Immunoregulation of dendritic and T cells by alpha-fetoprotein in patients with hepatocellular carcinoma

BACKGROUND/AIMS: Novel immunotherapeutic and other strategies are being explored for the treatment of hepatocellular carcinoma (HCC). Alpha-fetoprotein (AFP) may be a target antigen for immunotherapy. Little is known, however, about the immunobiology of AFP. Therefore, the impact of AFP on dendritic cells (DC), CD4+ and CD8+ T cells was studied in detail. METHODS: Immune cells from peripheral blood of 27 HCC patients were studied using FACS, ELISPOT, and proliferation assays. RESULTS: The in vitro generation, maturation, and T cell stimulatory capacity of DCs were not altered by AFP up to concentrations of 20 microg/ml. Higher AFP concentrations (> 20 microg/ml) resulted in phenotypic changes on DCs without impairing their capacity to stimulate CD4+ T cells. Frequencies and function of DCs and AFP specific T cells were not reduced in HCC patients independent on serum AFP levels. Finally, T lymphocytic infiltrations in the liver were not dependent on AFP serum levels. CONCLUSIONS: These studies clearly demonstrate that (i) DC-based immunotherapeutic approaches are a promising approach for HCC treatment and (ii) AFP-reactive T cell clones have not been deleted from the human T cell repertoire establishing AFP as a potential target for T cell based immunotherapy of HCC.     

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．     

肝细胞癌患者 Treg 细胞对 CD8＋T 淋巴细胞穿孔素表达的影响

目的：研究肝细胞癌患者免疫抑制性 Treg 细胞对 CD8＋ T 淋巴细胞穿孔素表达的影响。方法采集20例肝细胞癌患者和20名健康人的外周血,用流式分析法检测抗-CD3／CD28刺激48 h 后 CD8＋ T 淋巴细胞的穿孔素表达情况。免疫磁珠分离法分离健康人 CD8＋ T 淋巴细胞和肝细胞癌患者 Treg 细胞,一组 CD8＋ T 淋巴细胞单独培养,另一组CD8＋T 淋巴细胞与 Treg 细胞共同培养,用流式细胞法检测抗-CD3／CD28刺激48 h 后两组 CD8＋ T 淋巴细胞穿孔素表达情况。结果肝细胞癌患者外周血中 CD8＋ T 淋巴细胞穿孔素表达量与健康人相近,分别为（10．74±3．96）％和（12．6±2．48）％,差异无统计学意义（P ＞0．05）。CD8＋ T 淋巴细胞单独培养和与肝癌患者 Treg 细胞共培养后,健康人 CD8＋ T 淋巴细胞穿孔素表达量分别为（34．2±3．65）％和（20．43±4．52）％,差异有统计学意义（t＝11．42,P ＜0．01）。结论肝癌患者免疫抑制性 Treg 细胞可使 CD8＋ T 淋巴细胞穿孔素表达量降低。     

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     

Impaired cytotoxic T lymphocyte inductivity by dendritic cells derived from patients with hepatitis C virus-positive hepatocellular carcinoma

Aim: Peptide-based therapeutic vaccines are being developed. The aim of this study was to determine the feasibility of immunotherapy to hepatitis C virus (HCV)-positive hepatocellular carcinoma (HCC) by assessing the inductivity of peptide-specific cytotoxic T lymphocyte (CTL) by dendritic cells. Methods: The inductivity of CTL was characterized in six patients with HCV-positive HCC, and compared to seven healthy volunteers and six patients with chronic HCV hepatitis (control). Results: Peptide-specific CTL was comparably induced in controls, but not induced in any patients with HCC. To characterize this, the cytokine profile and the expression of surface molecules interacting between dendritic and T cells were evaluated. Among the cytokines, production of interferon (IFN)-gamma was found to be impaired and closely related to the results of CTL assays, while the expression of surface molecules showed no significant changes. Conclusions: In HCV-positive HCC patients, CTL inductivity by dendritic cells is impaired. This may be related to the impaired production of IFN-gamma.     

树突状细胞激活的肿瘤浸润性淋巴细胞抗胃癌活性的研究

目的　树突状细胞 (DC)是目前已知的功能最强的抗原提呈细胞 (APC) ,可以向包括肿瘤浸润性淋巴细胞 (TIL)在内的T淋巴细胞提呈抗原 ,并诱发细胞毒T淋巴细胞 (CTL)反应。该文探讨树突状细胞激活的肿瘤浸润性淋巴细胞体外对胃癌细胞 (SGC 790 1 )的杀伤活性。方法　从胃癌患者外周血获取DC ,应用粒 /巨噬细胞集落刺激因子 (GM CSF)、白介素 4(IL 4)和肿瘤抗原激活DC ,然后用DC激活TIL ,观察TIL在体外对自体胃癌细胞和人胃癌细胞株细胞的杀伤活性。结果　DC激活的TIL具有很高的对自体胃癌细胞杀伤活性 ,杀伤率为 (89.39± 3 .0 5) % ,明显高于未经DC激活的TIL、CD激活的T淋巴细胞和未经DC激活的T淋巴细胞对自体胃癌细胞的杀伤率 [杀伤率分别为 (54 .37±1 .50 ) % ,(53 .92± 1 .46) %和 (3 .55± 0 .2 5) % ]。而它们对SGC 790 1细胞的杀伤活性则相对较低。结论　胃癌患者外周血DC能诱导TIL产生高效而特异的抗胃癌免疫     

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。     

树突状细胞的非特异性免疫功能降低对HBV、HCV清除及细胞毒性T淋巴细胞应答无影响

目的 观察HBV、HCV感染者树突状细胞(DC)的非病毒特异性免疫功能状态与细胞毒性T淋巴细胞(CTL)免疫应答以及病毒清除的关系。方法 对25例成人慢性HBV和HCV合并感染者进行了间隔8年的两次调查、依据临床转归分为HBV和HCV均清除组(A组)14例、单独HCV清除者(B组)6例，单独HBV消除者(C组)3例，HBV和HCV均未清除者(D组)2例，对照组(N组)为同一地区健康献血员11例。体外分离培养DC，检测其表型及抗原摄取功能、刺激异体淋巴细咆增殖能力和4组感染者的CTL免疫应答情况。结果 B、C、D组与A组、N组比较，DC的非病毒特异性免疫功能降低，表现为CD86表达的降低、刺激异体淋巴细胞增殖的能力下降以及抗原摄取能力降低。A组对HBV和HCV的4条抗原表位多肽均有较高的CTL应签率(11／12)；B组对HCV的两条抗原表位多肽均有应答(5／5)，但无对HBV两条表位多肽均应签者、仅有1例对P2有反应；C组对HBV的抗原表位多肽均有应答，但无对两条HCV表位多肽均应答者；D组及N组对HBV或HCV所有实验多肽均无应答。结论 HBV和HCV的清除与病毒特异性的CTL应答相关。HBV和(或)HCV持续存在可能是导致DC功能异常的原因。     

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。     

Immunotherapy with dendritic cells and cytokine-induced killer cells for hepatocellular carcinoma: A meta-analysis

BACKGROUND Hepatocellular carcinoma(HCC) has been revealed as the second most common cause of cancer-related deaths worldwide. The introduction of cell-based immunotherapy, including dendritic cells(DCs) and cytokine-induced killer cells(CIKs), has brought HCC patients an effective benefit. However, the efficacy and necessity of cellular immunotherapy after different interventional therapy remains to be further explored.AIM To investigate the efficacy of cellular immunotherapy, involving DCs and CIKs,combined with different conventional treatments of HCC.METHODS We performed a literature search on PubMed and Web of Science up to February15, 2019. Long-term efficacy(overall survival and recurrence) and short-term adverse effects were investigated to assess the effectiveness of immunotherapy with DCs and/or CIKs. Review Manager 5.3 was used to perform the analysis.RESULTS A total of 22 studies involving 3756 patients selected by eligibility inclusion criteria were forwarded for meta-analysis. Combined with the conventional clinical treatment, immunotherapy with DCs and/or CIKs was demonstrated to significantly improve overall survival at 6 mo [risk ratio(RR) = 1.07; 95%confidence interval(CI): 1.01-1.13, P = 0.02], 1 year(RR = 1.12; 95%CI: 1.07-1.17, P 0.00001), 3 years(RR = 1.23; 95%CI: 1.15-1.31, P 0.00001) and 5 years(RR =1.26; 95%CI: 1.15-1.37, P 0.00001). Recurrence rate was significantly reduced by cellular immunotherapy at 6 mo(RR = 0.50; 95%CI: 0.36-0.69, P 0.0001) and 1 year(RR = 0.82; 95%CI: 0.75-0.89, P 0.00001). Adverse effect assessment addressed that immunotherapy with DCs and/or CIKs was accepted as a safe,feasible treatment.CONCLUSION Combination immunotherapy with DCs, CIKs and DC/CIK with various routine treatments for HCC was evidently suggested to improve patients' prognosis by increasing overall survival and reducing cancer recurrence.     

Induction of hepatitis C virus-specific cytotoxic T and B cell responses by dendritic cells expressing a modified antigen targeting receptor

AIM: To find a novel antigen (Ag) presentation strategy to improve the immune responses induced by dendritic cell (DC) vaccine expressing hepatitis C virus (HCV) core antigen (pcDNA3HCV C-Fc) in Balb/c mice (H-2d). METHODS: pcDNA3HCV C-Fc plasmid and eukaryotic expression vector pcDNA3 were injected into mice sc. Immune responses to pcDNA3HCV C-Fc were studied. Meanwhile the effect of pcDNA3HCV C-Fc on anti-translated subcutaneous tumor of SP2/0 cells stably expressing HCV C Ag (SP2/0-HCV C-FC) was also studied. Anti-HCV C in serum was detected by enzyme-linked immunoadsordent assay (ELISA) and HCV specific cytotoxic T lymphocyte (CTL) activity was measured by LDH release assay. After 3 wk of DNA immunization, the cells of SP2/0-HCV C-FC were inoculated into mice subcutaneously and tumor growth was measured every 5 d. The survival rate and living time of mice were also calculated. RESULTS: After 4 wk of DC immunization, the A450 nm values of sera in mice immunized with pcDNA3HCV C-Fc-DC and pcDNA3-DC were 0.56±0.17 and 0.12±0.03 respectively. The antibody titres in mice codeliveried with pcDNA3HCV C-Fc with DC were significantly higher than those of mice injected with pcDNA3-DC. The HCV specific CTL activities in mice coinjected with DC and pcDNA3HCV C-Fc or empty expression vectors were(73.2±3.1) % and (24.4±8.8) % , which were significantly higher than those of mice injected with water. The DC vaccine could evidently inhibit tumor growth, prolong the survival time of mice and improve the survival rate of mice and these effects could be improved by HCV C-Fc (pcDNA3HCV C-Fc) gene codelivered. CONCLUSION: DC vaccine has a strong antigenicity in humoral and cellular immunities, which can be promoted by transduced pcDNA3HCV C-Fc expressing HCV C or Fc. Thus, pcDNA3HCV C-Fc-transduced DCs may be a promising candidate for a CTL-based vaccine against HCV.     

HBV抗原基因修饰树突状细胞疫苗体外抗HBV的作用

目的：探讨腺病毒载体介导HBV抗原基因修饰的树突状细胞(DCs)诱导抗HBV特异性CTL反应方法：制备携带HBsAg、HBeAg和HBcAg基因的3种重组腺病毒Ad-HBs,Ad-HBe,Ad- HBc,分别转染自脐带血体外诱导培养的DCs,观察腺病毒转染DCs效率和DCs中HBV抗原的表达;混合淋巴细胞反应(MLR)测定HBV抗原基因修饰DCs刺激同种异体T淋巴细胞增殖能力;乳酸脱氢酶释放法检测特异性CTL细胞对HepG_222．1．5靶细胞的杀伤能力．结果：腺病毒载体能够高效介导HBV三个抗原基因在DCs中表达,90%以上DCs表达示踪基因EGFP,且DCs细胞形态完整：感染后72 h HBsAg和HBeAg含量分别为0．919和0．328(吸光度A值)．MLR实验显示,HBV抗原基因修饰DCs仍然具有刺激同种异体T细胞的增殖能力,Ad-HBs转染DCs组、Ad-HBe转染DCs组、Ad-HBc转染DCs组和未转染DCs组之间刺激T细胞的增殖水平无明显差异(F=1．194,P=0．389);在E：T比例为2：1,10：1和25：1时,Ad-HBs转染DC组、Ad-HBe转染DCs组和Ad-HBc转染DCs组对HepG_222．1．5细胞的杀伤率均明显高于未转染DCs组(P＜0．001);以Ad- HBc转染DC组对HepG_222．1．5细胞杀伤率最高．结论：HBV抗原基因修饰DCs疫苗具有刺激同种异体T细胞增殖能力,同时能增强抗HBV特异性CTL反应的能力,可能发展为一种新型抗病毒疫苗．     

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.     

双胰腺癌相关抗原RNA转染树突细胞诱导特异性抗癌免疫反应的实验研究

目的研究人胰腺癌MUC4与Survivin mRNA联合转染树突细胞(DC)诱导的特异性抗肿瘤免疫反应,为构建负载多抗原表位DC疫苗治疗胰腺癌提供实验依据。方法自胰腺癌患者外周血单核细胞中分离、培养DCs。使用体外转录和胰腺癌PCR技术扩增MUC4和Survivin mRNA后用电穿孔法将其联合转染DC。采用Western blot技术检测DCs中MUC4和Survivin的表达。用四甲基偶氮唑盐(MTT)法检测转染前后DCs存活率变化;使用IFN-γ酶联免疫法检测MUC4 mRNA与Survivin mRNA联合转染后DC诱导的细胞毒性T淋巴细胞(CTL)的活化反应。采用51Cr标准细胞毒实验检测转染MUC4和Survivin mRNA后DCs诱导的特异性CTL对体外胰腺癌细胞的杀伤作用。结果 MUC4与Survivin mRNA联合转染后72 h DCs中两者的相对表达量低于其分别转染。顺序转染后96 h DCs存活率降至50.2%,低于MUC4 mRNA与Survivin mRNA分别转染时DC 80%的存活率(P0.05)。MUC4和Survivin mRNA联合转染DC诱导的特异性CTL 24 h IFN-γ释放量达(33.84±3.51)U/mL,高于MUC4与Survivin mRNA分别转染DC诱导的CTL IFN-γ释放水平[(21.87±4.12)U/mL和(16.61±2.09)U/mL,P0.05]。DCs经MUC4 mRNA与Survivin mRNA联合转染后,可有效诱导HLA-A2+/MUC4+/Survivin+特异性CTL免疫反应,对体外培养的胰腺癌细胞具有显著的杀伤作用。结论 MUC4与Survivin mRNA联合转染的DCs可较单胰腺癌相关抗原负载DCs诱导出更加显著的特异性CTL抗肿瘤免疫。     

Generation of hepatitis C virus-specific cytotoxic T lymphocytes from healthy individuals with peptide-pulsed dendritic cells

BACKGROUND AND AIMS: In hepatitis C virus (HCV) infection, cytotoxic T lymphocytes (CTL) are involved in liver inflammation and contribute to the reduction of viral load. Antibodies for HCV-CTL precursor frequencies (CTLpf) are relatively low in chronic hepatitis C, and this may be related to the poor CTL response in vivo. The aim of this study was to assess the efficacy of dendritic cells (DC) as antigen-presenting cells in CTL generation from low CTLpf. METHODS: To confirm the rationale of using DC to prime naive T cells, five HCV-uninfected individuals were enrolled in the study. We obtained DC by maturation from peripheral progenitors under stimulation with granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin (IL)-4 and IL-1alpha. Autologous T cells were cultured with DC or concanavalin-A-induced blasts loaded with four HCV-derived peptides bearing human leukocyte antigen (HLA)-A*0201 or -A24 motifs for 28 days under IL-7 and IL-2 stimulation. The lytic activity against peptide-pulsed targets was assessed by using a [51Cr]-releasing assay. RESULTS: The DC strongly expressed HLA class I, II, B7-1 and B7-2, but not phenotypic markers of T-, B-, natural killer (NK)-cells or monocytes. The CD8-positive, HLA-class I-restricted and HCV peptide-specific CTL were generated with DC from HLA-A antigen-matched subjects, whereas no CTL activity was detected with concavalin (Con-A) blasts. We were thus able to generate HCV specific CTL from naive precursors with peptide-pulsed DC. CONCLUSIONS: This DC-based system can be used to generate CTL of desired antigen specificity, even from a source with low CTLpf.     

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.     

肝癌患者CD8^＋T淋巴细胞穿孔素表达和脱颗粒特点

目的观察肝癌患者外周血CD8^＋T淋巴细胞穿孔紊表达和脱颗粒特点及与临床分期的相关性。方法采集52例肝癌患者、20例健康人的外周血，用流式细胞仪分析CD8^＋T淋巴细胞穿孔素表达百分比；以抗CD3单抗刺激后CD107a表达量代表CD8^＋T淋巴细胞脱颗粒的数量。结果肝癌患者外周血CD8^＋T淋巴细胞穿孔素表达量（32．3％±17．4％）与健康对照（31．8％±14．1％）差异无统计学意义（P〉0．05）。但是抗CD3单抗刺激5h后CD8^＋T淋巴细胞CD107a表达量（6．8％±4．2％）低于健康对照（15．0％±4．3％），差异有统计学意义（P〈0．01）。结论肝癌患者CD8^＋T淋巴细胞脱颗粒能力明显下降。     

Current status and perspectives of immune-based therapies for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a frequent cancer with a high mortality. For early stage cancer there are potentially curative treatments including local ablation, resection and liver transplantation. However, for more advanced stage disease, there is no optimal treatment available. Even in the case of a “curative” treatment, recurrence or development of a new cancer in the precancerous liver is common. Thus, there is an urgent need for novel and effective (adjuvant) therapies to treat HCC and to prevent recurrence after local treatment in patients with HCC. The unique immune response in the liver favors tolerance, which remains a genuine challenge for conventional immunotherapy in patients with HCC. However, even in this “immunotolerant” organ, spontaneous immune responses against tumor antigens have been detected, although they are insufficient to achieve significant tumor death. Local ablation therapy leads to immunogenic tumor cell death by inducing the release of massive amounts of antigens, which enhances spontaneous immune response. New immune therapies such as dendritic cell vaccination and immune checkpoint inhibition are under investigation. Immunotherapy for cancer has made huge progress in the last few years and clinical trials examining the use of immunotherapy to treat hepatocellular carcinoma have shown some success. In this review, we discuss the current status of and offer some perspectives on immunotherapy for hepatocellular carcinoma, which could change disease progression in the near future.     

Blood donor derived dendritic cells and cytotoxic T cells for specific fusion-gene adoptive immunotherapy

BACKGROUND AND OBJECTIVES: Therapeutic immunological reagents tailored to individual patients have been shown to be a viable treatment strategy for some forms of leukaemia. This work investigates the possibility of using blood donations as a source of leukaemia-specific immune therapeutics. MATERIALS AND METHODS: The acute promyelocytic cell line NB4 carrying the PML-RAR alpha fusion was used as a target for cytotoxic T lymphocytes (CTL) stimulated to recognize the fusion. Stimulation of CTL was by production of dendritic cells pulsed with plasmid vectors containing polymerase chain reaction (PCR)-generated sequences of PML-RAR alpha derived from NB4 cells. PCR primer design included a Kozak consensus sequence to allow correct translation of the nucleic acid into protein. Identification of specific cytotoxicity was by both Granzyme B ELISPOT and by (51)Cr-release assays. RESULTS: Specific CTL activity targeting NB4 cells can be generated from donor-derived peripheral blood mononuclear cells. However, individual donors appear to respond differently to the length of stimulatory sequence encoded in the vector. Use of an internal methionine in the PML gene, which also satisfies the Kozak rules, allows translation in vitro and, thus, might provide a suitable start site for stimulation using acute promyelocytic leukaemia-specific sequence. CONCLUSION: The work presented here suggests that blood donor derived dendritic cells can be used to stimulate leukaemia-specific CTL from the same donation ex vivo. This would enable the generation of patient-specific therapeutics from major histocompatibility (MHC)-matched allogeneic donors. However, different MHC-matched donors might vary in their response depending on the length of the antigenic sequence.