小鼠肺间质树突状细胞的分离、纯化与鉴定

目的:建立肺间质树突状细胞(DCs)的分离与纯化方法,为肺间质DCs的相关研究提供实验基础。方法:雄性BALB/c小鼠肺组织经Ⅰ型胶原酶消化、密度梯度离心、CD11c+免疫磁珠分选纯化DCs,流式细胞术鉴定分选DCs纯度,倒置相差显微镜观察孵育细胞生长状态,扫描电镜和透射电镜观察DCs超微形态,流式细胞术检测肺间质DCs的CD11c、CD11b、CD86和I-Ab表型。结果:分选获得的肺间质DCs经鉴定,纯度为92.59%±5.62%,在RPMI1640培养基中生长状态良好,少数细胞形成小细胞集落。DCs超微形态观察显示细胞表面多见长1~2μm密集的树枝状突起,细胞器不发达,细胞核形不规则。90%以上肺间质DCs为未成熟状态或前体DCs,低表达成熟标志物I-Ab和CD86,并具有异质性,近40%起源于髓系细胞分化。结论:密度梯度离心和免疫磁珠分选是分离、纯化肺间质DCs的理想方法,获得的DCs纯度高、活性好、免疫表型稳定,但操作步骤比较复杂,技术要求高。     

Jagged-1对骨髓来源树突状细胞生成细胞因子的影响

目的:探讨可溶性Jagged-1/Fe嵌合蛋白(Jagged-1)对重组小鼠粒细胞-巨噬细胞集落刺激因子(rmGM-CSF)和白细胞介素4(rmIL-4)体外诱导小鼠骨髓来源树突状细胞(DC)产生细胞凶子的影响.方法:建立rmCM-CSF和rmIL-4体外诱导DC的模型,观察Jagged-1/Fc对DC分化的形态学影响.通过Luminex蛋白液相芯片技术和ELlSA检测其细胞因子的表达水平,藉MTT法测定可溶性Jagged-1/Fc诱导的DC对同种异基因淋巴细胞增殖的刺激能力.结果:除了TGF-β,Jag-ged-1/Fc诱导的DC与细菌脂多糖(LPS)或酵母聚糖A诱导的DC不同,表现为生成TNF-α的水平明显降低,IL-4显著增高,而IL-10、IL-6、IL-2、IL-12和IFN-γ的水平与对照组无明显差异.γ分泌酶抑制剂DAFT能逆转Jagged-1/Fc抑制DC生成TNF-α.混合淋巴细胞反应显示Jagged-1/Fc诱导的DC对T细胞增殖的刺激能力最弱,LPS诱导的DC的刺激能力最强.结论:Jagged-1/Fc诱导的DC倾向介导免疫耐受,指导初始T细胞向Th2细胞偏离.     

吴茱萸碱对小鼠树突状细胞分泌细胞因子的影响

目的:利用抗体芯片技术和ELISA检测吴茱萸碱(EVO)对小鼠骨髓来源树突状细胞(DC)分泌相关细胞因子的影响,研究EVO的生物学调节功能。方法:体外诱导培养未成熟DC细胞(iDC),经LPS和EVO处理后,通过混合淋巴反应检测DC诱导异源T细胞的应答能力,ELISA检测上清中IL-12p40、IL-12p70和IL-10,小鼠抗体芯片检测细胞上清中细胞因子。结果:EVO促进了iDC和成熟DC(mDC)抗原提呈功能(P0.05),对iDC、mDC的细胞因子IL-10、IL-12分泌功能无影响(P0.05),另外EVO处理iDC后上调大于2倍的细胞因子有7个(VEGF、DPPIV/CD26、IGF-Ⅰ、IL-17BR、MDC、Pro-MMP-9、Eotaxin-2),处理mDC后上调大于2倍的细胞因子有2个(Eotaxin-2、IL-13)。结论:EVO处理mDC和iDC后,细胞因子的分泌功能发生了明显改变,这些细胞因子影响着DC的抗原摄取、迁移、抗原提呈,为进一步寻找药物靶点提供了线索。     

IL-3对小鼠骨髓来源树突状细胞分化发育的影响

比较 GM- CSF IL- 4与 IL- 3 IL- 4两种方法培养制备的树突状细胞 (Dendritic cell,DC)在形态、产量、免疫表型和抗原摄取能力方面的差异。用 GM- CSF IL- 4和 IL- 3 IL- 4分别诱导小鼠骨髓来源的前体细胞分化为成熟树突状细胞 ,通过相差显微镜、扫描电镜、激光共聚焦扫描显微镜进行形态观察 ,流式细胞术分析细胞免疫表型和摄取抗原能力。结果表明 ,IL- 3 IL- 4诱导的 DC产量高 ,细胞纯度好 ,形态上与 GM- CSF IL- 4诱导的DC类似 ;细胞免疫表型显示高表达 MHC 类分子 ,但低表达或不表达 CD80、CD86 ;IL- 3 IL- 4诱导的 DC具有强大的摄取抗原能力。 IL- 3替代 GM- CSF可诱导低表达共刺激分子的耐受型 DC     

树突状细胞分化发育的研究进展

ＤＣ的来源和分化发育所处的阶段与其功能有非常密切的关系，未成熟的ＤＣ能摄取和加工处理抗原，处于成熟期的ＤＣ则能提呈抗原并活化处女型Ｔ细胞（ＮａｉｖｅＴｃｅｌｌｓ）来源于髓系的ＤＣ前体可发育为ＬＣ，再进一步发育为成熟的ＤＣ，也可先育为Ｍｏ再进一步发育为成熟的ＤＣ。髓系ＤＣ的主要功能为加工处理和提呈外源性抗原（包括自身细胞衰老，突变等产生的抗原）目前用于体外研究的髓系ＤＣ常来源于小鼠骨髓和脾脏，人ＣＤ     

LPS持续刺激对小鼠骨髓树突状细胞成熟的影响

目的　研究LPS持续刺激对小鼠骨髓树突状细胞 (DC)成熟的影响。方法　小鼠骨髓细胞用GM CSF培养 7d ,持续刺激组全程加入LPS ,短期刺激组在最后 48h加入LPS ,对照组不加LPS。流式细胞仪检测细胞表型和细胞摄取抗原的能力 ,ELISA检测细胞产生的细胞因子 ,混合淋巴细胞培养检测细胞提呈抗原的能力。结果　用LPS持续刺激的小鼠骨髓DC表达MHCⅡ、CD86、CD80和CD11c等分子和分泌TNF α和IL 12 (p70 )的能力并未增加 ,吞噬FITC OVA的能力显著升高 ,刺激同种异基因T细胞和刺激同种同基因T细胞增殖的能力亦显著低于LPS短期刺激组。结论　LPS持续刺激可抑制DC的发育成熟 ,可能是持续严重感染时免疫功能低下的原因     

细胞因子诱导不同来源的贴壁细胞分化为树突状细胞的研究

通过贴壁的方法分离胚肝、脐带血、造血动员后的外周血及正常人外周血中的树突状细胞 (DC )的前体细胞 ,体外采用细胞因子诱导 ,并对其进行形态学观察和细胞表型分析 ;同时比较了不同来源DC的增殖、分泌IL 12的能力及激发同种异体T细胞和脐带血幼稚型T细胞 (naiveTcell)的作用。实验结果表明 ,经过造血动员后的外周血细胞产生的DC数量和纯度均较高 ,而且能经体外细胞因子诱导为功能性DC ,是较理想的DC来源     

几种细胞因子对人脐血CD34+干细胞在体外诱导扩增为树突状细胞的研究

多种疾病用树突状细胞 (dendriticcell,DC)作免疫治疗具有一定的疗效。由于DC在人体组织中含量甚微 ,限制了DC的研究及临床应用。因此如何获得足够的成熟DC便成为DC广泛应用的关键技术问题。我们比较了不同细胞因子组合对脐血CD34 造血干细胞在体外诱导扩增为DC的效率及功能的影响 ,提供一种体外获得大量成熟DC的有效途径。脐血采自本院正常分娩志愿者 ,Fi coll淋巴细胞分离液离心获得单个核细胞 ,按CD34 细胞MACS免疫磁性分离试剂盒操作说明分离纯化CD34 细胞。纯化的CD34 细胞配制成含 5× 10 4 ml细胞的悬液 ,按以下 5组…     

抗CD86单克隆抗体对哮喘小鼠TH1/TH2细胞因子的影响

目的观察抗CD86单克隆抗体对卵蛋白干粉(OVA)致敏并刺激小鼠TH1和TH2细胞因子比例的变化,为防治哮喘提供实验依据.方法经OVA致敏的雌性Balb/c于激发前腹腔注射抗CD86单克隆抗体及同型对照IgG2α 50 μg,末次激发48 h后收集支气管肺泡灌洗液(BALF),以酶联免疫吸附法(ELISA)测定BALF中白细胞介素-4(IL-4)、白细胞介素-5(IL-5)和干扰素-γ(INF-γ)水平.结果以OVA致敏并激发的哮喘对照组小鼠BALF中IL-4、IL-5水平升高[分别为(64.23±3.91)pg/mL、(379.84±73.02)pg/mL],与PBS对照组[分别为(22±2)pg/mL、(245.75±50.01)pg/mL]比较,差异有显著性(P＜0.05);OVA致敏并激发的哮喘对照组小鼠BALF中INF-γ水平降低[(98.73±16.41)pg/mL],与PBS对照组[(218.35±48.63)pg/mL]比较,差异有显著性(P＜0.05).抗CD86单克隆抗体组小鼠BALF中IL-4、IL-5水平降低[分别为(35.78±4.88)pg/mL、(222.98±58.68)pg/mL],而INF-γ水平升高[(206.92±47.8)pg/mL],与哮喘对照组及同型对照IgG2α组(98.73±16.41)pg/mL、(102.32±15.49)pg/mL比较差异有显著性(P＜0.05).结论抗CD86单克隆抗体通过阻断共刺激信号,纠正TH1/TH2失衡,从而达到抗气道炎症的作用.     

雷帕霉素和地塞米松对小鼠树突状细胞分化成熟的调控

目的：观察雷帕霉素（rapamycin，Rap）和地塞米松（dexamethasone，Dex）对堵养的小鼠骨髓来源的树突状细胞（DC）分化发育的影响。方法：（1）用GM-CSF＋IL-4定向诱导C57BL／6小鼠骨髓细胞分化为DC，分别加入Rap或Dex，然后用脂多糖（LPS）刺激。在倒置显微镜和扫描电镜下，动态观察DC形态学E的变化。（2）通过流式细胞术（荧光抗体双标记法）测定CD11c^＋细胞的比例及CD86和MHC-Ⅱ类分子表达的变化。（3）通过单向混合淋巴细胞反应（MLR）观察，Rap和Dex处理的DC刺激BALB／c小鼠同种异基因T细胞增殖的情况。结果：（1）经Rap和Dex处理后，DC在形态学上呈现稳定不成熟状态。（2）Rap处理的细胞表面CDIlc和MHC-Ⅱ类分子的表达仅有轻度降低，而CD86的表达明显降低。Dex处理的细胞表面CDIlc的表达与Dex的剂量呈负相关，CD86和MHC-Ⅱ类分子的表达均明硅降低。两种药物处理的DC均可抵抗LPS的促成熟作用。（3）MLR的结果显示，Rap和Dex处理的DC刺激同种异基因BALB／c小鼠T细胞增殖的能力均较低。结论：Rap和Dex均可使DC处于稳定的不成熟状态。与Dex相比，Rap对骨髓造血F细胞向DC分化的过程影响较小，而且在抑制DC表面协同刺激分子CD86表达的同时，对MHC-Ⅱ类分子的表达影响较小。     

Complement C1q regulates LPS-induced cytokine production in bone marrow-derived dendritic cells

We show here that C1q suppresses IL-12p40 production in LPS-stimulated murine bone marrow-derived dendritic cells (BMDC). Serum IL-12p40 concentration of C1q-deficient mice was higher than that of wild-type mice after intraperitoneal LPS-injection. Because neither globular head of C1q (gC1q) nor collagen-like region of C1q (cC1q) failed to suppress LPS-induced IL-12p40 production, both gC1q and cC1q, and/or some specialized conformation of native C1q may be required for the inhibition. While C1q did not affect mRNA expression of Toll-like receptor 4 (TLR4), MD-2, and myeloid differentiation factor 88 (MyD88), BMDC treated with C1q showed the reduced activity of NF-kappaB and the delayed phosphorylation of p38, c-Jun N-terminal kinase, and extracellular signal-regulated kinase after LPS-stimulation. CpG oligodeoxynucleotide-induced IL-12p40 and TNF-alpha production, another MyD88-dependent TLR-mediated signal, was also suppressed by C1q treatment. Therefore, C1q is likely to suppress MyD88-dependent pathway in TLR-mediated signals. In contrast, C1q failed to suppress colony formation of B cells responding to LPS or LPS-induced CD40 and CD86 expression on BMDC in MyD88-deficient mice, indicating that inhibitory effects of C1q on MyD88-independent pathways may be limited. Taken together, C1q may regulate innate and adaptive immune systems via modification of signals mediated by interactions between invading pathogens and TLR.     

Adipose tissue-derived mesenchymal stem cells are more potent suppressors of dendritic cells differentiation compared to bone marrow-derived mesenchymal stem cells

Both mesenchymal stem cells (MSCs) and dendritic cells (DCs) are engaged in the regulation of the immune response parallel to their numerous functions.The main objective of this study was to compare the effects of mesenchymal stem cells isolated from human adipose tissue or human bone marrow on the expression of specific cell surface markers as well as the secretion of some cytokines by monocyte-derived dendritic cells. The set of methods used includes cell cultures, magnetic beads isolation of cells, flow cytometry, ELISA and proteome profiler kit assays. The results obtained show that MSCs isolated from human adipose tissue are more potent immunomodulators of differentiation of human DCs in comparison to the bone marrow-derived MSCs. In both cases the percentages of CD14+ cells were increased in co-cultures of MSCs and DCs and at the same time down-regulated the expression of CD80, CD86 and CD83 as in all experiments the effect of adipose tissue MSCs was stronger. Similarly, the secretion of IL-10 by dendritic cells was up-regulated in co-cultures of MSCs and dendritic cells and the effect was stronger when adipose tissue-derived MSCs were used.Taken together all results presented reveal the higher potential of the adipose tissue-derived MSCs to inhibit the differentiation and expression of functionally important co-stimulatory molecules on the surface of monocyte-derived dendritic cells than the bone marrow-derived MSCs.     

Toll-like receptor ligand activation of murine bone marrow-derived dendritic cells

Dendritic cells (DCs) are required for the initiation of primary immune responses. The pattern of Toll-like receptor (TLR) expression on various subsets of these cells has been shown to differ, suggestive of distinct roles in influencing immune responses. We have examined here the responses of immature DCs derived from murine bone marrow (BMDCs) to a range of TLR ligands. BMDCs cultured for 6 days in the presence of granulocyte-macrophage colony-stimulating factor were stimulated for 24 hr with ligands to TLR1-2 [Pam(3)Cys-Ser-(Lys)(4) (PAM)], TLR2-6 (macrophage-activating lipopeptide-2 (MALP-2); zymosan or peptidoglycan (PG)], TLR3 (polyinosinic-polycytidylic acid), TLR4 [lipopolysaccharide R515 (LPS)], TLR5 (flagellin), TLR7 (polyuridylic acid) and TLR9 [CpG ODN2395 (CpG)]. DC activation was monitored using membrane marker expression and analysis of culture supernatants for cytokine/chemokine release. Ligands to TLR3 and TLR7 failed to activate BMDCs. All other TLR ligands caused elevated expression of membrane markers. PAM, MALP-2 and LPS induced high-level expression of proinflammatory cytokines and chemokines. Treatment with CpG was associated with a preferential type 1 cytokine and chemokine profile. Zymosan and PG were proinflammatory but also skewed towards a type 2 pattern of cytokines and chemokines. In contrast, flagellin did not cause marked secretion by BMDCs of cytokines or chemokines. These data for BMDCs are largely consistent with the reported TLR repertoire of freshly isolated murine Langerhans cells. In addition, murine BMDCs show selective responses to TLR ligands with respect to general activation, with differentiated cytokine patterns suggestive of potential priming for divergent immune responses.     

Influence of extracellular matrix proteins on the development of cultured human dendritic cells

The development of dendritic cells (DC) is still only partly understood. Recently established culture systems using CD34⁺ cells or monocytes as precursor cells for the generation of DC indicate the necessity of pro-inflammatory cytokines for their development. In vivo the contact to other cells or to the proteins of the extracellular matrix might also be essential for their development. In our experiments we used granulocyte-macrophage colony-stimulating factor- and IL-4-treated human monocytes as precursor cells to investigate the interaction of DC at different maturation stages with the matrix proteins fibronectin, collagen type I and collagen type IV. We demonstrate a strong β₁-integrin-mediated adherence of immature DC to fibronectin that is lost completely during maturation. The binding to collagen type I was less strong but induced a maturation of the precursor cells. After 3 days of culture on this protein, the cells showed all features of fully matured DC such as expression of CD83 and an excellent allostimulatory capacity. The reason for this effect was shown to be the induction of TNF-α production by the DC themselves. In contrast to the adhesion to fibronectin, the maturation and the cytokine production of DC induced by collagen type I could not be inhibited by blocking of β₁-integrins. These results indicate that proteins of the extracellular matrix play an important role in the development and function of human DC.     

Oligomeric proanthocyanidins attenuate airway inflammation in asthma by inhibiting dendritic cells maturation

To date, although a promising anti-inflammatory activity of oligomeric proanthocyanidins (OPCs) has been observed in asthma, the mechanism responsible for these immunomodulatory properties remains obscure. Dendritic cells (DCs) that reside in the airway have been widely perceived as an important contributor to asthma. Our study was to demonstrate OPCs’ effects on maturation and immunoregulation of pulmonary CD11c⁺ dendritic cells (DCs). BALB/c mice were exposed to ovalbumin (OVA) to induce murine model of asthma. In addition, pulmonary DCs and bone marrow-derived DCs (BMDCs) cultures were used to evaluate impacts of OPCs on DCs function. The results obtained here indicated that OPCs treatment dramatically reduced airway inflammation, such as the infiltration of inflammatory cells and the levels of allergen-specific serum IgE and Th2 cytokines. The expression of co-stimulatory molecules especially CD86 distributed on pulmonary DCs and bone marrow-derived DCs (BMDCs) also markedly declined. The phosphorylation of cAMP responsive element-binding protein (CREB) was significantly inhibited while no changes were observed in the expression of cAMP responsive element modulator (CREM). By transferring BMDCs into the airways of naïve mice, we found that OPCs-treated DCs (DC + OVA + OPC) were much less potent in promoting CD4⁺ T cells proliferation than OVA-pulsed DCs (DC + OVA), followed by the ameliorated eosinophilic inflammation in airway. Our findings tailor a novel profile of OPCs in the regulation of DCs function, shedding new light on the therapeutic potential of OPCs in asthma management.     

Detection of restricted isoform expression and tyrosine phosphatase activity of CD45 in murine dendritic cells

CD45 is a cell surface transmembrane tyrosine phosphatase. It is expressed as distinct protein isoforms via alternative splicing of exons 4, 5 and 6. In T and B lymphocytes, CD45 is thought to play a critical role in antigen-dependent signaling through their respective antigen receptor complexes. However, the isoform expression and enzymatic activity of CD45 in other leukocytes remains largely unknown. Here, we examine the isoform expression and phosphatase activity of CD45 in murine dendritic cells (DC). Flow cytometric double-labeling analysis and biochemical analysis of purified splenic DC CD45 demonstrate that DC express both the CD45RB and CD45RO isoforms. Flow cytometric analyses of freshly isolated splenic DC and thymic DC also indicate the expression of CD45RB and CD45RO on these DC populations. In addition, we find that purified splenic DC CD45 possesses a high level of intrinsic tyrosine phosphatase activity. These data therefore establish the restricted isoform expression pattern of CD45 in murine DC and demonstrate that cells lacking specific antigen receptor complexes have active tyrosine phosphatase activity associated with CD45.     

带有IL-24的腺病毒扩增及其在小鼠树突状细胞中的表达

目的：在293细胞中扩增带有IL-24的腺病毒,感染小鼠树突状细胞,观察IL-24在树突状细胞中的表达。方法：将构建的重组腺病毒表达载体IL-24转染到293细胞中包装、扩增,感染分离培养的小鼠树突状细胞,RT-PCR、Westernblot、荧光显微镜检测IL-24的表达。结果：获得了大量的带有IL-24的腺病毒,成功的感染小鼠树突状细胞,RT-PCR和Westernblot检测结果显示,IL-24在树突状细胞中高表达。结论：带有IL-24的腺病毒可以高效的感染小鼠树突状细胞。     

Adoptive transfer of bone marrow-derived dendritic cells decreases inhibitory and regulatory T-cell differentiation and improves survival in murine polymicrobial sepsis

A decrease in the number of dendritic cells (DCs) is a major cause of post-sepsis immunosuppression and opportunistic infection and is closely associated with poor prognosis. Increasing the number of DCs to replenish their numbers post sepsis can improve the condition. This therapeutic approach could improve recovery after sepsis. Eighty C57BL/6 mice were subjected to sham or caecal ligation and puncture (CLP) surgery. Mice were divided into four groups: (i) Sham + vehicle, (ii) Sham + DC, (iii) CLP + vehicle, and (iv) CLP + DC. Bone-marrow-derived DCs (BMDCs) were administered at 6, 12 and 24 hr after surgery. After 3 days, we assessed serum indices of organ function (alanine aminotransferase, aspartate aminotransferase, creatinine, amylase and lipase), organ tissue histopathology (haematoxylin and eosin staining), cytokine [interferon-γ (IFN-γ), tumour necrosis factor-α, interleukin-12p70 (IL-12p70), IL-6 and IL-10] levels in the serum, programmed death-1 (PD-1) expression on T cells, regulatory T-cell differentiation in the spleen, and the survival rate (monitored for 7 days). BMDC transfer resulted in the following changes: a significant reduction in damage to the liver, kidney and pancreas in the CLP-septic mice as well as in the pathological changes seen in the liver, lung, small intestine and pancreas; significantly elevated levels of the T helper type 1 (Th1) cytokines IFN-γ and IL-12p70 in the serum; decreased levels of the Th2 cytokines IL-6 and IL-10 in the serum; reduced expression of PD-1 molecules on CD4⁺ T cells; reduced the proliferation and differentiation of splenic suppressor T cells and CD4⁺ CD25⁺ Foxp3⁺ regulatory T cells, and a significant increase in the survival rate of the septic animals. These results show that administration of BMDCs may have modulated the differentiation and immune function of T cells and contributed to alleviate immunosuppression, hence reducing organ damage and mortality post sepsis. Hence, the immunoregulatory effect of BMDC treatment has potential for the treatment of sepsis.