pcIL-18-MAGE-1共表达基因疫苗对肝癌细胞株SMMC-7721、Hepal-6增殖的影响

目的观察pc IL-18-MAGE-1共表达基因疫苗接种小鼠所引起的免疫应答情况以及对肝癌细胞株SMMC-7721、Hepal-6增殖抑制情况,探究pc IL-18-MAGE-1共表达基因疫苗抗肿瘤作用。方法用pc IL-18-MAGE-1基因疫苗免疫小鼠,同时设空白对照组和阴性对照组,免疫后收集脾细胞作为效应细胞,分别作用于靶细胞即肝癌细胞株SMMC-7721、Hepal-6。应用流式细胞仪(FCM)检测小鼠T细胞亚群情况及自然杀伤(NK)细胞活性,MTT法检测肿瘤特异性细胞毒性T淋巴细胞(CTL)对靶细胞的杀伤作用。结果与对照组比较,共表达pc IL-18-MAGE-1基因疫苗对靶细胞均有明显的杀伤作用(P<0.01);对SMMC-7721细胞杀伤作用高于Hepal-6细胞(P<0.05)。免疫组CD4+、CD8+、CD4+/CD8+均高于阴性对照组(P<0.05)。结论 pc IL-18-MAGE-1共表达基因疫苗通过同时激活CD4+T细胞及CD8+T细胞、增加NK细胞活性及诱导肿瘤特异性CTL直接杀伤肿瘤细胞,发挥抗肿瘤作用。     

加载野生型p53基因鼠树突细胞的抗肿瘤作用

目的 观察加载了野生型p53基因的树突细胞(DC)对不同位点p53基因突变肿瘤得庖咧瘟谱饔?方法通过锥虫蓝染色、同种异体混合白细胞反应及流式细胞仪检测DC细胞表面分子,评估腺病毒(Ad)-p53感染DC是否影响DC的免疫功能.以Ad或转导了野生型p53基因的Ad分别感染骨髓De(Ad-DC和Ad-p53-DC)后,静脉注射免疫C57BL/6小鼠各5只,分离脾细胞,采用标准6 h51 Cr释放试验测定其诱导不同肿瘤细胞系(MethA、D459和P815)细胞毒性T淋巴细胞(CTL)的杀伤活性;效应细胞(Ad-p53-DC免疫后的小鼠脾细胞)和靶细胞(Ad-p53-P815和D459)孵育时分别加入抗CD4抗体或抗CD8抗体,观察CTL的活性变化.使用MethA和D459肿瘤细胞系得到不同的荷瘤鼠,于肿瘤形成前后分别使用Ad-p53-DC免疫,Ad-DC对照,当实体瘤三维直径之和＞20 cm时处死小鼠,用生存曲线评估Ad-p53-DC免疫的预防或治疗作用.结果 (1)Ad-p53-DC免疫诱导的抗Ad-p53-P815、D459和MethA的CTL反应(效应细胞:靶细胞=50:1)分别为(27.8±3.4)%、(23.5±2.7)%及(58.3±9.2)%,与Ad-DC免疫诱导的反应[(9.3±1.8)%、(4.6±1.0)%及(23.5 ±3.7)%]相比,差异有统计学意义(td值分别为5.79、3.68、5.02,均P＜0.05).Ad-p53-DC免疫小鼠T淋巴细胞与靶细胞Ad-p53-P815或D459的CTL活性,抗CD4组[(59.8 ±4.6)%、(18.9±2.4)%]与无抗体组[(64.4±6.3)%、(22.2±3.0)%]相比,差异无统计学意义(td值分别为0.84、0.91,均P＞0.05),而抗CD8组[(26.7±2.8)%、(6.1±1.2)%]差异有统计学意义(td值分别为9.03、7.67,均P＜0.05).抗CD8组与抗CD4组比较,差异有统计学意义(td值分别为8.79、9.18,均P＜0.05).(2)Ad-p53-DC和Ad-DC静脉注射2次免疫小鼠后,分别以D459细胞或MethA肉瘤细胞荷瘤20只小鼠.在Ad-p53-DC免疫组分别有14只和16只小鼠肿瘤的生长得到完全抑制,与Ad-DC免疫组比较差异有统计学意义(x2值分别为6.72、5.86,P＜0.05).皮下接种小鼠D459后,Ad-p53-DC免疫治疗组的小鼠肿瘤生长速度比Ad-DC组延缓2周左右,二组比较差异有统计学意义(x2 值为9.48,P＜0.05).结论 Ad-p53-DC可诱导抗MethA、P815和D459靶细胞的由CD8+T淋巴细胞介导的CTL反应,并抑制鼠体内肿瘤细胞的形成和生长.     

共表达pcIL-18/MAGE-1 DNA疫苗对JEG-3细胞HLA-G基因表达的影响

目的观察共表达基因疫苗pc IL-18/MAGE-1对绒癌JEG-3细胞株HLA-G基因表达的影响,探究pc IL-18/MAGE-1抗肿瘤作用机制。方法应用构建的共表达pc IL-18/MAGE-1 DNA疫苗免疫小鼠,同时设阴性对照组和空白对照组,免疫后分别收集脾细胞,作用于靶细胞JEG-3,应用FCM检测小鼠T细胞亚群情况及NK细胞活性,MTT法检测肿瘤特异性CTL对靶细胞的杀伤率,RT-PCR法检测HLA-G基因表达情况。结果免疫组HLA-G基因表达降低,且对JEG-3细胞杀伤活性增加,与对照组比较,差异显著(P<0.05)。免疫组NK细胞活性及CD4+/CD8+、CD8+、CD4+值均高于对照组(P<0.05)。结论共表达基因疫苗pc IL-18/MAGE-1通过降低HLA-G基因的表达,进而增加NK细胞活性以及诱导肿瘤特异性CTL直接杀伤肿瘤细胞,发挥抗肿瘤作用。     

经树突状细胞递呈的HBcAg特异性细胞毒T淋巴细胞的体外研究

目的　从人的外周血树突状细胞 (DC)的抗原递呈方面研究慢性乙型肝炎的发病机制 ,并诱导出针对HBcAg特异性的细胞毒T淋巴细胞 (CTL)。方法　取健康人DC和患者DC ,比较两组的抗原递呈功能是否存在差异。以HBcAg体外冲击致敏DC ,与自体T淋巴细胞共育 ,诱导出HBcAg特异性CTL ;以HepG2细胞为对照靶细胞 ,转染HBVDNA的HepG2 2 15细胞为靶细胞 ,分别测定CTL在效靶比为 2∶1、6∶1和 2 0∶1时对HepG2细胞的非特异性杀伤率及对HepG2 2 15细胞的特异性杀伤率 ,并比较患者组与正常组特异性杀伤率的差异。结果　患者DC的抗原递呈功能(10 99.2 6 7± 2 39.12 ,1374 .8± 36 4 .15 5 ,2 717.78± 15 89.72 )较健康人 (314 7.933± 72 6 .5 7,384 3.0 0 0±10 6 0 .85 ,5 4 86 .86 7± 1790 .6 4 )弱 ;健康组与患者组CTL对HepG2各效靶比的非特异性杀伤作用差异无显著性。健康组与患者组CTL对HepG2 2 15的特异性杀伤作用差异有显著性 ;患者组CTL的活性 (7.1± 4 .33,15 .6 8± 3.3,2 7.6 6± 4 .5 9)较健康组 (2 0 .76± 6 .0 8,33.97± 8.0 0 ,4 9.6 3± 9.4 8)弱。结论　用HBcAg体外负载患者DC ,能诱导出抗原特异性的CTL ,这些CTL能特异性地杀伤相应靶细胞。     

结核分枝杆菌MPT64抗原DNA疫苗在小鼠体内诱导的免疫应答

目的研究结核分枝杆菌MPT64抗原DNA疫苗在小鼠体内诱导的免疫应答。方法用表达MPT64的真核表达质粒pcDNA-M免疫BALB/c小鼠,ELISA法检测免疫小鼠的特异性抗体滴度和抗体亚类。分离免疫小鼠的脾淋巴细胞,检测淋巴细胞增殖、IFN-γ和IL-12产生水平、流式细胞仪计CD4+细胞和CD8+细胞数、脾淋巴细胞特异性CTL杀伤效应。结果MPT64基因免疫可诱导小鼠高水平的体液免疫应答,免疫小鼠脾淋巴增殖显著,IFN-γ和IL-12含量增加,CD4+细胞和CD8+细胞百分比明显增加,CTL杀伤效应明显。结论MPT64 DNA疫苗可诱导小鼠有效的体液和细胞免疫应答,有可能作为新型TB疫苗的组分。     

4种甲胎蛋白抗原表位肽段致敏树突状细胞诱导细胞毒性T淋巴细胞对肝癌细胞的杀伤效应比较

目的 通过体外杀伤试验,比较4种人肝癌特异性甲胎蛋白抗原表位肽段PLFQVEPV[hAFP(137～145)],FMNKFIYEI[hAFP(158～166)]、GLSPNLNRFL[hAFP(325-334)]和GVAL,QTMKQ[hAFP(542～550)]修饰树突状细胞(DC)后诱导的细胞毒性T淋巴细胞(CTL)对人肝癌细胞的特异性杀伤效应. 方法 选取健康人外周血单个核细胞,体外诱导成熟DC;合成4种hAFP抗原表位肽段分别修饰和诱导DC,体外刺激CTL,通过流式细胞仪法和细胞毒性检测法检测该修饰后的DC所诱导的CTL在体外对肝癌细胞株SMMC-7721细胞的杀伤作用.组间比较应用t检验进行统计学分析. 结果 4种人肝癌特异性甲胎蛋白片段均能在体外修饰和诱导DC细胞的增殖和成熟;这些成熟DC在体外均能诱导特异性CTL,CTL对SMMC-7721细胞均可产生杀伤效应.其中FMNKFIYEI[hAFP(158～166)]肽段诱导的CTL在效靶比分别为80:1、40:1及10:1时对肿瘤细胞的杀伤效应分别达到了78.1%±9.8%、43.9%±5.9%和28.2%±4.9%,比其他3种肽段的杀伤效应高(P<0.05). 结论 短肽段具有单独体外诱导特异CTL的作用,其诱导效果和杀伤效果均优于完整hAFP蛋白,其诱导的CTL有特异地杀伤SMM C-7721细胞的作用.     

乙型及丙型肝炎DNA疫苗联合重复接种小鼠的免疫应答

目的 :观察由编码 HBs Ag与 HCV- CE2 抗原的两种重组真核细胞表达质粒制备的 DNA疫苗重复联合接种 BAL B/c小鼠后 ,其诱生的特异性免疫应答反应。方法 :应用上述两种 NDA疫苗重复联合免疫小鼠 ,动态观察血中特异性抗体水平、特异性细胞毒性 T淋巴细胞 (CTL )体外杀伤活性 ,并进行 CTL杀伤活性活体诱生实验。结果 :两种 DNA疫苗联合重复免疫小鼠 ,能够诱生机体特异性体液免疫及细胞免疫完全应答。其小鼠荷瘤表达目的抗原的靶细胞后 ,生存率明显高于未免疫鼠 (P <0 .0 5 )。结论 :乙型及丙型肝炎联合 DNA疫苗的重复接种 ,可有效地诱生小鼠机体特异性免疫应答反应。 DNA疫苗诱生的 CTL应答可与体液免疫应答分离存在 ,可能是 DNA疫苗免疫保护的更重要方面。     

GM-CSF分泌型肝癌疫苗对荷瘤鼠脾血细胞毒性T淋巴细胞杀伤活性的影响

目的观察粒细胞巨噬细胞集落刺激因子(GM-CSF)分泌型肝癌疫苗对移植性肝癌小鼠细胞毒性T淋巴细胞(CTL)杀伤活性的影响。方法取小鼠肝癌细胞株H22细胞1×106/只注入小鼠腹腔内,接种7d形成腹水瘤后再在小鼠体内传3代。取生长旺盛且无血性的腹水,在无菌条件下制成2×107/ml的细胞悬液,以2×106细胞/0.1ml/只接种于小鼠右前肢皮下。将肝癌细胞移植瘤动物分成3组。4天后,在右侧背部皮下进行免疫治疗,即制备GM-CSF分泌型H22肝癌瘤苗并免疫ICR小鼠(H22-GM-CSF组,n=5),同时设立无GM-CSF基因修饰H22肝癌瘤苗组(H22组,n=5)和PBs对照组(PBS组,n=5),测量各组小鼠肿瘤体积;采用细胞增殖计数法检测小鼠脾血CTL杀伤活性。结果随着效/靶比增加,各组CTL杀伤活性均增强。在效/靶比为50∶1时,GM-CSF-H22组CTL杀伤活性为60±6.1%,明显高于H22组(17.4±0.9%)和PBS组(12.2±0.6%,P<0.01);GM-CSF分泌型肝癌细胞瘤苗明显抑制H22荷瘤小鼠肿瘤生长。在21天时,H22-GM-CSF组、H22组和PBS组小鼠肿瘤体积分别为0.63±0.05mm3、1.47±0.75mm3和1.79±0.34mm(3P<0.01)。结论 GM-CSF分泌型肝癌细胞瘤苗可抑制肿瘤细胞生长,增强CTL杀伤活性。     

P356-1Y2L表位刺激BALB/c小鼠的特异性抗肿瘤免疫

目的检测MAGEC2衍生的免疫原性肽在小鼠体内抗肿瘤免疫效果。方法测定P356-1Y2L免疫BALB/c小鼠后诱导CTL以及分泌IFN-γ的能力,用MAGEC2衍生的表位免疫荷瘤小鼠,检测其抑制肿瘤生长的能力及观察小鼠的生存能力。结果 P356-1Y2L免疫BALB/c小鼠引发CD8~+T淋巴细胞的强烈增殖和活化,且能分泌较多的IFN-γ,并且可以有效的杀伤靶细胞。用P356-1Y2L免疫荷瘤小鼠,能够抑制小鼠肿瘤生长并延长小鼠的生存期。结论免疫原性肽P356-1Y2L能够在BALB/c小鼠中引发特异性CTL反应,成为癌症治疗性多肽疫苗的候选表位。     

细粒棘球绦虫转Eg95-EgA31融合基因苜蓿疫苗免疫BALB/c小鼠后脾T淋巴细胞亚群的动态观察

目的动态观察细粒棘球绦虫转Eg95-EgA31融合基因苜蓿疫苗免疫小鼠后诱导的脾T淋巴细胞亚群的变化。方法热絮凝法提取转基因苜蓿疫苗叶蛋白,将其浓度配制成20μg/μL,132只BALB/c小鼠随机分为3组,用100μL(约含1μg融合抗原)灌胃接种和10μL(约含0.1μg融合抗原)滴鼻接种分别免疫小鼠,每3 d 1次,连续免疫2个月,同时设非转基因苜蓿叶蛋白滴鼻免疫对照组。在末次免疫后0、2、4、6、8、10、12、14、16、18和20周各组随机剖杀4只小鼠,取脾,分离脾细胞,流式细胞仪(FCM)检测脾CD4+和CD8+T淋巴细胞亚群的百分比。结果灌胃接种组小鼠脾CD4+和CD8+T细胞亚群分别在免疫后6~10周和4~12周升高,分别在免疫后6周和8周达高峰,百分比分别为0.294±0.002和0.168±0.027;滴鼻接种组小鼠脾CD4+和CD8+T细胞亚群分别在免疫后4~6周和4~10周升高,分别在免疫后6周和8周达高峰,百分比分别为0.318±0.051和0.197±0.008。结论CD4+和CD8+T细胞亚群在细粒棘球绦虫转Eg95-EgA31融合基因苜蓿疫苗诱导的保护性免疫机制中起重要作用。     

Purification of antigenic peptide from murine hepatoma cells recognized by Class-I major histocompatibility complex molecule-restricted cytotoxic T-lymphocytes induced with B7-1-gene-transfected hepatoma cells

BACKGROUND/AIM: It has been reported that expression of costimulatory molecules, such as B7, on tumors is essential for priming tumor-specific cytotoxic T-lymphocytes (CTLs). Here, we have attempted to induce murine hepatoma-specific CTLs by immunizing with the B7-1-gene-expressing hepatoma cells, and to identify the epitope(s) presented on the hepatoma cells. METHODS: The B7-1-gene encoding plasmid was transferred into the murine hepatoma cell line, Hepa1-6. Syngeneic C57BL/6 mice were immunized with the B7-1-transfected cells via various routes to prime CTLs. The mild acid elution method was used to isolate antigenic fractions from the class-I major histocompatibility complex (MHC) molecules on the Hepa1-6 cells. Cytotoxicity was measured by standard 51Cr-releasing assay. The effect of the CTLs on hepatoma growth was evaluated in hepatoma-bearing SCID mice to which the cells were preadministered. RESULTS: A clone, termed L1, highly expressing the B7-1-gene, has been established. Killer cells generated from mice immunized intraperitoneally with L1 cells eliminated both L1 and Hepa1-6 cells, and also another syngeneic hepatoma cell line, Hepa1-clc7. The killer cells were CD8+ and the class-I MHC molecule-restricted CTLs which might recognize hepatoma-specific antigenic peptide(s) in association with the D(b)class-I MHC molecules. A functional peptide fraction was obtained from eluted fluid of the Hepa1-6 cells. In addition, intravenous preadministration of the CTLs inhibited the hepatoma growth in SCID mice. CONCLUSIONS: The hepatoma epitope-specific CTLs which suppressed hepatoma growth in vivo could be generated with the B7-1-gene-transfected hepatoma cells. These results will be useful in establishing immunotherapy against hepatocellular carcinoma.     

Targeting hepatitis B virus antigens to dendritic cells by heat shock protein to improve DNA vaccine potency

AIM： To investigate a novel DNA vaccination based upon expression of the HBV e antigen fused to a heat shock protein （HSP） as a strategy to enhance DNA vaccine potency.
METHODS： A pCMV-HBeAg-HSP DNA vaccine and a control DNA vaccine were generated. Mice were immunized with these different construct. Immune responses were measured 2 wk after a second immunization by a T cell response assay, CTL cytotoxicity assay, and an antibody assay in C57BL/6 and BALB/c mice. CT26-HBeAg tumor cell challenge test in vivo was Performed in BALB/c mice to monitor anti-tumor immune responses.
RESULTS： In the mice immunized with pCMV-HBe-HSP DNA, superior CTL activity to target HBV-positive target cells was observed in comparison with mice immunized with pCMV-HBeAg （44% ± 5% vs 30% ± 6% in E： T 〉 50：1, P 〈 0,05）, ELISPOT assays showed a stronger T-cell response from mice immunized with pCMV-HBe- HSP than that from pCMV-HBeAg immunized animals when stimulated either with MHC class I or class Ⅱ epitopes derived from HBeAg （74% ± 9% vs 31% ± 6%, P 〈 0.01）. ELISA assays revealed an enhanced HBeAg antibody response from mice immunized with pCMV- HBe-HSP than from those immunized with pCMV-HBeAg. The lowest tumor incidence and the slowest tumor growth were observed in mice immunized with pCMV- HBe-HSP when challenged with CT26-HBeAg.
CONCLUSION： The results of this study demonstrate a broad enhancement of antigen-specific CD4^＋ helper,CD8^＋ cytotoxic T-cell, and B-cell responses by a novel DNA vaccination strategy. They also proved a stronger antigen-specific immune memory, which may be superior to currently described HBV DNA vaccination strategies for the treatment of chronic HBV infection.     

肝癌细胞裂解物致敏的树突状细胞瘤苗体外诱导特异性抗肝癌免疫

目的 探讨肝癌患者肿瘤细胞裂解物致敏的树突状细胞(DC)瘤苗体外诱导自体T淋巴细胞特异性抗肝癌免疫效应。 方法 从肝癌患者外周血单个核细胞中诱导D C,用重组人粒细胞-巨噬细胞集落刺激因子(rhGM-CSF)和白细胞介素-4(rhIL-4)刺激活化,经自体肝癌细胞裂解物致敏。用流式细胞仪检测D C细胞表面分子的表达,酶联免疫吸附法检测T淋巴细胞培养上清液中干扰素(I F N)γ和白细胞介索-12(IL-12)的含量,液体闪烁计数仪测定肝癌细胞裂解物致敏的D C刺激自体T淋巴细胞增殖效应,四甲基偶氮唑盐法检测肝癌细胞裂解物致敏D C诱导的细胞毒T淋巴细胞对自体肝癌细胞的特异性杀伤作用。 结果 肝癌细胞裂解物致敏的DC瘤苗可上调DC表面CD1 a、CD40、CD86和人类白细胞抗原-DR分子表达水平,其与T淋巴细胞共培养产生的IFN γ、IL-12的浓度明显高于未致敏的D C组(t值分别为2.30、2.14,P<0.05),肝癌细胞裂解物组(t值分别为14.01、15.40,P<0.01)和对照组(t值分别为14.85、16.87,P<0.01)。同时肝癌细胞裂解物致敏的瘤苗可明显诱导T淋巴细胞的增殖,其诱导的细胞毒性T淋巴细胞对自体肝癌细胞的杀伤率(81.72％±9.49％)显著高于对HepG2的杀伤率(49.37％±11.21％)和人鼻咽癌肿瘤细胞的杀伤率(17.14％±5.65％),P<0.01。 结论 肝癌细胞     

慢性乙型肝炎患者外周血树突状细胞诱导特异性T淋巴细胞应答

目的 探讨慢性乙型肝炎患者外周血树突状细胞(Dc)是否诱导特异性T细胞应答。方法(1)将研究对象分为慢性乙型肝炎患者组、急性乙型肝炎痊愈组、健康志愿者组,分离各组研究对象的外周血单个核细胞(PBMC),细胞内细胞因子染色方法检测其对细胞毒性T淋巴细胞(CTL)特异表位多肽乙型肝炎病毒核心抗原(HBcAg)18-27的记忆性免疫应答;(2)培养慢性乙型肝炎患者DC,将负载有乙型肝炎抗原表位多肽的DC诱导特异的T细胞应答。采用细胞内细胞因子染色方法检测诱导的T细胞分泌的细胞因子,乳酸脱氢酶释放法测定诱导的T细胞杀伤活性。结果(1)急性乙型肝炎患者PBMC对HBcAg 18-27 CTL特异表位多肽存在记忆的免疫应答,其分泌干扰素-γ的CD8+T细胞占CD8+T细胞总数的(4.3±2.5)％,分泌白细胞介素-2的占总细胞数的(4.8±2.2)％,分泌肿瘤坏死因子-α占总细胞数的(4.6±2.3)％。而慢性乙型肝炎患者和健康志愿者对其记忆应答很低,与急性乙型肝炎患者比较差异有显著性,t值为2.508-3.305,P<0.05。(2)用多肽共孵育过的慢性乙型肝炎患者DC多次诱导的T细胞慢性乙型肝炎患者组,加肽孵育的靶细胞比例为30:1、10:1、3:1时,其杀伤率分别为(57.0±20.3)％、(49.5±20.2)％、(21.8±12.9)％,均高于对照组,表明慢性乙型肝炎患者DC可以诱导特异的T     

Costimulatory protein B7-1 enhances the cytotoxic T cell response and antibody response to hepatitis B surface antigen.

There is a need for more effective therapy for chronic virus infections. A principle natural mechanism for elimination of virus-infected host cells is activation of viral antigen-specific cytotoxic T lymphocytes (CTL). In an effort to develop methods of inducing virus-specific CTL responses that might be utilized in therapy of virus infections, we have investigated the effect of B7, a costimulatory factor for T-cell activation. In this study we show that delivery of genes encoding human B7-1 and a viral antigen in the same recombinant viral vector to cells of mice induces a greater viral antigen-specific CTL response than does similar delivery of the viral antigen gene alone. Two recombinant adenovirus vectors were constructed with the foreign genes inserted in the early region 3. One of them (Ad1312) directed expression of the surface antigen gene of hepatitis B virus (HBS); the other (Ad1310) directed coexpression of HBS and human B7-1 (CD80) by means of an internal ribosomal entry site placed between the two coding sequences. When inoculated into BALB/c mice, both vectors induced a viral surface antigen-specific CTL response. The response induced by Ad1310 was stronger than that by Adl312 as measured by a chromium release assay for CTL activity and limiting dilution analysis for CTL precursor frequency, indicating that the B7-1 gene co-delivered with the HBS gene had an enhancing effect on the CTL response against surface antigen. Ad1310 also induced a higher titer of antibody against surface antigen than did Ad1312. This result suggests that expression of a costimulatory protein and a viral antigen in the same cells in vivo induces stronger immune responses than expression of the antigen alone. This could be a novel strategy for development of both preventive and therapeutic vaccines against infectious agents.     

Alterations in T cell phenotype and human immunodeficiency virus type 1-specific cytotoxicity after potent antiretroviral therapy

Cytotoxic T lymphocytes (CTLs) are an important defense against human immunodeficiency virus (HIV) type 1 but ultimately fail to control infection. To determine whether more efficient sustained immunity is induced by suppressing replication, the evolution of T cell phenotypes and HIV-specific CD8+ lymphocytes was prospectively investigated in 41 patients initiating combination therapy. Suppression of viremia to <200 copies/mL was associated with increases in naive cells (CD45RA+62L+) and declines in activated T cells (CD95+ cell counts and CD38+ HLA-DR+). HIV-specific tetramer-staining CD8+ T cells were detected in 6 of 10 HLA-A*0201-positive persons, which declined in 5 with treatment. CTL precursor frequencies were markedly consistent before and after treatment. Eight (72%) of 11 recognized > or =1 immunodominant epitope, representing either a new or an increased CTL response after treatment. Thus, activated CD8+ T cells, including those recognizing immunodominant epitopes, decline with combination therapy. However, the overall level of antigen-specific cells that are capable of differentiating into effectors remains stable, and the recognition of new epitopes may occur.     

感染弓形虫小鼠脾脏CD4+CD25+T细胞的变化

目的 观察小鼠感染刚地弓形虫后脾脏CD4⁺CD25⁺调节性T细胞的动态变化。 方法 将28只雌性C57BL/6小鼠随机分为4组，其中3组每鼠腹腔接种弓形虫速殖子悬液200 μl（含弓形虫速殖子5×10⁴个/ml），对照组腹腔接种灭菌PBS 200 μl。分别于弓形虫感染后第2、4和6天取脾，制成单个核细胞，用实时荧光定量PCR检测脾CD4⁺ T细胞Foxp3基因表达水平，流式细胞仪检测脾CD4⁺CD25⁺调节性T细胞占CD4⁺ T细胞的比例，并对CD4⁺CD25⁺调节性T细胞和CD4⁺ T细胞进行绝对计数。 结果 感染后第4和6天，小鼠脾脏CD4⁺ T细胞Foxp3 mRNA相对表达水平分别为 1.89±0.23和1.79±0.24， 均显著高于正常水平（1.00±0.12）（P＜0.01）；CD4⁺CD25⁺调节性T细胞占CD4⁺ T细胞的比例从感染后第2天（15.07%±2.73%）开始上调（P＜0.05），至感染后第4 和6天分别为24.29%±3.19%和19.80%±2.66%，均明显高于正常水平（11.58%±2.04%） （P＜0.01）；脾脏CD4⁺ T细胞占脾细胞的比例及其绝对数量均从感染后第2 天开始降低，至感染后第6 天分别降至5.49%±1.71%和（1.71±0.44）×10⁶ （P＜0.01）。 结论 弓形虫感染导致小鼠脾脏CD4⁺CD25⁺调节性T细胞占CD4⁺ T细胞的比例上调，而脾脏CD4⁺ T细胞的显著减少是促成比例上调的主要原因。     

巨噬细胞炎性蛋白-1α联合4-1BB配体降低肝癌细胞体内致瘤性研究

目的 观察巨噬细胞炎性蛋白-1α(MIP-1α)联合4-1BB配体(4-1BB L)对肝癌细胞体内致瘤性的影响.方法 以小鼠4-1BB L(m4-1BB L)重组逆转录病毒感染Hepa 1-6小鼠MIP-1α(mMIP-1α),筛选并扩增抗性克隆,以流式细胞术检测m4-1BB L的表达,绘制并比较mMIP-1α和m4-1BB L同时或单独表达的Hepa 1-6细胞的生长曲线.C57B/L小鼠随机分为7组,每组9只,各组分别接种Hepa 1-6 mMIP-1α+m4-1BB L、Hepa 1-6 m4-1BB L、Hepa 1-6 mMIP-1α、Hepa 1-6 pBabe puro、Hepa 1-6、Hepa 1-6 pLXSHD和PBS,观察比较各组肝癌细胞的致瘤性,比较各组小鼠的存活率.结果 成功获得同时表达mMIP-1α和m4-1BB L的小鼠肝癌细胞Hepa 1-6 mMIP-1α+m4-1BB L,mMIP-1α和m4-1BB L同时或单独表达不影响Hepa 1-6的生长曲线.观察5周,Hepa 1-6 mMIP-1α+m4-1BB L接种的小鼠均未生长肿瘤,Hepa 1-6 mMIP-1α+m4-1BB L的体内致瘤性低于Hepa 1-6 mMIP-1α和Hepa 1-6 m4-1BB L.接种Hepa 1-6 mMIP-1α+m4-1BBL的小鼠12周末存活率(9/9)高于接种Hepa 1-6 m4-1 BB L小鼠(6/9)和Hepa 1-6 mMIP-1α小鼠(1/9).结论 趋化因子MIP-1α联合共刺激分子4-1BB L降低了肝癌细胞体内致瘤性,并使小鼠的生存期延长.

Abstract：

Objective To investigate the effects of macrophage inflammatory protein-1α (MIP-1α) combined with molecule 4-1BB L on the tumorigenicity of hepatocellular carcinoma cells in vivo. Methods Mouse MIP-1α (mMIP-1α) expressed Hepa 1-6 cells were transfected with m4-1BBL recombinant retrovirus, the anti-histidinol cells clones were selected and amplified. The expression of m4-1BB L was confirmed by flow cytometry. The growth curve of Hepa 1-6 cells transfected with mMIP-1α and m4-1BBL alone or together was drawn and compared. C57B/L Mice were randomly divided into 7 groups, 9 mice in each group, injected with mMIP-1α+m4-1BB L Hepa 1-6 cells, m4-1BB L Hepa 1-6 cells, mMIP-1α Hepa 1-6 cells, Hepa 1-6 cells, pLXSHD Hepa 1-6 cells or PBS respectively. The tumorigenicity of hepatocellular carcinoma cells and the mice survival rate were compared between each groups. Results Hepa 1-6 mMIP-1α+m4-1BB L cells which expressed both mMIP-1α and m4-1BB L were successfully established. The expression of mMIP-1α and m4-1BB L alone or together did not affect the growth curve of Hepa 1-6 cells. Observed for 5 weeks, no tumor developed in Hepa 1-6 mMIP-1α+m4-1BB L injected mice. The tumorigenicity of Hepa 1-6 mMIP-1α+m4-1BB L was lower than that of Hepa 1-6 mMIP-1α or Hepa 1-6 m4-1BB L in vivo. The survival rate of Hepa 1-6 mMIP-1α+m4-1BBL injected mice(9/9) was higher than that of Hepa 1-6 m4-1BB L injected mice (6/9)or Hepa 1-6 mMIP-1α injected mice (1/9). Conclusion Chemokine MIP-1α combined with costimulatory 4-1BB L lowered the tumorigenicity of hepatocellular carcinoma cells in vivo, and prolonged the mice survival period.     

Cytotoxic T lymphocyte (CTL) responses to human cytomegalovirus pp65, IE1-Exon4, gB, pp150, and pp28 in healthy individuals: reevaluation of prevalence of IE1-specific CTLs

The prevalence of human cytomegalovirus (HCMV) pp65-, pp150-, IE1-exon4-, gB- and pp28-specific cytotoxic T lymphocyte (CTL) responses was compared among 34 healthy individuals, grouped by neutralizing antibody titers. Moderately and highly seropositive donors showed predominantly pp65- and IE1-exon4-specific CTL responses (92% and 76% of the donors, respectively), with similar precursor frequencies in the 2 donors tested. In addition, highly seropositive and a few moderately seropositive donors showed CTL responses to gB and pp150 (33% and 30% of the donors, respectively). No individual recognized pp28 as a target in the CTL assay. Phenotypic analysis revealed a mixed effector population of CD4+ and CD8+ (1 donor) or only CD8+ cells for pp65-specific effectors (2 donors). IE1-exon4- and pp150-specific effectors were CD8+ (2 donors and 1 donor, respectively), whereas gB-specific CTLs were CD4+ (1 donor). These data may help to design a cellular immunity-based vaccine effective against HCMV diseases.     

Generation of Aspergillus-specific T lymphocytes with cytotoxic activity

Dendritic cells (DC) are highly specialized antigen presenting cells with the unique capacity to initiate and direct immune responses. The superior ability of DC to present antigens to T cells has led to the development of DC-based strategies for the purpose of enhancing the immune response against tumors and infectious agents. In this study Aspergillus (Asp)-pulsed DC were used to generate Asp-specific cytotoxic T-lymphocytes (CTL). Two different Asp-antigen preparations were used here. Asp-specific CTL were generated by four stimulations with autologous, mature, monocyte (Mo)-derived DC that are pulsed with either Aspergillus crude extract (CE) or culture filtrate (CF) antigens. The cytolytic activity of the generated CTL was assessed one week after the 4th stimulation by chromium release assay. No significant difference (p > 0.05) was found between the proliferative responses induced by either CF or CE Asp-pulsed DC. Both types of Asp-pulsed mature DC were capable of priming Asp-specific CTL responses. Analysis of the Asp-CTL effectors revealed that they are mixed of CD3+/CD4+ and CD3+/CD8+ populations and that they secrete IFN-gamma in response to Asp-pulsed mature DC and specifically kill autologous DC pulsed with the same Aspantigen. The killing was higher in bulk-cultures generated using Asp-CF pulsed DC. The percentage of CD3+/CD8+ cytotoxic T cells was significantly increased (p < 0.001) in Asp-CF bulk-culture when compared with Asp-CE bulk-culture (31.55 +/- 1.96% versus 9.70 +/- 1.84%, respectively). In conclusion, Asp-specific T cell lines with cytotoxic activity can be generated from healthy donors. These cells may be used as prophylaxis in high-risk immunocompromised patients.