Molina Ester, Tejero Marcos, Duzenli Ozgun Firat, Kuoch Hisae, Caine Colin, Krotova Karina, Paulaitis Michael, Aslanidi George
The Hormel Institute, University of Minnesota, Austin, MN 55912, USA.
Department of Ophthalmology, Center for Nanomedicine at the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
Mol Ther Methods Clin Dev. 2024 Oct 18;32(4):101358. doi: 10.1016/j.omtm.2024.101358. eCollection 2024 Dec 12.
We previously showed therapeutic advantages of using a capsid-modified and encoded antigen-optimized AAV-based cancer vaccine to initiate strong antigen-specific immune responses and increase survival in a syngeneic mouse model of melanoma. In this study, we further explore AAV vaccine dose reduction and possible mechanisms of the immune response. Immunization with extracellular vesicle (EV)-associated AAV6-S663V encoded ovalbumin (OVA) or tyrosinase-related protein 1 (TRP-1) induced significantly higher levels of antigen-specific CD8 T cells compared with standard AAV in mice. Importantly, a higher number of specific CD8 T cells was achieved with EV-AAV several logs lower than optAAV-based doses. EV-optAAV-OVA was used in a dose 100 times lower, and EV-optTRP-1 10 times lower than optOVA and optTRP-1 correspondingly. Our data suggest that significant dose reduction for optimized AAV-based vaccines is possible without sacrificing efficiency. In addition, we studied the role of conventional type 1 dendritic cells (cDC1) in optimized AAV-based immunization using a C57BL/6-Irf8em1Kmm (Irf8 32) mouse model lacking cDC1. Interestingly, we found that cDC1 are not essential for conveying effector T cell responses to AAV-encoded tumor antigens.
我们之前的研究表明，使用衣壳修饰且编码抗原优化的基于腺相关病毒（AAV）的癌症疫苗，在同基因黑色素瘤小鼠模型中可引发强烈的抗原特异性免疫反应并提高生存率，具有治疗优势。在本研究中，我们进一步探索了AAV疫苗剂量的降低以及免疫反应的可能机制。与标准AAV相比，用细胞外囊泡（EV）相关的AAV6-S663V编码卵清蛋白（OVA）或酪氨酸酶相关蛋白1（TRP-1）进行免疫，可在小鼠体内诱导出显著更高水平的抗原特异性CD8 T细胞。重要的是，EV-AAV在比基于优化AAV（optAAV）的剂量低几个对数的情况下，就能产生更多数量的特异性CD8 T细胞。EV-optAAV-OVA的使用剂量比optOVA低百倍，而EV-optTRP-1的使用剂量比optTRP-1相应低十倍。我们的数据表明，在不牺牲效率的情况下，基于优化AAV的疫苗有可能大幅降低剂量。此外，我们使用缺乏常规1型树突状细胞（cDC1）的C57BL/6-Irf8em1Kmm（Irf8 -/-）小鼠模型，研究了cDC1在基于优化AAV的免疫中的作用。有趣的是，我们发现cDC1对于将效应T细胞反应传递给AAV编码的肿瘤抗原并非必不可少。
