Mannose functionalized biomimetic nanovaccine enhances immune responses against tilapia lake virus

Abstract

Tilapia lake virus disease (TiLVD) caused by tilapia lake virus (TiLV) is a lethality truculence viral disease endangering the sustainable development of tilapia aquaculture. DNA vaccine present immense application potential in disease prevention and control, but the low gene transfection efficacy of naked DNA vaccine imposes restrictions on itself immune response that should have been induced. In this study, we constructed a biomimetic nanodelivery system (Cs-pS2@M-M) using the mannose modified erythrocyte membrane acted as a DNA vaccine carrier. The nanoparticle has a typical core-shell structure with a particle size of ~100 nm, and ensures sustained and efficient expression of plasmid DNA in muscle and spleen tissue. Intramuscular immunization of tilapia to evaluate the efficacy of the vaccine, the results showed that it has a high-effective induction of serum antibody production, enzyme activity, and immune-related gene expression compared to the same dose (10 μg/g) of non-mannosylated Cs-pS2@M nanoparticles and naked DNA vaccine. Notably, the TiLV challenge trial show that Cs-pS2@M-M provided 76.9% relative percentage survival (RPS), which was 26.9% higher than the 50.0% of the naked DNA vaccine (pS2), and not only that, it was 15.4% higher than that of Cs-pS2@M without mannose modification. These results showed that Cs-pS2@M-M biomimetic nanovaccine constructed in this study elicited robust immune responses to protect tilapia from TiLV challenge, and erythrocyte membrane-coated nanoparticles strategy show enormous promise potential as a vaccine delivery platform for aquatic animals.