The development of cancer neoantigen vaccines that prime the anti-tumor immune responses has been hindered in part by challenges in delivery of neoantigens to the tumor. Here, using the model antigen ovalbumin (OVA) in a melanoma model, we demonstrate a chimeric antigenic peptide influenza virus (CAP-Flu) system for delivery of antigenic peptides bound to influenza A virus (IAV) to the lung. We conjugated attenuated IAVs with the innate immunostimulatory agent CpG and, after intranasal administration to the mouse lung, observed increased immune cell infiltration to the tumor. OVA was then covalently displayed on IAV-CPG using click chemistry. Vaccination with this construct yielded robust antigen uptake by dendritic cells, a specific immune cell response and a significant increase in tumor-infiltrating lymphocytes compared to peptides alone. Lastly, we engineered the IAV to express anti-PD1-L1 nanobodies that further enhanced regression of lung metastases and prolonged mouse survival after rechallenge. Engineered IAVs can be equipped with any tumor neoantigen of interest to generate lung cancer vaccines.

引发抗肿瘤免疫反应的癌症新抗原疫苗的开发在一定程度上受到了向肿瘤递送新抗原的挑战的阻碍。在这里，我们在黑色素瘤模型中使用模型抗原卵清蛋白（OVA），展示了一种嵌合抗原肽流感病毒（CAP-Flu）系统，用于将与甲型流感病毒（IAV）结合的抗原肽递送至肺部。我们将减毒 IAV 与先天免疫刺激剂 CpG 结合，鼻内给药至小鼠肺部后，观察到肿瘤免疫细胞浸润增加。然后使用点击化学将 OVA 共价展示在 IAV-CPG 上。与单独的肽相比，用这种构建体进行疫苗接种可产生树突状细胞对抗原的强烈摄取、特异性免疫细胞反应以及肿瘤浸润淋巴细胞的显着增加。最后，我们设计了 IAV 来表达抗 PD1-L1 纳米抗体，进一步增强了肺转移的消退并延长了小鼠在再次攻击后的存活率。工程化 IAV 可以配备任何感兴趣的肿瘤新抗原，以生成肺癌疫苗。