Tuning the fluidity and protein corona of ultrasound-responsive liposomal nanovaccines to program T cell immunity in mice

Inducing high levels of antigen-specific CD8α+ T cells in the tumor is beneficial for cancer immunotherapy, but achieving this in a safe and effective manner remains challenging. Here, we have developed a designer liposomal nanovaccine containing a sonosensitizer (LNVS) to efficiently program T cell immunity in mice. Following intravenous injection, LNVS accumulates in the spleen in a protein corona and fluidity-dependent manner, leading to greater frequencies of antigen-specific CD8α+ T cells than soluble vaccines (the mixture of antigens and adjuvants). Meanwhile, some LNVS passively accumulates in the tumor, where it responds to ultrasound (US) to increase the levels of chemokines and adhesion molecules that are beneficial for recruiting CD8α+ T cells to the tumor. LNVS + US induces higher levels of intratumoral antitumor T cells than traditional sonodynamic therapy, regresses established mouse MC38 tumors and orthotopic cervical cancer, and protects cured mice from relapse. Our platform sheds light on the importance of tuning the fluidity and protein corona of naovaccines to program T cell immunity in mice and may inspire new strategies for cancer immunotherapy.