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.     

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.     

树突状细胞负载甲胎蛋白、细胞毒性T细胞表位肽后的免疫应答

目的 用负载hAFP 218-226位LLNQHACAV九肽的树突状细胞（dendritic cells,DC)诱导自身淋巴细胞，使之活化为肝细胞癌（HCC）特异性细胞毒性T细胞（cytotoxic T lymphocyte,CTL)，并特异性杀伤HCC细胞。方法 在体外用GM-CSF和IL-4诱导HLA-A2^ 健康志愿者外周血单核细胞，使其分化为高纯度DC。用负载hAFP 218-226位LLNQHACAV九肽的DC诱导自身淋巴细胞，使之成为HCC特异性CTL。结果 诱导的DC分泌较高水平的IL-12（17.6-21.5pg/ml)，其中以第7天为最高（21.5pg/ml)，经DC和DC负载AFP表位肽后活化的淋巴细胞培养上清液中TNF水平均比在IL-2条件下培养的未活化淋巴细胞高。L929细胞死亡百分率分别为80.65和11.6%；经DC和DC负载AFP表位肽后活化的淋巴细胞培养上清液中IL-12水平分别为20.5pg/ml和46.9pg/ml，经DC活化后淋巴细胞增殖指数大于3。活化后的淋巴细胞不但特异性杀伤HLA-A2^ 的HCC细胞HepG2和负载AFP表位肽的T2细胞，而且还不同程度杀伤HLA-A3^ HCC细胞Alexander和其它表型HCC细胞，对NK细胞敏感的靶细胞慢性髓原白血病细胞K562也有较强的杀伤作用。结论 负载hAFPHLA-A2限制性CTL九肽的DC对表达AFP HCC的研究和治疗有潜在应用价值。     

树突状细胞诱导的肿瘤特异性细胞毒性T淋巴细胞对裸鼠人肝癌转移的预防和治疗

目的探讨肿瘤抗原特异性细胞毒性T淋巴细胞(CTL)对裸鼠人肝癌转移模型LCI-D20的治疗作用。方法从健康人外周血单个核细胞中诱导树突状细胞,用重组人粒细胞-巨噬细胞集落刺激因子和白细胞介素-4刺激活化,经人肝癌细胞株MHCC97-H肿瘤抗原致敏后,诱导肿瘤抗原特异性CTL,经腹腔注射,以自然杀伤样T淋巴细胞(CIK)和磷酸盐缓冲液为对照,研究其对LCI-D20肝癌治疗和预防转移作用。结果肿瘤抗原特异性CTL组、CIK 组和对照组肝癌肿块重量、血清甲胎蛋白含量、肝癌肝内转移率和存活期依次为(1．11±0．63)g、(1．12±0．36)g 和(2．68±0．53)g;(52．1±9．7)μg／L、(48．6±5．2)μg／L和(82．2±7．2)μg/L;16．7％、16．7％和58．3％; (79．0±5．0)d、(73．3±7．0)d和(52．3±5．2)d。对照组与前两组比较差异均有统计学意义(P值均<0．01)。结论肿瘤抗原特异性CTL可以预防LCI-D20模型肝癌发生转移,延长动物存活时间。     

尿酸辅助树突细胞诱导乙型肝炎病毒抗原特异性细胞毒性T淋巴细胞效应的观察

近来研究提示,尿酸是免疫系统的一种重要的危险信号,它能刺激DC成熟,促进DC向T淋巴细胞呈递抗原．尿酸可能成为一种有效的免疫佐剂。本研究以尿酸辅助负载HBV表位肽S（28-39）的树突状细胞免疫接种小鼠,对其产生的HBV抗原特异性CTL免疫效应进行了报道。[第一段]     

肝癌树突状细胞疫苗诱导细胞毒性T淋巴细胞的效应

肝癌患者体内的树突状细胞(DC)负载肝癌相关抗原，诱导机体产生有效的免疫应答，是肝癌治疗的一条有效途径。     

慢性乙型肝炎患者树突状细胞诱导的HBV特异性细胞毒性T淋巴细胞PD-1的表达

目的 探讨慢性乙型肝炎(CHB)患者树突状细胞(DC)诱导的HBV特异性细胞毒性T细胞(CTL)表面程序性死亡受体1(PD-1)的表达情况及其与HBV DNA的关系.方法 采集30例CHB患者和10例健康人的抗凝外周静脉血,分离外周血单个核细胞(PBMC),在白细胞介素(IL)-4和粒-巨噬细胞集落刺激因子(GM-CSF)的作用下培养使DC增殖、成熟,培养第4d加入纯化的HBsAg进行冲击.采同一患者外周血,分离出自体T淋巴细胞,用含重组人白细胞介素(rhIL)-2的培养基维持T细胞的生长,培养第5d与HBsAg冲击的DC共培养.以流式细胞技术检测CTL的PD-1表达,并分析PD-1表达水平与HBV DNA的关系.结果 与健康对照组比较,CHB组DC诱导的HBV特异CTL的PD-1的表达明显升高(P=0.000).且HBeAg阳性组PD-1的表达率较HBeAg阴性组明显升高(P=0.000).CHB患者DC诱导的HBV特异性CTL的PD-1表达率与血清HBV DNA拷贝数的对数值呈正相关(r=0.53,P=0.008).结论 CHB患者DC诱导的HBV特异性CTL高表达PD-1分子,为HBV慢性感染过程中CTL功能低下,病毒难以清除提供了另一条重要线索.     

树突状细胞致敏的肿瘤疫苗对胰腺癌细胞的杀伤效应

目的:研究胰腺癌细胞冻融物致敏树突状细胞(DC)诱导的细胞毒性T细胞(CTL)对原代培养的自体胰腺癌细胞的杀伤作用．方法:从6例手术切除的胰腺癌组织中分离胰腺癌细胞,反复冻融获得肿瘤抗原;以该肿瘤抗原致敏外周血DC,诱导T细胞转变为CTL;采用Cr51释放法观察CTL对原代培养的自身胰腺癌细胞的杀伤活性,分别以来源于胰腺癌细胞株Pancl的肿瘤抗原致敏DC和未致敏DC刺激的CTL作为抗原对照和阴性对照．结果:实验组CTL对自身细胞的杀伤活性为69．05%±15．79%→88．05%±15．34％,抗原对照组CTL的杀伤活性为43．08％±6．92％→67．30％±8．91％,两组CTL杀伤率均显著高于阴性对照组(P<0．01);而实验组与抗原对照组相比,前者的杀伤活性显著高于后者者(P<0．05)．结论:胰腺癌细胞冻融物致敏的DC疫苗可以诱导T细胞产生高效的针对自体癌细胞的细胞毒效应;新鲜肿瘤组织来源的胰腺癌细胞比传代的Pancl细胞具有更好的抗原性．     

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。     

体外负载冻融抗原的脐血树突状细胞诱导的抗肝癌效应

目的评价体外应用肝癌细胞冻融抗原负载的脐血树突状细胞（DC）所诱导的抗肝癌效应。方法采集健康足月剖宫产孕妇胎盘端脐血,分离脐血单个核细胞（CBMNC）及T淋巴细胞,用GM-CSF、IL-4及TNF-α联合诱导CBMNC分化为DC,观察形态学变化并以流式细胞术鉴定,选培养的第3天以肝癌细胞冻融抗原负载的CBMNC-DC,以负载抗原的DC刺激自体淋巴细胞活化为自体细胞毒性T淋巴细胞（CTL）,并用CTL对肝癌细胞进行杀伤,MTT法测定活化的自体淋巴细胞的相对数量和CTL对肝癌细胞的杀伤率。结果体外负载肿瘤冻融抗原的脐血DC可诱导显著的自体效应淋巴细胞增殖及抗肝癌效应。结论体外负载抗原的脐血DC可诱导显著的抗肝癌效应,是具有临床应用前景的肝癌疫苗。     

急性髓性白血病细胞体外诱导脐血细胞毒性T淋巴细胞增殖及抗白血病作用的研究

目的研究体外培养急性髓性白血病树突状细胞（AML-DC）,并利用该细胞联合细胞因子诱导脐血产生细胞毒性T淋巴细胞（CTL）,观察CTL对急性白血病细胞的杀伤效应,探讨从AML．DC体外诱导产生CTL的可行性。方法从急性髓性白血病细胞诱导AML—DC,联合细胞因子体外诱导脐血T细胞活化及增殖,流式细胞术检测培养前后的T淋巴细胞亚群变化,利用LDH试剂盒检测诱导后T细胞对相应急性白血病细胞的杀伤活性。结果可从人AML细胞中诱导出AML-DC,脐血T细胞在体外经过诱导培养后可获得增殖,T淋巴细胞比例较培养前明显增高,其中在AML—DC诱导组中,CD3^＋T淋巴细胞亚群比例达到（79．7±3．70）％,该T淋巴细胞对相应急性白血病细胞的杀伤效率最高达（48．35±12．75）％,与培养前及培养后无AML—DC刺激组相比,经过特异诱导培养的T细胞对相应白血病细胞杀伤作用大大加强（P〈0．05）。结论AML—DC联合细胞因子可以诱导活化脐血白血病细胞特异性细胞毒性T淋巴细胞（CTL）,该细胞能对相应白血病细胞产生特异性杀伤效应。     

In-vitro activation of cytotoxic T lymphocytes by fusion of mouse hepatocellular carcinoma cells and lymphotactin gene-modified dendritic cells

AIM： To investigate the in-vitro activation of cytotoxic T lymphocytes （CTLs） by fusion of mouse hepatocellular carcinoma （HCC） ceils and lymphotactin gene-modified dendritic cells （DCs）.
METHODS： Lymphotactin gene modified DCs （DCLptn） were prepared by lymphotactin recombinant adenovirus transduction of mature DCs which differentiated from mouse bone marrow cells by stimulation with granulocyte/macrophage colony-stimulating factor （GM- CSF）, interleukin-4 （IL-4） and tumor necrosis factor alpha （TNF-α）. DCLptn and H22 fusion was prepared using 50% PEG. Lymphotactin gene and protein expression levels were measured by RT-PCR and ELISA, respectively. Lymphotactin chemotactic responses were examined by in-vitro chemotaxis assay. In-vitro activation of CTl_s by DCLptn/H22 fusion was measured by detecting CD25 expression and cytokine production after autologous T cell stimulation. Cytotoxic function of activated T lymphocytes stimulated with DCLptn/H22 cells was determined by LDH cytotoxicity assay. RESULTS： Lymphotactin gene could be efficiently transduced to DCs by adenovirus vector and showed an effective biological activity. After fusion, the hybrid DCLptn/H22 cells acquired the phenotypes of both DCLptn and H22 cells. In T cell proliferation assay, flow cytometry showed a very high CD25 expression, and cytokine release assay showed a significantly higher concentration of IFN-α, and IL-2 in DCLptn/H22 group than in DCLptn, DCLptn＋H22, DC/H22 or H22 groups. Cytotoxicity assay revealed that T cells derived from DCLptn/H22 group had much higher anti-tumor activity than those derived from DCLptn, H22, DCLptn ＋ H22, DC/H22 groups. CONCLUSION： Lymphotactin gene-modified dendritoma induces T-cell proliferation and strong CTL reaction against allogenic HCC cells. Immunization-engineered fusion hybrid vaccine is an attractive strategy in prevention and treatment of HCC metastases.     

Estimation of the rate of killing by cytotoxic T lymphocytes in vivo

Cytotoxic T lymphocytes (CTL) help control virus infections by killing virus-infected (target) cells. How fast do CTL find and kill target cells in vivo? Experiments allow us to follow populations of labeled target cells after their transfer into immune mice where they are killed by CTL. Here, we develop models of the migration and killing processes involved in these experiments and use them to quantitatively analyze the in vivo killing data. These models allow us to estimate the rate constant for killing of target cells by CTL.     

Induction of lymphokine-activated cytotoxic T lymphocytes stimulated by dendritic cells and autologous tumor from a patient with gastric cancer and their effects in vitro

BACKGROUND/AIMS: The purpose of the study was to generate lymphokine-activated cytotoxic T lymphocytes stimulated by dendritic cells (DC) and autologous tumor from a patient with gastric cancer and to clarify their cytotoxic effects in vitro. METHODOLOGY: DC was induced by interleukin-4 (IL-4) and granulocyte-macrophage-colony-stimulating factor (GM-CSF) from the peripheral blood mononuclear cells (PBMC). Then, PBMC was incubated with mitomycin C-treated tumor cells and DC, and following that was activated with IL-2 and anti-CD3. Induction of DC and cytotoxic T cells (CTL) were confirmed by the analyses of the cell surface antigens, killing activities, and blocking tests. RESULTS: Induction of DC and cytotoxic T cells (CTL) was confirmed by the analyses of the cell surface antigens, killing activities, and blocking tests. In vitro study demonstrated that lymphokine-activated lymphocytes pulsed by DCs and autologous tumor contained the largest population of CTLs, the greatest production of IFN-gamma, and the greatest ATK activity. CONCLUSIONS: Those results indicated that CTLs could be generated in vitro from a patient with gastric cancer more successfully by this method than by conventional methods, suggesting the possibility of a new immunotherapy for the treatment of gastric cancer.     

胰腺癌细胞总RNA转染树突细胞诱导特异性CTL能力的体外研究

目的观察人胰腺癌Mia Pa Ca-2细胞总RNA电转染树突细胞(Dendritic Cell,DC)体外激发抗原特异性细胞毒T淋巴细胞(Cytotoxic T Lymphocyte,CTL)的能力。方法自6例胰腺癌患者外周血单核细胞中分离、培养DC。使用电穿孔法将Mia Pa Ca-2细胞总RNA体外转录和PCR扩增的MUC1m RNA转染DC,以未负载抗原的DC为对照。采用实时定量PCR技术检测各组DC中MUC1表达。四甲基偶氮唑盐(MTT)检测转染各组DC存活率变化;混合细胞培养法评价各组DC体外刺激自体T淋巴细胞增殖能力;ELISA法检测各组DC体外激发抗原特异性CTL细胞因子释放量。结果 Mia Pa Ca-2总RNA与MUC1 m RNA分别转染后48 h DC中目标抗原的相对表达量分别为37.24±3.17和34.53±2.02,两者比较无显著差异(P0.05)。电转染后96 h Mia Pa Ca-2总RNA转染组DC存活率降至60.81%,低于MUC1 m RNA单转染时DC的存活率(80%左右)(P0.05)。转染Mia Pa Ca-2总RNA DC刺激自体T细胞增殖指数为8 432±611.25,显著高于MUC1单独转染组3 664±305.17(P0.05);且转染Mia Pa Ca-2总RNA DC激发特异性CTL分泌IL-2、IL-10、Granzyme B、IFN-γ水平亦显著高于MUC1 m RNA单独转染组(P0.05)。结论胰腺癌肿瘤细胞总RNA转染的DC较单一胰腺癌相关抗原负载DC有更强的体外抗原特异性CTL激发能力。     

负载不同转移潜能肝癌细胞exosomes的树突状细胞激活T淋巴细胞体外杀伤作用的初步研究

目的分离制备高、低转移潜能肝癌细胞exosomes,并研究负载相应exosomes的树突状细胞（DC）激活的T淋巴细胞在体外杀伤肿瘤细胞的作用。分析不同转移潜能肝癌细胞系分泌的exosomes的成分差异。方法采用四步离心法分离exosomes,电镜观察。分离小鼠DC,并且负载高、低转移潜能细胞株的exosomes,激活T淋巴细胞后,采用^3H-TdR掺入法进行体外混合淋巴细胞反应。应用蛋白质组学弱阳离子交换芯片（SELDI-TOF-MS）检测不同转移潜能肝癌细胞分泌的exosomes蛋白成分的差异。结果电镜观察高转移潜能的肝癌细胞分泌的exoxomes的密度分布、exosomes内容物均不同于低转移组。CD80、CD86、MHC-;Ⅰ、MHC-Ⅱ,在高转移组分别为64.27±5.00、44.89±10.11、84.35±19.89、59.03±19.37,低转移组分别为71.53.±4.85、50.01±9.50、80.68±29.87、58.86±21.11,与对照组相比P〉0.05,负载exosomes后测得cpm值在高转移组为528.40±179.06,低转移组为78.80±24.44,与对照组相比P〈0.01。蛋白质组学弱阳离子交换芯片结果表明高、低转移组细胞系的exosomes蛋白组分有着明显的差异。结论exosomes具有潜在的免疫治疗价值,在肝癌的转移和复发防治以及生物治疗中具有应用前景。     

Induction of cytotoxic T lymphocytes by dendritic cells pulsed with murine leukemic cell RNA

Peptide-pulsed dendritic cells can stimulate T cells showing specific cytotoxicity in chronic myelogenous leukemia. We tried to induce a specific cytotoxic T-cell response stimulated by RNA-pulsed dendritic cells in acute myelogenous leukemia. The total RNA of WEHI-3BD+, a myelomonocytic leukemia cell line derived from BALB/c mice, was transfected into dendritic cells induced from bone marrow nucleated cells of BALB/c mice with granulocyte macrophage colony-stimulating factor (GM-CSF) and lipopolysaccharide (LPS) using liposome. RNA-pulsed dendritic cells were injected into the peritoneal cavity of BALB/c mice, and splenic T cells were isolated for antigen-stimulated proliferation and leukemia-specific cytotoxicity assay. Cultured bone marrow nucleated cells expressed dendritic cell markers including MHC class II antigen, CD80, CD86, and CD11c. T cells stimulated by RNA-pulsed dendritic cells showed enhanced proliferation than those stimulated by unpulsed dendritic cells (P = 0.05) and showed dose-dependent specific cytotoxicity against WEHI-3BD+ cells. We concluded total RNA-pulsed dendritic cells could induce a specific T-cell cytotoxicity in acute myelogenous leukemia.