Interventional hydrogel microsphere vaccine as an immune amplifier for activated antitumour immunity after ablation therapy

Current chemotherapy or immunotherapy regimens for pancreatic cancer are limited. Although minimally invasive irreversible electroporation (IRE) ablation is a promising option for unresectable pancreatic cancers, the typical immunosuppressive tumour microenvironment promotes immune evasion and rapid tumour recurrence. Thus, triggering efficient amplification of endogenous adaptive antitumour immunity is critical for improving immunotherapy after ablation therapy. Here, we developed a hydrogel microsphere vaccine as an immune amplifier for post-ablation cancer immunotherapy. The vaccine acts as a general immune amplifier to trigger a rocket-like amplification of the cDC1-mediated antigen cross-presentation cascade, resulting in dramatic amplification of the antitumour immunity of endogenous CD8+ T cells. We also showed that the hydrogel microsphere vaccine promoted the transformation of pancreatic cancer from "cold" to "hot" tumours in a safe and efficient manner, significantly increased the survival of mice bearing orthotopic pancreatic tumours, and induced strong systemic antitumour immunity, which inhibited the growth of distant metastases. Comparative gene expression profiling analysis of RNA-seq data for irreversible electroporation (IRE) treated or non-treated pancreatic cancer