OBJECTIVETo study the cytotoxic effect of allogenetic natural killer (NK) cells in vitro on human CD34+ acute myelogenous leukemia cells.

METHODSCD34 expression on acute myelogenous leukemia KG1a cells was detected by flow cytometry. KG1a cells were co-cultured at different effector-to-target (E:T) ratios with NK cells isolated from 5 healthy individuals using magnetic cell sorting. Lactate dehydrogenase (LDH) release assay was employed to examine the cytolysis of KG1a cells in the co-culture, and the inhibition rate of the KG1a cell colony formation in methylcellulose was determined with K562 cells sensitive to NK cells as the control.

RESULTSA expression rate as much as (98.0-/+1.1)% was detected for CD34 antigen on KG1a cells, and the isolated NK cells (CD3(-)CD16+CD56+ cells) had a purity of (93.2-/+3.7)% after magnetic cell sorting. Allogenetic NK cells exhibited obvious cytotoxicity and colony inhibition in vitro against KG1a cells at different E:T ratios, and the effects were significantly enhanced as the E:T ratios increased (P<0.05). At the same E:T ratio, the cytotoxicity and colony inhibition rate of allogenetic NK cells against KG1a cells was lower than those against K562 cells (P<0.05).

CONCLUSIONAllogenetic NK cells exhibit obvious cytotoxicity and colony formation against CD34+ acute myelogenous leukemia cells.

Antigens, CD34 ; immunology ; Coculture Techniques ; Cytotoxicity, Immunologic ; Flow Cytometry ; Humans ; K562 Cells ; Killer Cells, Natural ; immunology ; Leukemia, Myeloid, Acute ; immunology

The study was purposed to explore the effect of panel reactive antibody (PRA) serum from patients with β-thalassemia on proliferation and apoptosis of the CD34(+)cells from cord blood and its mechanism. CD34(+) cells of umbilical cord blood were incubated with different sera and complement respectively. After incubation, the samples were centrifuged and the supernatants were collected for lactate dehydrogenase (LDH) detection, and the CD34(+) cells were harvested and measured for the apoptosis by flow cytometry with Annexin V/PI. The intracellular DNA synthesis were also quantified by [(3)H]TdR incorporation using liquid scintillation counter. The results showed that concentration of LDH in PRA positive groups was higher as compared with control group, and the DNA synthesis of CD34(+) cells in PRA positive groups were inhibited. There were no differences in the percentage of cell apoptosis and necrosis among different groups. It is concluded that thalassemic serum PRA impairs the cell membrane, inhibits the DNA synthesis, which can be increased by addition of the complement, but PRA had no significant effect on apoptosis of CD34(+) cells.
Antibodies ; blood ; immunology ; Antigens, CD34 ; Apoptosis ; immunology ; Cell Proliferation ; Child ; Fetal Blood ; cytology ; Humans ; beta-Thalassemia ; blood ; immunology ; pathology

OBJECTIVEThe low rate of engraftment in children with beta-thalassemia has seriously restricted the popularity of the hematopoietic stem cell transplantation (HSCT). Panel reactive antibody (PRA) has been regarded as one of the important factors for the success of kidney transplantation. Poly-transfusion before transplantation is associated with the production of PRA. Also PRA is produced in the children with beta-thalassemia major who need poly-transfusion for life. PRA might be one of factors inducing the low rate of engraftment in children with beta-thalassemia. This study focused on observing the effect of PRA on the proliferation, differentiation, apoptosis and necrosis of cord blood CD34(+) cells in vitro by incubating the cord blood CD34(+) cells with serum containing PRA.

METHODSeven samples of cord blood were collected and the HLA typing for every sample was done. Seven sera positive for PRA and seven negative sera were selected respectively. Mononuclear cells (MNCs) were obtained by Ficoll-Hypaque density gradient centrifugation. CD34(+) cells were isolated from MNCs by positive selection using an immunomagnetic separation (CD34(+) progenitor cell isolation kit and auto-MACS). The CD34(+) cells of umbilical cord blood were incubated with the serum and complement in the following groups: A (absence of serum), B (presence of PRA positive serum), C (presence of PRA positive serum and complement), D (presence of complement), and E (presence of PRA negative serum). After incubation the samples were centrifuged and the supernatant was collected for LDH detection. At the same time the CD34(+) cells were harvested for assessing the expression of Annexin V and CD95 of the CD34(+) cells by flow cytometry and also for the detection of the DNA synthesis by (3)H-TaR incorporation. Meanwhile the cells were inoculated into the methylcellulose cultural system. The proliferation and hematopoietic potential of the CD34(+) cell of cord blood by the colony formation assay were detected on the day 10.

RESULTThe concentration of LDH in group A was (20.71 +/- 2.81) U/L, which was significantly lower than that in group B (64.28 +/- 5.12) U/L and group C (84.29 +/- 4.99) U/L. The concentration of LDH in group B was significantly lower than that in group C, while there were no significant differences in the concentration of LDH among groups A, D and E (P > 0.05). The cpm in group A was (22 629 +/- 3288), which was significantly higher than that in group B (4598 +/- 2178) and group C (1626 +/- 1192). And the cpm in group B was significantly higher than that in group C. There were no significant differences in the cpm among groups A, D and E (P > 0.05). On day 10 of culture, the total colonies, granulocyte-macrophage colony forming unit (CFU-GM), mixed colony forming unit (CFU-GEMM) and erythroid burst colony forming unit (BFU-E) in group A were significantly higher than that in group B and C. The total colonies, CFU-GM and CFU-GEMM in group B were significantly higher than those in group C. No significant differences were found in the total colonies, CFU-GM, CFU-GEMM and BFU-E among groups A, D and E (P > 0.05). There were no statistically significant differences in the CD95 and Annexin V expression among all the groups (P > 0.05).

CONCLUSIONPRA could impair the membrane, decrease the DNA synthesis, and inhibit the colony formation of CD34(+) cord blood cells, which could be strengthened by the presence of the complement at the given concentration in our study. PRA had no significant influence on the apoptosis of CD34(+) cells in vitro.

Antibodies ; immunology ; Antigens, CD34 ; Apoptosis ; immunology ; Cell Differentiation ; immunology ; Cell Proliferation ; Cells, Cultured ; Child ; Fetal Blood ; cytology ; immunology ; metabolism ; Flow Cytometry ; Humans ; Quorum Sensing ; immunology ; beta-Thalassemia ; immunology

To investigate whether the RBC lysing solution can affect the results of relative enumeration of CD34(+) cells, 37 mobile peripheral blood apheresis products were stained using CD34-PE and CD45-FITC monoclone antibodies and RBCs were then lysed by two lysing solution commercially available (one named FACS Lysing Solution, FACS; another IOTest 3 Lysing Solution, IOTest) and one lysing solution self-prepared. After being processed by lyse-and-then-washed method, samples were detected by FACSC anto flow cytometer. The percentages of CD34(+) cells were determined based on ISHAGE gating strategy, forward and side scatter (FSC and SSC) characteristics, percentage of CD45(+) cells were recorded simultaneously. The results showed that by lyse-and-then-wash method, the percentages of CD34(+) cells in FACS-treated samples were significantly lower compared with that in IOTest-treated samples (0.50 +/- 0.42 vs 0.92 +/- 0.59, p = 0.004), but no statistical difference was observed between IOTest-treated and ourselves-prepared-treated samples. The intensities of FSC and SSC in cells of IOTest-treated sample were significantly higher compared with that in cells of FACS-treated sample (p < 0.01). The proportion of CD45(+) cells in IOTest-treated samples was lower than that in FACS-treated samples. The WBC count of samples was not correlated to the amount of CD34(+) cells (r(s) = 0.192, p = 0.357). It is concluded that the red cell lysing solution shows unexpected effect on detecting and counting CD34(+) cells, prudence should be taken to select such reagents at FCM performance.
Antigens, CD34 ; immunology ; Cell Count ; Cell Death ; Erythrocytes ; Flow Cytometry ; methods ; Humans ; Solutions ; pharmacology

OBJECTIVESTo investigate the stroma-independent growth ability, multilineage differentiation and expansion of the single hematopoietic stem/progenitor cell from patients with paroxysmal nocturnal hematoglobinuria (PNH).

METHODThe CD(34)(+) CD(59)(+) and CD(34)(+) CD(59)(-) cells from PNH patients and CD(34)(+) CD(59)(+) cells from normal volunteers were sorted as each single cell into a well of 96 well culture plates containing culture medium supplemented with SCF, IL-3, Epo, GM-CSF, G-CSF, IL-6, Tpo and Flt-3 ligand.

RESULTS(1) Single PNH CD(34)(+) CD(59)(-) cell had a higher capacities for plating efficiency, colony (>/= 50 cells) formation and cell expansion than that of the PNH CD(34)(+) CD(59)(+) cells (P < 0.05); (2) Both the single CD(34)(+) CD(59)(-) cells from PNH patients and the single CD(34)(+) CD(59)(+) cells from normal controls had similar capacities for cell plating efficiency and colony and large colony formation. The PNH CD(34)(+) CD(59)(-) cells had a lower average cell production and cell expansion capacity. (3) The single CD(34)(+) CD(59)(+) cells from both PNH patients and normal controls showed the same capacities for cell plating efficiency and colony formation. The PNH CD(34)(+) CD(59)(+) cells exhibited much lower capacity for large colony formation, average cell production and total cell expansion. (4) A diminished secondary colony formation ability was also observed in the PNH CD(34)(+) CD(59)(+) and CD(34)(-) CD(59)(-) clones.

CONCLUSIONThe single PNH CD(34)(+) CD(59)(-) cells had growth advantage over the single PNH CD(34)(+) CD(59)(+) cells to some extent, but they both had impaired growth abilities as compared with CD(34)(+) cells from normal volunteers.

Antigens, CD34 ; immunology ; CD59 Antigens ; immunology ; Cell Culture Techniques ; Cell Division ; physiology ; Colony-Forming Units Assay ; Hematopoietic Stem Cells ; immunology ; pathology ; Hemoglobinuria, Paroxysmal ; physiopathology ; Humans

This study was purposed to investigate the biological characteristics and immunogenicity changes of ex vivo expanded megakaryocyte progenitors from human umbilical cord blood CD34(+) cells in order to provide experimental basis for clinical application of ex vivo expanded umbilical cord blood megakaryocyte progenitor cells. Mononuclear cells (MNCs) were obtained from umbilical cord blood by Ficoll-Hyapaque density gradient separation. CD34(+) cells were enriched by magnetic cell sorting (MACS). The selected CD34(+) cells were seeded in serum-free medium stimulated with thrombopoietin (TPO, 50 ng/ml), interleukin 11 (IL-11, 50 ng/ml), and heparin (25 U/ml) for 14 days. The immunophenotyping (CD34(+), CD41a(+), CD61(+), CD34(+) CD41a(+) and CD34(+) CD61(+) cells) of amplificated products, matured megakaryocyte apoptosis, and expression of human leukocyte antigen (HLA) class I and class II molecules were measured by fluorescence-activated cell sorter (FACS). The number of colony-forming units-megakaryocyte (CFU-Mk) was also evaluated by CFU-Mk assay. The results showed that the umbilical cord blood CD34(+) mononuclear cells could be effectively differentiated into megakaryocytes. The peak expression ratios of CD41a(+) and CD61(+) cells were all at 14th days, while that of CD34(+) CD41(+) and CD34(+) CD61(+) cells were at 7th day [(3.41 +/- 2.80)% and (1.89 +/- 1.43)%, respectively]. The expansion times of large and small CFU-Mk reached peak at 7th day (20.66 +/- 32.79) and 10th day (435.62 +/- 482.65), respectively. The apoptotic rates of megakaryocytes at 7th, 10th, 14th day were (19.48 +/- 9.64)%, (26.87 +/- 9.03)%, and (52.46 +/- 11.74)%, respectively. The apoptotic rate of megakaryocytes had no significant difference in 7 and 10 days culture (p > 0.05), while that significantly increased in culture for 14 day culture, compared with culture for 7 and 10 days (p < 0.05, respectively). The expression of HLA class I and class II molecules on megakaryocytes decreased along with the prolongation of expansion time and sharply decreased in 0 to 10 days. It is concluded that the cytokines of TPO, IL-11, and heparin can promote the expansion of megakaryocyte progenitors from umbilical cord blood CD34(+) mononuclear cells effectively in vitro. The peaked expansion times of large CFU-Mk, the peaked expression ratios of CD34(+) CD41(+) and CD34(+) CD61(+) cells were all at 7th day. So the culture for 7 days appeared to be the optimal duration of expanding megakaryocyte progenitors.
Antigens, CD34 ; immunology ; Cell Differentiation ; Cell Division ; Cell Separation ; Cells, Cultured ; Fetal Blood ; cytology ; immunology ; Humans ; Megakaryocyte Progenitor Cells ; cytology

This study was purposed to clarify whether biology function of mesenchymal stem cells (MSCs) is changed by suppressing the development of dendritic cells (DC) derived from hematopoietic stem cells (HSCs). MSCs were cocultured with dendritic cells derived from CD34 positive hematopoietic stem cells (HSCs), and then the expression of cytokines and phenotypes of DCs/MSCs were detected by RT-PCR and flow cytometry respectively. Induced experiments were used to analyze the differentiation ability of MSCs. The results showed that DCs/MSCs were negative for the CD14, CD34, CD45, CD31, CD86, but positive for HLA-ABC, CD29, CD73, though the percentage decreased as MSCs vs DCs/MSCs (93.1% vs 13.44%, 98.3% vs 78.8%, 95.3% vs 75.9%). In addition, the expression of cytokines such as M-CSF, TGF-beta increased in DCs/MSCs. After differentiation induction, DCs/MSCs were deprived of the potential to differentiate into adipocytes, but maintained osteogenesis characteristics. It is concluded that the basic characteristics of MSCs are altered after coculture with DCs, and DCs/MSCs result in lower expression of mesenchymal phenotypes and decrease differentiation ability, but increase the expression of cytokines related to hematopoiesis and immunity.
Antigens, CD34 ; immunology ; Bone Marrow Cells ; cytology ; Cell Differentiation ; Cells, Cultured ; Dendritic Cells ; cytology ; immunology ; Humans ; Mesenchymal Stromal Cells ; cytology

OBJECTIVETo explore the role of stem cell mobilization on regeneration of partially grafted livers.

METHODSRats models with cross-sex 50% PLTx (partial liver transplantation) were established. The rats were divided into three groups: PLTx, WLTx (whole liver transplantation) and sham operation groups. Bone marrow and liver samples were collected on days 1, 3, 5, 7 postoperatively (each n = 6). The quantitative variations of the cells with stem cell markers in the bone marrow, including beta2m-/Thy-1.1+, CD45+/CD34+, Flt2/3+ and c-kit+ markers, were detected using flow cytometry. Sry gene positive cells in donor livers were detected by fluorescent in situ hybridization (FISH), and the expressions of CD34, c-kit and Thy-1.1 were detected by immunohistochemistry technique.

RESULTSCompared with the WLTx and sham operation groups, beta2m-/Thy-1.1+, CD45+/CD34+ cells in bone marrows in the PLTx group increased on the first postoperative day and decreased on the following days. The CD34, c-kit and Thy-1.1 positive cells detected in portal tract areas peaked during the 3-5 postoperative days. CD34+/CD45+ positive cells could be detected. The expressions of CD34, c-kit and Thy-1.1 positive cells were rare in the WLTx and sham operation groups. Sry+ cells could be detected in portal tract areas and few Sry+/CD34+ and Sry+/Thy-1.1+cells were detected.

CONCLUSIONIn the PLTx group, the stem cells in the bone marrow were mobilized and stem cells in the liver were activated.

Animals ; Antigens, CD34 ; immunology ; Bone Marrow Cells ; cytology ; immunology ; Female ; Hematopoietic Stem Cell Mobilization ; Leukocyte Common Antigens ; immunology ; Liver Transplantation ; methods ; Male ; Rats ; Rats, Sprague-Dawley ; Stem Cells ; cytology ; immunology ; Thy-1 Antigens ; immunology

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

OBJECTIVETo cultivate hematopoietic stem/progenitor cells (CD34(+)CD38(-)) isolated from umbilical cord blood (UCB) long for the observation of cell growth and expansion in vitro, surface marker expression, and chromosomal complements.

METHODSBy flow cytometry CD34-FITC and CD38-PE labeled CD34(+) and CD38(-) stem/progenitor cells were isolated from UCB. The cells were cultivated in vitro for 6 months in a stem cell culture system with addition of six kinds of cell growth factors (IL-3, IL-6, GM-CSF, Epo, SCF, IGF-1). One month after cultivation, cultured cells were investigated for surface marker expression by flow cytometry and karyotype by G banding method.

RESULTSAfter 7-12 days cultivation, the CD34(+)CD38(-) stem/progenitor cells began proliferation. The proliferation rate and the peak proliferation duration were greater in 1 cell/well cultivation conditions than in 10 cells/well. The cells remained CD34(+)CD38(-) and their karyotypic characteristics remained unchanged.

CONCLUSIONCD34(+)CD38(-) stem/progenitor cells from UCB may provide a larger than original amount of stem/progenitor cells for transplantation after long-term cultivation in vitro.

ADP-ribosyl Cyclase 1 ; immunology ; Adult ; Antigens, CD34 ; immunology ; Cell Proliferation ; Cells, Cultured ; Female ; Fetal Blood ; cytology ; immunology ; Hematopoietic Stem Cells ; cytology ; immunology ; Humans ; Immunophenotyping ; Karyotyping