通过增强树突状细胞成熟，源自树突状细胞吞噬CD40配体转基因工程化凋亡肿瘤细胞的增强保护性免疫。

Enhanced protective immunity derived from dendritic cells with phagocytosis of CD40 ligand transgene-engineered apoptotic tumor cells via increased dendritic cell maturation.

作者信息

Parameswaran Sreejit, Khalil Muhammad, Ahmed Khawaja Ashfaque, Sharma Rajendra K, Xiang Jim

机构信息

Department of Pathology & Laboratory Medicine, University of Saskatchewan, Saskatoon, Saskatchewan - Canada.

Department of Oncology, University of Saskatchewan, Saskatoon, Saskatchewan - Canada.

出版信息

Tumori. 2015 Nov-Dec;101(6):637-43. doi: 10.5301/tj.5000297. Epub 2015 May 15.

DOI:10.5301/tj.5000297

PMID:25983089

Abstract

AIMS AND BACKGROUND

Dendritic cells (DCs) play a pivotal role in regulating CD8+ cytotoxic T-lymphocyte (CTL) responses. Currently, DC vaccines have been used in experimental animal models and clinical trials for evaluation of antitumor immunity. However, their efficacy is limited, warranting the improvement of DC-based cancer vaccines. CD40 ligand (CD40L) stimulates DC activation and maturation via CD40-CD40L interaction. We demonstrated that DCs that had phagocytized apoptotic tumor cells induced antitumor immunity.

METHODS

We generated CD40L-expressing (EG7-CD40L) and the control (EG7-Null) EG7 tumor cells by transfection of EG7 tumor cells with CD40L-expressing adenoviral vector AdVCD40L and the control vector AdV(pLpA), respectively. We also generated DC vaccines (DC-EG7/CD40L and the control DC-EG7/Null) using DCs with phagocytosis of irradiated EG7-CD40L and EG7-Null tumor cells, and assessed their phenotype and immunogenicity by flow cytometry and animal studies in C57BL/6 mice.

RESULTS

We demonstrate that an irradiation of 9000-rad induced Annexin V-expressing cell apoptosis in most (~75%) tumor cells, and provide evidence for phagocytosis of apoptotic tumor cells by flow cytometry and confocal microscopy. The DC-EG7/CD40L cells showed higher expression of DC maturation markers (Ia(b), CD40, CD80, and CD86) and peptide/major histocompatibility complex I than the control DC-EG7/Null cells. In addition, DC-EG7/CD40L vaccine stimulates more efficient (0.97%) tumor-specific CTL responses than DC-EG7/Null cells (0.31%). Furthermore, 80% (4/5) of mice immunized with DC-EG7/CD40L vaccine become tumor-free after EG7 tumor cell challenge, whereas DC-EG7/Null vaccine only delays immunized mouse death.

CONCLUSIONS

Dendritic cells that have phagocytized CD40L-expressing apoptotic tumor cells appear to offer new strategies in DC cancer vaccines.

摘要

目的与背景

树突状细胞（DCs）在调节CD8 + 细胞毒性T淋巴细胞（CTL）反应中起关键作用。目前，DC疫苗已用于实验动物模型和临床试验以评估抗肿瘤免疫。然而，其疗效有限，因此需要改进基于DC的癌症疫苗。CD40配体（CD40L）通过CD40 - CD40L相互作用刺激DC活化和成熟。我们证明吞噬凋亡肿瘤细胞的DC可诱导抗肿瘤免疫。

方法

我们分别用表达CD40L的腺病毒载体AdVCD40L和对照载体AdV（pLpA）转染EG7肿瘤细胞，生成表达CD40L的（EG7 - CD40L）和对照（EG7 - Null）EG7肿瘤细胞。我们还用吞噬了经辐射的EG7 - CD40L和EG7 - Null肿瘤细胞的DC生成DC疫苗（DC - EG7 / CD40L和对照DC - EG7 / Null），并通过流式细胞术和在C57BL / 6小鼠中的动物研究评估其表型和免疫原性。

结果

我们证明9000拉德的辐射可诱导大多数（约75％）肿瘤细胞表达膜联蛋白V的细胞凋亡，并通过流式细胞术和共聚焦显微镜为凋亡肿瘤细胞的吞噬作用提供证据。DC - EG7 / CD40L细胞比对照DC - EG7 / Null细胞显示出更高的DC成熟标志物（Ia(b)、CD40、CD80和CD86）和肽/主要组织相容性复合体I的表达。此外，DC - EG7 / CD40L疫苗比DC - EG7 / Null细胞（0.31％）刺激更有效的（0.97％）肿瘤特异性CTL反应。此外，用DC - EG7 / CD40L疫苗免疫的小鼠中有80％（4/5）在受到EG7肿瘤细胞攻击后无肿瘤，而DC - EG7 / Null疫苗仅延迟免疫小鼠的死亡。