This study was aimed to find a better method to isolate and enrich mesenchymal stem cells (MSCs)from bone marrow between CD271 (low affinity nerve growth factor receptor, LNGFR) and CD133 used for immunomagnetic positive selections through comparison of characteristics of MSCs isolated by these two agents. CD271+ and CD133+ cells were isolated from bone marrow and their colony forming unit-fibroblast (CFU-F) efficiency and proliferative capacity were assessed. Cell surface phenotype, adipogenic and osteogenic inductions were also assayed on the cells (after passage 3) isolated by both methods. The results showed that the purities of immunomagnetically selected CD271+ and CD133+ cells were (89.50+/-0.98)% and (88.03+/-3.06)% respectively. The CFU-F median frequency of CD271+ cells was 3 times as high as that of CD133+ cells, no CFU-F was observed in CD271- cells, while a few CFU-F was found in the CD133- cells. Phenotype of cells (after passage 3) isolated by the two methods was same, that is CD34-, CD14-, CD45-, CD90+, CD29+, CD44+, CD105+, CD73+. CD271+ cells possessed faster proliferation and stronger osteogenic and adipogenic differentiation potential than that of CD133+ cells. It is concluded that as compared with CD133 positive selection, CD271 positive selection is a better method for isolating and enriching mesenchymal stem cells from bone marrow.
AC133 Antigen ; Antigens, CD ; immunology ; metabolism ; Bone Marrow Cells ; cytology ; Glycoproteins ; immunology ; metabolism ; Humans ; Immunomagnetic Separation ; methods ; Mesenchymal Stromal Cells ; cytology ; Nerve Tissue Proteins ; immunology ; metabolism ; Peptides ; immunology ; metabolism ; Receptors, Nerve Growth Factor ; immunology ; metabolism ; Stem Cells

Programmed cell death 1 ligand 1 (PD-L1) is an important immunosuppressive molecule, which inhibits the function of T cells and other immune cells by binding to the receptor programmed cell death-1. The PD-L1 expression disorder plays an important role in the occurrence, development, and treatment of sepsis or other inflammatory diseases, and has become an important target for the treatment of these diseases. Mesenchymal stem cells (MSCs) are a kind of pluripotent stem cells with multiple differentiation potential. In recent years, MSCs have been found to have a strong immunosuppressive ability and are used to treat various inflammatory insults caused by hyperimmune diseases. Moreover, PD-L1 is deeply involved in the immunosuppressive events of MSCs and plays an important role in the treatment of various diseases. In this review, we will summarize the main regulatory mechanism of PD-L1 expression, and discuss various biological functions of PD-L1 in the immune regulation of MSCs.
Humans ; B7-H1 Antigen/metabolism* ; Mesenchymal Stem Cells/immunology* ; T-Lymphocytes/metabolism* ; Immunomodulation

As pioneer of tumor stem cell research, leukemia stem cell research has not only important theoretical significance, but also clinical application potential. The survival and development of stem cells are directly impacted by their microenvironment. The research on leukemia stem cells and their microenvironment are now becoming a hot topic. The author presumes that stem cells are a population with heterogenecity and hierarchy; any single cell from the population is difficult to form a clone; the interaction between the leukemia stem cell and its microenvironment can be described by the concept of leukemia stem cell niche. In this article, the leukemia cell population with heterogenecity and hierarchy as well as leukemia stem cell niche were summarized and discussed.
Cell Line, Tumor ; Humans ; Leukemia ; genetics ; pathology ; Neoplastic Stem Cells ; metabolism ; pathology ; Stem Cell Niche ; cytology ; Stromal Cells ; cytology ; immunology

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

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

Animals ; Cell Proliferation ; Disease Progression ; Endothelial Cells ; pathology ; Humans ; Indoleamine-Pyrrole 2,3,-Dioxygenase ; metabolism ; Mesenchymal Stromal Cells ; immunology ; metabolism ; pathology ; Neoplasms ; immunology ; pathology ; Neoplastic Stem Cells ; pathology ; Neovascularization, Pathologic ; pathology ; Stem Cells ; pathology ; T-Lymphocytes ; immunology ; pathology

The induced pluripotent stem cells (iPSCs), derived by ectopic expression of reprogramming factors in somatic cells, can potentially provide unlimited autologous cells for regenerative medicine. In theory, the autologous cells derived from patient iPSCs should be immune tolerant by the host without any immune rejections. However, our recent studies have found that even syngeneic iPSC-derived cells can be immunogenic in syngeneic hosts by using a teratoma transplantation model (Nature 474:212-215, 2011). Recently two research groups differentiated the iPSCs into different germ layers or cells, transplanted those cells to the syngeneic hosts, and evaluated the immunogenicity of those cells. Both of the two studies support our conclusions that some certain but not all tissues derived from iPSCs can be immunogenic, although they claimed either "negligible" or "lack of" immunogenicity in iPSC derivatives (Nature 494:100-104, 2013; Cell Stem Cell 12:407-412, 2013). To test the immunogenicity of clinically valuable cells differentiated from human iPSCs are emergently required for translation of iPSC technology to clinics.
Animals ; Cell Cycle Proteins ; metabolism ; Cell Transplantation ; methods ; Graft Rejection ; immunology ; Induced Pluripotent Stem Cells ; immunology ; transplantation ; Membrane Proteins ; metabolism ; Mice, Knockout ; Teratoma ; immunology ; metabolism

The aim of this study was to detect the presence of human AML leukemia stem cells (LSC) in childhood patients with acute leukemia (AL) and analyze the correlation between LSC concentrations and minimal residual disease (MRD) levels in AML cases after remission. The multi-parameter flow cytometry (FCM) and a panel of monoclonal antibody combination were used to detect the AML LSC or AML LSC immunophenotype-identical cell (AML LSC-IPIC) concentrations in childhood AML or ALL leukemia both at new diagnosis and at remission and correlated AML LSC to the MRD levels at different time points after remission. The results indicated that the AML LSC or AML LSC-IPIC concentrations [in average 166 (range 14 - 1459)/100 000 mononuclear cells (MNCs)] in AML at initial diagnosis were significantly higher than those in ALL [7 (range 0 - 560)/100 000 MNCs, p < 0.017] and control [0 (range 0 - 6)/100 000 MNCs, p < 0.017], respectively. The AML LSC concentrations in AML at non-CR were in average 36 (range 5 - 224)/100 000 MNCs. No statistical difference (p > 0.05) was found between the AML LSC or AML LSC-IPIC concentrations in AML (in average 6 (range 0 - 41)/100, 000 MNCs) and ALL [10 (range 0 - 105)/100, 000 MNCs] after CR. The significantly negative correlation was noticed between AML LSC concentrations and MRD levels. It is concluded that the AML LSCs exist in newly diagnosed AML, which are significantly reduced when complete remission has achieved, but the low levels of these populations still remain. The phenotypically similar (CD34(+)CD38⁻CD123(+)) AML LSC populations have also been found in the bone marrow from ALL patients, but their concentrations are not significantly different when CR has achieved. The significantly negative correlation between AML LSC concentrations and MRD levels is observed in AML patients after remission.
Adolescent ; Child ; Child, Preschool ; Female ; Flow Cytometry ; Humans ; Immunophenotyping ; Leukemia, Myeloid, Acute ; immunology ; metabolism ; Male ; Neoplasm, Residual ; immunology ; metabolism ; Neoplastic Stem Cells ; cytology ; Tumor Stem Cell Assay

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

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