Vogt Annabelle, Sievers Elisabeth, Lukacs-Kornek Veronika, Decker Georges, Raskopf Esther, Meumann Nadja, Büning Hildegard, Sauerbruch Tilman, Strassburg Christian P, Schmidt-Wolf Ingo G H, Gonzalez-Carmona Maria A
Department of Medicine I, University of Bonn, Bonn, Germany.
Liver Int. 2014 Mar;34(3):447-61. doi: 10.1111/liv.12284. Epub 2013 Sep 2.
Interleukin 12 (IL-12), one of the most potent Th1-cytokines, has been used to improve dendritic cells (DC)-based immunotherapy of cancer. However, it failed to achieve clinical response in patients with hepatocellular carcinoma (HCC). In this study, improved conditions of immunotherapy with DC engineered to express IL-12 were studied in murine subcutaneous HCC.
Tumour-lysate pulsed DC were transduced with IL-12-encoding adenoviruses or cultivated with recombinant (r)IL-12. DC were injected intratumourally, subcutaneously or intravenously at different stages of tumour-development.
Dendritic cell overexpressing IL-12 by adenoviruses showed enhanced expression of costimulatory molecules and stronger priming of HCC-specific effector cells than DC cultured with rIL-12. Intratumoural but not systemic injections of IL-12-DC induced the strongest antitumoural effects reaching complete regressions in 75% of early-staged tumours and in 33% of advanced tumours. Importantly, antitumoural effects could be further enhanced through combination with sorafenib. Analysing the tumour-environment, IL-12-DC increased the levels of Th1-cytokines/chemokines and of CD4(+) -, CD8(+) -T- and NK-cells. Induced immunity was tumour-specific and sustained since all tumour-free animals were protected towards hepatic tumour-cell rechallenge. However, IL-12-DC also enhanced immunosuppressive cytokines, regulatory T cells and even myeloid-derived suppressor cells within the tumours.
Induced IL-12-overexpression by adenoviral vectors can effectively immunostimulate DC. Intratumoural but not systemic injection of activated IL-12-DC was crucial for effective tumour regression. The mechanism of this approach seems to be the induction of a sufficient Th1 tumour-environment allowing the recruitment of effector cells rather than the inhibition of tumour immunosuppression. Thus, improved immunotherapy with IL-12-DC represents a promising approach towards HCC.
白细胞介素12（IL-12）是最有效的Th1细胞因子之一，已被用于改善基于树突状细胞（DC）的癌症免疫治疗。然而，它在肝细胞癌（HCC）患者中未能取得临床反应。在本研究中，我们在小鼠皮下HCC模型中研究了用工程化表达IL-12的DC进行免疫治疗的改进条件。
用编码IL-12的腺病毒转导肿瘤裂解物脉冲DC或用重组（r）IL-12培养DC。在肿瘤发展的不同阶段，将DC瘤内、皮下或静脉注射。
与用rIL-12培养的DC相比，通过腺病毒过表达IL-12的树突状细胞显示出共刺激分子表达增强，对HCC特异性效应细胞的启动更强。瘤内而非全身注射IL-12-DC诱导出最强的抗肿瘤作用，在75%的早期肿瘤和33%的晚期肿瘤中达到完全消退。重要的是，通过与索拉非尼联合，抗肿瘤作用可进一步增强。分析肿瘤环境，IL-12-DC增加了Th1细胞因子/趋化因子以及CD4(+)、CD8(+) T细胞和NK细胞的水平。诱导的免疫是肿瘤特异性的且持续存在，因为所有无瘤动物都受到保护，免受肝肿瘤细胞再次攻击。然而，IL-12-DC也增强了肿瘤内的免疫抑制细胞因子、调节性T细胞甚至髓源性抑制细胞。
腺病毒载体诱导的IL-12过表达可有效免疫刺激DC。瘤内而非全身注射活化的IL-12-DC对有效的肿瘤消退至关重要。这种方法的机制似乎是诱导足够的Th1肿瘤环境，允许效应细胞的募集，而不是抑制肿瘤免疫抑制。因此，用IL-12-DC改进的免疫治疗是一种有前途的HCC治疗方法。
