Ultrasound-propelled nanomotors for improving antigens cross-presentation and cellular immunity

Efficient vaccine would strengthen cellular immunity and eliminate target cells through cytotoxic T lymphocytes (CTLs). However, it remains a great challenge to trigger such an adaptive immune response since the internalized exogenous antigens are usually degraded in lysosomes. Herein, an effective intracellular antigens delivery strategy based on ultrasound (US)-propelled gold nanowires (AuNWs) nanomotors modified with a model antigen (ovalbumin, OVA) is described. Specifically, the active and fast movement of these [email protected] facilitates their rapid internalization into the cytoplasm of the antigen-presenting cells (APCs). In addition, the AuNWs nanomotors had good biocompatibility and their internalization had no effect on the morphology of the cells. As a result, the activation and cross-presentation of the APCs can be achieved, accompanied with dramatic improvement in the expression level of MHC I-related molecules (~5-fold) and MHC II-related molecules (~7-fold). Compared to conventional passive vaccine carriers, this novel “on-the-fly” vaccine delivery strategy based on AuNWs nanomotors is expected to provide a new thoughtway for the development of effective vaccines with enhanced cellular immunity, which we envision will bring a new horizon of immunotherapy.