Identification and comparison of CD34-positive cells and their subpopulations from normal peripheral blood and bone marrow using multicolor flow cytometry

Abstract

Four-color flow cytometry was used with a cocktail of antibodies to identify and isolate CD34+ hematopoietic progenitors from normal human peripheral blood (PB) and bone marrow (BM). Mature cells that did not contain colony forming cells were resolved from immature cells using antibodies for T lymphocytes (CD3), B lymphocytes (CD20), monocytes (CD14), and granulocytes (CD11b). Immature cells were subdivided based on the expression of antigens found on hematopoietic progenitors (CD34, HLA-DR, CD33, CD19, CD45, CD71, CD10, and CD7). CD34+ cells were present in the circulation in about one-tenth the concentration of BM (0.2% v 1.8%) and had a different spectrum of antigen expression. A higher proportion of PB-CD34+ cells expressed the CD33 myeloid antigen (84% v 43%) and expressed higher levels of the pan leukocyte antigen CD45 than BM-CD34+ cells. Only a small fraction of PB-CD34+ cells expressed CD71 (transferrin receptors) (17%) while 94% of BM-CD34+ expressed CD71+. The proportion of PB-CD34+ cells expressing the B-cell antigens CD19 (10%) and CD10 (3%) was not significantly different from BM-CD34+ cells (14% and 17%, respectively). Few CD34+ cells in BM (2.7%) or PB (7%) expressed the T-cell antigen CD7. CD34+ cells were found to be predominantly HLA-DR+, with a wide range of intensity. These studies show that CD34+ cells and their subsets can be identified in normal PB and that the relative frequency of these cells and their subpopulations differs in PB versus BM.

Purified unfractionated G‐CSF/chemotherapy mobilized CD34+ peripheral blood progenitors and not bone marrow CD34+ progenitors undergo selective erythroid differentiation in liquid culture in the presence of erythropoietin and stem cell factor

“…Additionally, neither CD34 cell fractionation into distinct functional subsets nor serum deprivation of cultures are required to maintain the selectivity of erythroid differentiation, even though we found similar results in serum-free culture. This particular ability of purified G-CSF/ chemotherapy mobilized peripheral blood CD34 cells to undergo selective erythroid differentiation in liquid culture in response to EPO plus SCF is probably due to the intrinsic nature of circulating progenitors, because the characteristics of the progenitor cell population used in this study in terms of surface antigen expression and cell cycle status are similar to those reported elsewhere for circulating CD34 cells (Bender et al, 1991;Roberts & Metcalf, 1995). However, the exact mechanism through which SCF permits unilineage erythroid differentiation in liquid culture in the presence of EPO must be determined.…”

Collagen biomaterial stimulates the production of extracellular vesicles containing microRNA‐21 and enhances the proangiogenic function of CD34 + cells

“…One challenge facing CD34 + cell revascularization therapy is the relatively low number of basal cells. In the circulation, CD34 + cells account for only ;0.1% of the nucleated cells (63,64). Further complicating autologous use is that health and environmental factors, such as age, diabetes, smoking, and alcohol abuse, negatively affect the number and the function of CD34 + cells in the patients for whom this therapy is destined (reviewed in ref.…”

Isolation and identification of two CD34+cell subpopulations from normal human peripheral blood

“…The level of CD34' cells in the peripheral blood of healthy adults is about one-tenth of that in bone marrow [9,141 and is close to the lower limits of detection by two-color flow cytometry. Nevertheless, CD34' cells and their subfractions have been identified on the basis of surface markers from the blood of healthy adults using multicolor flow cytometry [14]. The surface markers used in human bone marrow studies indicate the lineage commitment and differentiation state of these CD34'subfractions [ 15-181.…”