Recently, many researches indicated the important role played by homeobox (HOX) gene family in normal hematopoiesis. As a kind of transcription factors, HOX gene products regulate and control the expression of target genes by binding to special DNA sequences. HOXB, a member of HOX gene family, especially HOXB(4), interests people greatly. It has been found that its expression relates closely to the self-renewal of hematopoietic stem cells and effective proliferation of hematopoietic progenitor cells. This review presents some new research progress in this area.
Animals ; Hematopoiesis ; genetics ; immunology ; physiology ; Hematopoietic Stem Cells ; cytology ; immunology ; metabolism ; Homeodomain Proteins ; genetics ; physiology ; Humans ; Multigene Family

To establish a basis for deep investigation of the role of microRNA (miRNA) in the regulation of hematopoiesis, differential expression profiles of miRNA between human cord blood CD34(+)CD38(-) and CD34(+)CD38(+) cells were analyzed. Mononuclear cells from cord blood (CB) of healthy donors were separated by Ficoll-Hypaque density gradients. CD34(+)CD38(-) and CD34(+)CD38(+) cells were sorted by using FACS Vantage SE. Their mRNA were then extracted and hybridized to miRNA microarray chip. The resulting data were analyzed with GeneSpring and informatics technique. The results showed that eleven miRNAs were found to be downregulated and 73 miRNAs to be upregulated by at least two-fold in the CD34(+)CD38(+) cells of CB, compared with the CD34(+)CD38(-) cells, which maintained CD34(+)CD38(-) cells' self-renewal and multiple lineage potential, that were defined as "stemness" miRNAs. 12 of the 84 genes (14.29%) were common to 33 hematopoietic-expressed miRNAs expressed by CD34(+) cells from both peripheral blood and bone marrow in Georgantas's study, which included 10 upregulated miRNAs (hsa-miR-23b, -26b, -92, -107, -130a, -181a, -197, -213, -222, -223) and 2 downregulated ones (hsa-miR-16a, -155). Some "stemness" miRNAs undergo CD34 antigen-like expression pattern during development and commmitted differeniation of hematopoietic stem cell/progenitors. Hematopoiesis-associated miRNA clusters and putative target genes could be found with informatics technique. It is concluded that the hematopoietic "stemness" miRNAs play important roles in normal hematopoiesis: miRNA expression profiles of hematopoietic stem cell/progenitors --> their gene expression profiles --> their self-renewal and lineage-commmitted differeniation.
ADP-ribosyl Cyclase 1 ; immunology ; Antigens, CD34 ; immunology ; Fetal Blood ; immunology ; metabolism ; Gene Expression Profiling ; Hematopoietic Stem Cells ; cytology ; immunology ; physiology ; Humans ; MicroRNAs ; genetics ; metabolism

A variety of immuno-deficient animal models has been used in the detection of human hematopoietic stem/progenitor cells and up to date make many remarkable contribution to the study of detectron cell biology. An ideal immuno-deficient animal should not only have complete immune defects, be able to transplant human hematopoietic stem/progenitor cells with high efficacy, but also survive long enough for observation. In this review, the development of immuno-deficient mice from nude, SCID, to NOD/SCID etc is introduced and much attention is put on the features, priority and shortcomings of those key animal models and their application in HSC research. The progress, the future directions and prospects of these immuno-deficient mice models are stressed.
Animals ; Hematopoietic Stem Cell Transplantation ; methods ; Hematopoietic Stem Cells ; cytology ; immunology ; metabolism ; Humans ; Mice ; Mice, Inbred NOD ; Mice, SCID ; Models, Animal ; Transplantation, Heterologous

OBJECTIVETo investigate whether fetal bone marrow stromal cells have hemangioblastic characteristics.

METHODSHuman fetal bone marrow stromal cells (hfMSCs) were isolated and cultured. Immunophenotypes of hfMSCs were tested by FACS. hfMSCs seeded in the matrigel were induced with vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in vitro. Vascularization and hematopoiesis were detected with immunohistochemistry and electron microscope.

RESULTSThe typical properties of this CD34- stromal cell population were that 99% cells expressed Flk1 (vascular endothelial cell growth factor receptor 2) and tube structure was formed. In the process of induction, hfMSCs could give rise to CD34+ round cells.

CONCLUSIONSWe have demonstrated that fetal bone marrow stroma-derived Flk1+ CD34- cells could differentiate into vascular endothelial cells and hematopoietic cells, indicating that fetal bone marrow stroma-derived Flk1+ CD34- cells have hemangioblastic characteristics.

Antigens, CD34 ; immunology ; Bone Marrow Cells ; cytology ; immunology ; metabolism ; Cell Differentiation ; Cells, Cultured ; Fetus ; Fibroblast Growth Factor 2 ; metabolism ; Hematopoiesis ; Hematopoietic Stem Cells ; cytology ; immunology ; metabolism ; Humans ; Immunophenotyping ; Stromal Cells ; cytology ; immunology ; metabolism ; Vascular Endothelial Growth Factor Receptor-2 ; physiology

OBJECTIVETo compare the expression profiles of a set of homing-related molecules (HRM) repertoire expressed on hematopoietic stem/progenitor cells (HS/PC) from different sources.

METHODThe expression levels of HRM on HS/PC from umbilical cord blood (UCB), mobilized peripheral blood (mPB) and bone marrow (BM) were assessed using a highly sensitive 4-color flow cytometric analysis.

RESULTSUCB-derived CD34(bright) cells, as well as mPB- and BM-derived CD34(bright) cells strongly expressed CD44, CD11a, CD18, CD62L, CD31 and CD49d. On the other hand, significantly lower expressions of CD49e, CD49f, CXCR-4 and CD54 on UCB-derived CD34(bright) and CD34(bright)CD38(-) cells, compared with those on mPB- and BM-derived CD34(bright) and CD34(bright)CD38(-) cells, were observed. None of UCB-, mPB- and BM-derived CD34(bright) cells expressed other chemokine receptors, including CCR-1, CCR-2, CCR-3, CCR-5, CXCR-1, CXCR-2, CXCR-3 and CXCR-5. Another striking finding was that only mPB-derived CD34(bright) cells expressed significant levels of both the matrix metalloproteinases MMP-2 \[(11.4 +/- 4.9)%\] and MMP-9 \[(27.6 +/- 7.8)%\].

CONCLUSIONHS/PC from UCB have some defects of expression of HRM repertoire, which might partly explain the cause(s) of delayed hematopoietic reconstitution after UCB transplant.

Antigens, CD34 ; immunology ; Bone Marrow Cells ; cytology ; immunology ; metabolism ; CD11a Antigen ; immunology ; CD18 Antigens ; immunology ; Cell Adhesion Molecules ; metabolism ; Cells, Cultured ; Fetal Blood ; cytology ; Flow Cytometry ; Hematopoietic Stem Cell Mobilization ; Hematopoietic Stem Cells ; cytology ; immunology ; metabolism ; Humans ; Hyaluronan Receptors ; immunology ; Infant, Newborn ; Matrix Metalloproteinases, Secreted ; metabolism ; Platelet Endothelial Cell Adhesion Molecule-1 ; immunology ; Receptors, CXCR4 ; metabolism

Cancer cells and the immune system are closely related and thus influence each other. Although immune cells can suppress cancer cell growth, cancer cells can evade immune cell attack via immune escape mechanisms. Natural killer (NK) cells kill cancer cells by secreting perforins and granzymes. Upon contact with cancer cells, NK cells form immune synapses to deliver the lethal hit. Mature NK cells are differentiated from hematopoietic stem cells in the bone marrow. They move to lymph nodes, where they are activated through interactions with dendritic cells. Interleukin-15 (IL-15) is a key molecule that activates mature NK cells. The adoptive transfer of NK cells to treat incurable cancer is an attractive approach. A certain number of activated NK cells are required for adoptive NK cell therapy. To prepare these NK cells, mature NK cells can be amplified to obtain sufficient numbers of NK cells. Alternatively, NK cells can be differentiated and amplified from hematopoietic stem cells. In addition, the selection of donors is important to achieve maximal efficacy. In this review, we discuss the overall procedures and strategies of NK cell therapy against cancer.
Cell Differentiation ; *Cell- and Tissue-Based Therapy ; Gene Expression Regulation ; Hematopoietic Stem Cells/cytology/metabolism ; Humans ; *Immunotherapy, Adoptive ; Killer Cells, Natural/cytology/*immunology/*metabolism ; Lymphocyte Activation/immunology ; Signal Transduction

The purpose of this study was to synthesize the complex of magnetic nanoparticles and antibody, and to apply them to isolate the CD34(+) cells from umbilical cord blood, then to evaluate its separation efficiency. The complex of magnetic nanoparticles and antibody was used to separate CD34(+) cells from umbilical cord blood in the outer magnetic field because of its superparamagnetism, specific identification and function of combination with CD34(+) cells. Scanning electron microscopy was used to observe the morphology of the separated CD34(+) cells. Flow Cytometer was applied to evaluate the sorting efficiency of magnetic nanoparticles, liquid culture and colony culture were taken to assay proliferation and differentiation capacity of the separated CD34(+) cells. The results showed that the CD34(+) cells from umbilical cord blood were isolated fast and effectively by the complex of magnetic nanoparticles and monoclonal antibody. Moreover, the isolated CD34(+) cells still maintained its normal morphology, highly proliferative and differentiative capacity. It is concluded that the complex of magnetic nanoparticles and monoclonal antibody has been successfully synthesized and developed as a technique which efficiently and quickly isolates CD34(+) cells from umbilical cord blood.
Antigens, CD34 ; metabolism ; Fetal Blood ; cytology ; Flow Cytometry ; Hematopoietic Stem Cells ; cytology ; immunology ; Humans ; Immunomagnetic Separation ; methods ; Magnetics ; Nanoparticles

OBJECTIVETo compare the in vivo homing potential of human hematopoietic stem/progenitor cells (HS/PCs) derived from fresh umbilical cord blood (UCB), cryopreserved UCB, mobilized peripheral blood (mPB) and bone marrow (BM) in xenotransplanted NOD/SCID mouse model, and to explore the relationship between the homing potential of HS/PCs and their expression levels of membrane receptor CXCR4.

METHODSThe expression levels of membrane CXCR4 on HS/PCs were assessed by flow cytometric analysis (FACS). CFSE-labeled human HS/PCs from different sources were transplanted into irradiated NOD/SCID mice. Human CD34 cells home in bone marrow and spleen of recipient mice were determined 20 hours after xenotransplantation by FACS and the homing efficiencies were calculated. Tissue sections of the recipient mice femurs were made and the distribution of CFSE-labeled human CD34 cells were observed under fluorescence microscope.

RESULTSThe expression levels of membrane CXCR4 on CD34+ cells from fresh UCB, cryopreserved UCB, mPB and BM were (49.52 +/- 1.12)%, (46.12 +/- 2.29)%, (48.50 +/- 2.48)% and (65.39 +/- 1.27)%, respectively. The homing efficiencies of CD34+ cells from fresh UCB, cryopreserved UCB, mPB and BM in recipient mice BM were (3.00 +/- 0.44)%, (2.84 +/- 0.46)%, (4.06 +/- 0.70)% and (5.76 +/- 0.52)% , respectively. Human CD34+ cells mainly located within endosteal region of recipient mice femurs.

CONCLUSIONCD34+ cells from UCB express lower levels of membrane CXCR4 than those from mPB and BM. The level of membrane CXCR4 on UCB CD34+ cells is down-regulated after freezing and thawing procedures. The homing efficiency of human CD34 cells from UCB in recipient mice is lower than that of mPB and BM.

Animals ; Antigens, CD34 ; Cell Movement ; Cells, Cultured ; Hematopoietic Stem Cell Transplantation ; Hematopoietic Stem Cells ; cytology ; immunology ; metabolism ; Humans ; Male ; Mice ; Mice, Inbred NOD ; Mice, SCID ; Receptors, CXCR4 ; metabolism ; Transplantation, Heterologous

Based on the requirement of culture conditions for hematopoietic stem and progenitor cells (HSPCs) ex vive expansion, we developed a new-type bioreactor by combining superiorities of static and stirred culture models. Stem cell factor (SCF), thrombopoietin (TPO), FLT-3 ligand(Flt-3) were used as the cytokines cocktails. The effects of the static and cyclic culture on the expansion characteristics of CD34+ selected cells were compared in the new-type bioreactor. After 7 d cultures, the expansion of total cells in the static culture was 13.86 +/- 4.26 fold, higher than that in the cyclic culture (7.23 +/- 2.67 fold). The analysis of the fold expansion and the proportion of CD34+ cells showed that there was no marked difference between the static culture and the cyclic culture. However, the fold expansion and the proportion of CD34+CD38- cells were higher in the cyclic culture than those in the static culture (3.90 +/- 0.85 versus 1.82 +/- 0.58), which reflected more primary CD34+CD38- cells were obtained in the cyclic culture. The above results demonstrated that both the static culture and the cyclic culture could be used in ex vive expansion of CD34+ cells with the new-type bioreactor. In static culture hematopoietic stem cells differentiated into progenitor cells, whilst the cyclic culture favored the expansion of primary HSPCs.
Antigens, CD34 ; metabolism ; Bioreactors ; Cell Culture Techniques ; methods ; Cell Differentiation ; physiology ; Cell Proliferation ; Cytokines ; pharmacology ; Fetal Blood ; cytology ; Hematopoietic Stem Cells ; cytology ; immunology ; Humans ; Stem Cell Factor ; pharmacology

Mesenchymal stem cells (MSC) are multipotent in nature and believed to facilitate the engraftment of hematopoietic stem cells (HSC) when transplanted simultaneously in animal studies and even in human trials. In this study, we transfected culture-expanded MSC with granulocyte macrophage-colony stimulating factor (GMCSF) and stem cell factor (SCF) cytokine genes and then cotransplanted with mononuclear cells (MNC) to further promote HSC engraftment. MNC were harvested from cord blood and seeded in long-term culture for ex vivo MSC expansion. A total of 1 x 10(7) MNC plus MSC/microliter were introduced to the tail vein of nonobese diabetic/severe combined immunodeficiency mice. After 6-8 weeks later, homing and engraftment of human cells were determined by flow cytometry and fluorescence in situ hybridization studies. The total nucleated cell count and the engraftment of CD45+/CD34+ cells and XX or XY positive human cells were significantly increased in cotransplanted mice and even higher with the cytokine gene-transfected MSC (GM-CSF>SCF, p<0.05) than in transplantation of MNC alone. These results suggest that MSC transfected with hematopoietic growth factor genes are capable of enhancing the hematopoietic engraftment. Delivering genes involved in homing and cell adhesions, CXCR4 or VLA, would further increase the efficiency of stem cell transplantation in the future.
Transfection/*methods ; Stem Cell Factor/genetics/*metabolism ; Mice, SCID ; Mice ; Mesenchymal Stem Cells/*metabolism ; Mesenchymal Stem Cell Transplantation/*methods ; Hematopoietic Stem Cell Transplantation/*methods ; Granulocyte Macrophage Colony-Stimulating Factors, Recombinant/*metabolism ; Graft Survival/*immunology ; Genetic Enhancement/methods ; Animals