Superior Health Institute, 00161 Rome, Italy
2Tisch Cancer Institute, Mount Sinai School of Medicine, New York, NY 10029, USA

Received 23 May 2011; Accepted 22 June 2011

Academic Editor: Michel Sadelain

Copyright © 2011 Valentina Tirelli et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


In Human Erythroid Massive Amplification (HEMA) cultures, AB mononuclear cells (MNC) generate 1-log more erythroid cells (EBs) than the corresponding C D 3 4 p o s cells, suggesting that MNC may also contain C D 3 4 n e g HPC. To clarify the phenotype of AB HPC which generate EBs in these cultures, flow cytometric profiling for CD34/CD36 expression, followed by isolation and functional characterization (colony-forming-ability in semisolid-media and fold-increase in HEMA) were performed. Four populations with erythroid differentiation potential were identified: C D 3 4 p o s C D 3 6 n e g (0.1%); (barely detectable-0.1%); (2%) and (75%). In semisolid-media, cells generated BFU-E and CFU-GM (in a 1 : 1 ratio), cells mostly BFU-E (87%) and and C D 3 4 n e g C D 3 6 l o w cells were not tested due to low numbers. Under HEMA conditions, C D 3 4 p o s C D 3 6 n e g , C D 3 4 p o s C D 3 6 p o s , C D 3 4 n e g C D 3 6 l o w and C D 3 4 n e g C D 3 6 n e g cells generated EBs with fold-increases of 9,000, 100, 60 and 1, respectively, and maturation times (day with >10% C D 3 6 h i g h C D 2 3 5 a h i g h cells) of 10–7 days. Pyrenocytes were generated only by C D 3 4 n e g / C D 3 6 n e g cells by day 15. These results confirm that the majority of HPC in AB express CD34 but identify additional C D 3 4 n e g populations with erythroid differentiation potential which, based on differences in fold-increase and maturation times, may represent a hierarchy of HPC present in AB.