We have recently described a system for the generation of dendritic cells (DC) and Langerhans cells (LC) from defined CD34+ precursors purified from peripheral blood of healthy adult volunteers. This study has now been extended by the characterization of two distinct subpopulations of CD34+ cells in normal human peripheral blood as defined by the expression of the skin homing receptor cutaneous...

Flt3 ligand (FL) has been proposed as a possible modulator hanced or depleted the number of precommitted cells in expansion culture, CD34 CD38 and HLA-DR fractions of early hematopoietic cell growth. The purpose of this study was to analyze the impact of FL on ex vivo expansion of were incubated in liquid culture and analyzed by flow cytometry. Inclusion of FL enhanced the absolute number of pr...

Putative myogenic and endothelial (myo-endothelial) cell progenitors were identified in the interstitial spaces of murine skeletal muscle by immunohistochemistry and immunoelectron microscopy using CD34 antigen. Enzymatically isolated cells were characterized by fluorescence-activated cell sorting on the basis of cell surface antigen expression, and were sorted as a CD34+ and CD45- fraction. Ce...

Human hematopoietic stem/progenitor cells (HSC) isolated based upon specific patterns of CD34 and CD38 expression, despite phenotypically identical, were found to be functionally heterogeneous, raising the possibility that reversible expression of these antigens may occur during cellular activation and/or proliferation. In these studies, we combined PKH67 tracking with CD34/CD38 immunostaining ...

To define the phosphatidylinositol glycanclass A (PIG-A) gene abnormality in precursor cells and the changes of expression of glycosylphosphatidylinositolanchored protein and contribution of paroxysmal nocturnal hemoglobinuria (PNH) clones with PIG-A gene abnormalities among various cell lineages during differentiation and maturation, we investigated CD59 expression on bone marrow CD34 cells an...

Human stem and progenitor cells have recently become objects of intensive studies as an important target for gene therapy and regenerative medicine. Retroviral vectors are among the most effective tools for genetic modification of these cells. However, their transduction efficiency strongly depends on the choice of the ex vivo transduction system. The aim of this study was to elaborate a system...

Tumor cells have been found in autologous hematopoietic cell transplants used after high-dose chemotherapy. To specifically eliminate contaminating mammary tumor cells during ex vivo expansion of CD34+ hematopoietic progenitor cells, we used recombinant immunotoxins (ITs) directed against cell-surface antigens expressed on mammary carcinoma cells. ITs were expressed from fusion cDNAs combining ...

Interleukin (IL)-27, one of the most recently discovered IL-6 family cytokines, activates both the signal transducer and activator of transcription (STAT)1 and STAT3, and plays multiple roles in pro- and anti-inflammatory immune responses. IL-27 acts on various types of cells including T, B, and macrophage through the common signal-transducing receptor gp130 and its specific receptor WSX-1, but...

Tyrosine kinase inhibitors (TKI) are the mainstay treatment of BCR-ABL1-positive leukemia and virtually all patients with chronic myeloid leukemia in chronic phase (CP CML) respond to TKI therapy. However, there is limited information on the cellular mechanisms of response and particularly on the effect of cell differentiation state to TKI sensitivity in vivo and ex vivo/in vitro. We used multi...

Despite the progress in our understanding of genes essential for stem cell regulation and development, little is known about the factors secreted by stem cells and their effect on tissue regeneration. In particular, the factors secreted by human CD34+ cells remain to be elucidated. We have approached this challenge by performing a cytokine/growth factor microarray analysis of secreted soluble f...