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Bone marrow-derived dendritic cells (BM-DCs) are generated from bone marrow (BM) cells cultured with granulocyte macrophage-colony stimulating factor (GM-CSF) for a week. In this study we investigated the effect of duration on the BM culture with GM-CSF. Within several months, the cells in the BM culture gradually expressed homogeneous levels of CD11c and major histocompatibility complex II on surface, and they became unable to stimulate allogeneic naïve T cells in mixed lymphocyte reaction (MLR). In addition, when the BM culture were sustained for 32 wk or longer, the BM cells acquired ability to suppress the proliferation of allogeneic T cells in MLR as well as the response of ovalbumin-specific OT-I transgenic T cells in antigen-dependent manner. We found that, except for programmed death-ligand 1, most cell surface molecules were expressed lower in the BM cells cultured with GM-CSF for the extended duration. These results indicate that BM cells in the extended culture with GM-CSF undergo 2 distinct steps of functional change; first, they lose the immunostimulatory capacity; and next, they gain the immunosuppressive ability.
Subject(s)
Bone Marrow , Dendritic Cells , Granulocyte-Macrophage Colony-Stimulating Factor , Granulocytes , Immunosuppression Therapy , Lymphocyte Culture Test, Mixed , Major Histocompatibility Complex , T-LymphocytesABSTRACT
Objective To observe the function of immature CD8α+ dentritic cells (DCs) in vitro. Methods The bone marrow and spleen of C57BL/6(H-2b) and Balb/c (H-2d) mice were got to prepare immature CD8α+ DCs and spleen lymphocytes,and treated by mytomycin. MTT test was used.MLR group, MLR plus variable density syngeneic CD8α+ DC group, MLR plus variable density allogeneic CD8α+ DC group,MLR plus variable density CD8α+ DC supernatant group,CD8α+ DC plus syngeneic T cell group and negative control group were established. MLR group was set up by responder cell ratio of 0.2,0.5,0.8,1.0,to build the MLR plus syngeneic and allogeneic CD8α+ DC experimental groups. Culture supernatant from different density (1 × 105/ml - 5 × 106/ml) of CD8α+DCs was added into MLR to build CD8α+ DC supernatant group. CD8α+ DCs were co-cultured with syngeneic T cells to build CD8α+ DCs plus syngeneic T cells group. 2 × 105/well responder cells served as the negative control group. ELISA was used to detect the concentrations of IFN-γ and IL-10 in the DCs could both suppress MLR (P＜0. 05), and the difference was not statistically significant (P＞0. 05). When CD8α+ DCs were increased, the suppressive effect was enhanced. When CD8α+ DC/responder cell ratio ＞0. 2, the inhibitory effect could be observed, and this effect reached the peak when the ratio was 1.0. The CD8α+ DCs had weak ability to stimulate syngeneic lymphocyte proliferation in vitro, and certain stimulating effect could be seen only when CD8α+ DC/responder cell ratio ＞2 (P＜0. 05). Its culture supernatant also showed suppressive effect (P＜0. 05), and the supernatant with a cell density of 5 × 105/ml showed the maximum effect. IL-10 concentration in the concentration was 1.0 ± 1.2 pg/ml. Conclusion The in vitro function of immature CD8α+ DCs was immunosuppression/tolerance,and they could secret high level of IL-10. The CD8α+ DCs and their culture supernatant could suppress MLR in vitro.
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Objective To explore the feasibility of mediating recipient lymphocyte reaction with donor dendritic cells (DCs) in renal allograft recipients. Methods Donor bone marrow monocytes (BMMCs) were isolated and cryopreserved in liquid nitrogen before kidney transplantation. At 0 day, 1month,3 month, 6 month and 9 month post-operation, CD34+ cells which were isolated from frozen BMMCs and cultured into DCs as well as the peripheral blood lymphocytes (PBLs) of donors were used as the stimulating cells to the PBLs of recipients and healthy volunteers. The number of viable DCs from frozen- and room temperature-preserved BMMCs was counted and the reactions of recipients'and healthy volunteers' lymphocytes to DCs and donor PBLs were measured. Results 6. 8 × 107BMMCs were isolated from each 10 ml of donor bone marrow on average while (4. 10 ± 0. 58) × 105CD34+ cells were isolated by magnetic active cell sorting (MACS). There was no significant difference in the isolating rate of recovered CD34+ cells at each observation point postoperatively. The percentage of viable BMMCs and CD34+ was decreased significantly at 1 month after surgery, then, decreased slowly and progressively. The decreasing rate of BMMCs was higher than CD34+. The rate of viable DCs was maintained stable (93. 2%-94. 8% ) in each group. The reactions of recipients' and healthy volunteers' lymphocytes to DCs were stronger than those to donor PBLs (P＜0. 05). The reactions of healthy volunteers' lymphocytes to DCs were maintained stable while those of recipients' were fluctuating. Conclusion Bone marrow-derived DCs are superior to PBLs in mediating long-term lymphocyte reaction after kidney transplantation due to their stable viability and stimulating ability to lymphocytes. Only once collection of a small quality of bone marrow of donors is needed to meet the demand of immune monitoring at any time after transplantation.
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Objective To establish a economic and stable method to induce and culture dendritic cells (DCs) from peripheral blood of human being, and compare with the magnetic activated cell sorting. Methods Monocytes were isolated from health donors peripheral blood mononuclear cells(PBMC) by density gradient separation,cultured and compared with that of cells isolated by the magnetic activated cell sorting or adherent culture,respectively. PBMC were cultured with recombinant human granulocyte macrophage colony stimulating factor (rhGM-CSF) and recombinant human interleukin-4(rhIL-4) for 6 days to induce the growth of DCs. Morphological changes was observed under inverted microscope. Meanwhile, cell viability was tested at the 3rd, 5th, 6th day,respectively. The phenotypes, like CD14, CDla, HLA-DR were analyzed with flow cytometry after PBMC were adherent cultured for 1, 2, 5 h. After adding human recombinant cytokines, the phenotypes of acquired cells surface markers, CD14, CD1a, CD86, CD83 and HLA-DR would be detected and compared with flow cytometry. T cells proliferating activity was determined by allogeneic mixed lymphocyte reaction in vitro. Results After adherent culture for 2 h, the acquired DCs showed typical morphology. Cell viability was decreased at days 5th, 6th[(53.333 ±5.774)%,(38.333 ± 7.638)%] than that at day of 3rd[(68.667 ± 3.215)%, all P ＜ 0.05] with the magnetic activated cell sorting, but with adherent culture method, the difference was not statistically significant (F = 0.737,P＞ 0.05) at days of 3rd, 5th, 6th[(92.667 ± 3.055)%,(94.000 ± 1.000)%,(94.667 ± 1.528)%]. Moreover,compared with the magnetic activated cell sorting, there were differences in cell viability of adherent culture method at days of 3rd, 5th, 6th(t = 9.374, 12.021,12.527, all P ＜ 0.05). Before and after using the magnetic activated cell sorting, the expression of CD14 were (32.457 ± 12.351) %, (41.914 ± 14.858)%, respectively. The difference was not statistically significant(t = 1.295, P ＞ 0.05). After culturing for 2 h, the expression of CD14[(35.267 ± 4.658)%]was higher than those of culturing for 1, 5 h[(15.033 ± 6.189)%, (21.233 ± 4.895)%, all P ＜ 0.05]. Compared with the 1st day[(32.328 ± 14.517)%], the CD14 expression level[(2.200 ± 1.356)%] on surface of DCs was significantly reduced(t = 5.467, P ＜ 0.05) at the 6th day of culturing, the CD1a expression level[(43.371 ±16.250)%] was remarkablely increased than that of the 1st day[(12.300 ± 6.223)%, t = 2.545, P ＜ 0.05];while the expressions of CD86, CD83, HLA-DR[(16.857 ± 5.686)%,(9.343 ± 5.230)%,(72.800 ± 17.881)%] were similar(t = 0.652,1.137,0.907, all P ＞ 0.05) compared with that of the 1st day[(12.550 ± 16.758)%, (6.250 ±1.323)%, (64.671 ± 15.588)%]. In mixed lymphocytes reactions, with increasing of lymphocytes, T lymphocytes proliferating activities were reduced. In the magnetic activated cell sorting, when the ratio of DCs and lymphocytes were 1: 50, 1: 100, cells proliferation ability(1.502 ± 0.055,1.507 ± 0.029) were lower than that of ratio of 1: 10(1.859 ± 0.049, all P ＜ 0.05);in adherent culture method, the ratio of DCs and lymphocytes was 1: 100, the cells proliferation ability(1.545 ± 0.066) was decreased than that of ratio 1: 10(2.015 ± 0.301, P ＜ 0.05). When the proportion of DCs and lymphocytes remained the same, the capacity to stimulate T lymphocyte was similar of the two methods(P ＞ 0.05). Conclusions Comparied with the magnetic activated cell sorting, after culture of PBMC for 2 h the induction of DCs can produce better formed and functional cells, and this method is stable, simple,economic, and is a suitable method for basic and clinical research of DCs in vitro.
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Objective To investigate the immunomodulatory effect of mesenchymal stem cells (MSCs) and their role in prolonging allograft survival in rat heart transplantation. Methods Inbred Wistar rats were used as donors, and Fisher 344 as recipients. MSC were isolated from femur and tibia bone marrow of donors and cultured in vitro. Mixed lymphocyte reaction assays were performed to assess the immunosuppressive effects of different concentrations of MSC on allogeneic T cell proliferation. Cardiac allograft model was established and according to different intervention measures recipients were divided into two groups (MSC treatment group and control group) (n=8 in each group). In MSC treatment group, recipients were infused with 2×106 MSC via the tail vein at designated intervals (one week before operation, during operation and consecutive three days postoperation), while in control group, the recipients were treated with Ringer's solution at the same interval& At day 5 posttransplantation real-time PCR was used to detect the changes in the expression of Thl and Th2 cytokine genes in transplanted hearts. Results In vitro allogeneic T cell response was greatly suppressed by MSC in a dose-dependent manner. Real-time PCR revealed that IL-1β,IFN-γ, IL-4 and IL-10 were expressed in MSC treatment group, while IL-4 and IL-10 were not expressed in control group but with significantly higher expression of IL-1β and IFN-γ. As compared with control group, survival of MSC-treated allografts was markedly prolonged as compared with control group (mean survivaldays: 12.4±5.3 vs 6.4±2.0, P＜0.05). Conclusion Intravenous adrninistmtion of MSC can prolong the survival of transplanted heart possibly by induction of allograft tolerance through changing Th1/Th2 balance.
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Objective To explore effect of fetal lymphocyte on pathogenesis of intrahepatic cholestasis of pregnancy(ICP).Methods Twenty pregnant women with ICP and 20 normal pregnant women were enrolled in the study.The single mixed lymphocyte culture/reaction(MLC/MLR)was conducted using inactive lymphocyte obtained from maternal peripheral blood and lymphocyte of cord blood from fetus.Antigen-induced-lymphocyte-proliferation-reaction was used for dermic soluble antigen and decidual soluble antigen obtained from maternal blood and cord blood from fetus.The intense of proliferation was calculated and compared between normal and ICP-complicated pregnancies.Results(1)The level of intense of proliferation of fetal lymphocyte was significantly increased in ICP group 2.75?0.36 than those of normal control group 1.45?0.19 in single mixed lymphocyte culture(P＜0.05).(2)The level of intense of proliferation of fetal lymphocyte was significantly increased in ICP group 1.45?0.19 than those of normal control group 0.67?0.24 in decidual soluble antigen induced lymphocyte proliferation reaction(P＜0.05). (3)The level of intense of proliferation of fetal lymphocyte was significantly increased in ICP group(1.22?0.44)than those of normal control group(0.66?0.27)in dermic soluble antigen induced lymphocyte proliferation reaction.Conclusions(1)The fetal lymphocyte may be one of the effector cells in pathogenesis of ICP.(2)The disturbance of fatal-maternal immune-tolerance is one of the important mechanisms underlying ICP.
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Objective To explore the difference of immunosuppresive effect between the expanded Stro-1+ and Stro-1-subgroups of human mesenchymal stem cells in vitro. Methods Mononuclear cells (MNCs) were isolated from bone marrow (BM) samples and seeded in a T-75 cm2 tissue culture flask contained with Dexter medium. When 50% confluence was obtained, adherent cells were collected and incubated with anti-stro-1 antibody, and the Stro-1+ and Stro-1-MSCs were further seeded for expansion. The total culture time (median) was 15 days. Cells were then analyzed by flow cytometry. One-way mix lymphocyte reaction (MLR) (1?105 responding cells and an equal number of stimulating cells/well were co-cultured in 96-well plates) and nonspecific mitogenic stimuli phytohemagglutinin (PHA) plus interleukin-2 (IL-2) induced lymphocytes proliferation (PBL 1?105/well were mixed with PHA 10?g/ml and IL-2 500U/ml in 96-well culture plates) were established in vitro. 1?103-3?104 irradiated Stro-1+ MSCs and Stro-1-MSCs were added into the two systems at the beginning of reaction. Immunosuppressive actions of both Stro-1+ or Stro-1-MSCs were compared. Results Adherent cells contained a median of 9% (range 5%-26%) Stro-1+ cells, which expressed higher immunophenotype of MSCs. In both reaction systems, suppressive actions occurred in a dose-dependent fashion when whatever Stro-1+ MSC or Stro-1-MSC were added. However, that the addition of 1?103 Stro-1-cells enhanced rather than inhibited the lymphocyte proliferation in one-way MLR. In the presence of various concentrations of MSCs, Stro-1+ MSCs always showed a significantly increased inhibitory effects in comparison to Stro-1-MSCs (P
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Objective To observe the biological activity of the recombinant immunotoxin hIL-2-LuffinP1 derived by gene engineering in vitro.Methods To observe the inhibitory effect on lymphocytes in vitro,the splenocytes isolated from C57 and BALB/c mice were used for mixed mouse lymphocyte response(MLR),and the lymphocyte proliferation was observed in vitro with BALB/c mice splenocytes stimulated by concanavalin A(ConA).Different concentrations of hIL-2-LuffinP1 was added into the reaction system,with LuffinP1 adopted as control.3H-TdR incorporation assay was used to detect the effects of hIL-2-LuffinP1 on lymphocyte proliferation,and its effects on CTLL-2 cells(IL-2 dependent cells) were also observed.The experiments consisted of six groups(PBS,IL-2,LuffinP1,LuffinP1+IL-2,hIL-2-LuffinP1 and hIL-2-LuffinP1+IL-2).CTLL-2 cells were cultured for 12h after being treated with different agents,and then the cells were stained by trypan blue to estimate the dead cells in every 100 cells.Results It was showed that CPM declined correspondingly to the gradually increased concentration of hIL-2-LuffinP1,and cell proliferation was inhibited obviously.The inhibition rate was up to 97% at the concentration of 10-6mmol/L of hIL-2-LuffinP1.The activity of inhibiting lymphocyte proliferation was proportional to the dosage.On the contrary,no obvious inhibition to lymphocyte proliferation was found in the control group treated with LuffinP1,the inhibition ratio only reached to 14% with the same concentration of hIL-2-LuffinP1.It was also found that,when hIL-2-LuffinP1 and LuffinP1 in different concentrations added to spleen cells stimulated by ConA,hIL-2-LuffinP1 still exhibited strong ability of inhibition on the splenocyte proliferation,while LuffinP1 has no obvious inhibiting effect on the lymphocyte proliferation in the two reaction systems mentioned above.MLR showed the same results.Furthermore,in the experiment of cytotoxic effects of IL-2-LuffinP1 on CTLL-2 cells,the inhibition rates of hIL-2-LuffinP1+IL-2 group and hIL-2-LuffinP1 group were 29.6% and 47.4% respectively,the difference was significant compared with IL-2 group(P