负载NY-ESO-1多肽的树突状细胞激发特异性细胞毒性T淋巴细胞反应

目的:探讨以NY-ESO-1为靶抗原、树突状细胞(dendritic cell,DCs)为抗原载体激发特异性细胞毒性T淋巴细胞(cytotoxic T lymphocytes,CTLs)反应的能力,以明确特异性CTLs的抗肿瘤免疫功能.方法:在临床前实验基础上选择2014年11月至2015年10月于中国医学科学院肿瘤医院治疗的符合入选标准的15例Ⅱ～Ⅲ期HLA-A0201+NY-ESO-1+胃癌患者外周血,分离单个核细胞(peripheral blood mononuclear cells,PBMCs)和外周血淋巴细胞(peripheral blood lymphocytes,PBLs),并诱导出成熟DCs (mature dendritic cell,mDCs);将人工合成的NY-ESO-1多肽负载mDCs后通过流式细胞仪(flow cytometry,FCM)分析细胞表型,检测体外反复致敏PBLs后负载NY-ESO-1的DCs激发特异性CTLs的能力以及CTLs对NY-ESO-1+胃癌细胞的体外杀伤活性,同时患者回输CTLs细胞,每2周1次,共回输2次,检测回输前后患者外周血细胞因子和特异性CTLs水平变化.结果:采用FCM分析DCs细胞表型显示HLA-DR+ CD11c+细胞为93.6％±1.2％,其中CD80+细胞为87.3％±3.6％,CD83+细胞为82.8％±2.5％,CD86+细胞为93.4％±6.4％.患者外周血分离的PBLs经NY-ESO-1多肽负载的DCs反复诱导后,细胞不断增殖,其中未负载多肽的DCs也能促进PBLs增殖,但细胞增殖指数(proliferation index,PI)明显低于负载多肽的DCs,两者比较差异有统计学意义(P＜0.05).负载NY-ESO-1多肽DCs诱导的NY-ESO-1多肽特异性的CTLs比例较未负载NY-ESO-1多肽DCs诱导的对照组明显升高(5.2％±1.2％vs0.4％±0.1％,P＜0.05),且致敏后CTLs对NY-ESO-1+胃癌细胞及负载NY-ESO-1+多肽T2靶细胞的杀伤率明显高于对照组.输注CTLs细胞后,患者体内血清中细胞因子IFN-γ、IL-2、IL-12水平较治疗前显著升高(132.9±10.2)μg/Lvs.(46.4±3.1)μg/L;(101.3±6.4) μg/Lvs.(26.7±1.2) μg/L;(51.3±2.6) μg/Lvs.(26.4±1.1) μg/L;P均＜0.05],且患者外周血特异性CTLs细胞比例明显升高.结论:负载NY-ESO-1多肽的DCs体内外均具有激发特异性CTLs反应的能力,可诱导明显的抗肿瘤免疫效应.

Immune effects of specific CTLs response induced by dendritic cells pulsed with NY-ESO-1 peptide

Objective:To exptore the potential of autologous dendritic cells (DCs) pulsed with caner/ testis antigen NY-ESO-1 peptides in inducing specific cytotoxic T lymphocyte (CTLs) response and an tineoplastic immune function of specific CTLs.Methods:Fifteen patients with Ⅱ to Ⅲ stage positive HLA-A0201 + and NY-ESO-1 + were enrolled in the Cancer Hospital Chinese Academy of Medical Sciences on the basis of preclinical experiments from November 2014 to October 2015,and their peripheral blood mononuclear cells (PBMCs) and peripheral blood lymphocytes (PBLs) were isolated.The PBMCs were induced into DCs and pulsed with NY-ESO-1 peptide.The phenotypes of DCs were stained with antibodies against HLA-DR+ CD11c +,CD80 +,CD83 + and CD86 +,and subsequently analyzed by multichannel flow cytometry (FCM).The killing effects of CTLs pulsed with HLA-A0201-binding peptide NY-ESO-1 and the potential of autologous DCs pulsed with NY-ESO-1 peptides in inducing specific cytotoxic T lymphocytes (CTLs) responses were determined.The patients were administered two infusions of autologous CTLs for 1 time every two weeks.The total infusion was with 2 times.The immunological responses and clinical responses were examined in 1 week after the final administration.Results:The immunophenotype of DCs pulsed with NY-ESO-1 peptide was analyzed,HLA-DR+ CD11c+ cells (93.6％ ± 1.2％),CD80 + cells (87.3％ ± 3.6％),CD83 + cells (82.8％ ± 2.5％) and CD86 + cells (93.4％ ± 6.4％).PBLs isolated from patients primed by DCs pulsed with NY-ESO-1 peptide proliferated continuously and the proliferation index (PI) of the PBLs were analyzed.There was significant difference between the DCs loaded with polypeptides and those unloaded,though it could promote the proliferation of PBLs,but the PI was significantly lower than that of the DCs loaded with NY-ESO-1 peptide (P ＜ 0.05).The average percentage of special CTLs primed by DCs pulsed with NY-ESO-1 peptides was significantly higher than that in the control group (5.2％ ± 1.2％ vs.0.4％ ± 0.1％).CTLs induced by NY-ESO-1 pulsed DCs exerted a stronger killing effect on T2 cell line pulsed with NY-ESO-1 peptide than that in the control group at the ratio of E (effect) to T (target) as 30 ∶ 1,P ＜ 0.05.The cytokine levels in the patients' sera such as IFN-γ,IL-2 and IL-12 were increased after treatments (132.9 ± 10.2) μg/Lvs.(46.4±3.1) μg/L;(101.3 ±6.4) μg/Lvs.(26.7 ±1.2) μg/L;(51.3 ±2.6) μg/L vs.(26.4 ± 1.1) μg/L;all P ＜ 0.05],and the percentages of antigen-specific CD8 + IFN-γ + increased in these patients (P ＜0.01).Conclusion:Auto-DCs pulsed with NY-ESO-1 peptides can in duce the proliferation of allogenic CTLs,which elicit specific immune responses ex vivo or in vivo,and boost anticancer immunity markedly.