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1.
This study was to determine whether BMDCs cultured in the presence of IL-10 (G/10-DCs) could promote T cell tolerance and prevent autoimmune diabetes in two different animal models of T1D. Our results showed that G/10-DCs suppressed both insulitis and spontaneous diabetes in NOD and HLA-DQ8/RIP-B7.1 mice. The suppression was likely to be mediated by T cells, as we found that regulatory CD4(+)CD25(+)Foxp3(+) cells were significantly increased in G/10-DC treated animals. In vivo, the G/10-DCs inhibited diabetogenic T cell proliferation; in vitro, they had reduced expression of costimulatory molecules and produced little IL-12/23 p40 or IL-6 but a large amount of IL-10 when compared with DCs matured in the presence of IL-4 (G/4-DC). We conclude that IL-10-treated DCs are tolerogenic and induce islet-directed immune tolerance, which was likely to be mediated by T regulatory cells. This non-antigen-specific DC-based approach offers potential for a new therapeutic intervention in T1D.  相似文献   

2.
RNA interference (RNAi), a process that specifically silences target gene expression, is a powerful technique to modulate cellular functions. In this study, we identified two small interference RNA (siRNA) sequences that can specifically and efficiently silence the expression of the granulocyte colony-stimulating factor receptor (GCSF-R) gene and achieved stable knockdown of GCSF-R using pFIV lentivirus containing the GCSF-R siRNA. GCSF-R knockdown significantly reduces the expression of IL-lalpha, IL-lbeta, IL-6, IL-10, H-2Kb, I-Ab, CD80 and CD86, and increases PDL1 and PDL2 expression, while IL-12p35, TGFbeta, TNFalpha and CD40 expression is unaltered. Furthermore, GCSF-R knockdown significantly changes the endocytosis and micro-pinocytosis abilities as well as surface expression of antigens of DC2.4 cells.  相似文献   

3.
目的:研究可溶性小鼠CD83(mCD83)对树突状细胞(DC)表达共刺激分子及共刺激活性的影响。方法:克隆mCD83基因,构建mCD83胞外功能区与人IgG1αFc段融合基因的真核表达载体pmCD83-hIg,并在COS-7细胞中表达可溶性mCD83-hIg融合蛋白。采用ELISA、Western blot和RT-PCR技术检测mCD83-hIg融合基因在COS-7细胞中的表达。用mCD83-hIg处理小鼠DC细胞系(DC2.4)采用流式细胞术检测DC细胞周期、细胞凋亡和共刺激分子CD80、CD86的表达影响;采用混合白细胞培养试验,检测mCD83-hIg对DC2.4刺激同种异基因T细胞增殖及产生IL-2和IFN-γ的影响。结果:酶切和序列测定鉴定显示构建的真核表达载体完全正确;mCD83-hIg对DC2.4细胞周期和细胞凋亡无影响,但可下调DC2.4表面共刺激分子CD80和CD86的表达;mCD83-hIg处理过的DC2.4刺激同种异基因T细胞增殖及产生IL-2和IFN-γ的能力显著下降。结论:mCD83-hIg可抑制DC表达共刺激分子并下调DC共刺激活性,从而抑制同种异基因T细胞增殖和产生细胞因子。  相似文献   

4.
Invariant natural killer T (iNKT) cells are a distinct lineage of innate-like T lymphocytes and converging studies in mouse models have demonstrated the protective role of iNKT cells in the development of type 1 diabetes. Recently, a new subset of iNKT cells, producing high levels of the pro-inflammatory cytokine IL-17, has been identified (iNKT17 cells). Since this cytokine has been implicated in several autoimmune diseases, we have analyzed iNKT17 cell frequency, absolute number and phenotypes in the pancreas and lymphoid organs in non-obese diabetic (NOD) mice. The role of iNKT17 cells in the development of diabetes was investigated using transfer experiments. NOD mice exhibit a higher frequency and absolute number of iNKT17 cells in the lymphoid organs as compared with C57BL/6 mice. iNKT17 cells infiltrate the pancreas of NOD mice where they express IL-17 mRNA. Contrary to the protective role of CD4(+) iNKT cells, the CD4(-) iNKT cell population, which contains iNKT17 cells, enhances the incidence of diabetes. Treatment with a blocking anti-IL-17 antibody prevents the exacerbation of the disease. This study reveals that different iNKT cell subsets play distinct roles in the regulation of type 1 diabetes and iNKT17 cells, which are abundant in NOD mice, exacerbate diabetes development.  相似文献   

5.
A deficit in IL-4 production has been previously reported in both diabetic human patients and non-obese diabetic (NOD) mice. In addition, re-introducing IL-4 into NOD mice systemically, or as a transgene, led to a beneficial outcome in most studies. Here, we show that prediabetic, 12-week old female NOD mice have a deficit in IL-4 expression in the pancreatic lymph nodes (PLN) compared to age-matched diabetes-resistant NOD.B10 mice. By bioluminescence imaging, we demonstrated that the PLN was preferentially targeted by bone marrow-derived dendritic cells (DCs) following intravenous (IV) administration. Following IV injection of DCs transduced to express IL-4 (DC/IL-4) into 12-week old NOD mice, it was possible to significantly delay or prevent the onset of hyperglycemia. We then focused on the PLN to monitor, by microarray analysis, changes in gene expression induced by DC/IL-4 and observed a rapid normalization of the expression of many genes, that were otherwise under-expressed compared to NOD.B10 PLN. The protective effect of DC/IL-4 required both MHC and IL-4 expression by the DCs. Thus, adoptive cellular therapy, using DCs modified to express IL-4, offers an effective, tissue-targeted cellular therapy to prevent diabetes in NOD mice at an advanced stage of pre-diabetes, and may offer a safe approach to consider for treatment of high risk human pre-diabetic patients.  相似文献   

6.
Previously, we showed that transgenic expression of the MHC (major histocompatibility complex) class II I-E molecules prevented insulitis in non-obese diabetic (NOD) mice at the age of 19 weeks. To rule out the possibility that the I-E expression merely delays the onset of insulitis, we have further characterized the expression and function of the I-E molecule expressed in transgenic NOD mice and confirmed our previous observations. Northern blot analysis showed that the transgenic E alpha d gene was expressed in a pattern similar to the endogenous E alpha d gene in BALB/c mice. The newly expressed I-E molecules were recognized as an alloantigen by the T lymphocytes of normal NOD mice as shown by mixed lymphocyte reaction (MLR). Transgenic NOD mice were resistant to the treatment by cyclophosphamide, which effectively induces diabetes in normal NOD mice, and did not develop diabetes up to 40 weeks of age. On the basis of these findings, we discuss the role of I-E molecules in the prevention of diabetes in NOD mice.  相似文献   

7.
目的 通过检测哮喘小鼠肺组织中树突状细胞(dendritic cells,DC)表面共刺激分子的表达以及细胞因子分泌的能力,探讨哮喘发生免疫耐受缺陷的原因.方法 Balb/c小鼠60只,分为3组(每组20只):哮喘组、磷酸盐缓冲液(PBS)对照组、健康对照组.对3组小鼠取肺组织做病理观察,行支气管肺泡灌洗液(BALF)计数细胞并分类,ELISA检测血清特异性IgE(sIgE)及BALF中细胞因子的水平.分离、培养肺脏DC,用流式细胞仪(FACS)测CD11c表达,并进一步用FACS分析哮喘小鼠DC表面共刺激分子CD11cCD80、CD11cCD86表达的变化.结果 哮喘小鼠肺组织表现为以嗜酸性粒细胞、淋巴细胞浸润为主的炎症改变,BALF中嗜酸性粒细胞计数显著增加(P<0.01),血清sIgE水平显著升高(P<0.01).与PBS对照组比较,哮喘小鼠CD11cCD80、CD11cCD86表达上调(P<0.01),其分泌IL-10细胞因子的水平明显下降.结论 肺脏DC可能通过上调CD11cCD80、CD11cCD86在哮喘的免疫耐受缺陷中发挥作用.  相似文献   

8.
Despite encouraging results in the NOD mouse, type 1 diabetes prevention trials using subcutaneous insulin have been unsuccessful. To explain these discrepancies, 3-week-old NOD mice were treated for 7 weeks with subcutaneous insulin at two different doses: a high dose (0.5 U/mouse) used in previous mouse studies; and a low dose (0.005 U/mouse) equivalent to that used in human trials. Effects on insulitis and diabetes were monitored along with immune and metabolic modifications. Low-dose insulin did not have any effect on disease incidence. High-dose treatment delayed but did not prevent diabetes, with reduced insulitis reappearing once insulin discontinued. This effect was not associated with significant immune changes in islet infiltrates, either in terms of cell composition or frequency and IFN-γ secretion of islet-reactive CD8(+) T cells recognizing the immunodominant epitopes insulin B(15-23) and islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP)(206-214). Delayed diabetes and insulitis were associated with lower blood glucose and endogenous C-peptide levels, which rapidly returned to normal upon treatment discontinuation. In conclusion, high- but not low-dose prophylactic insulin treatment delays diabetes onset and is associated with metabolic changes suggestive of β-cell "rest" which do not persist beyond treatment. These findings have important implications for designing insulin-based prevention trials.  相似文献   

9.
目的:分析羊胎盘免疫调节因子(GPIF)对BALB/c小鼠T淋巴细胞共刺激表面抗原分子表达及其细胞因子分泌的影响,探讨羊胎盘免疫调节因子免疫促进作用机理。方法: 60Coγ-ray辐射所致免疫抑制小鼠连续7 d腹腔注射GPIF,流式细胞分析术分析BALB/c小鼠脾细胞表达CD28+、CD152+单阳性细胞百分率,表达CD4+CD28+、CD8+CD28+、CD4+CD152+、CD8+CD152+双阳性细胞百分率;ELISA法检测小鼠血清IL-2、IFN-γ分泌水平。结果: 羊胎盘免疫调节因子显著提高免疫损伤小鼠脾淋巴细胞CD28+、CD4+CD28+、CD8+CD28+阳性细胞百分率(P<0.05,P<0.01),降低CD152+、CD4+CD152+阳性细胞百分率(P<0.05,P<0.01),提高小鼠血清IL-2、IFN-γ分泌水平(P<0.01)。结论: 羊胎盘免疫调节因子的免疫促进作用与其调节T淋巴细胞CD28、CD152共刺激分子通路的活化信号传递,降低T淋巴细胞的功能抑制,促进T淋巴细胞的活化有关。活化的T淋巴细胞分泌细胞因子IL-2、IFN-γ,参与细胞因子介导的免疫网络调节。  相似文献   

10.
目的 :分析过继转输的小鼠胚胎抗原耐受T细胞内细胞因子及细胞表面协同刺激分子的表达特征。方法 :以♀CBA/J×♂DBA/ 2为自然流产模型 ,将自然流产模型CBA/J孕鼠于孕 4天 (着床期 )分别腹腔注射大鼠抗小鼠CD80和CD86mAb或大鼠同型IgG。于孕 9天 ,应用免疫磁珠阴性分选两组孕鼠的脾脏T细胞 ,将T细胞进行碳氧氢化荧光素双乙酸盐琥珀酰亚胺酯 (CFSE)体外荧光标记 ,再分别过继转输至孕 4天的CBA/J×DBA/ 2孕鼠。在宿主孕鼠孕第 9天 ,处死小鼠取脾细胞 ,用流式细胞术分析在DBA/ 2父系抗原刺激下过继转输的T细胞细胞因子IL 2、IL 4、IL 10和IFN γ及协同刺激分子CD2 8和CTLA 4的表达。结果 :与过继转输的胚胎抗原非耐受T细胞相比 ,过继转输的胚胎抗原耐受T细胞IL 10的表达显著增加 ,IL 2和IFN γ的表达则显著下降 (P <0 0 5 ) ,IL 4的表达无明显改变 (P >0 0 5 ) ;细胞表面CD2 8的表达显著下降 ,而CTLA 4的表达却显著增加 (P <0 0 5 )。结论 :过继转输的小鼠胚胎抗原耐受T细胞内Th2型细胞因子和表面CTLA 4表达上调 ,而Th1型细胞因子和表面CD2 8的表达则下降。胚胎抗原耐受T细胞通过Th2型细胞因子表达优势和协同刺激信号降调节 ,在母 胎免疫耐受的维持中发挥着重要作用。  相似文献   

11.
Type 1 diabetes results from the breakdown of peripheral tolerance. As regulators of T cell activation, antigen-presenting cells (APC) modulate peripheral tolerance and hence contribute to the immune dysregulation characteristic of insulin-dependent diabetes mellitus (IDDM). We initially observed an increased importance of NOD B cell APC function in a T cell priming assay as compared to non-autoimmune strains. Consistent with this increased APC function, we found that NF-kappa B nuclear translocation is increased in unmanipulated NOD and NOD.B10Sn-H2(b) B cells and that, in addition, NOD B cells are more sensitive to NF-kappa B-activating stimuli. We obtained similar results using NOD bone marrow-derived dendritic cell (BMDC) cultures. As costimulatory molecules have been shown to be NF-kappa B responsive, we examined the expression of these markers on NOD APC. Both B cells and BMDC expressed elevated levels of CD80 and CD40. Finally, NOD B cells provided better allostimulation than B cells from non-autoimmune strains. Therefore, hyperactivation of NF-kappa B and increased expression of CD80 and CD40 by NOD B cells and BMDC may be a contributing factor in the selection of effector T cells observed in IDDM.  相似文献   

12.
Immunization with autoantigenic peptides skews T cell responses in type 1 diabetes (T1D), yet the gene-expression signature characterizing this change is unclear. We used cDNA microarray technology to identify genes differentially regulated in splenocytes of T1D prone NOD mice after immunization with a disease protective glutamic acid decarboxylase 65 (GAD(65) P14) peptide. We identified 96 genes involved in cytokine secretion, humoral immune response, T cell activation, signal transduction, cell proliferation, complement activation and inflammatory responses. Up-regulation of seven chemokine and cytokine genes confirmed our previous findings of increased interferon-gamma (IFN-gamma) secretion, which may lead to a protective response in T1D. Hierarchical clustering was used to organize treated and control groups on the basis of their overall similarity in gene-expression patterns, suggesting association or co-regulation. Semi-quantitative RT-PCR was used to confirm the expression of selected genes in spleen and pancreatic draining lymph nodes. These findings can be used to compare other immunization strategies affecting the expression of these genes and explore their mechanisms of action. This microarray-based study, thus, unravels the molecular mechanism of beta-cell associated autoantigenic peptide immunization in T1D prone NOD mice, paving the way for identification of diagnostic markers and drug targets for modulating immune responses in T1D.  相似文献   

13.
Despite tuberculosis resurgence and extensive dendritic cell (DC) research, there are no in vivo studies evaluating DC within regional lymphoid tissue during airways infection with virulent Mycobacterium tuberculosis (Mtb) H37Rv. Using DC-specific antibodies, immunocytochemistry, flow cytometry and Ziehl-Neelsen (ZN) for bacilli staining, we searched for Mtb and DC changes within mediastinal lymph nodes, after intratracheal (ITT) inoculation of virulent Mtb. ZN and immunocytochemistry in frozen and paraffin sections of mediastinal lymph nodes identified Mtb until day 14 after ITT inoculation, associated with CD11c(+) and Dec205(+) DC. Analysing CD11c, MHC-CII, and Dec205 combinations by flow cytometry in MLN suspensions revealed that CD11c(+)/MHC-CII(+) and CD11c(+)/Dec205(+) DC did not increase until day 14, peaked on day 21, and sharply declined by day 28. No changes were seen in control, saline-inoculated animals. The costimulatory molecules evaluated in CD11c(+) DCs followed a similar trend; the CD80 increase was negligible, slightly surpassed by CD40. CD86 increased earlier and the three markers peaked at day 21, declining by day 28. While antigen-specific proliferation was not evident for MLN CD4(+) T cells at 2 weeks postinfection, delayed-type hypersensitivity responses upon ITT inoculation revealed that, as early as day 3 and 7, both the priming and peripheral systemic immune responses were clearly established, persisting until days 14-21. While airways infection with virulent Mtb triggers an early, systemic peripheral response maintained for three weeks, this seems dissociated from regional events within mediastinal lymph nodes, such as antigen-specific T-cell reactivity and a delay in the influx and local activation of DC.  相似文献   

14.
Langerhans cell histiocytosis (LCH) is a neoplastic disorder that results in clonal proliferation of cells with a Langerhans cell (LC) phenotype. The pathogenesis of LCH is still poorly understood. In the present study, serial analysis of gene expression (SAGE) was applied to LCs generated from umbilical cord blood CD34+ progenitor cells to identify LC-specific genes and the expression of these genes in LCH was investigated. Besides the expression of several genes known to be highly expressed in LCs and LCH such as CD1a, LYZ, and CD207, high expression of genes not previously reported to be expressed in LCs, such as GSN, MMP12, CCL17, and CCL22, was also identified. Further analysis of these genes by quantitative RT-PCR revealed high expression of FSCN1 and GSN in all 12 LCH cases analysed; of CD207, MMP12, CCL22, and CD1a in the majority of these cases; and CCL17 in three of the 12 cases. Immunohistochemistry confirmed protein expression in the majority of cases. The expression of MMP12 was most abundant in multi-system LCH, which is the LCH type with the worst prognosis. This suggests that expression of MMP12 may play a role in the progression of LCH. These data reveal new insight into the pathology of LCH and provide new starting points for further investigation of this clonal proliferative disorder.  相似文献   

15.
The effect of simultaneous blockade of adhesion molecules on the development of long-term resistance to type 1 diabetes was investigated in an adoptive transfer model in NOD mice. Splenocytes isolated from acutely diabetic NOD mice injected into NOD-scid mice caused diabetes at 43 +/- 5.0 days. Treatment with anti-alpha4-integrin monoclonal antibody (mAb) delayed the onset of insulitis and significantly delayed hyperglycemia to 66 +/- 5.8 days. Combination treatment with anti-alpha4-integrin and anti-LFA-1 mAbs delayed the onset of diabetes to >100 days (p<0.0001). Combination-treated mice were subjected to a second challenge with diabetogenic splenocytes after 85 days of normoglycemia. Without additional mAb treatment they developed hyperglycemia after significant delay (72 +/- 8.1 days post-reinoculation). Splenocytes from combination-treated mice transferred protection from diabetes to naive NOD-scid mice when co-transferred with diabetogenic splenocytes. The long-surviving mice showed periislet infiltration with CD62L+ cells, which were not seen in the insulitis developing in control animals. These findings suggest that adhesion molecule blockade does not prevent homing and may affect effector cell action through activation of immunoregulatory suppressor cells, leading to protection against development of diabetes.  相似文献   

16.
Levels of expression of costimulatory molecules have been proposed to influence the outcome of antigen-specific T cell priming. We found that Leishmania major selectively modulated the expression of costimulatory molecules on various populations of epidermal cells. B7.2 expression was down-regulated on Thy1.2+ epidermal cells (keratinocytes) from disease-resistant C3H mice, but not from disease-susceptible BALB/c mice. In addition, epidermal cells from BALB/c mice showed a down-regulation of B7.1 expression on NLDC 145+ Langerhans cells. In vitro T cell priming experiments, using syngeneic epidermal cells as antigen-presenting cells (APC), showed that the production of IFN-gamma was inhibited when either B7.1 or B7.2 signaling pathways were blocked. Blockade of B7.2, but not B7.1, significantly inhibited the ability of epidermal cells to induce IL-4 production from CD4+ T cells. In addition, C3H CD4+ T cells, which were unable to secrete detectable levels of IL-4 in cultures with syngeneic APC, were now able to secrete IL-4 following presentation of L. major antigens by congenic BALB/K epidermal cells. Conversely, C3H epidermal cells supported the priming of BALB/K CD4+ T cells for IL-4 production in vitro. Thus, the differential expression of B7 molecules on epidermal cells may not represent the sole factor governing the polarization of L. major-specific CD4+ T cells in vitro.  相似文献   

17.
Distinct subsets of dendritic cells (DCs) are present in blood, probably "en route" to different tissues. We have investigated the chemokines and adhesion molecules involved in the migration of myeloid (CD11c(+)) and plasmacytoid (CD123(+)) human peripheral blood DCs across vascular endothelium. Among blood DCs, the CD11c(+) subset vigorously migrated across endothelium in the absence of any chemotactic stimuli, whereas spontaneous migration of CD123(+) DCs was limited. In bare cell migration assays, myeloid DCs responded with great potency to several inflammatory and homeostatic chemokines, whereas plasmacytoid DCs responded poorly to all chemokines tested. In contrast, the presence of endothelium greatly favored transmigration of plasmacytoid DCs in response to CXCL12 (stromal cell-derived factor-1) and CCL5 (regulated on activation, normal T expressed and secreted). Myeloid DCs exhibited a very potent transendothelial migration in response to CXCL12, CCL5, and CCL2 (monocyte chemoattractant protein-1). Furthermore, we explored whether blood DCs acutely switch their pattern of migration to the lymph node-derived chemokine CCL21 (secondary lymphoid-tissue chemokine) in response to microbial stimuli [viral double-stranded (ds)RNA or bacterial CpG-DNA]. A synthetic dsRNA rapidly enhanced the response of CD11c(+) DCs to CCL21, whereas a longer stimulation with CpG-DNA was needed to trigger CD123(+) DCs responsive to CCL21. Use of blocking monoclonal antibodies to adhesion molecules revealed that both DC subsets used platelet endothelial cell adhesion molecule-1 to move across activated endothelium. CD123(+) DCs required beta(2) and beta(1) integrins to transmigrate, whereas CD11c(+) DCs may use integrin-independent mechanisms to migrate across activated endothelium.  相似文献   

18.
19.
Dendritic cells (DCs) play a pivotal role in the interface between immunity and maintenance of peripheral tolerance. The capture of immunoglobulin G (IgG)-containing immune complexes (ICs) by low-affinity Fcγ receptors (FcγRs) expressed on DCs may influence the immunogenicity/tolerogenicity of these cells, depending on the activating/inhibitory potential of FcγRs. Because of the key role that low-affinity FcγRs play in determining the magnitude of the response in IC-driven inflammation, these receptors are likely to play a role in autoimmune diseases, such as systemic lupus erythematosus (SLE). To evaluate if an altered expression of costimulatory molecules and/or FcγRs could account for disease severity, we evaluated the expression of these molecules on immature and mature DCs derived from peripheral blood monocytes of SLE patients and healthy donors. Our results show an increased expression of the costimulatory molecules CD40 and CD86. Furthermore, the ratio of CD86/CD80 is higher in SLE patients compared with healthy donors. Conversely, while the expression of activating FcγRs was higher on DCs from SLE patients, expression of inhibitory FcγRs was lower, compared with DCs obtained from healthy donors. As a result, the activating to inhibitory FcγR ratio was significantly higher in DCs from SLE patients. The altered ratio of activating/inhibitory FcγRs on mature DCs showed a significant correlation with the activity of SLE, as determined by the SLE Disease Activity Index (SLEDAI) score. We postulate that the increased ratio of activating/inhibitory FcγRs expressed on DCs from SLE patients can contribute to the failure of peripheral tolerance in the IC-mediated phase of autoimmune pathogenesis.  相似文献   

20.
探讨小鼠髓系树突状细胞(bone marrow-derived dendritic cells,BMDC)共刺激分子4-1BB及其配体4-1BBL表达的变化。将促DC成熟活化因子CD40L-CHO、TNF-α、LPS和IFN-γ,免疫负性调节因子IL-10以及各成熟活化因子与IL-10联合加入BMDC中,观察BMDC上4-1BB及4-1BBL表达的变化。结果显示,加入成熟活化因子的各组BMDC上4-1BB及4-1BBL表达与对照组相比有显著上调(P<0.05)。而IL-10组与对照组相比两者的表达显著下调(P<0.05),且各成熟活化因子与IL-10联合应用与单用IL-10组相比,BMDC上4-1BB和4-1BBL表达上调,有显著性差异(P<0.05)。提示成熟活化因子不仅能上调BMDC上4-1BB和4-1BBL的表达并且能有效拮抗mIL-10对BMDC上4-1BB和4-1BBL表达的下调作用。  相似文献   

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