Polypeptide sono-adjuvant for ultrasound-activatable regulation of innate immunity and cancer vaccination therapy.

Spatiotemporally-controllable regulation of innate immunity in lymph node remains a critical challenge to implement effective cancer vaccination. Here we report an ultrasound-activatable strategy to precisely stimulate innate immunity activation in vivo. Mechanistically, ultrasound-triggered mechanical and oxidative forces synchronously activate innate immune pathways in antigen-presenting cells via calcium ion influx and mitochondria DNA release. We next design a polypeptide sono-adjuvant (SONA) library with adjustable physicochemical properties for lymph node-targeting delivery. The top-performed SONA specifically activates robust and durable innate immune responses in lymph node upon localized ultrasound stimulation. The combination of SONA-based vaccine with ultrasound stimulation induces about 3.0-fold higher antigen-specific T cell responses than conventional adjuvant-based vaccines. Moreover, in syngeneic mouse models of orthotopic breast and liver tumors, the combination of SONA-based neoantigen vaccine with ultrasound stimulation markedly boosts immune checkpoint blockade therapy to suppress tumor growth and distant metastasis. Collectively, the polypeptide sono-adjuvant offers great promise for precise regulation of innate immunity and cancer vaccine therapy.