hKDR基因胞外区mRNA转染树突状细胞诱发对表达mKDR的Hepa1-6细胞的特异性杀伤效应

目的探讨人血管内皮细胞生长因子受体-2(KDR)胞外段(Ig1~3)mRNA修饰的树突状细胞(DC)诱发的体外特异性细胞免疫效应。方法构建pmRNA IRES-hKDR)(Ig1~3),体外转录出相应的mRNA,Western blot鉴定其蛋白表达;以hKDR(Ig1~3)mRNA致敏来源于小鼠骨髓的DC,并免疫小鼠,同时设空白DC对照组,7d后取鼠脾细胞为效应细胞,表达mKDR的肿瘤细胞为靶细胞按100∶1、50∶1、25∶1的比例混合,用乳酸脱氢酶(LDH)释放法检测细胞毒作用。结果未经修饰DC激活的细胞毒性T淋巴细胞(CTL)对靶细胞的杀伤率为(19.6±3.7)%、(10.2±2.6)%、(6.2±2.2)%,经mRNA修饰的DC激活的CTL对靶细胞杀伤率为(75.2±2.3)%、(54.3±3.4)%、(20.9±3.1)%,同一效靶比情况下显著强于其他3组。结论hKDR(Ig1~3)mRNA致敏的DC能诱导针对Hepa1-6(mKDR)的特异性细胞免疫反应。     

卡介苗联合Poly I:C接种对新生期小鼠脾脏T细胞的影响

目的 研究卡介苗(BCG)联合Poly I:C新生期接种对小鼠脾脏T细胞功能亚群发育的影响.方法 新生清洁级BALB/c小鼠32只,分4组:对照组、BCG组、Poly I:C组、BCG和Poly I:C联合接种组,新生期接种4周后取脾细胞用流式细胞仪检测CD3+ CD8+ IFN-γ+、CD3+ CD8- IFN-γ+、CD3+ CD8+ IL-4+ 、CD3+ CD8- IL-4+、CIM+ Foxp3+ T细胞的比例,其分别代表Tc1、TH1、Tc2、TH2和调节性T细胞(Treg)亚群.结果 BCG组、Poly I:C组、BCG和Poly I:C联合接种组TH1、Tc1细胞比例明显高于对照组(P＜0.05或P＜0.01),3个接种组间比较差异无统计学意义;Tc2、TH2和Treg比例各组间比较差异没有统计学意义;3个接种组TH1/TH2和总IFN-γ/IL-4比值明显高于对照组(P＜0.05或P＜0.01),联合接种组TH1/TH2比值高于BCG组(P＜0.05),Tc1/Tc2比值各组间差异没有统计学意义;CD4+ Foxp3+ T细胞比例各组间比较差异没有统计学意义.结论 新生期BCG和Poly I:C接种均能促进TH1、Tc1细胞亚群的发育,提高TH1/TH2比值,其联合接种在TH1/TH2水平可能具有一定的协同作用,但不能影响CD4+ Foxp3+ Treg细胞的比例.     

CpG-ODN在T细胞活化和抑制中的作用

CpG-ODN是人工合成的含有CpG基序的ODNs,能够模拟细菌DNA的免疫刺激活性,通过细胞内定位的Toll样受体9活化抗原递呈细胞（APC）,如树突状细胞（DC）和B细胞,分泌大量Th1型细胞因子诱导产生Th1型免疫应答。CpG—ODN不仅增强T淋巴细胞的活化,在特定条件下还可以抑制T淋巴细胞功能。在抗感染、抗肿瘤疾病中,CpG—ODN作为新型的免疫佐剂得到了广泛的应用,但其安全性问题应引起足够的重视。     

CFSE和AnnexinV双标记技术检测细胞毒性T淋巴细胞的杀伤效应

目的 利用CFSE和AnnexinV对靶细胞进行染色,建立一种通过流式细胞仪技术检测细胞毒性T淋巴细胞(CTL)杀伤效应的新方法.方法 应用磁珠分 OT-Ⅰ T细胞受体(TCR)转基因小鼠CD8+CTL细胞和脾脏树突状细胞(sDC),将2种细胞和鸡卵蛋白(OVA)抗原肽共培养65 h后分析其细胞分裂增殖、IFN-γ和IL-4细胞内因子及穿孔素、颗粒酶等效应分子的表达特性,收获具备杀伤效应的CD8+CTL细胞.利用预先激活的小鼠CD8+CTL细胞作为效应细胞,CFSE标记的同系小鼠脾细胞作为靶细胞,体内体外2种条件下利用AnnexinV染色靶细胞检测特异性CTL杀伤效应,并与CFSEhigh和CFSElow标记靶细胞检测体内CTL杀伤效应的经典方法进行比较.结果 OT-Ⅰ初始CD8+CTL细胞体外活化培养后有4个分裂峰,54.1%的CTL细胞表达IFN-γ,0.78%的细胞表达IL-4,穿孔素、颗粒酶2种CTL效应分子均为阳性表达,CD8+CTL细胞已经具备CTL杀伤活性.体外实验结果显示OVA+靶细胞在共培养条件下,AnnexinV阳性细胞比例明显高于分离培养条件下[(62.4±3.5)%比(28.3±2.2)%,P＜0.01],OVA-的AnnexinV阳性靶细胞比例在不同培养条件下差异无统计学意义[(20.3±4.8)%比(17.3±2.9)%,P＞0.05].共培养条件下OVA+靶细胞其AnnexinV阳性细胞比例也明显高于OVA-靶细胞(P＜0.01),在分离培养条件下差异则无统计学意义(P＞0.05).活化的CD8+CTL细胞所介导的杀伤效应具有抗原依赖性和部分的细胞接触依赖性.体内CTL实验中,利用CFSE和AnnexinV双标记的方法检测出靶细胞的杀伤率高于未孵育OVA抗原肽的对照组靶细胞[(52.63±8.12)%比(13.84±4.37)%,P＜0.01].而同等条件下利用CFSEhigh和CFSElow双标记的方法检出靶细胞杀伤率为41%.结论 CFSE和AnnexinV双标记靶细胞的方法检测CTL杀伤效应与单纯的使用CFSEhigh和CFSElow标记靶细胞方法有很好的可比性,该策略为利用流式细胞仪技术检测细胞杀伤功能的方法学提供了新的选择.     

转染FasL基因树突状细胞诱导异基因小鼠脾脏T细胞凋亡的研究

目的 制备稳定表达FasL蛋白的小鼠骨髓源树突状细胞(dendritic cell,DC)并探讨其诱导异基因小鼠脾脏T细胞凋亡的机理.方法 采用培养基选择法体外培养小鼠骨髓源DC,脂质体法转染FasL基因至小鼠成熟DC,实时定量PCR检测转染前后FasL mRNA的表达,流式细胞仪和免疫蛋白印迹检测转染前后FasL蛋白的表达.异系小鼠静脉分别输注未转染DC、转染空质粒DC和转染FasL的DC,7 d后TdT介导的原位末端标记法(TUNEL)和流式细胞仪检测脾脏中T淋巴细胞凋亡.结果 体外培养可获得成熟的小鼠骨髓源DC,转染FasL基因的DC较未转染DC FasL mRNA和FasL蛋白表达明显升高.对脾脏中T淋巴细胞凋亡的检测发现,转染FasL的DC组凋亡指数(11.67±1.53)明显高于未转染DC组(2.67±0.58)和转染空质粒组(3.33±0.58),P＜0.01.结论 培养基选择法可收获大量骨髓源DC,脂质体转染FasL基因至小鼠骨髓源DC,可以使DC高表达FasL蛋白.转染FasL的DC输注能明显诱导异系小鼠脾脏T淋巴细胞凋亡.     

肠道菌群失调促进小鼠肺树突状细胞成熟并增强TLR2和TLR4表达

目的 观察卵清蛋白(OVA)雾化吸入激发对抗生素所致肠道菌群失调小鼠肺组织中树突状细胞(DC)成熟度和Toll样受体2(TLR2)、TLR4表达的影响.方法 将64只3周龄雌性BALB/c小鼠随机分为4组,菌群失调组、菌群失调加激发组、激发组、对照组,每组16只.于实验第14天用流式细胞术检测肺组织中DC成熟度(MHC-Ⅱ类分子)及其膜表面TLR2、TLR4的表达水平,采用免疫组织化学法检测肺组织中转化生长因子p1(TGF-β1)、白细胞介素-6(IL-6)蛋白表达,ELISA检测支气管肺泡灌洗液(BALF)中TGF-β1、IL-6的产生水平.结果 与对照组和激发组比较,菌群失调组及菌群失调加激发组小鼠肺组织中DC细胞膜表面MHC-Ⅱ类分子及TLR2、TLR4的表达均增加,但这些分子在上述2组中的表达无差异(P＞0.05).与其他3组比较,菌群失调加激发组小鼠肺组织及BALF中TGF-β1、IL-6水平增高.结论 肠道菌群失调使肺部DC成熟度增高,TLR2、TLR4表达增强.     

Toll样配体(R-848)与IL-12对人NK细胞亚群IFN-γ产生的作用

目的:研究Toll样配体(R-848)与IL-12对人NK细胞IFN-γ产生的作用和细胞亚群分析。方法:分离人外周血PBMC和纯化的NK细胞,分别与R-848、IL-12或R-848和IL-12共同培养。利用ELISA法检测培养上清中IFN-γ的水平,再利用流式检测并分析产生IFN-γ的NK细胞亚群。结果:正常人PBMC分别与不同浓度的Toll样配体R-848、LPS、CpG培养后,均以剂量依赖的方式诱导IFN-γ的产生,但以R-848的效果最佳。细胞亚群分析的结果表明,R-848对CD4 T和CD8 T细胞IFN-γ的表达无明显作用,但显著地促进CD56 细胞表达IFN-γ。同样地,在IL-12刺激之下,CD56bright和CD56dimNK细胞表达IFN-γ。当R-848和IL-12与PBMC和纯化NK细胞孵育后,对CD56bright和CD56dimNK细胞IFN-γ的表达具有协同作用。结论:Toll样配体与NK细胞Toll样受体结合后,促进CD56brightNK细胞亚群IFN-γ的产生,而且Toll样配体与IL-12具有协同作用,提示Toll样受体与细胞因子在调控NK细胞的生物活性中发挥着十分重要的作用。     

Ⅰ型干扰素参与调节SLE外周T细胞活化和TLR表达谱的研究

血清高水平Ⅰ型干扰素(typeⅠinterferon)是系统性红斑狼疮(SLE)患者重要的病理特征之一,外周高水平IFN-α对T细胞的免疫调节作用值得深入探讨。本研究首先比较分析了SLE患者外周血T细胞活化和TLR分子表达格局,结果显示SLE患者外周血CD4~+或CD8~+T细胞和正常人相比呈现出更加活化的表型变化,其表面活化标志CD69和HLA-DR表达阳性率均高于正常人;分析T细胞表达TLR分子格局发现,SLE患者较正常人T细胞中TLR分子的表达有明显升高,其中CD4~+T细胞中TLR8和TLR9的升高明显,而在CD8~+T细胞中明显升高的TLR分子有TLR3和TLR8;结合SLE病理状态下外周高水平IFN-α的持续存在,我们进一步分析了IFN-α对正常T细胞活化和TLR分子表达谱的影响,结果显示IFN-α协同TCR信号可以促进T细胞的活化,并上调T细胞中部分TLR分子的表达,其中CD4~+和CD8~+T细胞中TLR8的表达均明显上升。综合分析SLE患者和经IFN-α活化的正常T细胞的活化和TLR分子表达谱的变化格局,提示SLE病理状态下高水平的Ⅰ型干扰素可以与T细胞的持续活化有关,其对T细胞表达TLR分子格局的影响,特别是与核酸类分子配体相关的TLR分子的表达增高为内源性核酸类配体参与T细胞的活化提供了分子基础。     

TLR7 激动剂替代IFN鄄酌诱导CIK 细胞杀伤肿瘤的研究

目的:探讨TLR7 激动剂(Toll like receptor 7 agonist,Tlr7a)替代IFN体外培养细胞因子诱导杀伤性细胞(Cytokine-induced killer cell,CIK)抗肿瘤的免疫效应。方法:分离健康人外周血单个核细胞,在体外诱导CIK。分两组:CIK 组和Tlr7a-CIK 组。对各组分别进行免疫杀伤性研究,检测细胞免疫表型并分析对K562 肿瘤细胞的杀伤活性。结果:CD56+ 细胞在Tlr7a-CIK 组显著增加(P<0.05),Tlr7a-CIK 组杀伤活性较CIK 组显著增强(P<0.05)。结论:Tlr7a 可以替代IFN促进CIK 细胞杀伤肿瘤。     

负载乳腺癌细胞冻融抗原的DC对CTL体外特异性杀伤活性的影响

目的：研究乳腺癌患者腋下淋巴结单个核细胞来源的DC,经自体肿瘤细胞冻融抗原刺激后,对CTL体外特异性杀伤活性的影响。方法：以细胞因子分别诱导、培养乳腺癌腋下淋巴结单个核细胞中的DC及TDLNC,用自体癌细胞冻融抗原刺激DC,并和TDLNC共培养,诱导成为肿瘤抗原特异性CTL;检测特异性CTL对自体乳腺癌细胞及MCF-7细胞的体外杀伤活性。结果：DC-Ag-TDLNC、DC-TDLNC和TDLNC对自体乳腺癌细胞的杀伤率分别为67.64%、31.25%和26.36%,P〈0.001;三种TDLNC细胞对MCF-7细胞的杀伤率无明显差异（P〉0.05）。结论：乳腺癌患者腋下引流淋巴结中的单个核细胞在细胞因子的诱导、活化及自体肿瘤抗原刺激下,可分化为成熟DC,DC可促进TDLNC增殖、分化为特异性CTL,后者对自体肿瘤细胞有较高的杀伤活性。     

miR-221通过下调PTEN促进肺癌A549细胞增殖

目的:探讨微小RNA-221(miR-221)对肺癌A549细胞增殖的影响及其相关作用机制。方法:通过脂质体转染试剂Lipofectamine 2000把miR-221 mimics转染入肺癌细胞A549内,RT-q PCR检测miR-221和PTEN mRNA的表达;Western blot检测PTEN蛋白表达;CCK-8及平板克隆形成实验检测细胞增殖能力。构建含PTEN 3'-UTR的萤光素酶报告载体,检验miR-221对PTEN的靶向调控作用。结果:转染miR-221后肺癌细胞中miR-221表达水平明显高于对照组及空白组(P0.01),PTEN mRNA及蛋白表达均显著下降(P0.05);细胞增殖及集落形成能力明显增强(P0.05);miR-221能抑制PTEN的萤光素酶活性。结论:miR-221能够抑制肺癌A549细胞中PTEN的表达,并促进细胞增殖。     

Expression and secretion of antiviral factors by trophoblast cells following stimulation by the TLR-3 agonist, Poly(I : C)

BACKGROUND: During pregnancy, the placenta may become exposed to micro-organisms, such as viruses, which may pose a substantial threat to the embryo/fetus well-being. Recent insight into the immunological capabilities of the trophoblast suggests that the placenta may function as an active barrier by recognizing and responding to pathogens through Toll-like receptors (TLRs). METHODS: The objective of this study was to determine whether the engagement of TLR-3 with viral dsRNA by first-trimester trophoblast could induce the production of factors necessary to generate an antiviral response. Therefore, trophoblast cells were exposed to the TLR-3 agonist, Poly(I : C). RESULTS: We report that following stimulation with Poly(I : C), first-trimester trophoblast cells produce interferon beta (IFNbeta) and secretory leukocyte protease inhibitor (SLPI), as well as the intracellular factors 2',5'-oligoadenylate synthetase (OAS), Myxovirus-resistance A (MxA) and apolipoprotein B mRNA-editing enzyme-catalytic polypeptide-like 3G (APOBEC3G). This response is TLR-3 specific because the TLR-4 ligand, lipopolysaccharide (LPS), had no effect on the production of these antimicrobial factors. Furthermore, we describe a positive feedback mechanism in which IFNbeta enhances the antiviral response by promoting the production of OAS, MxA and APOBEC3G. CONCLUSIONS: These findings suggest that trophoblast cells are able to recognize and specifically respond to viral products in a highly regulated fashion and that the placenta may be pivotal in the control of viral infections at the maternal-fetal interface.     

树突状细胞诱导的CIK细胞对肺癌生长的抑制作用

目的探讨树突状细胞诱导的CIK细胞对肺癌移植瘤细胞生长的抑制作用。方法建立肺癌皮下移植瘤模型;分离患者外周血单个核细胞,培养成熟的DC及CIK细胞;用反复冻融肺癌组织的方法制备肿瘤细胞裂解物并负载DC,诱导DC-CIK细胞;进行肺癌移植瘤内注射,比较两组裸鼠移植瘤体积及重量,观察其抑瘤情况。结果 DC-CIK细胞对肺癌皮下移植瘤细胞的抑制率为70.3%,抑制作用明显强于DC或CIK细胞的抑制作用(P0.05)。结论树突状细胞诱导的CIK细胞能够有效抑制肺癌移植瘤生长。     

Rab27A regulates exosome secretion from lung adenocarcinoma cells A549: involvement of EPI64

Exosomes are small membrane vesicles secreted into the extracellular compartment by exocytosis. The unique composition of exosomes can be transported to other cells which allow cells to exert biological functions at distant sites. However, in lung cancer, the regulation of exosome secretion was poorly understood. In this study, we employed human lung adenocarcinoma A549 cells to determine the exosome secretion and involved regulation mechanism. We found that Rab27A was expressed in A549 cells and the reduction of Rab27A by Rab27A‐specific shRNA could significantly decrease the secretion of exosome by A549 cells. EPI64, a candidate GAP that is specific for Rab27, was also detected in A549 cells. By pull‐down assay, we found that EPI64 participated in the exosome secretion of A549 cells by acting as a specific GAP for Rab27A, not Rab27B. Overexpression of EPI64 enhanced exosome secretion. Taken together, in A549 cells, EPI64 could regulate the exosome secretion by functioning as a GAP specific for Rab27A.     

赫赛汀对吉非替尼诱导肺癌A549细胞凋亡的影响

目的： 研究吉非替尼与赫赛汀联合应用对人肺腺癌A549 细胞凋亡的影响。方法: 应用MTT法,流式细胞仪Annexin V－PI 双标法、DAPI荧光染色等多项方法,体外研究吉非替尼与赫赛汀联合对A549 细胞的促凋亡作用。结果: 吉非替尼与赫赛汀单独应用及联合应用均可以明显抑制人肺腺癌A549细胞的生长，促进细胞凋亡,并呈浓度及时间依赖性,2者联合作用人肺腺癌A549 细胞24 h、48 h、72 h 的凋亡率显著高于单用吉非替尼或赫赛汀组(P<0.05),2者呈现出相加的抗瘤效果。结论: 吉非替尼与赫赛汀联合应用在体外对人肺腺癌A549 细胞有明显的促凋亡作用。     

Induction of immunosuppressive functions of dendritic cells in vivo by CD4+CD25+ regulatory T cells: role of B7-H3 expression and antigen presentation

Suppressive functions of CD4+CD25+ regulatory T cells (Treg) are mainly studied by their interaction with conventional T cells. However, there is evidence that Treg also interact with antigen-presenting cells (APC), leading to suppression of APC function in in vitro coculture systems. Studying the in vivo distribution of Treg after injection, we found that Treg are located in direct proximity to dendritic cells (DC) and affect their functional maturation status. After contact to Treg, DC up-regulate the inhibitory B7-H3 molecule and display reduced numbers of MHC-peptide complexes, leading to impaired T cell stimulatory function. When Treg-exposed DC were used to immunize animals against antigens, the DC failed to produce a robust immune response as compared to control DC. Thus, these data indicate that Treg are able to inhibit DC activation and produce an inhibitory phenotype of DC. Accordingly, Treg may recruit DC for the amplification of immunosuppression by restraining their maturation in vivo and inducing an immunosuppressive phenotype of DC.     

The viral TLR3 agonist poly(I:C) stimulates phagocytosis and intracellular killing of Escherichia coli by microglial cells

Stimulation of murine primary microglia with Toll-like receptor (TLR) agonists enhances their ability to phagocytose and kill bacteria. Here we show that the viral TLR3 agonist poly(I:C) stimulates the release of cyto-/chemokines and nitric oxide by microglia. Poly(I:C) increases microglial phagocytosis and intracellular killing of Escherichia coli K1, a pathogenic encapsulated bacterial strain, after 30 and 90 min of co-incubation. Stimulation with a viral epitope may strengthen the resistance of the brain to bacterial infections in vivo. Our data encourage animal experiments with poly(I:C) derivatives to assess whether this approach can increase the resistance of the CNS against bacterial infections.     

Combined use of toll-like receptor agonists and prostaglandin E(2) in the FastDC model: rapid generation of human monocyte-derived dendritic cells capable of migration and IL-12p70 production

Phenotypical maturation, IL-12p70 production and migration upon chemokine receptor CCR7 ligation are currently proposed as requirements for the use of human monocyte-derived dendritic cells (DC) in antitumoral vaccination. We have previously described a short-term protocol for DC generation from monocytes including stimulation with TNF-alpha, IL-1beta and PGE(2) (FastDC). These "conventional" FastDC are mature, migrate in response to CCR7 ligation and effectively stimulate autologeous T cells in vitro, but are deficient in IL-12p70 production. Here, conventional FastDC were compared to FastDC activated with different TLR ligands. High levels of IL-12p70 were induced by combined activation of FastDC with TLR4 and TLR7/8 ligands. IL-12 secretion could be maximized by additional T cell-derived stimulation. However, TLR-stimulated FastDC failed to migrate upon CCR7 ligation, independent of additional activation with CD40 ligand and IFN-gamma. The presence of PGE(2) during TLR ligation fully restored migratory capacity of FastDC, but left IL-12p70 production and activation of tumor antigen-specific cytotoxic T cells unaffected, challenging previous findings obtained with standard 7-day monocyte-derived DC. The FastDC model thus not only represents an effective tool for antitumoral vaccination, but may also provide novel insights into human DC biology.     

视黄酸对TNF-α和IL-6诱导的肺癌细胞分泌C3和B因子的影响

目的:从免疫治疗的角度探讨近年用来治疗恶性肿瘤的视黄酸(RA)与TNF-α、IL-6相互作用对人肺癌细胞株A549分泌C3及B因子的影响。方法:用ELISA、W estern b lot的方法检测培养上清中C3及B因子蛋白,用RT-PCR检测细胞内C3及B因子的mRNA。结果:当TNF-α、IL-6和RA分别为10μg/L、50μg/L和1μmol/L时,ELISA、W estern b lot和RT-PCR法均显示TNF-α、IL-6增进A549细胞分泌C3及B因子和其mRNA表达;RA对A549细胞分泌C3及B因子没有影响;TNF-α组和TNF-α+RA组培养上清中C3的量分别为91.40±12.59和133.59±11.25(ng/106cells)(P<0.01),B因子的量分别为100.54±10.39和190.92±15.40(ng/106cells)(P<0.01);IL-6组及IL-6+RA组培养上清中C3的量分别为63.48±9.42和59.89±5.88(ng/106cells)(P>0.05),B因子的量分别为13.07±2.50和32.89±4.22(ng/106cells)(P<0.01);RA(1μmol/L)对B因子的调节作用与TNF-α的浓度有关,随着TNF-α浓度的升高(0~10μg/L),RA的调节作用减低。结论:RA能上调TNF-α诱导的A549细胞分泌C3和B因子及IL-6诱导的A549分泌B因子。