@Article{ecn.2009.0145,
AUTHOR = {Aleksandra Krstić, Marija Vlaski, Mohammad Hammoud, Jean Chevaleyre, Pascale Duchez, Gordana Jovčić, Diana Bugarski, Pavle Milenković, Philippe Bourin, Jean-Michel Boiron, Vincent Praloran, Zoran Ivanović},
TITLE = {Low O<sub>2</sub> concentrations enhance the positive effect of IL-17 on the maintenance of erythroid progenitors during co-culture of CD34+ and mesenchymal stem cells},
JOURNAL = {European Cytokine Network},
VOLUME = {20},
YEAR = {2009},
NUMBER = {1},
PAGES = {10--16},
URL = {http://www.techscience.com/ECN/v20n1/65912},
ISSN = {1952-4005},
ABSTRACT = {Co-culture of haematopoietic cells with a stromal cell layer does not mimic the physiological,
micro-environmental niche, whose major feature is a low oxygen (O<sub>2</sub>) concentration. Thus, in order to study
the effects of IL-17 in a context which better approximates the physiological state, we investigated its effects on
cell expansion, colony-forming ability, and the phenotypical profile of normal, human blood CD34<sup>+</sup>
 cells co-cultured
for five days with MSC layers at various O<sub>2</sub> concentrations (20%, 12.5% and 3% O<sub>2</sub>). We demon-strated
that IL-17 enhances CD34<sup>+</sup> and total CFC production during the five days of MSC/CD34<sup>+</sup> co-culture.
This effect depends upon the O<sub>2</sub> concentration, reaching its maximum at 3% O<sub>2</sub>, and is more pronounced on
erythroid progenitors (BFU-E). In addition, the stimulation of IL-6 production by IL-17 in MSC cultures and
co-cultures is enhanced by low O<sub>2</sub> concentration. The expression of some differentiation markers (CD34, CD13
and CD41) on haematopoietic cells in co-cultures also depends upon the oxygen concentration. Our results
strengthen the concept that physiological levels of O<sub>2</sub> (mistakenly called hypoxia), should be considered as an
important environmental factor that significantly influences cytokine activity.},
DOI = {10.1684/ecn.2009.0145}
}