Rationally Designed Self-Assembling Nanovaccines Elicit Robust Mucosal and Systemic Immunity against Rhabdovirus.

Viral diseases have constantly caused great threats to global public health, resulting in an urgent need for effective vaccines. However, the current viral vaccines often show low immunogenicity. To counter this, we report a smart strategy of a well-designed modular nanoparticle (LSG-TDH) that recapitulates the dominant antigen SG, low-molecular-weight protamine, and tetralysine-modified H-chain apoferritin (TDH). The constructed LSG-TDH nanovaccine could self-assemble into a nanocage structure, which confers excellent mucus-penetrating, cellular affinity, and uptake ability. Studies demonstrate that the LSG-TDH nanovaccine could strongly activate both mucosal and systemic immune responses. Importantly, by immunizing wild-type and TLR2 knockout (TLR2-KO) zebrafish, we found that TLR2 could mediate LSG-TDH-induced adaptive mucosal and systemic immune responses by activating antigen-presenting cells. Collectively, our findings offer new insights into rational viral vaccine design and provide additional evidence of the vital role of TLR2 in regulating adaptive immunity.