黄芪多糖对树突状细胞表型及功能成熟的影响

目的 通过体外试验研究黄芪多糖（Astragalus mongholicus, ASP） 对树突状细胞（dendritic cells，DC）功能调节的机制，为进一步阐明黄芪多糖的免疫学活性提供依据。方法 应用流式细胞仪检测技术、扫描电镜技术、酶联免疫吸附试验检测DC表型和功能的各种指标。结果 本实验应用小鼠骨髓来源的DC，通过体外试验证明了黄芪多糖能够提高DC表面分子CD11c和MHCⅡ的表达，并且呈黄芪多糖浓度依赖性；空白组DC的吞噬功能很强，LPS组DC和黄芪多糖处理组DC吞噬功能都明显下降；黄芪多糖能够促进DC白细胞介素-12（IL-12）的表达；电镜观察DC的超微结构，可见黄芪多糖处理组DC突起增多，形态上更加成熟。结论 本实验结果证实了黄芪多糖能促进小鼠骨髓来源的DC表型及功能的成熟。     

雷公藤内酯醇对浆细胞样树突状细胞功能及成熟的影响

目的 通过体外试验研究雷公藤内酯醇(triptolide)对浆细胞样树突状细胞(plasmacytoid dendritic cell,pDC)功能及成熟的影响,为进一步阐明雷公藤内酯醇的免疫学活性提供依据.方法 从健康志愿者外周血分离单个核细胞,流式细胞仪分选pDC,加入0、5、10、30 μg/L的雷公藤内酯醇共孵育,24 h后收集上清液,ELISA检测pDC分泌的IFN-α、IL-6、TNF-α量,5 d后收集细胞,流式细胞仪检测树突状细胞表型CD11c、CD80、CD86阳性率,光镜观察DC的形态,扫描电镜观察DC的超微结构.结果 雷公藤内酯醇显著降低pDC分泌的IFN-α、IL-6、TNF-α,并呈雷公藤内酯醇浓度依赖性(P＜0.05);雷公藤内酯醇可抑制pDC向DC的分化和成熟,并呈雷公藤内酯醇浓度依赖性(P＜0.05).结论 雷公藤内酯醇能够降低pDC的功能,并抑制其向DC的分化和成熟.

Abstract：

Objective To explore the mechanism of immunomodulatory activity of triptolide on healthy volunteers peripheral blood mononuclear cells (PBMC)-derived plasmacytoid dendritic cells (pDCs). Methods Healthy volunteers-derived pDCs were sorted by flow cytometry, then incubated with triptolide (0, 5, 10, 30 μg/L). After 24 hours, we detected the concentration of IFN-α, IL-6, TNF-α using ELISA. After 5 days, the cultrural cells were collected and analyzed by flow cytometry, light microscope and electron microscope scanning. Results Triptolide-treated pDCs secreted lower level of IFN-α,IL-6 ,TNF-α, triptolide could inhibit pDCs differentiation to DCs which displayed more immature morphology and immunophenotypes than untreated-pDCs. Conclusion Triptolide could decrease the immune function of pDCs, inhibit differentiation and maturation of pDCs.     

浆细胞样树突状细胞研究进展

浆细胞样树突状细胞(pDC)是一类近年来被认识并被证明在免疫应答与免疫耐受中发挥重要作用的免疫细胞，其最突出的功能特点是在病毒、CPG ODN的刺激下产生大量的Ⅰ型干扰素，因此又被称为是天然Ⅰ型干扰素产生细胞(IPC)。由于其在来源、表型等方面都与我们以前所熟知的髓系树突状细胞有着很大的差异并具备独特的功能而引起广泛的关注。本文综述了pDC的来源、表型、功能特点，包括对T细胞的诱导分化及其与疾病的关系等方面的研究进展。     

浆细胞样树突状细胞免疫调节功能研究进展

浆细胞样树突状细胞(plasmacytoiddendriticcell,pDC)是近年来颇受关注的一类免疫细胞,其在病毒感染的刺激下可分泌大量的I型干扰素,使其在抗病毒免疫中发挥重要的作用。近年来发现pDC尚具有多种免疫功能,且与其不同的组织来源、诱导激活刺激有关。pDC对T细胞免疫功能具有重要的诱导和调控作用,参与CD4+T细胞失能的形成、CD8+Tr的产生和免疫耐受的诱导。此外,尚可诱导B细胞分化为浆细胞,激活NK细胞,诱导单核细胞向DC分化等。其通过分泌趋化因子可对某些免疫细胞产生趋化效应。本文仅就pDC与T、B、NK、单核细胞等的相互关系的研究进展作一综述,以期对pDC的免疫调节功能有更全面的认识。     

浆细胞样树突状细胞研究进展

浆细胞样树突状细胞(pDC)是一类近年来被认识并被证明在免疫应答与免疫耐受中发挥重要作用的免疫细胞,其最突出的功能特点是在病毒、CPG ODN的刺激下产生大量的Ⅰ型干扰素,因此又被称为是天然Ⅰ型干扰素产生细胞(IPC)。由于其在来源、表型等方面都与我们以前所熟知的髓系树突状细胞有着很大的差异并具备独特的功能而引起广泛的关注。本文综述了pDC的来源、表型、功能特点,包括对T细胞的诱导分化及其与疾病的关系等方面的研究进展。     

浆细胞样树突状细胞与免疫耐受

浆细胞样树突状细胞(PDC)来源于淋巴系干细胞,其表面标志、功能有别于髓系DC,不仅在抗病毒免疫中发挥重要作用,而且通过多种途径诱导T细胞失能和调节性T细胞的形成,从而参与免疫耐受的诱导.PDC诱导T细胞免疫耐受的分子机制与吲哚胺2,3-双加氧酶(IDO)-色氨酸代谢通路和具有抑制功能的膜分子密切相关.深入阐明PDC诱导耐受的机制,将为免疫耐受异常相关的疾病的治疗提供新方案.     

浆细胞样树突状细胞与疾病

目前对于浆细胞样树突状细胞(pDC)的来源、分布和功能研究不断深入,对于pDC在疾病发病、诊断、治疗中的作用正越来越受到关注。本文综述了pDC与抗病毒免疫特别是HIV感染、肿瘤、自身免疫病的关系,并总结了目前所发现的可以调控pDC生成和功能的药物,希望能为某些疾病的防治提供新的思路和方法。     

黄芪多糖诱导的树突状细胞增强CIK细胞的杀伤作用

目的:观察黄芪多糖(Astragalus polysaccharides,APS)对树突状细胞(Dendritic cell,DC)抗原提呈功能的影响,并和同源CIK(Cytokine induced killer)细胞共培养,观察DC-CIK和黄芪多糖诱导DC-CIK细胞杀伤A549肺腺癌细胞的活性.方法:提取健康供血者的外周血单个核细胞(PBMC),常规诱导出DC与CIK细胞后,将其共培养,观察黄芪多糖对DC表型变化的影响,定量检测DC-CIK和黄芪多糖诱导DC-CIK细胞培养上清中的IFN-γ和IL-12;并用MTT法测定其体外细胞毒活性.结果:黄芪多糖能提高DC表面分子CD40、CD80、HLA-DR的表达,经黄芪多糖诱导的DC活化的CIK,对A549肺腺癌细胞的杀伤活性高于单纯DC-CIK细胞,差异显著(P＜0.05).结论:黄芪多糖能增强DC的抗原提呈功能,证实黄芪多糖诱导的DC能明显提高CIK对肿瘤细胞的杀伤活性,具有更广阔的应用前景.     

HIV感染中的浆细胞样树突状细胞研究进展

浆细胞样树突状细胞(pDC)是体内产生干扰素(IFN)-α最有力的细胞,并且是固有免疫和适应性免疫之间的重要联系.HIV-1感染者产生IFN-α不足,循环中pDC数量减少并且功能缺陷,其机制尚不明确.IFN-α在HIV感染中是有益还是有害目前仍存在争论.pDC数量和功能的平衡在HIV发病中起重要作用,利用pDC绝对计数...     

不同分子量的枸杞多糖组分对树突状细胞成熟的影响

目的:本研究旨在筛选诱导树突状细胞(DCs)成熟活性最强的枸杞多糖(LBPs)组分.方法:体外诱导培养未成熟DCs,加入不同剂量的LBPs各组分(LBP2、LBP3、LBP4和LBP5)处理.Griess试剂检测细胞培养上清的一氧化氮(NO)浓度,CBA法检测培养上清中细胞因子(IL-6、IL-10、MCP-1、TNF...     

Regulation on maturation and function of dendritic cells by Ganoderma lucidum polysaccharides

Ganoderma lucidum polysaccharides (Gl-PS) exhibits a variety of immunomodulatory activities, and dendritic cells (DC) are professional antigen presenting cells, which are pivotal for initiation of primary immune response. In this study, the regulatory effects of Gl-PS on maturation and function of cultured murine bone marrow derived DC were investigated in vitro. Gl-PS (0.8, 3.2, or 12.8 microg/ml) could increase the co-expression of CD11c and I-A/I-E molecules on DC surface, promote mRNA expression of cytokine IL-12 p40 in DC and augment protein production of IL-12 P40 in culture supernatants. The lymphocyte proliferation of mixed lymphocyte culture (MLC) induced by mature DC was enhanced by Gl-PS, either. Gl-PS was shown to promote not only the maturation of cultured murine bone marrow derived DC in vitro, but also the immune response initiation induced by DC.     

MHC class II signaling function is regulated during maturation of plasmacytoid dendritic cells

Dendritic cells (DC) play a central role in the immune response, linking innate and adaptative responses to pathogens. Myeloid DC (MDC) produce interleukin-12 in response to bacterial stimuli, whereas plasmacytoid DC (PDC) produce high levels of type I interferon upon viral infection. Human leukocyte antigen (HLA)-DR engagement has been shown to induce apoptosis in various antigen-presenting cells (APC). We now report the consequences of HLA-DR molecule engagement in human PDC, which had thus far not been studied as a result of the difficulty in isolating such cells. HLA-DR engagement on PDC, obtained using a two-step, immunomagnetic separation, led to recruitment of HLA-DR molecules at the site of engagement in mature but not immature PDC. In contrast, relocalization of protein kinase C (PKC) isoenzymes, indicating PKC activation, was observed at the site of HLA-DR engagement and was accompanied by relocalization of a lipid raft marker, the ganglioside M1 staining, in immature and mature PDC. Similar to MDC, HLA-DR-mediated apoptosis was regulated throughout PDC maturation. Freshly isolated PDC were resistant, whereas CD40 ligand-matured PDC were sensitive to HLA-DR-mediated apoptosis. Neither caspase activation nor PKC activation was required for HLA-DR-mediated apoptosis. However, the intrinsic pathway of apoptosis was implicated as mature PDC underwent mitochondrial depolarization in response to HLA-DR engagement. These data provide further arguments for considering HLA-DR-mediated apoptosis as a conserved mechanism of regulating survival of diverse APC and support the ongoing development of humanized ligands for HLA class II molecules as therapeutic tools for use in lymphoproliferative disease.     

雷公藤内酯醇对系统性红斑狼疮患者DC细胞功能及成熟的影响

目的 通过体外实验研究雷公藤内酯醇(triptolide)对系统性红斑狼疮(systemic lupus erythematosus,SLE)患者树突状细胞(dendritic cell,DC)功能及成熟的影响,为进一步阐明雷公藤内酯醇的免疫学活性提供依据.方法 从SLE患者外周血分离单个核细胞,流式细胞仪分选DC,加入0、5、10、30μg/L的雷公藤内酯醇共孵育,24h后收集上清液,ELISA检测IFN-α、IL-6、TNF-α量,5d后收集细胞,流式细胞仪检测DC表型CD11c、CD80、CD86阳性率,光镜观察DC的形态,扫描电镜观察DC的超微结构.结果 雷公藤内酯醇显著减低活动期与非活动期SLE患者IFN-α、IL-6、TNF-α量,并呈雷公藤内酯醇浓度依赖性(P＜0.05);雷公藤内酯醇可抑制SLE患者DC的分化和成熟,并呈雷公藤内酯醇浓度依赖性(P＜0.05).结论 雷公藤内酯醇能够减弱SLE患者DC的功能,并抑制其分化和成熟.     

载脂蛋白A-I对树突状细胞表型及功能影响

目的:探讨载脂蛋白A-I(ApoA-I)对人外周血树突状细胞(PBDC)及体外培养的单个核诱导的树突状细胞(MD-DC)的影响及其机制。方法:采用免疫磁珠法,直接分离PB-DC或通过GM-CSF,IL-4诱导生成MDDC,DC经ApoA-I,LPS或TNF-α刺激后,用流式细胞技术(FCM)检测树突状细胞表面协同刺激分子表达的变化及细胞的吞噬能力;酶联免疫吸附法(ELISA)检测DC分泌的细胞因子;CFSE法检测经刺激后DC对T细胞增殖的影响。结果:分离高纯度PBDC,并成功诱导生成未成熟MDDC;经FCM检测,ApoA-I刺激后的PBDC和MDDC膜表面CD83分子表达上调,同时MDDC表面的CD40、CD86及MHC-Ⅱ分子的表达均增强;吞噬能力减弱;IL-12和TNF-α的分泌增加;并且可以诱导Th细胞的增殖。结论:在体外ApoA-I可以诱导PBDC和MDDC的成熟、活化,刺激其分泌细胞因子,发挥其免疫应答中抗原呈递,促进Th分化的作用;通过该作用ApoA-I可能参与了动脉粥样硬化的发生,发展中的免疫应答。     

青藤碱促进树突状细胞分化抑制其成熟

目的 探讨青藤碱对树突状细胞(Dendritic cell,DC)体外分化发育、成熟、抗原递呈及刺激T细胞活化能力的影响.方法 DC体外培养时,青藤碱处理,观察细胞生长情况,流式检测细胞表型及抗原内吞能力,混合淋巴细胞反应检测DC刺激T细胞活化的能力,E(I)ISA检测细胞因子分泌.结果 与对照组相比,青藤碱处理DCCD1a表达上调而CD14下调,IL-12分泌减少,共刺激分子表达减少,同种T细胞刺激活性降低.结论 合适剂量的青藤碱能刺激单核细胞分化为不成熟DC但能抑制其进一步成熟.     

Highly efficient transduction of human plasmacytoid dendritic cells without phenotypic and functional maturation

Background  

Gene modified dendritic cells (DC) are able to modulate DC functions and induce therapeutic immunity or tolerance in an antigen-specific manner. Among the different DC subsets, plasmacytoid DC (pDC) are well known for their ability to recognize and respond to a variety of viruses by secreting high levels of type I interferon.     

Antigen crosspresentation by human plasmacytoid dendritic cells

Crosspresentation is a specialized function of myeloid dendritic cells (mDCs), allowing them to induce CD8+ T cell responses against exogenous antigens that are not directly produced in their cytotosol. Human plasmacytoid DCs (pDCs) are not considered so far as able to perform crosspresentation. We showed here that purified human pDCs crosspresented vaccinal lipopeptides and HIV-1 antigens from apoptotic cells to specific CD8+ T lymphocytes. Apoptotic debris were internalized by phagocytosis and the lipopeptide LPPol reached nonacidic endosomes. This crosspresentation was amplified upon influenza virus infection. Importantly, the efficiency of crosspresentation by pDCs was comparable to that of mDCs. This property of human pDCs needs to be taken into account to understand the pathogenesis of infectious, allergic, or autimmune diseases and to help achieve desired responses during vaccination by targeting specifically either type of DCs.