Bifunctional Phage Particles Augment CD40 Activation and Enhance Lymph Node-Targeted Delivery of Personalized Neoantigen Vaccines
Xiaotong Chen, Lei Lei, Jiayao Yan, Xingzhou Wang, Lin Li, Qin Liu, Ying Wang, Tianran Chen, Jie Shao, Lixia Yu, Zijian Li, Lijing Zhu, Lifeng Wang, Baorui Liu
Abstract
Although personalized neoantigen cancer vaccines have emerged as a promising strategy for cancer treatment, challenges remain to develop immune-stimulatory carriers which allow simultaneous transport of adjuvants and vaccines to lymph nodes (LNs). With inherent immunogenicity, genetic plasticity, and efficiency for large-scale production, M13 phages represent an attractive platform for vaccine delivery as natural bionanomaterials. Here, we report the discovery of an anti-CD40 designed ankyrin repeat protein (DARPin) and propose a bifunctional M13 ph age for neoantigen delivery based on this anti-CD40 DARPin protein (M13 CD40 ). M13 CD40 -based neoantigen vaccines show improved accumulation and prolonged antigen retention in LNs compared with nontargeting phage vaccines due to the abundance of CD40-positive cells in LNs. Besides the intrinsic immunogenicity of phages, M13 CD40 -based neoantigen vaccines also benefit from additional CD40 stimulation due to multiple copies of anti-CD40 DARPins displayed on M13 CD40 phages. Subcutaneous immunization with M13 CD40 -based neoantigen vaccines results in more robust antigen-specific immune responses and superior antitumor efficacy in poorly immunogenic tumor models compared with nontargeting phage vaccines. Combination therapy with PD-1 blockade further enhances T cell cytotoxicity and improves tumor control. To summarize, our findings highlight M13 CD40 as a CD40 nanoagonist as well as an efficient vehicle for LN-targeted delivery of personalized neoantigen vaccines.