Engineered outer membrane vesicle is potent to elicit HPV16E7-specific cellular immunity in a mouse model of TC-1 graft tumor.
Engineered outer membrane vesicle is potent to elicit HPV16E7-specific cellular immunity in a mouse model of TC-1 graft tumor.
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工程化外膜囊泡能够在 TC-1 移植肿瘤小鼠模型中引发 HPV16E7 特异性细胞免疫。
DOI：
10.2147/ijn.s143264
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发表时间：
2017
影响因子：
8
通讯作者：
Ma Y
中科院分区：
文献类型：
--
作者：
Wang S;Huang W;Li K;Yao Y;Yang X;Bai H;Sun W;Liu C;Ma Y
目前，正在开发的治疗性肿瘤疫苗在人体临床试验中普遍缺乏显著效果。探索一种强大的抗原递送系统是提高疫苗效力的潜在途径。我们试图探索工程化细菌外膜囊泡（OMVs）作为一种新的疫苗载体，有效地递送肿瘤抗原并引发强大的抗肿瘤免疫反应。首先，通过基因工程方法将肿瘤抗原人乳头瘤病毒16型早期蛋白E7 （HPV16E7）表达于大肠埃希菌衍生的OMV上，获得重组OMV疫苗。其次，在体外巨噬细胞Raw264.7细胞和骨髓源树突状细胞中研究重组omv向抗原提呈细胞递送其组分和模型抗原绿色荧光蛋白的能力。第三，在小鼠TC-1移植瘤模型中评估了表达HPV16E7的重组omv刺激特异性细胞免疫反应，干预已建立肿瘤的生长。大肠杆菌dh5 α衍生的omv可以被树突状细胞迅速吸收，而树突状细胞的囊泡结构已被证明是重要的。omv显著刺激树突状细胞成熟标志物CD80、CD86、CD83和CD40的表达。通过基因重组技术成功地将HPV16E7嵌入到工程的omv中。经改造的omv皮下免疫可诱导E7抗原特异性细胞免疫应答，酶联免疫斑点试验显示表达干扰素- γ的脾细胞数量增加，流式细胞术分析显示表达干扰素- γ的CD4+和CD8+细胞数量增加。此外，治疗性疫苗接种可显著抑制小鼠移植TC-1肿瘤的生长。与与野生型omv混合或单独给药相比，omv呈递的重组E7蛋白在诱导特异性细胞免疫和抑制肿瘤生长方面更有效。结果表明，纳米级omv可能是癌症免疫治疗中抗原递送的有效疫苗平台。
Currently, therapeutic tumor vaccines under development generally lack significant effects in human clinical trials. Exploring a powerful antigen delivery system is a potential approach to improve vaccine efficacy. We sought to explore engineered bacterial outer membrane vesicles (OMVs) as a new vaccine carrier for efficiently delivering tumor antigens and provoking robust antitumor immune responses. First, the tumoral antigen human papillomavirus type 16 early protein E7 (HPV16E7) was presented on Escherichia coli-derived OMVs by genetic engineering methods, acquiring the recombinant OMV vaccine. Second, the ability of recombinant OMVs delivering their components and the model antigen green fluorescent protein to antigen-presenting cells was investigated in the macrophage Raw264.7 cells and in bone marrow-derived dendritic cells in vitro. Third, it was evaluated in TC-1 graft tumor model in mice that the recombinant OMVs displaying HPV16E7 stimulated specific cellular immune response and intervened the growth of established tumor. E. coli DH5α-derived OMVs could be taken up rapidly by dendritic cells, for which vesicle structure has been proven to be important. OMVs significantly stimulated the expression of dendritic cellmaturation markers CD80, CD86, CD83 and CD40. The HPV16E7 was successfully embedded in engineered OMVs through gene recombinant techniques. Subcutaneous immunization with the engineered OMVs induced E7 antigen-specific cellular immune responses, as shown by the increased numbers of interferon-gamma-expressing splenocytes by enzyme-linked immunospot assay and interferon-gamma-expressing CD4+ and CD8+ cells by flow cytometry analyses. Furthermore, the growth of grafted TC-1 tumors in mice was significantly suppressed by therapeutic vaccination. The recombinant E7 proteins presented by OMVs were more potent than those mixed with wild-type OMVs or administered alone for inducing specific cellular immunity and suppressing tumor growth. The results indicated that the nano-grade OMVs might be a useful vaccine platform for antigen delivery in cancer immunotherapy.