Engineering pyroptotic vesicles as personalized cancer vaccines.

Tumour vaccines are designed to stimulate the host's immune system against existing tumours or tumour recurrence. However, individual differences, tumour heterogeneity and side effects hinder the applications of current tumour vaccines and require the development of personalized cancer vaccines. To overcome these challenges, we engineered pyroptotic vesicles-extracellular vesicles formed during tumour cell pyroptosis-as a tumour vaccine platform. The extracted pyroptotic vesicles possess abundant tumour antigens and potent immune-stimulating ability and, loaded into a biocompatible hydrogel, they can be implanted into post-surgical tumour cavities to prevent tumour recurrence. The pyroptotic-vesicle-based vaccine outperforms both exosome- and apoptotic-body-based vaccines in inhibiting tumour recurrence and metastasis in different post-surgical mouse models. Mechanistic studies reveal that the pyroptotic-vesicle-based vaccine could stimulate robust antigen-specific dendritic cell and T cell immune responses against both artificial OVA antigens and cancer neoantigens. In sum, our vaccine platform can be tailored to stimulate robust antitumour immune responses for treating individual cancer patients.