Mesenchymal stem cell-mediated immature dendritic cells induce regulatory T cell-based immunosuppressive effect

Immature dendritic cells (imDCs) are increasingly viewed as mediators of T-cell tolerance. We investigated factors enabling induction of regulatory T (Treg) cells through syngeneic imDC/mesenchymal stem cell (MSC) co-cultures in vitro and immunosuppressive effects of MSC-mediated imDCs (MSCs were excluded after 72 h co-culture) in vivo. In these experiments, we found that Foxp3(+) Treg cell population remarkably increased after the T cell priming phase when splenocytes were co-cultured with both imDCs and MSCs, presumably inducing na?ve T cells into Treg cells by MSCs and imDCs. In parallel, TGF-β secretion was markedly induced from the imDC+MSC+splenocyte culture supernatant to a significant level at 72-h co-culture, compared to the MSC or imDC+splenocyte co-culture. Based on these results, using a murine melanoma tumor model, we confirmed that the subcutaneous injection of B16 cells induced a perfect tumor incidence in allogeneic recipients when MSC-mediated DCs were coinjected. Consequently, these results suggested that immune tolerance with MSC-mediated DCs leads to immunosuppression induced by at least Foxp3-specific Treg cells. This tool may be useful in clinical trials due to the yet unknown side effects of stem cell therapy.     

Prolonged survival effects induced by immature dendritic cells and regulatory T cells in a rat liver transplantation model

BackgroundDendritic cells (DCs) and regulatory T (Treg) cells are crucial for inducing immune tolerance. However, the suppressive function of infused Treg cells and immature DCs (imDCs) following solid organ transplantation remains unclear.MethodsImDCs derived from DA-donor rats and Treg cells isolated from spleens of Lewis rats were prepared. A heterotopic liver transplantation model was established to examine the immune tolerance effects of infusion of Treg-imDCs, imDCs and Treg cells individually. Th1/Th2 cytokines and TRAL were detected by ELISA. The overall rejection grade was assessed and the rejection activity index (RAI) was calculated. TUNEL-positive lymphocytes were detected in the portal area in liver sections.ResultsThe infusion of Treg-imDCs was more effective than imDCs or Treg cells individually. Moreover, the expression of IL-10 and TGF-β1 was significantly up-regulated, and IL-12 expression was significantly down-regulated, especially in the Treg-imDCs group. The percentage of TUNEL-positive cells was significantly higher in the Treg cells and imDCs groups. The RAI values in Treg-imDCs group on days 3 and 7 were lower than control, imDCs and Treg cells groups individually (p < 0.05). Both TBIL and ALT levels in the Treg-imDCs and imDCs groups were significantly lower than those of the control and Treg cells groups, and serum TRAL levels increased significantly 10 days after transplantation in the imDC and Treg-imDC groups compared with the control and Treg cells groups (P < 0.001).ConclusionThese data demonstrated that infusion of Treg cells and/or imDCs induces alloantigen tolerance and prolongs liver allograft survival. The infusion of Treg-imDCs was more effective than imDCs or Treg cells individually. ImDCs synergize with Treg cells in inducing and maintaining the feedback loop between imDCs and Treg cells in vivo.     

Notch1 modulates mesenchymal stem cells mediated regulatory T‐cell induction

Notch1 signaling is involved in regulatory T (Treg)‐cell differentiation. We previously demonstrated that, when cocultured with CD3⁺ cells, mesenchymal stem cells (MSCs) induced a T‐cell population with a regulatory phenotype. Here, we investigated the molecular mechanism underlying MSC induction of human Treg cells. We show that the Notch1 pathway is activated in CD4⁺ T cells cocultured with MSCs. Inhibition of Notch1 signaling through GSI‐I or the Notch1 neutralizing antibody reduced expression of HES1 (the Notch1 downstream target) and the percentage of MSC‐induced CD4⁺CD25^highFOXP3⁺ cells in vitro. Moreover, we demonstrate that FOXP3 is a downstream target of Notch signaling in human cells. No crosstalk between Notch1 and TGF‐β signaling pathways was observed in our experimental system. Together, these findings indicate that activation of the Notch1 pathway is a novel mechanism in the human Treg‐cell induction mediated by MSCs.     

Immunomodulatory function of regulatory dendritic cells induced by mesenchymal stem cells

Mesenchymal stem cells (MSCs) provide an excellent model for development of stem cell therapeutics, and their potential treatment in the immunopathogenic diseases have gained further interest after demonstration of immunomodulatory effects on complicated interactions between T cells and even dendritic cells (DCs). However, the mechanisms underlying these immunoregulatory effects of MSCs are poorly understood. In this study, we show that bone marrow derived MSCs can differentiate mature DCs (mDCs) into a distinct regulatory DC population. Compared with mDCs, they have lower expression of CD1a, CD80, CD86 and CD40, but higher expression of CD11b. MSCs induced DCs (MSC-DCs) can hardly stimulate T-cell proliferation even when MSC-DCs are stimulated by LPS. In addition, high endocytosic capacity, low immunogenicity, and strong immunoregulatory function of MSC-DCs are also observed. Moreover, MSC-DCs can efficiently generate CD4+CD25+Foxp3+ Treg cells from CD4+CD25-Foxp3-T cells. The inhibitory function of MSC-DCs is mediated not only through TGF-β1, but also by inducing the production of Treg cells or T-cell anergy. These results demonstrate that the immunomodulatory effects of regulatory DCs induced by MSCs provide efficacious treatment for immunopathogenic diseases.     

Mesenchymal stem cells from periapical lesions modulate differentiation and functional properties of monocyte‐derived dendritic cells

Immunoregulatory mechanisms within periapical lesions (PLs) are as of yet unexplored. Considering the crucial role of DCs in controlling the immune response within PLs, the immunomodulatory properties of mesenchymal stem cells (MSCs), and the colocalization of MSCs and DCs in situ, we wondered whether MSCs from PLs modulate the development and functions of DCs. Using a model of monocyte‐derived DCs, we showed that PL‐MSCs inhibited differentiation of DCs via soluble factors, of which IL‐6 had a minor effect, but did not impair their subsequent maturation induced by pro‐inflammatory cytokines. However, upon maturation such DCs favored the production of Th2/Th17 cytokines by allogenic CD4⁺ lymphocytes in coculture, compared with mature DCs differentiated without PL‐MSCs. PL‐MSC‐differentiated DCs, cultivated with pro‐inflammatory cytokines and PL‐MSCs, although phenotypically mature, exhibited poor allostimulatory activity, induced anergy, Th2 polarization, differentiation of suppressive CD4⁺CD25^highCD39⁺ Treg‐cell subsets via IDO‐1‐, ILT‐3‐, and ILT‐4‐dependent mechanisms, and increased production of TGF‐β in the coculture. In contrast, DCs cultivated with PL‐MSCs only during maturation stimulated proliferation and Th1 polarization of CD4⁺ T cells in an IL‐12‐independent manner. In conclusion, PL‐MSCs significantly modulate the development and functions of DCs, depending on the phase of DCs development during which the interaction occurs.     

Jagged1-expressing adenovirus-infected dendritic cells induce expansion of Foxp3+ regulatory T cells and alleviate T helper type 2-mediated allergic asthma in mice

Dendritic cells (DCs) are professional antigen-presenting cells that play a key role in directing T-cell responses. Regulatory T (Treg) cells possess an immunosuppressive ability to inhibit effector T-cell responses, and Notch ligand Jagged1 (Jag1) is implicated in Treg cell differentiation. In this study, we evaluated whether bone marrow-derived DCs genetically engineered to express Jag1 (Jag1-DCs) would affect the maturation and function of DCs in vitro and further investigated the immunoregulatory ability of Jag1-DCs to manipulate T helper type 2 (Th2) -mediated allergic asthma in mice. We produced Jag1-DCs by adenoviral transduction. Overexpression of Jag1 by ovalbumin (OVA) -stimulated Jag1-DCs exhibited increased expression of programmed cell death ligand 1 (PD-L1) and OX40L molecules. Subsequently, co-culture of these OVA-pulsed Jag1-DCs with allogeneic or syngeneic CD4⁺ T cells promoted the generation of Foxp3⁺ Treg cells, and blocking PD-L1 using specific antibodies partially reduced Treg cell expansion. Furthermore, adoptive transfer of OVA-pulsed Jag1-DCs to mice with OVA-induced asthma reduced allergen-specific immunoglobulin E production, airway hyperresponsiveness, airway inflammation, and secretion of Th2-type cytokines (interleukin-4, interleukin-5, and interleukin-13). Notably, an increased number of Foxp3⁺ Treg cells associated with enhanced levels of transforming growth factor-β production was observed in Jag1-DC-treated mice. These data indicate that transgenic expression of Jag1 by DCs promotes induction of Foxp3⁺ Treg cells, which ameliorated Th2-mediated allergic asthma in mice. Our study supports an attractive strategy to artificially generate immunoregulatory DCs and provides a novel approach for manipulating Th2 cell-driven deleterious immune diseases.     

瘦素预处理的MSC 体外调节SLE 患者淋巴细胞亚群的初步研究

目的:前期研究证实系统性红斑狼疮(SLE)患者血清异常升高的瘦素可加剧间充质干细胞(MSC)衰老,本研究旨在探讨瘦素预处理MSC 对淋巴细胞亚群免疫调节的变化情况。方法:分离脐带MSC,并收集SLE 患者外周血单个核细胞(PBMC),分为三组:PBMC 组,MSC+PBMC,瘦素(100 ng/ ml)预处理MSC 3 d+PBMC,1 .10 共培养3 d,收集悬浮细胞。流式细胞仪检测淋巴细胞亚群:CD4+ CD25+ Foxp3+调节性T(Treg)细胞、CD4+ IL-17+ Th17 细胞、CD4+ CXCR5+ PD-1+滤泡辅助T(Tfh)细胞、CD19+ B 细胞,并检测CD3+ T 细胞、CD19+ B 细胞表面CD25、CD69 平均荧光强度(MFI)。结果:与对照组相比,瘦素预处理的MSC 对Treg 细胞上调作用受损[(8.53±2.33)% vs (6.79±2.14)%,P<0.01],对Th17 细胞下调亦受影响[(1.28±0.70)%vs (1.64±0.55)%,P<0.01],Tfh 细胞比例有增加的趋势,但差异无统计学意义[(1.48±1.36) % vs (2.08±1.52)%,P =0.051]。与MSC 组比较,瘦素预处理组T 细胞活化分子CD25、CD69 表达增加。而在B 淋巴细胞活化指标,瘦素预处理后CD25 MFI 较前有升高[(19.16±3.62) vs (21.05±2.36),P<0.05],但对CD69 影响则无统计学差异。结论:瘦素体外作用于MSC,不仅使加剧其细胞衰老,亦损伤其对T、B 淋巴细胞的免疫调节能力。     

Monocyte-derived immature dendritic cells negatively regulate hepatic stellate cells in vitro by secreting IL-10

The development of liver fibrosis is associated with inflammatory responses resulting from chronic liver disease. Immature dendritic cells (imDCs) play an important role in modulating the inflammatory environment of the liver. This study investigated the effects of imDCs on the regulation of hepatic stellate cells (HSCs) during liver fibrosis. We isolated and induced imDCs from monocytes of healthy volunteers, activated LX-2 cells with TGF-β to establish in vivo liver fibrosis HSCs model, and then set up a cell co-culture system with transwell membranes. imDC surface markers and apoptosis rates of LX-2 cells were detected by flow cytometry. The concentration of IL-10 secreted by imDC was measured through ELISA. The expression of α-SMA in LX-2 after co-culture was examined by qRT?PCR. Proliferation of LX-2 cells were detected by CCK-8. The western blot was used to illustrate the LX-2 activation-related proteins such as Smad3/7 and TGF-β1. The imDCs co-culture group and the interleukin-10 (IL-10) treatment group had similar results, as they were both able to increase apoptosis, inhibit proliferation, downregulate α-SMA mRNA, and reduce TGF-β1 and Smad3 protein expression in LX-2 cells. Additionally, the Smad7 protein level was increased after treatment with imDC and IL-10. However, the results in the IL-10 antagonist group showed the opposite trend to that of imDCs and IL-10 groups. Thus, these results suggest that imDC secretion of IL-10 negatively regulates activated LX-2 cells, probably via inhibition of the TGF-β1/Smad3 pathway and increased expression of Smad7 protein. This may be a potential therapeutic target for liver fibrosis.     

P21‐activated kinase 2 is essential in maintenance of peripheral Foxp3+ regulatory T cells

The p21‐activated kinase 2 (Pak2), an effector molecule of the Rho family GTPases Rac and Cdc42, regulates diverse functions of T cells. Previously, we showed that Pak2 is required for development and maturation of T cells in the thymus, including thymus‐derived regulatory T (Treg) cells. However, whether Pak2 is required for the functions of various subsets of peripheral T cells, such as naive CD4 and helper T‐cell subsets including Foxp3⁺ Treg cells, is unknown. To determine the role of Pak2 in CD4 T cells in the periphery, we generated inducible Pak2 knockout (KO) mice, in which Pak2 was deleted in CD4 T cells acutely by administration of tamoxifen. Temporal deletion of Pak2 greatly reduced the number of Foxp3⁺ Treg cells, while minimally affecting the homeostasis of naive CD4 T cells. Pak2 was required for proliferation and Foxp3 expression of Foxp3⁺ Treg cells upon T‐cell receptor and interleukin‐2 stimulation, differentiation of in vitro induced Treg cells, and activation of naive CD4 T cells. Together, Pak2 is essential in maintaining the peripheral Treg cell pool by providing proliferation and maintenance signals to Foxp3⁺ Treg cells.     

ICOS controls Foxp3+ regulatory T‐cell expansion,maintenance and IL‐10 production during helminth infection

Foxp3⁺ regulatory T (Treg) cells are key immune regulators during helminth infections, and identifying the mechanisms governing their induction is of principal importance for the design of treatments for helminth infections, allergies and autoimmunity. Little is yet known regarding the co‐stimulatory environment that favours the development of Foxp3⁺ Treg‐cell responses during helminth infections. As recent evidence implicates the co‐stimulatory receptor ICOS in defining Foxp3⁺ Treg‐cell functions, we investigated the role of ICOS in helminth‐induced Foxp3⁺ Treg‐cell responses. Infection of ICOS^?/? mice with Heligmosomoides polygyrus or Schistosoma mansoni led to a reduced expansion and maintenance of Foxp3⁺ Treg cells. Moreover, during H. polygyrus infection, ICOS deficiency resulted in increased Foxp3⁺ Treg‐cell apoptosis, a Foxp3⁺ Treg‐cell specific impairment in IL‐10 production, and a failure to mount putatively adaptive Helios^?Foxp3⁺ Treg‐cell responses within the intestinal lamina propria. Impaired lamina propria Foxp3⁺ Treg‐cell responses were associated with increased production of IL‐4 and IL‐13 by CD4⁺ T cells, demonstrating that ICOS dominantly downregulates Type 2 responses at the infection site, sharply contrasting with its Type 2‐promoting effects within lymphoid tissue. Thus, ICOS regulates Type 2 immunity in a tissue‐specific manner, and plays a key role in driving Foxp3⁺ Treg‐cell expansion and function during helminth infections.     

间充质干细胞诱导小鼠CD8α+ CD11b+ jagged2high调节性树突状细胞的方法

目的:研究小鼠骨髓间充质干细胞(BMSCs)体外诱导CD8α+CD11b+jagged2high调节性树突状细胞(DCregs)的方法。方法:应用4种细胞因子体外刺激BALB/c(H-2d)小鼠骨髓有核细胞(BMCs)3 d,流式细胞术(FCM)分选树突状细胞(DCs),与BMSCs共培养10 d,诱导DCregs产生。FCM分析共培养前后DCs的表型、细胞周期及Notch信号通路中Jagged1、Jagged2配体的表达变化。结果:小鼠BMSCs在体外成功诱导新型DCs转变为DCregs,其CD86、CD80、CD40、MHC-II表达均明显下降(P<0.05),而CD205、Jagged1、Jag-ged2表达均明显上升(P<0.05);细胞周期中(G2+S)期细胞增加。结论:MSC可诱导DC细胞向DCregs转化,该MSC-DCregs具有致免疫耐受性表型,增殖能力提高;MSC诱导免疫耐受的机制可能与上调DC的Jagged1和Jagged2基因表达,激活T细胞Notch信号通路相关。     

Plasmodium yoelii infection of BALB/c mice results in expansion rather than induction of CD4+ Foxp3+ regulatory T cells

Recently, we demonstrated elevated numbers of CD4⁺ Foxp3⁺ regulatory T (Treg) cells in Plasmodium yoelii‐infected mice contributing to the regulation of anti‐malarial immune response. However, it remains unclear whether this increase in Treg cells is due to thymus‐derived Treg cell expansion or induction of Treg cells in the periphery. Here, we show that the frequency of Foxp3⁺ Treg cells expressing neuropilin‐1 (Nrp‐1) decreased at early time‐points during P. yoelii infection, whereas percentages of Helios⁺ Foxp3⁺ Treg cells remained unchanged. Both Foxp3⁺ Nrp‐1⁺ and Foxp3⁺ Nrp‐1^? Treg cells from P. yoelii‐infected mice exhibited a similar T‐cell receptor Vβ chain usage and methylation pattern in the Treg‐specific demethylation region within the foxp3 locus. Strikingly, we did not observe induction of Foxp3 expression in Foxp3^? T cells adoptively transferred to P. yoelii‐infected mice. Hence, our results suggest that P. yoelii infection triggered expansion of naturally occurring Treg cells rather than de novo induction of Foxp3⁺ Treg cells.     

Membrane‐bound Dickkopf‐1 in Foxp3+ regulatory T cells suppresses T‐cell‐mediated autoimmune colitis

Induction of tolerance is a key mechanism to maintain or to restore immunological homeostasis. Here we show that Foxp3⁺ regulatory T (Treg) cells use Dickkopf‐1 (DKK‐1) to regulate T‐cell‐mediated tolerance in the T‐cell‐mediated autoimmune colitis model. Treg cells from DKK‐1 hypomorphic doubleridge mice failed to control CD4⁺ T‐cell proliferation, resulting in CD4 T‐cell‐mediated autoimmune colitis. Thymus‐derived Treg cells showed a robust expression of DKK‐1 but not in naive or effector CD4 T cells. DKK‐1 expression in Foxp3⁺ Treg cells was further increased upon T‐cell receptor stimulation in vitro and in vivo. Interestingly, Foxp3⁺ Treg cells expressed DKK‐1 in the cell membrane and the functional inhibition of DKK‐1 using DKK‐1 monoclonal antibody abrogated the suppressor function of Foxp3⁺ Treg cells. DKK‐1 expression was dependent on de novo protein synthesis and regulated by the mitogen‐activated protein kinase pathway but not by the canonical Wnt pathway. Taken together, our results highlight membrane‐bound DKK‐1 as a novel Treg‐derived mediator to maintain immunological tolerance in T‐cell‐mediated autoimmune colitis.     

骨髓间充质干细胞对重症哮喘患儿外周血Th17/Treg的免疫调节作用

 目的：探讨骨髓间充质干细胞（MSCs）在体外对重度哮喘患儿外周血辅助性T细胞17（Th17）和CD4+ CD25+ 调节性T细胞（Treg）的免疫调节作用。方法：体外分离、培养和鉴定MSCs。MSCs经丝裂霉素处理后按不同比例（1∶1、1∶2、1∶10和1∶20）与哮喘患儿外周血T淋巴细胞（TLC）直接接触共培养,检测各组MSCs 对TLC的增殖调节作用。选取上述1∶2比例共培养体系和单独TLC培养体系,ELISA法分别检测Th17的效应分子白细胞介素17（IL-17）和Treg效应分子转化生长因子β（TGF-β）水平,qRT-PCR法检测转录因子维甲酸相关孤儿核受体（RORC）及叉头框蛋白3（Foxp3）mRNA表达水平。结果：MSCs可显著抑制重度哮喘患儿TLC增殖,且随着MSCs数量的增加,抑制作用增强。MSCs+TLC共培养组Th17转录因子RORC mRNA和效应因子IL-17表达较TLC组下降,同时TGF-β表达增高,而Treg细胞调控基因Foxp3 mRNA表达无明显改变。结论：MSCs在体外可能通过抑制Th17分化及IL-17的分泌,同时上调TGF-β的表达,进而有效改善哮喘患儿的Th17/Treg失衡状态。     

CTLA4-Ig modifies dendritic cells from mice with collagen-induced arthritis to increase the CD4+CD25+Foxp3+ regulatory T cell population

Cytotoxic T lymphocyte antigen-4 (CTLA4) and IgG fusion protein, CTLA4-Ig, is a therapeutic agent used for rheumatoid arthritis. It binds B7 molecules on dendritic cells (DCs) and thereby blocks B7/CD28 costimulatory interaction and inhibits effective T cell proliferation. However, the effect of CTLA4-Ig on the regulatory T cell (Treg) is still not known. In this study, we investigated the influence of CTLA4-Ig on the CD4+CD25+Foxp3+ Treg population in collagen-induced arthritis (CIA) mouse model. CTLA4-Ig suppressed CIA and increased the CD4+CD25+Foxp3+ Treg population in joint and spleen. When CD11c + DCs and CD4+T cells from CIA mice were cultured with anti-CD3, CTLA4-Ig increased the CD4+CD25 + Foxp3+ Treg population in a TGF-β-dependent manner. When CD11c + DCs from CIA mice were treated with CTLA4-Ig and adoptively transferred into CIA-induced mice, arthritis did not develop in association with the increase in CD4+CD25+Foxp3+ Treg population. However, in CTLA4-Ig-untreated DC-transferred CIA mice, arthritis developed and then rapidly progressed. Our study demonstrated that CTLA4-Ig suppressed CIA by modifying DCs from CIA mice into tolerogenic DCs to increase the CD4+CD25+Foxp3+ Treg population and this seems to be the new immune regulatory mechanism of CTLA4-Ig.     

Foxp3转染小鼠CD4+CD25-T细胞抑制NK细胞活性

目的： 通过逆转录病毒载体转染Foxp3基因到小鼠CD4+CD25-T细胞,以研究体外诱导获得的调节性T细胞对NK细胞免疫活性的调节作用及其机制。方法： 携带Foxp3基因的逆转录病毒转染初始CD4+CD25-T细胞,以获得持续性高表达Foxp3的CD4+ T细胞模型。CD4+Foxp3+ T细胞与NK细胞共培养后,用［51Cr］标记的YAC-1细胞检测NK细胞的杀伤毒性。在TGF-β阻断实验中,通过Transwell共培养实验以及向细胞共培养体系加入抗TGF-β抗体,并检测NK细胞杀伤毒性。结果：逆转录病毒转染初始CD4+CD25-T细胞,成功建立了表达Foxp3的CD4+T细胞模型,转染后1周Foxp3阳性表达的T细胞比例为38.0%。CD4+Foxp3+ T细胞在与NK细胞共培养的24 h和48 h后,对NK细胞的细胞毒性杀伤效应的抑制率分别为42.9%和22.7%。在CD4+Foxp3+ T细胞与NK细胞的共培养体系中加入抗TGF-β抗体后,其抑制率分别由原来的42.9%(24 h)、22.7%(48 h)变为3.2%(24 h)、2.1%(48 h)。在Transwell共培养实验中与NK细胞直接接触的Foxp3+CD4+T细胞可以诱导NK细胞免疫抑制,而没有直接接触的Foxp3+CD4+T细胞则不能抑制NK细胞的杀伤作用。结论：强制性表达Foxp3的CD4+CD25-T细胞可以在体外发挥免疫抑制作用,可以抑制NK细胞的细胞毒性杀伤作用。转染 Foxp3的CD4+CD25-T细胞对NK细胞发挥作用依赖于细胞之间的直接接触,与转染后T细胞表面表达TGF-β有关。     

Copulsing tumor antigen-pulsed dendritic cells with zoledronate efficiently enhance the expansion of tumor antigen-specific CD8+ T cells via Vgamma9gammadelta T cell activation

We demonstrate that Vgamma9gammadelta T cells activated by zoledronate can link innate and acquired immunity through crosstalk with dendritic cells (DCs) in a way that can amplify activation and proliferation of tumor antigen-specific CD8+ T cells. DCs pulsed with antigen alone or antigen plus zoledronate were used to stimulate the in vitro expansion of antigen-specific CD8+ T cells. MART-1-modified peptide (A27L peptide) and apoptotic HLA-A*0201-positive, MART-1-positive JCOCB tumor cell lines were used as tumor antigen sources. The percentage of A27L-specific CD8+ T cells within the responding lymphocytes on Day 7 when immature DCs (imDCs) were cultured in the presence of A27L peptide and 0.01 microM zoledronate was significantly higher (P=0.002, n=11) than that observed when imDCs were cultured with the lymphocytes in the presence of the A27L peptide alone. This enhancing effect of zoledronate was significantly reduced when gammadelta T cells were depleted from responding lymphocytes (P=0.030, n=5), indicating that the effect is mediated mainly through Vgamma9gammadelta T cells activated by zoledronate-pulsed imDCs. When imDCs copulsed with zoledronate and apoptotic JCOCB tumor cell lines were used, the percentage of A27L-specific CD8+ T cells was higher than that observed using imDCs with the apoptotic JCOCB lines alone, suggesting that zoledronate treatment of imDCs enhances the cross-presentation ability of DCs. These findings suggest a potentially valuable role for Vgamma9gammadelta T cell activation for expanding antigen-specific CD8+T cells using DCs copulsed with tumor antigen and zoledronate in the design of vaccine therapies for malignancy.     

Lewis肺癌细胞通过TLR9对CD4~+CD25~+Treg细胞影响的研究

目的:本研究以Lewis肺癌细胞为研究对象,探讨肿瘤细胞通过TLRs对CD4+CD25+Treg细胞的影响。方法:我们采用流式细胞术检测了Lewis肺癌细胞与脾淋巴细胞共培养系统中CD4+CD25+Treg细胞数量变化;通过RT-PCR方法检测了共培养对Foxp3和TLR1-9mRNA表达的影响;采用TLR9受体阻断剂氯喹阻断Lewis肺癌TLR9的表达。结果:与对照组相比,共培养组CD4+CD25+Treg细胞数量及Foxp3 mRNA表达均明显增高(P0.05);Lewis肺癌细胞与淋巴细胞共培养后可影响多种TLRs表达,其中TLR9 mRNA表达与对照组相比明显增高(P0.05),阻断Lewis肺癌细胞TLR9可明显降低CD4+CD25+Treg细胞数量及Foxp3 mRNA表达(P0.05)。结论:Lewis肺癌细胞可通过TLR9促进CD4+CD25+Treg细胞产生及功能增强,参与诱导肿瘤的免疫耐受,从而促进肿瘤的发生和发展。     

The epigenetic modification during the induction of Foxp3 with sodium butyrate

Context: CD4?+?CD25+ regulatory T (Treg) lymphocytes are critical for immune homeostasis. Foxp3 (Forkhead Box protein P3) is always considered as a marker of function and identities determination of Treg cells because of special occurring in Treg cell. People who lack Treg cells or have a low expression of Foxp3 gene will suffer fatal autoimmunity. Scientists are trying to use Treg cells as a treatment for autoimmune disease, such as systemic lupus erythematosus.

Objective: Our objective was to induce Foxp3?+?CD4+ T cells from naïve CD4?+?T cells isolated from C57 mice spleen in vitro using stimuli that include the short chain fatty acid sodium butyrate. Furthermore, to explore the relationship between Foxp3+ T cells induction and epigenetic modification, by observing the changes of Foxp3, Ezh2 (Enhancer of Zeste Homolog 2) and phosphorylated Ezh2 in the induced Treg cells.

Materials and methods: The naïve CD4+ T cells were separated from C57 mice spleen by immunomagnetic separation. Anti-CD28, anti-CD3, IL-2, TGF-β1, and sodium butyrate were added with proper concentration to induce Foxp3 expression during 72?hours. Then, we observed the effect of GSK126 (Ezh2 inhibitor) on the induction within the same over 72?hours duration. Then, western blot and Q-PCR were used to see the changes in gene/protein expression of Foxp3, Ezh2, and phosphorylated Ezh2.

Results: According to our results, group 3 that received full stimulus had a significant higher level of Foxp3 and Ezh2 expression (p?p?p?p?p?p?Conclusion: In this study, we were able to transform CD4?+?T cells into CD4?+?Foxp3?+?T cell by using stimulus like antibodies (anti-CD28, anti-CD3) and cytokines (IL-2, TGF-β1). Sodium butyrate contributes to CD4?+?Foxp3?+?T cell induction in vitro and at an optimum concentration of 5?mM. Sodium butyrate promotes expression of Ezh2 and Fxop3 of T cells in vitro; in addition, to lowering relative expression of phosphorylated Ezh2 probably be influencing some pathways like PI3K-Akt. Epigenetic modification is also thought to take essential part into the upregulation of Foxp3 from naïve CD4?+?Tcells.