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。     

MAGE-3抗原肽致敏树突状细胞的体内抗膀胱癌作用及机制

目的 探讨黑色素瘤-3基因(MAGE-3)抗原肽致敏的树突状细胞(DC)体内对膀胱癌肿瘤的抑制作用及机制.方法 采用Ficoll法从HLA-A2型个体外周血中分离单个核细胞,用GM-CSF和IL-4诱导扩增DC,再经MAGE-3抗原肽致敏,致敏DC细胞和同型T淋巴细胞共培养诱导细胞毒性T淋巴细胞(CTL),经过尾静脉注入膀胱癌荷瘤小鼠,观察其对肿瘤体积及重量的影响.结果 MAGE-3抗原肽致敏的DC诱导产生的CTL可明显缩小瘤体、降低瘤重.结论 MAGE-3九肽致敏DC诱导CTL体内具有抑制膀胱癌细胞增长的作用;其机制可能为激活T淋巴细胞.     

热休克肝癌细胞来源囊泡诱导细胞毒性T细胞的杀伤作用

目的研究热休克肝癌细胞来源囊泡(exosomes)刺激人树突状细胞(DC)能否诱导出肝癌细胞特异性细胞毒性T淋巴细胞(CTL)。方法 43℃热休克(水浴)1h培养肝癌细胞提取胞外囊泡,诱导DC刺激细胞毒性T淋巴细胞,MTT法测定CTL在体外对肝癌细胞的杀伤作用。结果热休克前后肝癌细胞胞外囊泡和肿瘤细胞裂解物刺激的DC均能促进对肝癌细胞的杀伤活性,热休克肝癌细胞胞外囊泡实验组较胞外囊泡和肝癌细胞冻融裂解物对照组有显著性差异(P0.05和P0.01)。结论热休克能够增强肝癌细胞胞外囊泡诱导的特异性抗肝癌细胞免疫反应。     

负载肝癌抗原树突细胞瘤苗对癌细胞免疫抑制作用

目的探讨人自体肝癌细胞裂解物致敏的树突细胞(DC)瘤苗对自体肝癌细胞免疫功能的影响。方法从肝癌患者外周血单个核细胞中诱导DC,用相关细胞因子及自体肝癌细胞刺激活化,制备DC瘤苗;应用流式细胞仪检测T淋巴细胞增殖情况,观察刺激术前及术后自体的T淋巴细胞以及产生的特异性的细胞毒性T淋巴细胞(CTL)对自身肿瘤细胞的抑制效果。结果肝癌DC瘤苗刺激术后自体T淋巴细胞增殖能力及抑制肿瘤细胞作用显著强于术前,T淋巴细胞增殖指数术后(1.86±0.15)较术前(1.18±0.13)显著增高、CD8+T细胞增殖指数术后(1.55±0.35)较术前(0.95±0.12)增加显著,术后与术前比较差异均有统计学意义(均P0.05)。肝癌DC瘤苗活化的术后自体CTL对自体肝癌细胞有较强杀伤作用,杀伤率由术前的(32.35±2.26)%增加到术后的(69.80±3.45)%。结论肝癌DC瘤苗活化的术后自体CTL对自体肝癌细胞杀伤作用比术前作用显著,DC瘤苗能有效地诱导抗肿瘤免疫反应,有望在肝癌术后的治疗中发挥作用。     

带有HPV-16 E6/E7基因的DC疫苗抑制裸鼠宫颈癌生长的机制

目的 观察由携带HPV-16 E6/E7基因的树突细胞(dendritic cell,DC)疫苗免疫得到的细胞毒性T淋巴细胞(CTL)在裸鼠体内对官颈癌的抑制作用及相关机制.方法 诱导培养C57B L/6小鼠骨髓的未成熟DC(imDC),将已经成功构建的携带人乳头状瘤病毒(HPV)-16 E6/E7基因的重组腺病毒感染imDC,Western印迹检测E7蛋白的表达;构建裸鼠官颈癌细胞移植瘤模型,应用DC疫苗诱导的CTL处理后,观察裸鼠肿瘤的体积变化;CCK8(cell counting kit8)法检测经DC疫苗免疫的BALB/c小鼠脾脏T淋巴细胞的增殖;免疫组化法检测裸鼠脾脏组织CD4+T淋巴细胞的表达.结果 成功培养出DC并制备出DC疫苗;第28天各组裸鼠肿瘤体积pAd-E6E7-DC-CTL-CaSki组与对照组pAd-mock-DC-CTL-CaSki组、DC-CTL-CaSki组、CaSki组相比较,pAd-E6E7-DC-CTL-CaSki组裸鼠肿瘤体积最小(P＜0.05);CCK8法检测经DC疫苗免疫的BALB/c小鼠脾脏T淋巴细胞的增殖,结果pAd-E6/E7-DC组淋巴细胞OD值明显高于pAd-mock-DC组、DC组和PBS组(P＜0.01);免疫组化检测各组裸鼠脾脏组织CD4 T淋巴细胞的表达结果显示,pAd-E6E7-DC-CTL-CaSki组CD4表达量最高,pAd-mock-DC-CTL-CaSki组和DC-CTL-CaSki组CD4表达量次之,CaSki组CD4表达量最低.结论 带有HPV-16 E6/E7基因修饰的DC疫苗,能够促进小鼠体内T淋巴细胞的增殖,诱导CTL抑制裸鼠宫颈癌移植瘤的生长.     

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。     

DC活化的特异性CTL对裸鼠胃癌移植瘤的杀伤效应

用人胃癌细胞抗原致敏成熟树突状细胞（DC）。将DC活化的特异性细胞毒性T细胞（CTL）注射到胃癌裸鼠体内。用流式细胞术（FCM）检测移植瘤细胞C0／G1、S、G2／M期细胞凋亡情况。结果DC活化的特异性CTL作用于裸鼠皮下移植瘤，可显著抑制其生长，瘤细胞出现不同程度的坏死、变性。特异性CTL作用后，裸鼠皮下移植瘤细胞的增殖指数（PI）为（24.39±2.46）％，显著低于非抗原特异CTL作用后组的（31.24±3.85）％和对照组的（32.78±4.17）％；凋亡细胞比率为（15.83±2.77）％，显著高于非抗原特异CTL组的（7.28±2.26）％和对照组的（9.15±1.33）％，P均〈0.05。认为胃癌细胞抗原致敏DCs活化的CTL在体内可特异性的抑制裸鼠移植瘤细胞生长、增殖，促进瘤细胞凋亡，有效预防裸鼠移植瘤的发生。     

负载胰腺癌抗原的树突状细胞疫苗诱导T淋巴细胞抗肿瘤效应的研究

培养树突状细胞(DC),反复冻融法裂解培养的负载胰腺癌细胞(PC-3),提取细胞抗原,致敏DC,获得负载胰腺癌抗原的DC疫苗后诱导特异性细胞毒性T淋巴细胞(CTL)的生成,MTT法检测CTL对不同肿瘤细胞的杀伤作用.发现负载PC-3细胞抗原的DC疫苗能诱导产生肿瘤特异性的CTL,其对PC-3细胞具有明显地杀伤效应,而对人乳腺癌细胞MCF-7、人肝癌细胞7721细胞杀伤作用弱.认为负载胰腺癌抗原的DC疫苗能够诱导高效而特异地CTT杀瘤活性,为将来DC疫苗在胰腺癌的免疫治疗中提供了实验依据.     

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。     

Dendritic cells fused with allogeneic hepatocellular carcinoma cell line compared with fused autologous tumor cells as hepatocellular carcinoma vaccines

Purpose: To investigate the specific antitumor responses against autologous hepatocellular carcinoma (HCC) cells of dendritic cells (DCs) fused with allogeneic HCC cell line, and evaluated the feasibility of BEL7402 as an alternative strategy to deliver shared HCC antigens to DCs. Methods: Previous studies demonstrated fusions of patient‐derived DCs and autologous tumor cells could induce T‐cell responses against autologous tumors. These fusion cells require patient‐derived tumor cells, which are not, however, always available. Here, we report the fusing of autologous DCs with allogeneic HCC cell line to induced cytotoxic T‐lymphocyte (CTL) response against autologous HCC cells compare with autologous tumor cells. Results: These DC/ BEL7402 fusion cells co‐expressed tumor‐associated antigens and DC‐derived costimulatory and major histocompatibility complex molecules. Both CD4+ and CD8 T+ cells were activated by the fusion cells as demonstrated by the proliferation of T‐cells, the production of cytokines and the simultaneous induction of specific CTL responses. Significantly, CTL induced by dendritic cell/allogeneic BEL7402 fusion cells were able to kill autologous HCC cells by human leukocyte antigen‐A2 restricted mechanisms. The results did not show significant difference between DC fusion with autologous hepatocellular carcinoma cells and DC fusion with allogeneic hepatocellular carcinoma cell line. Conclusions: The fusion of allogeneic HCC cell line and autologous DCs may have applications in antitumor immunotherapy through cross‐priming against shared tumor antigens and may provide a platform for adoptive immunotherapy.     

树突细胞负载骨髓瘤抗原介导的免疫反应

目的 研究负载肿瘤抗原的树突细胞能否诱导特异性细胞霉T淋巴细胞反应。方法 用多发性骨髓瘤患者骨髓CD34^ 细胞诱生树突细胞，并将骨髓瘤冻融物冲击致敏树突细胞。采用MTT法检测骨髓瘤抗原致敏及未致敏树突细胞诱导的自身T细胞对不同靶细胞(患者骨髓瘤细胞、K562细胞株)的杀伤率。结果 骨髓瘤冻融物致敏树突细胞诱导的自身T细胞对患者骨髓瘤细胞的杀伤远大于对K562细胞的杀伤。结论 患者骨髓瘤冻融物致敏的树突细胞能有效诱导自身T细胞发生特异性抗肿瘤免疫。     

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     

Dendritic cells pulsed with unfractionated helminthic proteins to generate antiparasitic cytotoxic T lymphocyte

Dendritic cells (DC) are sentinels of immunity. We determined their role in the induction of immunity against alveolar echinococcosis, caused by the larval stage of the cestode Echinococcus multilocularis. Furthermore, we evaluated if unfractionated protein from E. multilocularis (Em-Ag) can be used as loading agent for DC (comparable to unfractionated tumour proteins) in order to generate antiparasitic cytotoxic T lymphocyte (CTL). Interestingly, immature DC did not mature in the presence of 1 microg/ml Em-Ag as analysed by FACS and mixed leucocyte reactions. Yet, their capacity to take up dextran was markedly reduced. Further maturation of immature Em-Ag pulsed DC could be induced by proinflammatory cytokines. These mature DC were slightly better inducers of T cell proliferation when compared with unpulsed mature DC. Importantly, by repetetive stimulation of autologous CD8+ lymphocytes with the Em-Ag pulsed mature DC, we were able to generate specifically proliferating CTL lines. Thus, immunotherapy with ex vivo generated Em-Ag pulsed DC might be of benefit for patients inheriting this incurable disease.     

Dendritic cells pulsed with hsp70-peptide complexes derived from human hepatocellular carcinoma induce specific anti-tumor immune responses

AIM: To investigate the anti-tumor effect of dendritic cells (DCs) pulsed with hsp70-peptide complexes derived from human hepatocellular carcinoma (HCC) cells on human T cells. METHODS: Hsp70-peptide complexes were purified from human HCC cells with column chromatography using ADP-agarose and DEAE-Sepharose. DCs were derived from peripheral blood mononuclear cells of healthy donors in the presence of human GM-CSF and IL-4. The anti-tumor effect of DCs pulsed with hsp70-peptide complexes on human T-cell was assayed by CTL and enzyme-linked immunospot (ELISPOT) tests. RESULTS: Hsp70-peptide complexes derived from human HCC cells activated phenotypic and functional maturation of DCs. The matured DCs stimulated a high level of autologous T-cell proliferation and type I cytokine secretion, and induced HCC-specific cytotoxic T lymphocytes (CTLs), which specifically killed HCC cells by a MHC class I restricted mechanism. CONCLUSION: Hsp70-peptide complexes derived from human HCC cells can serve as a potent tumor antigen source for pulsing DCs, the pulsed DCs are very effective in activating specific T-cell responses against HCC cells.     

Alpha-type 1-polarized dendritic cells loaded with apoptotic allogeneic myeloma cell line induce strong CTL responses against autologous myeloma cells

To induce a potent cytotoxic T lymphocyte (CTL) response, various tumor antigens should be loaded onto dendritic cells (DCs). In multiple myeloma (MM), it is difficult to obtain a sufficient number of autologous tumor cells as a source of tumor antigens in the clinical setting. We investigated the feasibility of immunotherapy in patients with MM, using myeloma-specific CTLs generated in vitro by alpha-type 1-polarized DCs (αDC1s) loaded with the ultraviolet B-irradiated allogeneic myeloma cell line, ARH77. αDC1s significantly increased the expression of several costimulatory molecules without differences in loading with tumor antigens. αDC1s showed a high production of interleukin-12 during maturation and after subsequent stimulation with CD40L but were not significantly affected by loading tumor antigens. Myeloma-specific CTLs against autologous myeloma cells from MM patients were induced by αDC1s pulsed with apoptotic ARH77 cells. Our data indicate that autologous DCs loaded with an allogeneic myeloma cell line can generate potent myeloma-specific CTL responses against autologous myeloma cells and might provide a practical method for cellular immunotherapy in patients with MM.     

Induction of tumor immunity and cytotoxic t lymphocyte responses using dendritic cells transduced by adenoviral vectors encoding HBsAg: comparison to protein immunization

Dendritic cells (DC) are specialized antigen-presenting cells with powerful immunostimulatory properties. Their use for induction of anti-tumor immunity has been limited by several factors, including identification of appropriate tumor-associated antigens, delivery of antigens to DC, and maintaining DC in a highly activated state. Here, DC propagated in vitro were transduced with an adenoviral (Ad) vector to express hepatitis B surface antigen (HBsAg), an antigen present in hepatocellular carcinoma (HCC). Many patients with HCC demonstrate evidence of prior HBV exposure, suggesting that the presence of the virus in a quiescent state may promote tumorigenesis. Ad-HBsAg-transduced DC stimulated strong cytotoxic T lymphocyte (CTL) responses to HBsAg-expressing tumor cells, and protected mice from lethal tumor challenge. Immunity was antigen-specific, as wild-type tumor (HBsAg -) grew normally. Furthermore, DC transduced with an irrelevant vector had no effect. Vaccination with HBsAg protein, a clinically utilized preparation that confers immunity to HBV infection, did not protect against tumor challenge even though it induced a strong antibody response. These studies describe for the first time the contributions of humoral and cellular immune responses to tumor immunity induced by Ad-transduced DC compared to protein vaccination.     

Interferon-gamma produced by interleukin-12-activated tumor infiltrating CD8+T cells directly induces apoptosis of mouse hepatocellular carcinoma

BACKGROUND/AIMS: Interleukin-12 (IL-12), a cytokine with antitumor activity, was examined for the suppressive effect on hepatocellular carcinoma (HCC) in mouse model, and its mechanism of antitumor activity was analyzed. METHODS: Mice implanted with MIH-2 HCC cells were treated with recombinant mouse IL-12 (500 ng/mouse). Involvement of CD4(+), CD8(+), NK cells and interferon (IFN)-gamma on tumor suppression by IL-12 was examined by treatment of mice with each antibody. Interferon-gamma (IFN-gamma) production by tumor infiltrating cells was analyzed by immunofluorescence microscopy and flow cytometric analysis. Signal transduction for apoptosis induction was examined by immunoblot analysis. RESULTS: The growth of implanted MIH-2 tumors was significantly suppressed by IL-12 and the suppression was inhibited by depletion of CD8(+)T cells. IL-12 treatment caused numerous IFN-gamma-producing CD8(+)T cells to infiltrate into MIH-2 tumors. Antitumor activity of IL-12 was blocked by treating mice with anti-IFN-gamma mAb. CD8(+)T cells from IL-12-treated mice attached to MIH-2 cells and produced IFN-gamma in vitro. Cell attachment might be associated with intercellular adhesion molecule-1 induced by IFN-gamma. In vitro treatment with IFN-gamma induced apoptosis of MIH-2 cells via a mitochondria-dependent pathway. CONCLUSIONS: IL-12 suppressed HCC growth in mouse model. IFN-gamma produced by IL-12-activated tumor-infiltrating CD8(+)T cells directly induced apoptosis of HCC cells.