@article{Esther Heideveld_Francesca Masiello_Manuela Marra_Fatemehsadat Esteghamat_Nurcan Yağcı_Marieke von Lindern_Anna Rita F. Migliaccio_Emile van den Akker_2015, place={Pavia, Italy}, title={CD14+ cells from peripheral blood positively regulate hematopoietic stem and progenitor cell survival resulting in increased erythroid yield}, volume={100}, url={https://haematologica.org/article/view/7552}, DOI={10.3324/haematol.2015.125492}, abstractNote={Expansion of erythroblasts from human peripheral blood mononuclear cells is 4- to 15-fold more efficient than that of CD34<sup>+</sup> cells purified from peripheral blood mononuclear cells. In addition, purified CD34<sup>+</sup> and CD34<sup>−</sup> populations from blood do not reconstitute this erythroid yield, suggesting a role for feeder cells present in blood mononuclear cells that increase hematopoietic output. Immunodepleting peripheral blood mononuclear cells for CD14<sup>+</sup> cells reduced hematopoietic stem and progenitor cell expansion. Conversely, the yield was increased upon co-culture of CD34<sup>+</sup> cells with CD14<sup>+</sup> cells (full contact or transwell assays) or CD34<sup>+</sup> cells re-constituted in conditioned medium from CD14<sup>+</sup> cells. In particular, CD14<sup>++</sup>CD16<sup>+</sup> intermediate monocytes/macrophages enhanced erythroblast outgrowth from CD34<sup>+</sup> cells. No effect of CD14<sup>+</sup> cells on erythroblasts themselves was observed. However, 2 days of co-culturing CD34<sup>+</sup> and CD14<sup>+</sup> cells increased CD34<sup>+</sup> cell numbers and colony-forming units 5-fold. Proliferation assays suggested that CD14<sup>+</sup> cells sustain CD34<sup>+</sup> cell survival but not proliferation. These data identify previously unrecognized erythroid and non-erythroid CD34<sup>−</sup> and CD34<sup>+</sup> populations in blood that contribute to the erythroid yield. A flow cytometry panel containing CD34/CD36 can be used to follow specific stages during CD34<sup>+</sup> differentiation to erythroblasts. We have shown modulation of hematopoietic stem and progenitor cell survival by CD14<sup>+</sup&gt; cells present in peripheral blood mononuclear cells which can also be found near specific hematopoietic niches in the bone marrow.}, number={11}, journal={Haematologica}, author={Esther Heideveld and Francesca Masiello and Manuela Marra and Fatemehsadat Esteghamat and Nurcan Yağcı and Marieke von Lindern and Anna Rita F. Migliaccio and Emile van den Akker}, year={2015}, month={Oct.}, pages={1396-1406} }