食管癌组织微环境对树突状细胞的影响

目的:探讨食管癌组织匀浆上清液体外模拟肿瘤微环境对人树突状细胞(DC)分化发育的影响, 揭示肿瘤免疫逃逸机制, 为DC疫苗的应用提供理论基础.方法:制备新鲜食管癌及癌旁组织匀浆上清液, ELISA检测其VEGF-A含量.密度梯度离心法分离人外周血单个核细胞, 含rhGM-CSF和rhIL- 4 RPMI1640培养液诱导DC, 第2天在继续诱导DC基础上设食管癌匀浆上清组、癌旁匀浆上清组、 VEGF-A组, 均隔天半量换液, 第4天加入食管癌细胞株EC9706抗原, 第6天加入脂多糖, 第8天收集各组细胞.观察DC形态, 流式细胞术(FCM)检测免疫表型, RT-PCR检测CD1a表达, CCK-8检测T细胞增殖率及杀伤率.结果:食管癌组织匀浆上清VEGF-A含量[(0.987±0.319) μg/L]明显高于癌旁[(0.152±0.105) μg/L, P<0.05]; 食管癌匀浆上清组细胞形态明显受到抑制, CD86分子阳性率(%)与正常DC相比由69±8降为42±11、 CD1a由56±12降为27±12、 CD11c由21±13降为18±13(P<0.01), CD1a基因几乎无表达, 刺激T细胞增殖率(%)由112.5±7.2降为70.2±3.5(P<0.01), 杀伤率(%)由62.4±0.6 降为46.8±1.6(P<0.01); 癌旁匀浆上清液组、 VEGF-A组结果与正常DC组无统计学意义.结论:食管癌组织匀浆上清液所模拟的微环境对DC的诱导分化及其功能有明显的抑制作用, 在该抑制作用中VEGF-A并不起主要作用.     

结肠癌组织微环境对树突状细胞的影响

目的 探讨结肠癌组织匀浆上清液模拟肿瘤微环境对人树突状细胞(DC)分化发育的影响,以及血管内皮生长因子A(VEGF-A)在其中所起的作用.方法 制备新鲜结肠癌及癌旁组织匀浆上清液.分离人外周血单个核细胞,含重组人粒细胞.巨噬细胞集落刺激因子(rhGM-CSF)和rhIL-4的1640培养液诱导DC,第2天在此基础上设结肠癌匀浆上清组、癌旁组织匀浆上清组、VEGF-A组及正常DC组,第4天加入结肠癌细胞株SW620抗原,第6天加入脂多糖,第8天收集各组细胞.ELISA检测肿瘤组织匀浆上清液中VEGF-A含量.观察DC形态,流式细胞术检测其免疫表型,RT-PCR检测CD1a表达,CCK-8检测T细胞增殖率及杀伤率.结果 结肠癌组织匀浆上清VEGF-A含量明显高于癌旁组织(P＜0.05);与正常DC组相比,结肠癌匀浆上清组细胞形态明显受到抑制,数目减少,表面抗原表达率明显下降(P＜0.01),混合淋巴细胞反应能力及杀伤力也明显下降(P＜0.01);而VEGF-A组细胞数目及形态与正常DC组相比无明显改变,对所检测的Dc表面抗原并无明显抑制(P＞0.05),但在功能实验中它却起到了明显抑制T细胞增殖及杀伤功能的作用.结论 结肠癌组织匀浆上清液所模拟的微环境对DC的诱导分化及功能有明显的抑制作用,在该过程中VEGF-A起到抑制T细胞免疫功能的作用,但该作用并非通过抑制DC共刺激分子表达而实现.     

人胎盘因子对小鼠体内抗体分泌的影响

为探索ＨＰＳ对小鼠体内ＩｇＭ型抗分泌的影响；用ＳＢＲＣ免疫雌性Ｂａｌｂ／ｃ健康小白鼠的财时，腹腔注射不同浓度的ＨＰＳ，免疫第４天检测小鼠血清中ＩｇＭ型抗ＳＲＢＣ抗体的效价。     

日本血吸虫感染BALB／c小鼠脾脏细胞学的变化

目的观察BALB／c小鼠感染日本血吸虫（Schistosoma japonicum，$）6．8周后脾脏细胞学的改变情况。方法用日本血吸虫尾蚴腹贴法建立日本血吸虫感染的小鼠模型。6～8周后观察肝脏、脾脏大小．称重：做脾脏淋巴细胞计数；用流式细胞仪检测脾脏淋巴细胞的大小、密度和T、B细胞分类以及Th细胞亚群睛况：用酶联免疫吸附实验（enzyme linked immunosorbent assay，ELISA）检测血清中可溶性虫卵抗原（soluble egg antigen，SEA）所诱导的特异性抗体IgG的产生情况。结果日本血吸虫感染BALB／c小鼠6～8周后，脾脏体积明显增大，重量增加，细胞数量明显增多。流式细胞仪检测发现脾脏中出现一群体积明显增大的细胞群，该群细胞表达少量的CD4、CD8、CD19和DX－5分子；Th1／Th2轴发生偏移，Th17细胞数量增多；ELISA结果表明血清中SEA特异性抗体IgG水平明显升高。结论日本血吸虫感染的BALB／c小鼠脾脏出现明显的细胞学改变，尤其是Th1细胞数目下降，浆细胞、Th2细胞及Th17细胞数目增多，为研究日本血吸虫感染后期虫卵肉芽肿形成的免疫病理机制奠定了基础。     

卵清白蛋白特异性T细胞免疫诱导BALB/c小鼠的调节性免疫应答

目的：研究T细胞免疫后正常小鼠的调节性免疫应答，方法：应用体外扩增的卵清白蛋白（OVA）特异的T细胞克隆免疫BALB／c小鼠，3H－TdR掺入法分析细胞增殖，3H－TdR标记靶细胞检测杀伤T细胞的杀伤效应，间接免疫荧光法分析血清中抗T细胞抗体水平。结果：T细胞免疫后能诱导BALB/c小鼠产生调节性T细胞的增殖反应，对靶细胞的杀伤效应以及针对于活化的T细胞的体液免疫应答，并进一步降低机体对OVA抗原的应答，结论：T细胞免疫能诱导正常机体的调节性免疫应答。     

人参皂甙对小鼠脾脏树突状细胞增殖的影响

树突状细胞 (DC )是已知机体内功能最强的抗原递呈细胞 (APC ) ,能在体内外直接激活初始 (naive)T细胞 ,是自体、异体混合淋巴细胞反应中重要的刺激细胞 ,其作用比其他APC强 10～ 10 0倍[1] 。目前DC在感染免疫、移植排斥、肿瘤免疫及免疫缺陷等病理过程中所起的作用越来越受到人们的重视。但DC数量极微 ,分离纯化困难 ,给DC的研究和应用带来极大困难。目前 ,体外扩增DC多采用GM CSF与IL 4联用[2 ,3 ] ,但其成本较高。本实验应用人参皂甙 (ginsensides,GS )观察其对小鼠脾脏DC增殖的影响 ,以期为DC的体外扩增提供新的方法。1　…     

当归多糖对小鼠脾脏树突状细胞增殖的影响

目的：研究当归多糖（ASP）对体外小鼠脾脏树突状细胞（DCs）增殖的影响。方法：采用MTT法,以细胞因子即粒-巨细胞集落刺激因子（GM-CSF）＋白细胞介素4（IL-4）作比较,观察不同浓度ASP以及细胞因子＋不同浓度的ASP对小鼠脾脏DCs的增殖作用。结果：ASP31.25-250μg／ml可明显刺激小鼠脾脏DCs增殖,与细胞因子组相比,其中间浓度62.5～125μg／ml作用明显;ASP＋细胞因子,与对照组相比,均有显著的增殖作用,且其在较低浓度31.25、62.5、125μg／ml明显高于细胞因子组。结论：ASP不仅能促进小鼠脾脏DCs的增殖,而且与细胞因子有显著的协同作用,具有类生长因子和协同生长因子的作用。     

脂多糖诱发的同基因妊娠BALB/c和NOD/SCID小鼠早产模型

目的：研究脂多糖（LPS）诱发同基因妊娠BALB/c小鼠和非肥胖性糖尿病/重度联合免疫缺陷（NOD/SCID）小鼠早产的机制。方法：在预先阻断或未阻断Toll样受体4（TLR4）的条件下采用LPS刺激,并比较各组BALB/c和NOD/SCID小鼠的早产率和胚胎死亡率。由于预实验显示预期的早产均发生于孕16d,因此,实验中在早产发生之前处死小鼠,收集每只孕鼠的胎盘。采用流式细胞术检测胎盘CD45^＋细胞表面TLR4、CD80和细胞内TNF-α的表达率。结果：采用LPS可诱发BALB/c小鼠早产,而NOD/SCID小鼠则对LPS的诱导有抵抗。经LPS刺激后,TLR4的表达在BALB/c和NOD/SCID小鼠均无显著改变,但是两组小鼠CD45^＋CD80^＋细胞的百分率均升高。相反,LPS刺激后仅BALB/c小鼠CD45＋TNF-α＋细胞的百分率升高,而NOD/SCID小鼠则否。通过预先阻断TLR4的表达可消除LPS对BALB/c小鼠CD80和TNF-α表达的影响,并显著降低LPS诱发的早产率。结论：虽然LPS未能改变TLR4的表达,但是二者相互作用,可激发CD45^＋CD80^＋细胞的动员,导致炎性细胞因子产生增多,并最终导致早产。BALB/c和NOD/SCID小鼠对LPS刺激的敏感性存在差异,提示NOD/SCID小鼠缺乏功能正常的T细胞和NK细胞,可能是这种小鼠对LPS诱发的早产有抵抗的原因之一。     

催乳素对小鼠脾脏CD11c+树突状细胞合成细胞因子的调控

本研究采用逆转录-多聚酶链反应(RT-PCR)方法,在mRNA水平上了解不同浓度的催乳素(PRL)对小鼠脾脏树突状细胞CD11c+(spleen CD11c-positive dendritic cells,SDC)合成细胞因子的影响。结果表明,低(0.01 nmol/L)、中浓度(0.1nmol/L)的PRL可以上调IL-6、IL-10、IL-12和TNF-α的水平而高浓度(1 nmol/L)则降低它们的表达(IL-12除外)。这提示PRL可能通过改变抗原提呈细胞SDC细胞因子的合成,进而参与调节机体的生理或病理性免疫反应。     

NOD/SCID孕鼠脾脏和胎盘CD45+细胞内细胞因子的表达

目的研究NOD/SCID孕鼠胚胎吸收率（Resorption rate,RR）与母-胎界面局部免疫状况的关系。方法计算并比较孕13.5天同基因妊娠NOD/SCID×NOD/SCID小鼠和非免疫缺陷的BALB/c×BALB/c小鼠的RR,并采用4色流式细胞术检测NOD/SCID小鼠非孕期和孕13.5天脾脏和胎盘细胞内细胞因子的表达状况,以明确其与妊娠耐受相关的淋巴细胞功能亚群。结果NOD/SCID小鼠的RR与对照组BALB/c小鼠相比无显著差异。与此相应,虽然能够证实NOD/SCID小鼠具有多重免疫缺陷,但是孕期母-胎界面多种功能性细胞亚群的百分率发生自发性改变。结论NOD/SCID小鼠脾脏和胎盘某些细胞百分率的自发性改变可能对妊娠结局有利。     

Adipose tissue dendritic cells in steady-state

Healthy white adipose tissue (WAT) participates in regulating systemic metabolism, whereas dysfunctional WAT plays a prominent role in the development of obesity-associated co-morbidities. Tissue-resident immune cells are important for maintaining WAT homeostasis, including conventional dendritic cells (cDCs) which are critical in the initiation and regulation of adaptive immune responses. Due to phenotypic overlap with other myeloid cells, the distinct contribution of WAT cDCs has been poorly understood. This review will discuss the contribution of cDCs in the maintenance of WAT homeostasis. In particular, the review will focus on the metabolic cross-talk between cDCs and adipocytes that regulates local immune responses during physiological conditions.     

Tolerogenic dendritic cells and their potential applications

Dendritic cells (DCs) play a pivotal role in regulating the balance between immunity and tolerance of the immune system. Recent advancements in DC biology and techniques for manipulating the function of these cells have shown their immense therapeutic potential for treating a variety of immune disorders. Theoretically, antigen-specific tolerogenic DCs can be generated in vitro and delivered to patients to correct the dysfunctional immune responses that attack their own tissues or over-react to innocuous foreign antigens. However, DCs are a heterogeneous population of cells with differences in cell surface makers, differentiation pathways and functions. Studies are needed to examine which subset of DCs can be used for what type of applications. Furthermore, most of the information on tolerogenic DCs has been obtained from animal models and translational studies are needed to examine how a DC therapeutic strategy can be implemented clinically to modulate immunity.     

尿酸钠对BALB/c小鼠抗体应答及树突状细胞和迟发型超敏反应的影响

目的:探讨尿酸钠作为佐剂对BALB/c小鼠体液和细胞免疫应答的影响。方法:利用尿酸钠悬浮液为佐剂、天花粉蛋白(TCS)为免疫原对BALB/c小鼠进行免疫,以酶联免疫测定法检测特异性抗体IgG的效价。体外诱导小鼠树突状细胞(DC),流式细胞术分析DC表型,评价尿酸钠体外对DC成熟的效应。以二硝基氟苯建立迟发型超敏反应(DTH)模型,分析尿酸钠在体内对细胞免疫应答的影响。结果:传统弗氏佐剂可极大地增强小鼠对TCS的抗体应答,尿酸钠佐剂对抗体应答不但没有促进,与单独使用免疫原相比,抗体应答反而明显降低。流式细胞术分析显示,尿酸钠对DC表达CD11c和CD83没有影响,但可明显提高MHCII的表达水平。DTH模型中,尿酸钠增强致敏原引发的耳廓肿胀程度,并促进DTH小鼠淋巴细胞的体外增殖能力。结论:尿酸钠悬浮液作为佐剂,对细胞免疫有显著增强作用,而对体液免疫应答却有一定的抑制作用,提示该佐剂在疫苗研究中有潜在应用前景。     

Programmed cell death of dendritic cells in immune regulation

Summary: Programmed cell death is essential for the maintenance of lymphocyte homeostasis and immune tolerance. Dendritic cells (DCs), the most efficient antigen-presenting cells, represent a small cell population in the immune system. However, DCs play major roles in the regulation of both innate and adaptive immune responses. Programmed cell death in DCs is essential for regulating DC homeostasis and consequently, the scope of immune responses. Interestingly, different DC subsets show varied turnover rates in vivo. The conventional DCs are relatively short-lived in most lymphoid organs, while plasmacytoid DCs are long-lived cells. Mitochondrion-dependent programmed cell death plays an important role in regulating spontaneous DC turnover. Antigen-specific T cells are also capable of killing DCs, thereby providing a mechanism for negative feedback regulation of immune responses. It has been shown that a surplus of DCs due to defects in programmed cell death leads to overactivation of lymphocytes and the onset of autoimmunity. Studying programmed cell death in DCs will shed light on the roles for DC turnover in the regulation of the duration and magnitude of immune responses in vivo and in the maintenance of immune tolerance.     

Contribution of dendritic cells to the autoimmune pathology of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a heterogeneous disease in which excessive inflammation, autoantibodies and complement activation lead to multisystem tissue damage. The contribution of the individual genetic composition has been extensively studied, and several susceptibility genes related to immune pathways that participate in SLE pathogenesis have been identified. It has been proposed that SLE takes place when susceptibility factors interact with environmental stimuli leading to a deregulated immune response. Experimental evidence suggests that such events are related to the failure of T-cell and B-cell suppression mediated by defects in cell signalling, immune tolerance and apoptotic mechanism promoting autoimmunity. In addition, it has been reported that dendritic cells (DCs) from SLE patients, which are crucial in the modulation of peripheral tolerance to self-antigens, show an increased ratio of activating/inhibitory receptors on their surfaces. This phenotype and an augmented expression of co-stimulatory molecules is thought to be critical for disease pathogenesis. Accordingly, tolerogenic DCs can be a potential strategy for developing antigen-specific therapies to reduce detrimental inflammation without causing systemic immunosuppression. In this review article we discuss the most relevant data relative to the contribution of DCs to the triggering of SLE.     

Tolerogenic dendritic cells and their applications in transplantation

In transplantation immunology, the ultimate goal is always to successfully and specifically induce immune tolerance of allografts. Tolerogenic dendritic cells (tol-DCs) with immunoregulatory functions have attracted much attention as they play important roles in inducing and maintaining immune tolerance. Here, we focused on tol-DCs that have the potential to promote immune tolerance after solid-organ transplantation. We focus on their development and interactions with other regulatory cells, and we also explore various tol-DC engineering protocols. Harnessing tol-DCs represents a promising cellular therapy for promoting long-term graft functional survival in transplant recipients that will most likely be achieved in the future.     

树突状细胞的标志物CD1a和CD83在子宫腺肌症中的表达及意义

目的:探讨不同分化阶段树突状细胞(DCs)在子宫腺肌症发病中的作用。方法:收集子宫腺肌症组异位内膜、在位内膜及正常对照组内膜,应用免疫组织化学和免疫印迹检测不同分化阶段DCs的分布、形态及其标志物CD1a、CD83蛋白的表达情况。结果:DCs均分布于腺体间、血管间,CD1a~+imDCs呈圆形、卵圆形,CD83~+mDCs形态不规则,有多个突起;子宫腺肌症组CD1a的表达较正常对照组明显增高,且子宫腺肌症异位内膜CD1a的表达较在位内膜显著增高;子宫腺肌症组CD83的表达较正常对照组明显降低,且子宫腺肌症异位内膜CD83的表达较在位内膜显著降低。结论:局部组织CD1a~+imDCs数量的增加及CD83~+mDCs数量的减少促进子宫腺肌症的发生发展。     

The current immune function of hepatic dendritic cells

While only a small percentage of the liver as dendritic cells, they play a major role in the regulation of liver immunity. Four major types of dendritic cell subsets include myeloid CD8α^-B220^-, lymphoid CD8α^＋B220^-, plasmacytoid CD8α^-B220^＋, and natural killer dendritic cell with CD8α^-B220^-NK1.1^＋ phenotype. Although these subsets have slightly different characteristics, they are all poor naive T cell stimulators. In exchange for their reduced capacity for allostimulation, hepatic DCs are equipped with an enhanced ability to secrete cytokines in response to TLR stimulation. In addition, they have increased level of phagocytosis. Both of these traits suggest hepatic DC as part of the innate immune system. With such a high rate of exposure to the dietary and commensal antigens, it is important for the hepatic DCs to have an enhanced innate response while maintaining a tolerogenic state to avoid chronic inflammation. Only upon secondary infectivity does the hepatic DC activate memory T cells for rapid eradication of recurring pathogen. On the other hand, overly tolerogenic characteristics of hepatic DC may be responsible for the increase prevalence of autoimmunity or liver malignancies.