Cancer Sciences Unit and Cancer Research UK and Experimental Cancer Medicine Centre Protein Core Facility, Faculty of Medicine, University of Southampton, Tremona road, Southampton, SO16 6YD, UK.
Touchlight Genetics Ltd, Morelands and Riverdale Buildings, Lower Sunbury Road, Hampton, London, TW12 2ER, UK.
Cancer Immunol Immunother. 2018 Apr;67(4):627-638. doi: 10.1007/s00262-017-2111-y. Epub 2018 Jan 12.
Vaccination with DNA that encodes cancer antigens is a simple and convenient way to raise immunity against cancer and has already shown promise in the clinical setting. Conventional plasmid DNA is commonly used which together with the encoded antigen also includes bacterial immunostimulatory CpG motifs to target the DNA sensor Toll-like receptor 9. Recently DNA vaccines using doggybone DNA (dbDNA™), have been developed without the use of bacteria. The cell-free process relies on the use of Phi29 DNA polymerase to amplify the template followed by protelomerase TelN to complete individual closed linear DNA. The resulting DNA contains the required antigenic sequence, a promoter and a poly A tail but lacks bacterial sequences such as an antibiotic resistance gene, prompting the question of immunogenicity. Here we compared the ability of doggybone DNA vaccine with plasmid DNA vaccine to induce adaptive immunity using clinically relevant oncotargets E6 and E7 from HPV. We demonstrate that despite the inability to trigger TLR9, doggybone DNA was able to induce similar levels of cellular and humoral immunity as plasmid DNA, with suppression of established TC-1 tumours.
用编码癌症抗原的 DNA 进行疫苗接种是一种提高癌症免疫力的简单便捷方法,并且已经在临床环境中显示出了潜力。通常使用常规质粒 DNA,它与编码抗原一起还包括细菌免疫刺激性 CpG 基序,以靶向 DNA 传感器 Toll 样受体 9。最近,使用犬骨 DNA(dbDNA™)的 DNA 疫苗已经开发出来,无需使用细菌。无细胞过程依赖于使用 Phi29 DNA 聚合酶来扩增模板,然后使用 protelomerase TelN 来完成单个闭合线性 DNA。产生的 DNA 包含所需的抗原序列、启动子和 poly A 尾巴,但缺乏细菌序列,如抗生素抗性基因,这引发了免疫原性的问题。在这里,我们比较了犬骨 DNA 疫苗和质粒 DNA 疫苗诱导适应性免疫的能力,使用 HPV 中临床相关的致癌基因 E6 和 E7。我们证明,尽管不能触发 TLR9,犬骨 DNA 能够诱导与质粒 DNA 相似水平的细胞和体液免疫,抑制已建立的 TC-1 肿瘤。