树突状细胞诱导的抗肿瘤免疫诱导移植瘤细胞凋亡并抑制其增殖

目的研究树突状细胞(DC)体外诱导的细胞免疫能否抑制裸鼠移植瘤生长及其机制.方法联合应用粒/巨噬细胞集落刺激因子(GM-CSF)及白介素-4(IL-4)直接从肝癌患者外周血中培养出DC,以源于人肝癌细胞系HepG2肿瘤细胞的肿瘤抗原粗提物刺激DC,DC激活同源的T淋巴细胞产生细胞毒性T淋巴细胞(CTL),建立裸鼠人肝癌细胞系HepG2移植瘤模型.以CTL治疗裸鼠HepG2移植瘤并观察治疗效果,检测移植瘤标本肿瘤细胞凋亡情况.结果DC诱导的CTL通过诱导肿瘤细胞凋亡并抑制其增殖而抑制移植瘤生长.结论经肿瘤抗原激发的DC有可能在肿瘤的治疗中发挥重要作用.     

树突状细胞诱导抗胃癌移植瘤免疫

目的　研究树突状细胞 (DC)体外诱导的抗肿瘤免疫能否抑制裸鼠移植瘤生长并预防其发生。方法　联合应用粒 /巨噬细胞集落刺激因子 (GM -CSF)及白介素 4(IL 4)直接从胃癌患者外周血中培养出DC ;以SGC -790 1细胞的肿瘤抗原粗提物刺激DC使其激活同源的T淋巴细胞产生细胞毒性T淋巴细胞 (CTL) ;建立裸鼠SGC -790 1细胞移植瘤模型 ;DC诱导的CTL治疗裸鼠SGC -790 1细胞移植瘤 ,观察移植瘤生长 ;DC诱导的CTL预防性治疗裸鼠 ,观察随后接种的SGC -790 1细胞移植瘤发生情况。结果　DC诱导的CTL不仅能抑制裸鼠移植瘤生长并能预防其发生。结论　经肿瘤抗原激活的DC作为一新概念上的抗肿瘤疫苗有可能在治疗肿瘤及预防其术后复发和转移中发挥重要作用。     

经沉默免疫负调控基因技术处理的树突状细胞联同细胞毒性T淋巴细胞对HepG2细胞移植瘤的抑制作用

目的观察经沉默免疫负调控基因(iAPA)技术处理的树突状细胞(DC)联同细胞毒性T淋巴细胞(CTL)(iAPA-DC/CTL)对HepG2细胞移植瘤的抑制作用。方法利用人肝癌细胞系HepG2建立裸鼠皮下移植瘤模型,将12只裸鼠随机分为2组:生理盐水对照组(C组)和iAPA-DC/CTL组(DC组),每组6只,行iAPA-DC/CTL治疗4次(1周/次)后处死。实验期间观察各组裸鼠的肿瘤生长,测量肿瘤长短径并描绘肿瘤生长曲线,称量瘤重并计算抑瘤率,病理检测。两组间均数比较采用成组t检验。结果造模成功率为92.31%。C组和DC组肿瘤体积分别为:(697.69±143.99)、(485.64±188.75)mm3,DC组生长相对缓慢(t=2.28,P0.05);C组和DC组肿瘤重量分别为:(0.32±0.07)、(0.22±0.08)g,DC组肿瘤重量小于对照组(t=2.31,P0.05),抑瘤率为30.39%。肿瘤免疫组化染色后T淋巴细胞计数分别为:C组未见、DC组(39.74±5.11)个/高倍视野,DC组肿瘤内T细胞数多于对照组(t=19.05,P0.05)。结论 iAPA-DC/CTL能够有效抑制HepG2细胞裸鼠皮下移植瘤的生长。     

乙型肝炎病毒转基因小鼠B7-H1表达水平与免疫耐受的相关性

目的 探讨HBV转基因(Tg)小鼠脾脏树突状细胞(DC)及肝脏B7-H1表达水平与HBV免疫耐受的相关性. 方法 制备小鼠脾脏DC,混合淋巴细胞反应检测其同种抗原刺激能力,流式细胞仪检测DC表面主要组织相容性复合物-Ⅱ(MHC-Ⅱ)及CD80、CD86、B7-H1等共刺激分子表达水平,酶联免疫吸附法检测白细胞介素-2(IL-2)、干扰素γ、IL-10水平,逆转录聚合酶链反应法和Western blot法检测肝组织B7-H1表达水平.计量数据组间比较采用f检验.结果 DC和T淋巴细胞比例分别为1:1、1:10、1:100时,HBV Tg小鼠脾脏DC刺激同种小鼠T淋巴细胞增殖数量(每分钟放射细胞数)分别为(865.4±39.3)个、(680.2±34.8)个和(320.0±12.7)个,正常小鼠刺激同种小鼠T淋巴细胞增殖数量分别为(22 385.6±99.7)个,(17 850.6±79.4)个和(760.0±32.1)个,HBV Tg小鼠脾脏DC刺激同种小鼠T淋巴细胞增殖能力明显均弱于正常小鼠DC,t值分别为16.674、19.674和21.712,P值均<0.01,差异有统计学意义.同时,HBV Tg小鼠MHC-Ⅱ,CD80表达下调,而CD86、B7-H1表达差异无统计学意义.HBV Tg小鼠分泌IL-2、干扰素γ、IL-10水平均降低,而HBV Tg小鼠和正常小鼠肝组织表达B7-H1的差异无统计学意义. 结论 HBV免疫耐受与MHC-Ⅱ、CD80下调表达导致的HBV Tg小鼠脾脏DC功能缺陷有关,而与负性共刺激分子B7-H1表达无关.     

负载MB49肿瘤细胞抗原的DC疫苗对膀胱癌的抑制效应及机制

目的探讨负载MB49肿瘤细胞抗原的树突状细胞疫苗（DC疫苗）治疗膀胱癌的可行性及机制。方法采用反复冻融法提取MB49抗原并用其致敏DC2.4,制备DC疫苗。将24只膀胱癌荷瘤小鼠随机分为两组各12只。DC组皮下注射DC疫苗,对照组注射PBS。注射3周观察两组肿瘤体积变化,计算肿瘤抑制率;分离两组脾脏T淋巴细胞进行培养,MTT法检测细胞毒性T淋巴细胞（CTL）对MB49的杀伤率;ELISA法检测培养上清中IFN-γ水平。结果 DC组肿瘤抑制率及细胞杀伤率均明显高于对照组,P〈0.01;IFN-γ水平亦明显高于对照组,P〈0.01。结论以DC2.4为基础的DC疫苗体内具有抑制肿瘤细胞MB49增长的作用;其机制可能为激活T淋巴细胞。     

丙型肝炎病毒多CTL表位树突状细胞疫苗的构建及体外刺激T细胞应答

目的构建丙型肝炎病毒（HCV）多细胞毒性T淋巴细胞（CTL）表位树突状细胞（DC）疫苗,观察其体外刺激的T细胞反应,为下一步做体内免疫实验提供一定的资料。方法构建和制备出含绿色荧光蛋白（GFP）标签的HCV两个CTL表位的重组腺病毒,感染DC,直接在荧光显微镜下或用流式细胞仪检测其感染率;RT-PCR和Western Blot方法检测HCV多CTL表位的表达。流式细胞术分析感染前后DC的CD80、CD83、CD86和人类白细胞抗原（HLA）-DR的表达,CCK-8法观察感染重组腺病毒的DC促进T细胞的增殖效应。ELISA检测重组腺病毒刺激后的DC培养上清液内白细胞介素（IL）-12及DC和T细胞混合培养上清液内干扰素（IFN）-γ的含量。用乳酸脱氢酶（LDH）释放法检测特异性CTL的杀伤活性。结果成功构建含GFP标签的HCV多CTL表位的重组腺病毒,并在DC中表达。重组腺病毒能促进DC成熟,DC的CD80、CD83、CD86和HLA-DR的表达分别为（71.19±3.29）%、（81.21±5.07）%、（91.23±4.24）%、（97.95±5.31）%。感染DC后促进同源T细胞增殖,DC：T为1：10时增殖指数为6.806±0.247。分泌的IL-12和IFN-γ也明显增多,分别达到（193.83±6.25）pg/ml和（111.14±2.09）pg/ml。感染DC刺激的CTL能特异性杀伤转染FL-J6/JFH的Huh-7.5细胞,当效靶比为100：1时,AD1-DC-L的杀伤率为35.99%。结论重组多CTL表位腺病毒在体外能有效感染DC,促进了T细胞反应,为下一步抗HCV的DC疫苗研制打下基础。     

尿酸辅助树突细胞免疫对小鼠淋巴细胞增殖及CTL效应的影响

目的：观察尿酸辅助HBsAg蛋白负载的树突细胞免疫接种对小鼠免疫功能的影响。方法：将负载HB-sAg的小鼠骨髓来源树突细胞经尾静脉注射接种小鼠，1次／w，共2次。分DC（树突状细胞）对照组、联合尿酸组、尿酸对照组。MTT法检测体外经HBsAg或PBS重刺激的脾T淋巴细胞增殖反应；流式细胞仪法检测CTL（细胞毒性T淋巴细胞）活性。结果：免疫2周时，小鼠脾T细胞增殖反应及体内HBsAg特异性CTL的杀伤活性，联合尿酸组明显强于各对照组。结论：尿酸可促进负载HBsAg树突细胞免疫后小鼠脾T淋巴细胞的增殖及HBsAg特异性CTL效应。尿酸具有增强DC疫苗免疫效应的活性，可用作研制抗HBV的治疗性疫苗的免疫佐剂。     

经卡介苗活化的树突状细胞疫苗治疗胰腺癌的基础及临床运用展望——暨向2011年诺贝尔医学奖得主Ralph Steinman教授致敬

目的 探讨经卡介苗(BCG)活化的树突状细胞(DC)疫苗体外直接抗胰腺癌细胞Panc02的机制,以及观察经不同部位注射DC疫苗抗小鼠胰腺癌移植瘤的效应.方法 从C57BL/6小鼠骨髓中诱导培养DC,并予以BCG促成熟,用流式细胞技术检测DC成熟度,CCK-8细胞计数检测DC直接抑制Panc02增殖情况,流式细胞仪检测BCG促成熟DC表面凋亡诱导配体(TRAIL)的表达量.C57BL/6小鼠皮下接种Panc02胰腺癌细胞制成荷瘤小鼠,第7d予以DC疫苗注射免疫治疗(DC疫苗为经Panc02细胞冻融抗原致敏后BCG促成熟的DC),分为3组:瘤内注射生理盐水组、皮下注射DC疫苗组和瘤内注射DC疫苗组,1周后再治疗1次,第2次治疗后15d处死小鼠,观察不同治疗抗肿瘤的效果.结果 BCG活化后DC疫苗成熟度明显增加,其表型CD86表达增加;经BCG活化成熟的DC能直接抑制Panc02细胞生长,这一作用可被TRAIL抗体部分抑制,且流式细胞术检测发现成熟DC表面分子TRAIL明显高于未经BCG促成熟组未成熟DC.肿瘤体重:瘤内注射DC疫苗组＜皮下注射DC疫苗组＜瘤内注射生理盐水组(P＜0.01).结论 BCG活化的胰腺癌DC疫苗的生物活性明显增加,并可通过TRAIL这一途径直接杀伤肿瘤细胞;且经BCG活化的DC疫苗瘤内注射免疫治疗抗肿瘤作用更强.     

胞质转导肽-HBcAg18-27-Tapasin体外诱导HBV转基因小鼠髓源性树突状细胞成熟及在T淋巴细胞增殖中的作用

目的:观察融合蛋白胞质转导肽(cytoplasmic transduction peptide,CTP)-HBcAg18-27-Tapasin体外诱导HBV转基因小鼠髓源性树突状细胞(dendritic cell,DC)成熟和对T淋巴细胞增殖的作用.方法:体外分离、培养HBV转基因小鼠及近交系C57BL/6小鼠髓源性DC,加入重组粒细胞-巨噬细胞集落刺激因子和白介素(interleukin,IL)-4培养5d,再加入实验组10μg/mL CTP-HBcAg18-27-Tapasin、对照组10μg/mL CTP-HBcAg18-27、10μg/mL HBcAg18-27-Tapasin及空白组RPMI1640完全培养液.流式细胞术测定DC表面分子CD80、CD83、MHC-1的表达,ELISA法测定DC培养上清液中的IL-12p70的水平,细胞计数试剂盒(CCK-8)检测T淋巴细胞增殖反应,流式细胞仪检测增殖的T淋巴细胞内的细胞因子.结果:体外成功诱导小鼠髓源性DC;CTP-HBcAg18-27-Tapasin能明显上调DC表面分子CD80、CD83、MHC-1的表达;并且CTP-HBcAg18-27-Tapasin组诱导DC分泌的IL-12p70水平及诱导DC增殖T淋巴细胞增殖能力明显高于对照组及空白组[IL-12p70转基因小鼠(F=205.85,P=0.000);C57BL/6小鼠(F=406.20,P=0.000)];流式细胞仪检测实验组融合蛋白诱导的CTL水平也高于对照组[转基因小鼠(F=155.45,P=0.000);C57BL/6小鼠(F=392.90,P=0.000)],同时HBV转基因小鼠DC表面分子及在T淋巴细胞增殖中的作用要比C57BL/6小鼠低.结论:分子伴侣Tapasin修饰胞内化抗原肽能促进HBV转基因小鼠髓源性DC的分化、成熟,并能增强DC刺激T淋巴细胞增殖能力及诱导CTL的产生.     

HCV C-Fc融合基因修饰的树突状细胞疫苗抗HCV功能研究

目的　探讨丙型肝炎病毒 (HCV)C Fc基因修饰的树突状细胞 (DCs)能否诱导抗HCV细胞和体液免疫反应。方法　将pcDNA3 HCV Fc质粒用电穿孔法转染经过白介素 4 (IL 4 ) ,粒 巨噬细胞集落刺激因子 (GM CSF)刺激增殖的小鼠DCs前体细胞 ,观察HCV、Fc抗原表达 ;将制备的 5×10 5/ 10 0 μlDC疫苗皮下免疫Balb/c小鼠 ,两周后检测特异性抗体、脾脏CD4 、CD8 细胞增殖作用以及诱导的细胞毒性T淋巴细胞 (CTL)反应。结果　HCVC Fc基因电穿孔法转染细胞在上述细胞因子作用下发育成能有效表达HCVC Fc并具有典型形态学与表型特征的DCs。免疫小鼠后 ,HCVC Fc基因转染DCs能诱导产生抗HCV特异性抗体和较强的CTL反应。结论　HCVC Fc基因修饰的DCs能增强对HCV特异性CTL效应的诱导能力 ,提示它在抗病毒疫苗发展中的潜力     

Ectopic expression of E47 or E12 promotes the death of E2A-deficient lymphomas

Mice with null mutations in the E2A gene are highly susceptible to the spontaneous development of thymic lymphomas. To understand better how E2A deficiency may contribute to lymphomagenesis, we have observed the consequences of enforced expression of the E2A gene products E12 and E47 in cell lines derived from lymphomas that arose spontaneously in E2A-deficient mice. E2A-expressing cells are steadily eliminated from lymphoma cultures into which E47 or E12 was introduced. The mechanism underlying the loss of E2A-expressing cells does not involve an arrest in cell-cycle progression. Rather, the E2A proteins activate a programmed cell death pathway in these lymphomas. This E2A-mediated cell death appears to be preceded by a loss of mitochondrial transmembrane potential. These data provide direct evidence that E2A gene products can act as tumor suppressors.     

Minimal representations of E6, E7, and E8 and the generalized Capelli identity

We explicitly construct, in a uniform fashion, the (unique) minimal and spherical representation pi0 of the split real Lie group of exceptional type E6, E7, or E8. We obtain several algebraic and analytic results about pi0.     

Formation of the complex of bovine papillomavirus E1 and E2 proteins is modulated by E2 phosphorylation and depends upon sequences within the carboxyl terminus of E1.

The 68-kDa bovine papillomavirus (BPV) type 1 replication protein E1 and the 48-kDa transactivator protein E2 form a complex that specifically binds DNA [Mohr, I.J., Clark, R., Sun, S., Androphy, E.J., MacPherson, P. & Botchan, M.R. (1990) Science 250, 1694-1699]. We have confirmed this observation and shown that the E1-E2 complex binds to DNA fragments that contain the BPV plasmid maintenance sequence 1 and a site for the initiation of bidirectional BPV DNA synthesis. The E1 protein was found to bind preferentially to non- or underphosphorylated species of E2, suggesting that the phosphorylation state of E2 modulates the association of the two proteins. Replication-deficient E1 mutants with single amino acid substitutions and deletions in the carboxyl terminus failed to interact with E2, indicating that a region in the E1 carboxyl terminus is required for E1 to interact with E2. Our results suggest that the replication deficiency of some E1 mutants reflects their inability to associate with E2.     

Folding and misfolding of the papillomavirus E6 interacting peptide E6ap

All-atom Langevin dynamics simulations have been performed to study the folding pathways of the 18-residue binding domain fragment E6ap of the human papillomavirus E6 interacting peptide. Six independent folding trajectories, with a total duration of nearly 2 micros, all lead to the same native state in which the E6ap adopts a fluctuating alpha-helix structure in the central portion (Ser-4-Leu-13) but with very flexible N and C termini. Simulations starting from different core configurations exhibit the E6ap folding dynamics as either a two- or three-state folder with an intermediate misfolded state. The essential leucine hydrophobic core (Leu-9, Leu-12, and Leu-13) is well conserved in the native-state structure but absent in the intermediate structure, suggesting that the leucine core is not only essential for the binding activity of E6ap but also important for the stability of the native structure. The free energy landscape reveals a significant barrier between the basins separating the native and misfolded states. We also discuss the various underlying forces that drive the peptide into its native state.     

三种戊型肝炎诊断试剂可靠性的研究

目的评价不同戊型肝炎诊断试剂对临床急性戊型肝炎诊断的可靠性。方法用273份健康人血清和525份肝炎患者血清对三种戊型肝炎诊断试剂进行比较。结果E2-IgM试剂用于急性戊型肝炎诊断的特异度为100．0％，显著优于GL-IgM试剂(96．7％)和GL—IgG试剂(85．4％)。E2-IgM，GL-IgG试剂用于急性戊型肝炎诊断的灵敏度(分别为97．9％、93．8％)，均显著高于GL-IgM(72．9％)。在65例GL-IgM阳性而E2-IgM阴性的患者中，有58例(89．2％)同时为抗甲型肝炎病毒IgM抗体阳性，提示GL—IgM试剂的检测受其他IgM抗体的干扰较大。结论E2-IgM是良好的戊型肝炎急性诊断指标。     

Hepatitis E and the traveller

The risk of infection with hepatitis E virus to international travellers to endemic regions such as the subcontinent of India, Nepal, South-East Asia, China, parts of the Middle East, Africa, Mexico and some countries of South America is underestimated. Hepatitis E virus is transmitted enterically usually by drinking water contaminated by sewage and also by raw or uncooked shellfish. Outbreaks occur in number of hot climate countries where the infection is endemic, and a zoonotic element may be significant both in endemic areas and in developed countries where sporadic cases also occur. The clinical course of the infection can be severe with high mortality of up to 20% during the third trimester of pregnancy. Advice to travellers must include strict precautions with regard to drinking water and the consumption of raw food. Specific prophylaxis and treatment against hepatitis E infection are not available at present. Specific immunoglobulin and several recombinant and subunit vaccines are under development. One baculovirus, expressed viral protein vaccine is under phase II/III trial in Nepal.