早期和晚期凋亡细胞对骨髓源性不成熟DC影响的实验研究

目的 研究早期、晚期凋亡细胞对骨髓源性不成熟DC（imDC）的影响。方法 体外以紫外线照射诱导出早期凋亡细胞；将照射后的细胞在37℃，5％CO2条件下孵育10h，得到晚期凋亡细胞；在-70℃条件下反复冻融得到坏死细胞碎片。提取、纯化并培养骨髓源性imDC；分别以流式细胞仪、ELISA、^3H-TdR掺入的混合淋巴细胞反应等方法分析imDC吞噬早期、晚期凋亡细胞或坏死细胞碎片后在表达共刺激分子、分泌IL-12 p70以及刺激T淋巴细胞增殖等方面的差异。结果 imDC吞噬晚期凋亡或坏死细胞碎片后，明显趋于成熟，表现为MHCⅡ、CD40、CD80、CD86的表达均显著上调，分泌IL-12 p70增强，和T淋巴细胞混合培养后可以充分激活T淋巴细胞。而吞噬早期凋亡细胞后，仍然维持不成熟状态，表现为MHCⅡ、CD40、CD80、CD86的表达均维持于低水平，和培养中的imDC相比差异无统计学意义；分泌IL-12 p70的水平以及刺激T淋巴细胞增殖的能力均显著低于吞噬坏死细胞或晚期凋亡细胞后的DC，和培养中的imDC相比差异无统计学意义。结论 早期凋亡细胞和晚期凋亡细胞的性质完全不同，晚期凋亡细胞可以充分活化抗原提呈细胞，并进一步激活T淋巴细胞，而早期凋亡细胞没有这种活化作用。     

对早期凋亡细胞的吞噬抑制T淋巴细胞活化的实验研究

目的:研究早期凋亡细胞及吞噬早期凋亡细胞的巨噬细胞对T淋巴细胞活化的影响。方法:体外以紫外线照射,诱导出早期凋亡的Jurkat细胞;建立早期凋亡细胞的吞噬模型;ELISA法分析早期凋亡细胞对LPS刺激下巨噬细胞分泌细胞因子的影响及在早期凋亡细胞和吞噬了早期凋亡细胞的巨噬细胞干预下,ConA刺激T淋巴细胞活化后CD69、CD25、CD71表达的变化。结果:巨噬细胞吞噬了早期凋亡细胞后,抑制性细胞因子(TGF_β1)的分泌明显上调,并且在一定程度上抑制了ConA刺激下的T淋巴细胞活化;具体表现为CD69、CD25、CD71等T淋巴细胞活化标志的表达受到明显抑制。当加入TGF_β1中和抗体后,这种抑制作用消失。结论:巨噬细胞吞噬了早期凋亡细胞后抑制ConA刺激下的T淋巴细胞CD69、CD25、CD71的表达,这种抑制作用依赖于的TGF_β1分泌增强。     

负载滋养层细胞抗原对小鼠树突状细胞表型及功能的影响

目的 研究负载滋养层细胞抗原对小鼠髓源性树突状细胞(DC)分化成熟过程的影响,获得致耐受性DC.方法 体外使用粒细胞巨细胞集落刺激因子(GM-CSF)诱导小鼠骨髓细胞定向分化、经LPS刺激获得成熟DC;通过外胎盘锥组织块培养法获得滋养层细胞,制备可溶性抗原,加入DC培养体系.流式细胞术检测DC表面共刺激分子及MHC-Ⅱ的表达,ELISA法检测DC分泌IL-10和IL-12的浓度,混合淋巴细胞培养评估 DC刺激同种T细胞增殖、活化的功能.结果 成熟DC表型为CD40high CD80highCD86highMHC-Ⅱhigh,分泌大量的IL-12和极少量的IL-10 ,体外能有效刺激T细胞的增殖;负载滋养层细胞抗原的DC表型为CD40midCD80lo wCD86lowMHC-Ⅱlow,在分泌大量IL-12的同时IL-10也明显升高,不能有效刺激T细胞增殖,并使T细胞分泌细胞因子呈现明显Th2偏倚.结论 负载滋养层细胞抗原后的DC表面共刺激分子及MHC-Ⅱ表达降低,刺激T细胞增殖能力下降;其自分泌和促使T细胞旁分泌的细胞因子呈现Th2偏倚,是一种耐受性DC.     

结核分枝杆菌Rv2986c对小鼠树突状细胞成熟和功能的影响

目的探索结核分枝杆菌Rv2986c蛋白诱导小鼠树突状细胞成熟及Na?ve CD4~+T细胞极化的作用。方法克隆表达Rv2986c蛋白,用纯化后的蛋白刺激小鼠树突状细胞,流式检测树突状细胞MHC-Ⅱ表面分子,ELISA检测培养上清中IL-6和IL-12p40分泌情况。将Na?ve CD4~+T细胞与经Rv2986c刺激后的树突状细胞共培养,检测培养上清中IFN-γ的分泌水平。结果成功克隆表达了Rv2986c蛋白。经Rv2986c蛋白刺激后,树突状细胞MHC-Ⅱ表面分子表达水平显著增高,IL-6和IL-12p40释放水平显著升高。淋巴细胞共培养上清液中IFN-γ分泌量显著增加。结论结核分枝杆菌蛋白Rv2986c能促进小鼠树突状细胞成熟,激活抗原递呈作用,诱导CD4~+T向Th1型极化。     

孕酮对人树突状细胞成熟和免疫功能的影响

目的：研究孕酮（P₄）对人外周血来源树突状细胞（DCs）成熟和免疫学功能的影响。方法：在人外周血来源DCs体外培养时加入两种浓度的P₄ (10-7 mol/L和10-6 mol/L)处理，光镜和电镜下观察DCs的生成情况及形态变化，以流式细胞仪分析各组细胞的免疫表型，用ELISA方法测定其分泌的IL-10和IL-12水平，［3H］-TdR掺入法检测体外混合淋巴细胞反应中DCs刺激同种反应性T细胞的增殖能力。结果：加入P4培养后, DCs树突状和膜面状伪足减少，表达低水平MHC-II分子和共刺激分子CD40、CD80和CD86，其分泌的IL-10水平升高，IL-12水平明显下降，DCs刺激同种反应性T细胞的功能显著下降。结论：P₄抑制人外周血来源DCs的成熟，对其免疫学功能具有负性调节作用。     

microRNA-27a对树突状细胞表型及功能的影响

目的:研究microRNA-27a(miR-27a)对脂多糖(Lipopolysaccharide,LPS)刺激的小鼠树突状细胞(Dendritic cell,DC)的成熟和细胞因子分泌的影响。方法:小鼠骨髓来源的未成熟树突状细胞(immature dendritic cell,im DC)转染miR-27a的模拟物(miR-27a mimics)后,用LPS刺激24 h,采用流式细胞仪检测其表面共刺激分子CD80、CD86及MHCⅡ表达,ELISA方法检测其上清中的IL-12p70及IL-10蛋白水平,RT-PCR方法检测其细胞内IL-12p40及IL-10 mRNA水平,混合淋巴细胞反应(MLR)检测其刺激T细胞增殖能力。结果:与未处理的im DC比较,LPS刺激24 h后的DC表面的共刺激分子CD80、CD86及MHCⅡ表达均显著增高(均P0.001);LPS刺激24 h后,与对照组比较,转染miR-27a mimics细胞的共刺激分子CD80、CD86及MHCⅡ表达均显著降低(均P0.001),且显著抑制IL-12分泌(P0.01)、促进IL-10分泌(P0.05),并显著减弱LPS刺激的DC促CD4+T细胞增殖的能力(P0.01)。结论:miR-27a影响小鼠树突状细胞的成熟以及细胞因子的分泌。     

烟草烟雾提取物促进髓样树突状细胞共刺激分子的表达北大核心CSCD

目的通过体外实验研究烟草烟雾提取物(CSE)对小鼠髓样树突状细胞(mDC)成熟的影响及可能的机制。方法小鼠骨髓来源的单个核细胞加入粒-单集落刺激因子(GM-CSF)、白细胞介素-4(IL-4)和含100 mL/L胎牛血清的RPMI1640培养液诱导出可供实验用的高纯度的未成熟DC(iDC),分空白对照组和CSE刺激组;CSE刺激组按15 mL/L的终浓度加入CSE,两组继续培养24 h,流式细胞检测技术检测mDC的共刺激分子CD40、CD80、CD86和MHC-Ⅱ的表达。结果空白对照组的mDC低表达CD40、CD80、CD86和MHC-Ⅱ;CSE刺激后mDC表达CD40、CD80和MHC-Ⅱ比空白对照组明显增加,差异有统计学意义(P<0.05)。结论烟草烟雾提取物促进小鼠骨髓来源的mDC的CD40、CD80和MHC-Ⅱ的表达。     

烟草烟雾提取物促进髓样树突状细胞共刺激分子的表达

目的通过体外实验研究烟草烟雾提取物(CSE)对小鼠髓样树突状细胞(mDC)成熟的影响及可能的机制。方法小鼠骨髓来源的单个核细胞加入粒-单集落刺激因子(GM-CSF)、白细胞介素-4(IL-4)和含100 mL/L胎牛血清的RPMI1640培养液诱导出可供实验用的高纯度的未成熟DC(iDC),分空白对照组和CSE刺激组;CSE刺激组按15 mL/L的终浓度加入CSE,两组继续培养24 h,流式细胞检测技术检测mDC的共刺激分子CD40、CD80、CD86和MHC-Ⅱ的表达。结果空白对照组的mDC低表达CD40、CD80、CD86和MHC-Ⅱ;CSE刺激后mDC表达CD40、CD80和MHC-Ⅱ比空白对照组明显增加,差异有统计学意义(P0.05)。结论烟草烟雾提取物促进小鼠骨髓来源的mDC的CD40、CD80和MHC-Ⅱ的表达。     

小反刍兽疫病毒对鼠源树突状细胞成熟分化的影响

目的研究和探讨小反刍兽疫病毒(PPRV)对小鼠骨髓来源的树突状细胞(BM-DCs)成熟和分化功能的影响。方法从小鼠骨髓中分离得到DCs,经过IL-4和GM-CSF诱导成熟;流式细胞术检测DCs表面共刺激分子表达及吞噬FITC-Dextran的能力;ELISA检测细胞因子IL-6、IL-12p40、IL-1β和IL-10的表达水平。结果利用LPS和PPRV处理DCs 24 h,发现与阳性对照LPS组相比,PPRV作用后显著抑制了CD40和MHC-Ⅱ的表达(P<0.05);滴度适度的PPRV可以显著增加CD40、CD80和CD86的表达,显著升高IL-6和IL-10的分泌(P<0.05),吞噬FITC-Dextran的能力并无显著差异,各组之间也无影响,且不同比例的PPRV对DC存活率无显著影响(P>0.05)。结论 PPRV在一定滴度范围内具有潜在的促进小鼠DC成熟的功能,为免疫学研究奠定基础。     

TLR2激动剂Pam3CK逆转IL-10转染小鼠髓样树突状细胞免疫功能的研究

目的:观察TLR2激活剂Pam3CK对IL-10转染小鼠髓样树突状细胞免疫功能影响。方法:转染IL-10至小鼠髓样树突状细胞(mDC),TLR2配体Pam3CK刺激48小时,利用流式细胞仪检测DC表面标志MHCⅡ、CD80、CD86及FasL等分子的表达;ELISA检测细胞产生IL-6、TNF-α。结果:IL-10抑制mDC表达CD80、CD86、MHCⅡ类分子,降低其分泌IL-6、TNF-α,促进其表达FasL,而TLR2激动剂刺激增加了IL-10转染DC表达MHC-Ⅱ类分子及CD80、CD86,促进其产生IL-6及TNF-α,抑制了FasL表达。结论:TLR2激动剂可逆转IL-10诱发的DC免疫应答低下。     

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.     

Dysfunction of murine dendritic cells induced by incubation with tumor cells

In vivo studies showed that dendritic cell （DC） dysfunction occurred in tumor microenvironment. As tumors were composed of many kinds of cells, the direct effects of tumor cells on immature DCs （imDCs） are needed for further studies in vitro. In the present study, bone marrow-derived imDCs were incubated with lymphoma, hepatoma and menaloma cells in vitro and surface molecules in imDCs were determined by flow cytometry. Then, imDCs incubated with tumor cells or control imDCs were further pulsed with tumor lysates and then incubated with splenocytes to perform mixed lymphocyte reaction. The DC-dependent tumor antigen-specific T cell proliferation, and IL-12 secretion were determined by flow cytometry, and enzyme-linked immunosorbent assay respectively. Finally, the DC-dependent tumor-associated antigen-specific CTL was determined by enzyme-linked immunospot assay. The results showed that tumor cell-DC incubation down-regulated the surface molecules in imDCs, such as CD80, CD54, CDIIb, CDIIa and MHC class II molecules. The abilities of DC-dependent antigen-specific T cell proliferation and IL-12 secretion were also decreased by tumor cell incubation in vitro. Most importantly, the ability for antigenic-specific CTL priming of DCs was also decreased by incubation with tumor cells. In the present in vitro study demonstrated that the defective abilities of DCs induced by tumor cell co-incubation and the co-incubation system might be useful for future study of tumor-immune cells direct interaction and for drug screen of immune-modulation. Cellular ＆ Molecular Immunology.     

Apoptotic cell capture by DCs induces unexpectedly robust autologous CD4+ T‐cell responses

Apoptotic cells represent an important source of self‐antigens and their engulfment by dendritic cells (DCs) is usually considered to be related to tolerance induction. We report here an unexpectedly high level of human CD4⁺ T‐cell proliferation induced by autologous DCs loaded with autologous apoptotic cells, due to the activation of more than 10% of naive CD4⁺ T cells. This proliferation is not due to an increase in the costimulatory capacity of DCs, but is dependent on apoptotic cell‐associated material processed through an endo‐lysosomal pathway and presented on DC MHC class II molecules. Autologous CD4⁺ T cells stimulated with apoptotic cell‐loaded DCs exhibit suppressive capacities. However, in the presence of bacterial lipopolysaccharide, apoptotic cell‐loaded DCs induce the generation of IL‐17‐producing cells. Thus, apoptotic cell engulfment by DCs may lead to increased autologous responses, initially generating CD4⁺ T cells with suppressive capacities able to differentiate into Th17 cells in the presence of a bacterial danger signal such as LPS.     

Apoptotic tumor cells induce IL-27 release from human DCs to activate Treg cells that express CD69 and attenuate cytotoxicity

Intrinsic immunosuppression is a major obstacle for successful cancer therapy. The mechanisms for the induction and regulation of immunosuppression in humans are ill defined. A microenvironmental component that might prevent antitumor immunity is the presence of dying tumor cells, which are abundant following conventional cancer ablation methods such as chemo- or radiotherapy. Shedding of apoptotic debris and/or secretion of factors to the tumor bed or draining lymph nodes thus might have a profound impact on professional phagocytes, such as DCs, and subsequent priming of lymphocytes. Here, we exposed human DCs to supernatants of live, apoptotic, or necrotic human breast cancer cells and cocultured them with autologous T cells. Priming with apoptotic debris prevented DCs from establishing cytotoxicity toward live human tumor cells by inducing a Treg-cell population, defined by coexpression of CD39 and CD69. Immunosuppression via Treg cells was transferable and required the release of sphingosine-1-phosphate (S1P) from apoptotic cells, acting via S1P receptor 4 on DCs to induce IL-27 secretion. We propose that CD69 expression on CD39(+) Treg cells enables them to interact with CD73-expressing CD8(+) T cells to generate adenosine, thereby suppressing cytotoxicity. These findings aid the understanding of how dying tumor cells limit antitumor immunity.     

小鼠骨髓来源树突状细胞的分离与扩增培养

目的 :探讨树突状细胞 (DC)分离纯化及其体外扩增的方法。方法 :无菌制备C57BL/6小鼠骨髓 ;依次用红细胞裂解液去除红细胞 ,通过半粘附法去除T、B细胞 ,又在粒细胞巨噬细胞集落刺激因子 (GM CSF)和白细胞介素 4 (IL 4 )协同诱导下培育 ,DC前体分化发育成DC并扩增。在第 7天用脂多糖 (LPS)和肿瘤坏死因子 a (TNF a)刺激 4 8h ,检测细胞因子白介素 12 (IL 12 )浓度及细胞表面标志CD11c、CD80、CD86和MHCⅡ。结果 :DC细胞数增加 ,其形态在光镜下多为特征性星形 ,也有梭形和多角形 ;至培养第 9天DC细胞表面标志CD11c、CD80、CD86、MHCⅡ阳性率分别为 86 .32± 12 .14 %、76 .4 2± 8.4 5%、77.12± 9.0 5%、6 8.4 5± 6 .84 % ,IL 12浓度较未用LPS和TNF a组明显增加 (P <0 .0 1)。结论 :①结果所得细胞的形态和功能符合DC ;②用LPS和TNF a刺激可以获得成熟DC。     

林可霉素对树突状细胞系DC2.4免疫功能影响的初步研究

目的:探讨林可霉素(lin)对树突状细胞(DCs)系DC2.4免疫功能的影响。方法:设立3个组:DC2.4细胞组,DC2.4细胞+LPS组及DC2.4细胞+LPS+lin组(LPS及lin均为500 ng/mL)。在倒置显微镜下观察各实验组中DC2.4细胞的形态学变化。同时采用流式细胞仪分析DC2.4细胞表面标志MHC-Ⅱ类分子、CD86和CD80的表达。采用同种异体混合淋巴细胞反应(MLR)检测各实验组中DC2.4细胞刺激同种异体T淋巴细胞增殖的能力。用ELISA试剂盒检测干扰素-γ(IFN-γ)水平的变化。结果:倒置显微镜下显示,DC2.4细胞组为未成熟DCs形态,DC2.4细胞+LPS组及DC2.4细胞+LPS+lin两组均为成熟DCs的形态。流式细胞术分析证实,500 ng/mL LPS可以促进DC2.4细胞表面MHC-Ⅱ类分子、CD86和CD80的表达,并增强其刺激T细胞增殖及IFN-γ的分泌。但500 ng/mL lin联合500 ng/mL LPS能够部分抑制DC2.4细胞免疫调节作用。结论:Lin可以部分抑制成熟DC2.4细胞的免疫调节功能。     

LPS介导的树突状细胞成熟过程中的表型变化

目的:探讨树突状细胞成熟过程中,DC表面MHC分子和共刺激分子的表达变化及MHCⅡ的胞内分布变化。方法:制备小鼠骨髓来源的树突状细胞,LPS分别刺激0、3、6、12和24小时,荧光抗体标记后,用流式细胞仪检测MHCⅠ、MHCⅡ分子和CD86、CD80、CD40等共刺激分子在细胞表面的表达,同时以激光共聚焦显微镜观察MHCⅡ的胞内分布变化。结果:在LPS刺激后,DC细胞表面的不同表型分子,其表达水平随时间延长有不同的上升趋势。同时在未成熟DC中,MHCⅡ主要集中在细胞核附近,LPS刺激后,MHCⅡ朝细胞外围扩散,到刺激12小时,有较多的MHCⅡ出现在细胞表面。结论:LPS介导的树突状细胞成熟过程中的表型分子有不同的变化趋势。     

丹参酮ⅡA 对树突状细胞表型的影响及对功能的调控

目的:提取小鼠骨髓树突状细胞(DCs),体外给予丹参酮ⅡA 干预,观察药物刺激后DCs 功能的改变,从而探讨丹参酮ⅡA 在免疫系统中的作用机制。方法:提取小鼠的骨髓DCs,体外给予10 ng/ ml GM-CSF 及IL-4 的完全培养液培养,并在第5 天,磁珠分选得到纯度90%以上的树突状细胞,体外给予一定浓度的丹参酮ⅡA 及LPS 刺激,收集细胞及上清,运用流式细胞技术检测DCs 表型,ELISA 方法检测细胞上清TNF-β、IL-12 含量变化,同种混合淋巴细胞反应检测树突状细胞刺激淋巴细胞增殖及分化的能力。结果:在丹参酮ⅡA 浓度为500 ng/ ml 时,药物对DCs 抑制作用达到最大,因此选取该浓度为实验作用浓度;即在500 ng/ ml 作用下,实验组与对照组相比,DCs 表达MHCⅡ、CD86 及CD80 水平均显著降低(P<0.05);实验组DCs 分泌的TNF-β及IL-12 含量均显著降低(P<0.05);实验组DCs 刺激淋巴细胞增殖反应能力明显降低(P<0.05);实验组DCs 刺激T 淋巴细胞分泌IL-4 含量明显高于对照组,IFN-β含量明显低于对照组(P<0.05)。结论:丹参酮ⅡA 可以通过降低LPS 诱导的DCs 成熟状态,来参与免疫系统或自身免疫性疾病的发生发展。     

卡介苗诱导小鼠脾脏树突状细胞分化作用研究

目的探讨卡介苗(BCG)诱导小鼠脾脏树突状细胞分化作用。方法分别用PBS和BCG免疫小鼠,收集免疫鼠脾单核细胞培养,通过瑞士-姬姆萨染色观察脾单核细胞形态;流式细胞术分析脾巨噬细胞、树突状细胞表型;MTS法检测小鼠脾淋巴细胞增殖;ELISPOT法检测脾淋巴细胞IFN-γ的分泌;ELISA法测定小鼠脾单核细胞分泌IL-2情况。结果与对照组相比,BCG免疫组镜下可见体积大、带毛刺状突起的细胞较多;CD14(P<0.05)、CD40、CD11C、CD86、CD68表达水平增高;小鼠脾淋巴细胞刺激指数增高(P<0.05);分泌IFN-γ的细胞频数增多(P<0.01);脾单核细胞培养上清中IL-2水平明显增高(P<0.01)。结论 BCG可诱导小鼠树突状细胞分化并活化Th1细胞。