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BACKGROUND: Bone marrow mesenchymal stem cells (BMSCs) can prolong the survival time of mice and baboons' alloskin graft and degrade acute and chronic graft-versus-host disease (GVHD) incidence after hematopoietic stem cell transplantation. But, at present there is no report that rat umbilical cord mesenchymal stem cells (UC-MSCs) reduced rejection response following heart transplantation. OBJECTIVE: To study the immunomodulatory effects of rat UC-MSCs on a model of allogeneic heart transplantation. METHODS: A total of 20 DA rats served as donors, and 20 Lewis rats as recipients. They were equally and randomly assigned to 2 groups: drug intervention and control groups (n=10). Using double cannulation, the left pulmonary artery and innominate artery of rat donors and external jugular vein and common carotid artery of rat recipients received end-to-end anastomosis under a microscope to establish heterotopic cardiac transplantation. One Wistar pregnant rat was selected to harvest UC-MSCs by collagenase digestion method. Following model establishment, rats in the cell transplantation group received UC-MSCs via caudal vein. Rats in the control group received sodium chloride. Survival time of the transplanted heart was determined. The transplanted heart received histopathology score using the acute rejection diagnosis criteria. Lymphocyte infiltration of transplanted heart was observed using hematoxylin-eosin staining. RESULTS AND CONCLUSION: Compared with the control group, the survival time of the transplanted heart was significantly longer in the cell transplantation group (P = 0.001), and the pathological score of acute rejection was significantly reduced (P = 0.000 4). There were lots of lymphocyte and monocyte infiltration in the myocardium in the control group. Little lymphocyte infiltration was detected in the myocardium in the cell transplantation group, with the presence of mild edema of myocardial interstitial substance. Results verified that rat UC-MSCs can induce immune tolerance of heart transplantation, soften immunological rejection and prolong xenograft survival.
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BACKGROUND:There are many studies concerning rat bone marrow mesenchymal stem cells for immune tolerance following transplantation and tissue repair.However,there are no reports on umbilical cord mesenchymal stem cells(UCMSCs).OBJECTIVE:To establish a method of separating mesenchymal stem cells(MSCs)from rat umbilical cord,and to study its biological characteristics.METHODS:MSCs were separated from rat umbilical cord with enzyme method and tissue mass method,and then incubated in DMEM-LG medium.Cell morphology was observed under an inverted microscope.Growth curves of cells were drawn using cell counting.Cell cycle and surface antigen were detected with flow cytometry.Adipogenic differentiation and osteogenic differentiation were tested by immunohistochemistry.RESULTS AND CONCLUSION:Both of the two methods could obtain plenty of MSCs from rat umbilical cord.Primary culture showed that the efficiency of enzyme method was higher than tissue mass method.Passage time of the former was about 10 days and the latter was 14 days.The passage time of latter except primary culture was the same.Immunophenotype analysis showed that MSCs from rat umbilical cord expressed adhesion molecule and stromal cell markers,CD90 and CD106,but did not express hematopoietic cell markers,CD34 and CD45.In vitro induction test verified that rat UCMSCs have the potentials of adipogenic and osteogenic differentiation.
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Objective Donor derived naive T cells initiated GVHD by contacting with,mesenchymal stem cells(MSC)have been used to prevent or treat graft-versus-host disease(GVHD).although we stiff puzzle about its mechanisms.Observe the effect of MSC on phenotypes of Naive T cell to study the mechanism of MSC immunomodulation. Methods After 3 passages, MSC Was incubated with Naive T cell differentiated from COrd blood CD+34 cells in vitro.Then the variances of naive T cell phenotypes were analyzed by flow cytometric.Results CD+8 T cells were relatively increased after 7 days co-culture with allogenic MSC when compared to control:(35.9±6.3)%VS(18.4±4.5)%.CD+8 CD+3 cells also showed the same trend (27.6±2.8)%vs(15.2±3.1)%.Conclusion MSC may partly reduce the incidence of GVHD by increase of CD+8 naive T cell.The result may provide new clue to explain immunoregulatory mechanism of MSC.
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BACKGROUND: Recently, a few studies have reported the correlation between transforming growth factor-α (TGF-α) and graft-versus-host disease (GVHD); however, the combination of TGF-α with other cytokines in patients with chronic or acute GVHD requires further study.OBJECTIVE: To analyze the changes of serum tumor necrosis factor-α (TNF-α), interleukin-4 (IL-4), and transforming growth factor-α (TGF-α) in leukemic patients after allogeneic hematopoietic stem cell transplantation (Allo-HSCT) and investigate the effects of these cytokines on different grades of GVHD.DESIGN: Case control study.SETTING: Department of Hematology, Organ Transplantation Center, the Second Affiliated Hospital, General Hospital of Chinese PLA; Department of Nuclear Medicine, the Second Affiliated Hospital, General Hospital of Chinese PLA.PARTICIPANTS: Forty-two leukemic patients (23 males and 19 females, 16-68 years old, mean age of 35 years) who underwent Allo-HSCT for the first time were selected from the Department of Hematology, Organ Transplantation Center, the Second Affiliated Hospital, General Hospital of Chinese PLA and Department of Transplantation, the 307 Hospital of Chinese PLA from June 2005 to June 2007. Twelve patients had acute granulocytic leukemia (AGL), fifteen patients had acute lymphocytic leukemia (ALL), and fifteen patients had chronic granulocytic leukemia (CGL). Among the 42 patients, 37 underwent peripheral blood transplantation and five received bone marrow transplantation. Twenty-one patients had acute GVHD (18 cases in grades Ⅰ-Ⅱ and three cases in grades Ⅲ-Ⅳ) after Allo-HSCT, but the other 21 patients did not. Fourteen patients had chronic GVHD (five cases of limited type and nine cases of extensive type), but the other 28 patients did not. An additional 30 healthy subjects (18 males and 12 females, 20-70 years old, mean age of 44 years) were collected as a normal control group. All patients provided confirmed consent, and the study was approved by the local ethics committee.METHODS: Levels of serum TNF-α, IL-4, and TGF-α in leukemic patients with Allo-HSCT and normal subjects were measured by radio-immuno-assay, the cytokines levels of the patients with/without acute GVHD, of those with/without chronic GVHD and of different grades of GVHD were compared.MAIN OUTCOME MEASURES: Comparisons of serum TNF-α, IL-4, and TGF-α among the groups.RESULTS: All 42 leukemic patients and 30 healthy subjects were included in the final analysis. Levels of TNF-α, IL-4, and TGF-α in patients with acute or chronic GVHD were significantly higher than those in the normal subjects (P<0.05-0.01). Levels of TNF-α and IL-4 in patients without acute GVHD were significantly higher than those in the normal subjects (P<0.01,0.05). Levels of TNF-α, IL-4, and TGF-α in patients with acute GVHD were significantly higher than those in patients without acute GVHD (P<0.05). Levels of TNF-α, IL-4, and TGF-α in patients with chronic GVHD were significantly higher than those in patients without chronic GVHD (P<0.05). Levels of serum TNF-α and TGF-α in patients with acute GVHD of grades Ⅲ-Ⅳ or chronic GVHD of extensive type were significantly higher than those in patients with acute GVHD of grades Ⅰ-Ⅱ or chronic GVHD of limited type (P<0.05-0.01).CONCLUSION: After Allo-HSCT, dynamically monitoring changes of levels of TNF-α, IL-4, and TGF-α may serve as a possible means of predicting the onset of acute or chronic GVHD and may contribute considerably to deciding clinical severity of GVHD.