Whole-Cell-Mimicking Carrier-Free Nanovaccines Amplify Immune Responses Against Cancer and Bacterial Infection

Whole-cell vaccines that provide broad-spectrum antigens have been explored for recent decades. But so far, they have revealed limited success in clinical trials, possibly owing to their inefficiency in targeting immune organs and antigen-presenting cells (APCs). Herein, a facile strategy is developed to convert the whole-cell vaccines into the nanoscale size to promote their lymphatic migration and subsequent intracellular antigen presentation to maximize immune responses. Briefly, the study designs a multiple antigen delivery platform based on alum-induced and cancer/bacterial cell membrane coated protein antigen nanoparticles. Through a simple two-step vortex-sonification method, a universal carrier-free nano-vaccine without additional excipients could be quickly fabricated. After subcutaneous vaccination, the developed nanovaccines rapidly migrate to lymph nodes, leading to their effective uptake by lymph node-resident APCs, and subsequent antigen presentation and activation of downstream immune processes. Overall, the described promising work offers a safe, effective, facile, and widely applicable vaccine strategy, which has great potential for clinical transformation.