Repetitive administration of cultured human CD34+cells improve adenine-induced kidney injury in mice

BACKGROUND There is no established treatment to impede the progression or restore kidney function in human chronic kidney disease(CKD).AIM To examine the efficacy of cultured human CD34+cells with enhanced proliferating potential in kidney injury in mice.METHODS Human umbilical cord blood(UCB)-derived CD34+cells were incubated for one week in vasculogenic conditioning medium.Vasculogenic culture significantly increased the number of CD34+cells and their ability to form endothelial progenitor cell colony-forming units.Adenineinduced tubulointerstitial injury of the kidney was induced in immunodeficient non-obese diabetic/severe combined immunodeficiency mice,and cultured human UCB-CD34+cells were administered at a dose of 1×106/mouse on days 7,14,and 21 after the start of adenine diet.RESULTS Repetitive administration of cultured UCB-CD34+cells significantly improved the time-course of kidney dysfunction in the cell therapy group compared with that in the control group.Both interstitial fibrosis and tubular damage were significantly reduced in the cell therapy group compared with those in the control group(P<0.01).Microvasculature integrity was significantly preserved(P<0.01)and macrophage infiltration into kidney tissue was dramatically decreased in the cell therapy group compared with those in the control group(P<0.001).CONCLUSION Early intervention using human cultured CD34+cells significantly improved the progression of tubulointerstitial kidney injury.Repetitive administration of cultured human UCB-CD34+cells significantly improved tubulointerstitial damage in adenine-induced kidney injury in mice via vasculoprotective and anti-inflammatory effects.

Apoptosis of Leukemia Cells Induced by CD34^+ Cells Transferred Exogenous Fas Ligand

To assess the value of CD34 + cells transferred exogenous Fas ligand (FasL) in inducing apoptosis of human leukemic cells, the CD34 + cells transfected with F asL or without, pretreated with mitomycin C, was mixed with leukemic cell line U937 cells in presence or absence of daunorubicin (DNR) or cytosine arabinoside (Ara C). After l8 h, apoptosis of cells was detected by FCM and TUNEL. Induced for l8 h by CD34 + cells transfected with FasL or without, the ratio of apoptos is of U937 cells was (5.0±1.3) %, (10.8±0.6) % ( P < 0.01), respectively. Induced by FasL +CD34 ++DNR, FasL +CD34 ++Ara C, the ratio was (13.4±1.0) % ( P < 0.05), (17.9±1.3)% ( P <0.01), respectively. The result demonstrated that CD34 + cells transfected with exogenous FasL could induce apoptosis of human leukemic cells and showed a cytotoxic synergistic effect when used in combination with chemotherapeutic drugs, suggesting that it was possible to develop a new method in treatment of leukemia.

Separation of CD34 Positive Cells and Determination of Surface Homing Antigen

To study the differences in homing potential between bone marrow cells and umbilical blood cells, CD34 positive cells were obtained from bone marrow (BM) and umbilical blood (UB) by the direct cell separation with domestic immunomagnetic beads. The expression of the two adhesion molecules CD11a/CD18 and CD44 were examined. After separation, CD34 positive cells accounted for 51 %-82 % of the harvested cells and dye-resistance rate was 82 %-88 %. The expression of CD11a/CD18 and CD44 on the surfaces of UB cells was 49. 6 % 1 10. 2 % and 37. 7 % ± 10. 3 % respectively. On BM cells they were 50. 2 % ± 6. 2 % and 34 % ± 13. 3 % respectively. There were no significant differences in the expression of these two molecules. It was concluded .that the cell separation method with domestic immunomagnetic beads was effective and the stem cells from UB could serve as an alternative source for transplantation.

Effect of Homoharringtonine on Bone Morrow CD34^+CD7^+ Cells in Chronic Granulocytic Leukemia

Objective： To explore the effect of homoharringtonine （HHT） on bone morrow CD34^＋CD7^＋ cells in chronic granulocytic leukemia （CGL）. Methods： The changes of bone morrow CD34^＋CD7^＋ cells were observed after the treatment of HHT in 23 cases with CGL. The proliferation and apoptosis of CD34^＋CD7^＋ cells treated with HHT in vitro were studied. Results： The proportion of CD34^＋CD7^＋ cells in CGL （0.145±0.021） was higher than that of normal control （0.052±0.013）. The proportion of CD34^＋CD7^＋ cells in patients who got cytogenetic responses to HHT （0.072±0.020） decreased remarkably, but not in those patients who did not got cytogenetic responses to HHT, （0.137±0.023）. the proliferation of CD34^＋ cells was inhibited and the proportion of CD34^＋CD7^＋ cells decreased after cultured with HHT （0.134 in 24 h, 0.126 in 48 h and 0.102 in 72）. The apoptosis rate of CD34^＋CD7^＋ cells was higher than that in CD34^＋CDT cells （35.39%±4.39% versus 24.57%±4.01%, P〈0.05） 72 h after culture with HHT. Conclusion： The proportion of CD34^＋CD7^＋ cells in CGL was higher than that of normal control and HHT may inhibit the proliferation and induce apoptosis of bone marrow CD34^＋CD7^＋ cells.

Selective Depletion of the Allo-Antigen Specific T Cells by Fas/FasL Pathway by Cytokine IFN-γ and IL-2

To investigate the value of apoptosis of the allo antigen specific T cells induced by Fas/FasL pathway in preventing graft versus host disease (GVHD), the CD34 + cells transfected with FasL or not, used as stimulus cells, were mixed with allo antigen specific T lymphocytes in presence or absence of IFN γand IL 2. After 5 days, apoptosis of T cells was detected by TdT nick end mediated dUTP labeling (TUNEL) and flow cytometry (FCM). The affects of these two cytokines on CD34 + cells in the graft were also compared. The ratio of apoptosis of T cells was 12.1±1.5 % when CD34 + cells transfected with FasL was used as stimulus cells, much higher than that of CD34 + cells non transfected (3.2 ±1.1 %, P <0.01). And in presence of IFN γ or IL 2, the ratio reached 20.1±2.3 %, 17.6±1.3 % respectively ( P <0.01). However, IFN γ up regulated Fas expression of CD34 + cells and increased the sensibility of CD34 + cells to soluble FasL(sFasL); IL 2 showed no such affect. It is possible to induce apoptosis of the allo antigen specific T cells of grafts activated by allo antigen by exogenous Fas ligand expressed on recipient cells and this might provide a new approach for preventing GVHD and IL 2 may be more suitable for clinical application.

An Effective Method for Depleting MatureT Lymphocytes from Bone Marrow Cells──Two－step Percoll Centrifugation

In the present paper we have observed the effect of discontinuous gradient two-step Percoll centrifugation on depleting mature T lymphocytes from normal bone marrow. The pre-/post-Percoll percentage of CD34+, and Leu4+ cells in MNC was counted by using APAAP technique. As the two-step Percoll centrifugation is simple,and time saving, and decreases the incidence of contamination of cultured cells as well,This technique may be of value in serum-free culture of hematopoietic cells and immunological studies.

Efficacy and long-term evaluation of intramyocardial injection of autologous CD34-enriched PBMSC in old myocardial infarction

Aims: We have shown that autologous transplant of CD34+-enriched peripheral-blood mononuclear cells (PBMSC) could restore depressed myocardial function, and sustain adequate myocardial function 12 months after surgery in patients with old (>one year-old) myocardial infarction. Our aim is to report the long-term morbidity and mortality efficacy of this procedure. Methods and results: Seventy patients with an old anteroseptal myocardial infarction were followed for 2 to 7 years, 35 had a revascularization procedure and received an intra-myocardial injection of autologous CD34+-enriched PBMSC (8 × 108 mononuclear cells/ml including 3 × 107 CD34+ cells/ml)(Group A). Group B patients only had the revascularization. Abnormal pre-surgical values of LVEF (33.2% ± 4.8%), LVDV (178 ± 13.7 ml), LVSV (120 ± 16 m), LVDD (58.9 ± 3.84 mm), E and A waves without contractility in infarction area in group A patients improved to approximate normal values (50% ± 3% for LVEF;90 ± 9.3 ml for LVDV;80 ± 9.9 ml for LVSV;55.3 ± 3 mm for LVDD;5.2 ± 0.5 cm/s for E wave and 4.18 ± 0.3 cm/s for A wave) 1 year after the procedure and have remained unaltered for all the follow-up period. All the patients remain alive. Only seven patients have been readmitted to the hospital for non-myocardial related events. Group B only 11 patients continued alive to 5 years after surgery and LEVF never increased more than 6%, all of them with many hospitalizations (n ≥ 10) by heart failure events. Conclusion: Intramyocardial injection of CD34+ highly enriched PBSC represent an encouraging alternative for patients with severely scarred and dysfunctional myocardium.

Effect of intracranial transplantation of CD34^+ cells derived from human umbilical cord blood in rats with cerebral ischemia

As a source of transplantable stem cells, the CD34^＋ subpopulation in human umbilical cord blood （HUCB） has been used extensively to treat some hematopoietic system diseases. However, whether CD34^＋ cells hold the therapeutic potential to cerebral ischemia is unknown. The purpose of this study was to observe the recovery of neural function after transplantation of CD34^＋ cells derived from HUCB into ischemic cerebral tissue in rats.

LONG-TERM EFFECT OF HOMOHARRINGTONINE ON CHRONIC GRANULOCYTIC LEUKEMIA

Objective: To observe the long-term effect of homoharringtonine (HHT) on chronic granulocytic leukemia (CGL) and its pharmacological mechanism. Methods: 76 patients with newly diagnosed early chronic phase CGL received treatment of merely 1.5 mg/m2 daily HHT for induction remission and long-term maintenance treatment. The apoptosis rate of bone marrow CD34+ cells induced by HHT was assayed with flow cytometer. Results: 86.8% patients achieved CHR, 13.2% patients PHR and 31.8% patients got cytogenetic response in HHT treatment group, which was longer than 31 (8-54) months in hydroxyurea (HU) group (P<0.05). The effect of apoptosis induction HHT was stronger on CGL-CP patients bone marrow CD34+ cells than on normal person bone marrow CD34+ cells. Conclusion: HHT is a very effective drug for remission induction and long-term maintenance treatment in early chronic phase CGL patients.

Expansion of CD34^+ cells from human umbilical cord blood by FL and/or TPO gene transfected human marrow stromal cell lines

To elucidate the effect of gene transfected marrow stromal cell on expansion of human cord blood CD34+ cells, a culture system was established in which FL and TPO genes were transfected into human stromal cell line HFCL. To establish gene transfected stromal cells co-culture system, cord blood CD34+ cells were purified by using a magnetic beads sorting system. The number of all cells and the number of CD34+ cells and CFC (CFU-GM and BFU-E) were counted in different culture systems. The results showed that in all 8 culture systems, SCF+IL-3+HFT manifested the most potent combination, with the number of total nucleated cells increasing by (893.3±52.1)-fold, total progenitor cells (CFC) by (74.5±5.2)-fold and CD34+ cells by 15.7-fold.Maximal expansions of CFC and CD34+ cells were observed at the end of the second week of culture. Within 14 days of culture, (78.1 ± 5.5)-fold and (57.0 ± 19.7)-fold increases in CFU-GM and BFU-E were obtained. Moreover, generation of LTC-IC from amplified CD34+ cells within 28 days was found only in two combinations, I.e. SCF+IL-3+FL+TPO and SCF+IL-3+HFT, and there was no significant difference between these two groups statistically. These results suggest that human umbilical cord blood CD34+ cells can be extensively expanded ex vivo by using gene transfected stromal cells along with cytokines.

Functional expression of CD95/Fas Antigen and Bcl-2 on Cord bloodHematopoietic Progenitor Cell

The cell surface expression and functional status of the CD95/Fas antigen on primitive hematopoietic progenitors isolated from human cord blood (CB) were studied. The CD34 + cells freshly isolated from CB displayed low CD95 expression. The combinations of cytokines such as SCF+FL could up regulate the expression of CD95 in vitro culture and tumor necrosis factor α (TNF α) and interon γ (IFN γ) further increased the CD95 expression induced by positive cytokines. The functional status of CD95 mediated apoptosis were analyzed by incubation of CD34 +CB cells in the presence of anti CD95 monoclonal antibodies (McAbs). The effects of anti CD95 McAbs were measured by viable cell counting, flow cytometry, LTIC and CFU C assays. A decrease of viable cells, CFU C and LTIC numbers were observed in the presence of anti CD95 McAbs and TNF α or IFN γ. However, growth factor deprivation or the early acting cytokine such as SCF and FL cross linking to CD95 caused low apoptosis of CD34 + cells. The correlation of increased intracytoplasmic levels of bcl 2 and the presence of CD95 on fresh CB CD34 + cells suggested that bcl 2 might be involved in protecting against CD95 mediated apoptosis of CB CD34 + cells.

Oocyte-like cells induced from CD34-positive mouse hair follicle stem cells in vitro

Adult stem cells have been identified in a variety of mammalian organs including skin, hair follicles, pancreas, and bone marrow （Kruse et al., 2004）. These stem cells reside in a specific cellular environment where they remain in an undifferentiated state （Theise, 2006）. In addition, they are generally considered to be mul- tipotent, possessing the capacity to generate multiple cell types within the tissue, and thus play an important role in tissue mainte- nance and regeneration.

Retroviral transduction of a mutant erbB-2 gene into human CD34^+ derived dendritic cells

Objective To successfully transduce a mutant erbB 2 gene into normal human CD34 + derived dendritic cells (DCs) and verify gene expression in these transduced dendritic cells Methods The packaging cell line PA317 was transfected with mutant erbB 2 gene DNA and the virus produced was used to infect packaging cell line PG13 The virus produced by PG13 was used to infect CD34 + derived dendritic cells by the spinoculation method using flasks coated with fibronectin material to facilitate retrovirus gene transter efficiency and the mutant erbB 2 gene expression was assessed by ABC staining and FACScan methods Results A mutant erbB 2 gene packaging cell line was produced and this mutant gene was transduced into human CD34 + derived DCs It was verified that the relatively large numbers of the transduced DCs expressed the mutant erbB 2 protein which was eradicated of the ability to transform mouse NIH3T3 fibroblast cells Conclusions Human DCs can be gene modified and these gene modified DCs may be useful in stimulating T lymphocytes for immunotherapy

Relationship of Cell Compositions in AIIografts with Outcomes after Haploidentical Transplantation for Acquired Severe Aplastic Anemia： Effects of CD34＋ and CD14＋ Cell Doses

Background： The dose of certain cell types in allografts affects engraftment kinetics and clinical outcomes after allogeneic stem cell transplantation （SCT）. Hence, the present study investigated the association of cell compositions in allografts with outcomes after unmanipulated haploidentical SCT （haplo-SCT） for patients with acquired severe aplastic anemia （SAA）. Methods： A total of 131 patients with SAA who underwent haplo-SCT were retrospectively enrolled. Cell subsets in allografts were determined using flow cytometry. To analyze the association of cellular compositions and outcomes, Mann-Whitney U nonparametric tests were conducted for patient age, sex, weight, human leukocyte antigen mismatched loci, ABO-matched status, patient ABO blood type, donor-recipient sex match, donor-recipient relationship, and each graft component. Multivariate analysis was performed using logistic regression to determine independent influence factors involving dichotomous variables selected from the univariate analysis. Results： A total of 126 patients （97.7%） achieved neutrophil engraftment, and 121 patients （95.7%） achieved platelet engraftment. At 100 days after transplantation, the cumulative incidence of II-IV acute graft-versus-host disease （GVHD） was 32.6%. After a median follow-up of 842 （range： 124-4110） days for surviving patients, the cumulative incidence of total chronic GVHD at 3 years after transplantation was 33.7%. The probability of overall survival at 3 years was 83.0%. Multivariate analysis showed that higher total doses of CD14＋ （P = 0.018） and CD34＋ cells （P 〈 0.001） were associated with a successful platelet engraftment. A successthl platelet was associated with superior survival （P 〈 0.001）. No correlation of other cell components with outcomes was observed. Conclusions： These results provide evidence and explain that higher doses ofCD34＋ and CD 14＋ cells in haploidentical allografts positively affect platelet engraftment, contributing to superior survival for patients with SAA.

Increased circulating of myeloid-derived suppressor cells in myelodysplastic syndrome

Myelodysplastic syndrome （MDS） is a group of clonal .hematopoietic stem cell disorders, characterizedby varying degrees ot peripheral cytopema caused by ineffective dysplasia of the myeloid lineages. MDS also has a high risk of progression to acute myeloid leukemia. But the role of immune abnormalities in the pathogenesis of MDS is still not clear. Myeloid-derived suppressor cells （MDSCs） constitute a heterogeneous population of immature cells derived from the bone marrow. In the recent years, MDSCs were reported to play an important role in suppressing lymphocytes in tumor-bearing animal models and cancer patients. This could be one of the mechanisms on tumor immune evasion, which aggravates the development and growth of tumors. In a mice model, MDSCs are characterized by co- expression of GR1 and CDllb. In humans, the phenotype of MDSCs was accepted as Lin- HLA-DR- CD33＋.l In the present study, we investigated the level of circulating MDSCs （Lin- HLA-DR- CD33＋） in patients with MDS and evaluated the association between MDSCs and malignancy in MDS. METHODS Patients Thirty-five patients with MDS （24 men and 11 women, median age 59 years （age range 21-83）, including refractory anemia （n=3）; refractory anemia with ringed sideroblasts （n=3）; refractory cytopenia with multilineage dysplasia （n=9）; refractory anemia with excess blast-I （n=4）; refractory anemia with excess blast-II （n=16））, and without other systemic diseases, were enrolled in the present study. All the patients underwent diagnosis in the Department of Hematology, General Hospital of Tianjin Medical University from March 2011 to April 2012, according to the diagnostic criteria of MDS proposed between 2007 and 2008. After treatment for three months, 14 MDS patients were investigated again for their MDSCs changes. Twenty normal healthy individuals were selected as controls （9 men and 11 women, median age 34 years （age range 26-82））. The study was approved by the Ethics Committee of Tianjin Medical University. Informed written consent was obtained from all the patients and normalindividuals in accordance with the Declaration of Helsinki Flow cytometric analysis Peripheral blood samples were collected in EDTA- anticoagulant tubes from the patients and normal individuals. The number of circulating MDSCs was measured by using flow cytometry （FCM） assay. The markers used in the assay were anti-CD33-APC, anti-LIN- FITC （CD3, CD14, CD16, CD19, CD20, CD56） and anti- HLA-DR-PE antibodies （BD Biosciences, USA）. The number of stem cells from the bone marrow, which was collected in heparin-anticoagulant tubes, was measured by FCM using anti-CD34-PerCP antibodies （BD Biosciences）. Data acquisition and analysis were carried out by using FACS-Calibur flow cytometer （BD Biosciences）, with the Cell Quest software （Becton Dickinson, version 3.1）.

Negative association of donor age with CD34＋ cell dose in mixture allografts of G-CSF-primed bone marrow and G-CSF-mobilized peripheral blood harvests

Background The effects of donor characteristics on CD34＋ cell dose remain controversial. Recently, we developed a novel haploidentical transplant protocol, in which mixture allografts of granulocyte colony-stimulating factor （G-CSF）- primed bone marrow （G-BM） and G-CSF-mobilized peripheral blood （G-PB） were used. The aim of this study was to investigate the effects of donor characteristics on CD34＋ cell dose in mixture allografts of G-BM and G-PB. Methods A total of 162 healthy adult donors, who underwent bone marrow harvest and peripheral blood collection between January 2009 and November 2010 in Peking University People＇s Hospital, were prospectively investigated. G-CSF was administered subcutaneously at a dose of 5 pg/kg once a day for 5-6 consecutive days. Bone marrow and peripheral blood stem cells were harvested on the fourth day and fifth day, respectively. A final total CD34＋ cell dose less than 2× 106 cells/kg recipient body weight was considered a poor mobilization. Results Of the 162 donors, 31 （19.1%） did not attain this threshold. The obtained median CD34＋ cell doses in bone marrow, peripheral blood, and mixture allografts were 0.83×106/kg, 2.40×106/kg, and 3.47×106/kg, respectively. Multiple regression analysis showed that donor age had a significant negative effect on CD34＋ cell dose in either G-BM, or G-PB, or mixture allografts of G-BM and G-PB. And a 1-year increase in age was associated with a 5.6% decrease in the odds of achieving mobilization cutoff. No significant correlation was found for donor gender, body mass index （BMI）, and weight. Conclusion Donor age is the only factor among the four parameters, including age, gender, weight, and BMI, that influence CD34＋ cell dose in mixture allografts of G-BM and G-PB, and younger donors should be chosen to obtain sufficient CD34＋ cells for transplantation.