National Center for Clinical Laboratory, Beijing Hospital of the Ministry of Health, Beijing, 100730, People's Republic of China.
Int J Cancer. 2014 Apr 1;134(7):1683-94. doi: 10.1002/ijc.28482. Epub 2013 Oct 8.
Prostate cancer (PCa) is the most diagnosed cancer in the western male population with high mortality. Recently, alternative approaches based on immunotherapy including mRNA vaccines for PCa have shown therapeutic promise. However, for mRNA vaccine, several disadvantages such as the instability of mRNA, the high cost of gold particles, the limited production scale for mRNA-transfected dendritic cells in vitro, limit their development. Herein, recombinant bacteriophage MS2 virus-like particles (VLPs), which based on the interaction of a 19-nucleotide RNA aptamer and the coat protein of bacteriophage MS2, successfully addressed these questions, in which target mRNA was packaged by MS2 capsid. MS2 VLP-based mRNA vaccines were easily prepared by recombinant protein technology, nontoxic and RNase-resistant. We show the packaged mRNA was translated into protein as early as 12 hr after phagocytosed by macrophages. Moreover, MS2 VLP-based mRNA vaccines induced strong humoral and cellular immune responses, especially antigen-specific cytotoxic T-lymphocyte (CTL) and balanced Th1/Th2 responses without upregulation of CD4(+) regulatory T cells, and protected C57BL/6 mice against PCa completely. As a therapeutic vaccine, MS2 VLP-based mRNA vaccines delayed tumor growth. Our results provide proof of concept on the efficacy and safety of MS2 VLP-based mRNA vaccine, which provides a new delivery approach for mRNA vaccine and implies important clinical value for the prevention and therapy of PCa.
前列腺癌(PCa)是西方男性人群中最常见的癌症,死亡率很高。最近,基于免疫疗法的替代方法,包括用于 PCa 的 mRNA 疫苗,已经显示出治疗潜力。然而,对于 mRNA 疫苗,其稳定性差、金颗粒成本高、体外转染的树突状细胞 mRNA 生产规模有限等缺点限制了其发展。在此,基于 19 个核苷酸 RNA 适体与噬菌体 MS2 衣壳蛋白相互作用的重组噬菌体 MS2 病毒样颗粒(VLPs)成功解决了这些问题,其中靶 mRNA 由 MS2 衣壳包装。基于 MS2 VLP 的 mRNA 疫苗可以通过重组蛋白技术轻松制备,具有非毒性和抗 RNA 酶性。我们发现,被巨噬细胞吞噬后 12 小时,包装的 mRNA 就可以被翻译成蛋白质。此外,基于 MS2 VLP 的 mRNA 疫苗可诱导强烈的体液和细胞免疫应答,特别是抗原特异性细胞毒性 T 淋巴细胞(CTL)和平衡的 Th1/Th2 应答,而不会上调 CD4+调节性 T 细胞,并且可以完全保护 C57BL/6 小鼠免受 PCa 的侵害。作为一种治疗性疫苗,MS2 VLP 基于 mRNA 疫苗可延缓肿瘤生长。我们的研究结果证明了 MS2 VLP 基于 mRNA 疫苗的疗效和安全性,为 mRNA 疫苗的递送提供了一种新方法,并为 PCa 的预防和治疗提供了重要的临床价值。