[CD271 enrichment does not help isolating mesenchymal stromal cells from]

Reports on the isolation of mesencnymal stromal cells (MSCs) from granulocyte colony stimulating factor mobilized peripheral blood (G-CSF-mobilized PB) using regular culturing techniques are controversial. Enrichment techniques such as CD133 isolation have increased the success rates. CD271 is a well-known marker for enrichment of MSCs from bone marrow (BM). In the present study, we aimed to find out whether CD271 enrichment can help isolation of MSCs from G-CSF-mobilized PB. Five G-CSF-mobilized PB samples were collected from the remnant parts of the bags used for BM transplantation. Five BM samples were used as the control. Mononuclear cells (MNCs) from both resources were collected and underwent magnetic sorting for CD271-positive cells. The isolated cells were cultured, undergoing flowcytometry and differentiation assays to determine if they fulfill MSCs characteristics. CD271-positive portion of G-CSF-mobilized PB did not yield any cell outgrowth but the BM counterpart could successfully form MSC colonies. Although the percentage of CD271+ cells showed no difference between BM-MNCs and G-CSF-mobilized PB-MNCs, hematopoietic markers such as CD45, CD34 and CD133 composed a higher percentage of CD271-positive cells in the G-CSF-mobilized PB group. Results obtained indicated that CD271 enrichment does not help isolation of MSCs from G-CSF-mobilized PB. In this source, almost all of the CD271+ cells are from hematopoietic origin and the frequency of MSCs is so low that possibly during the process of cell isolation most of them are lost and the isolation fails.