Delivery of double stranded RNA by Macrobrachium rosenbergii nodavirus-like particles to protect shrimp from white spot syndrome virus

We tested the use of Macrobrachium rosenbergii nodavirus-like particles (MrNv-VLPs) as a delivery mechanism to carry therapeutic agents against white spot syndrome in shrimp. We used constructed double-stranded RNA called VP28 (VP28 dsRNA) against WSSV envelope genes to confer protection against the pathogen. Results showed that MrNv-VLP was able to encapsulate VP28 dsRNA. Using enhanced green fluorescent protein (EGFP) as a reporter, we found that VLP penetrated various shrimp tissues including the muscle, hepatopancreas, and gill. A statistically significant relative survival rate of 44.5% was obtained in the group of shrimp receiving encapsulated VP28 dsRNA-VLP after WSSV challenge as compared to 100% mortality in the control shrimp at 7days post-infection. Shrimp treated with EGFP dsRNA loaded into MrNv-VLPs showed relatively similar motility rates as those of controls. Moreover, MrNv-VLP encapsulation improved VP28 dsRNA efficiency against WSSV. A higher survival rate of 16.7% was observed in the group of shrimp receiving encapsulated VP28 dsRNA-VLP when compared to those receiving naked VP28 dsRNA. These results indicate that MrNv-VLP is a good candidate for use as a therapeutic delivery system against shrimp diseases due to its self-reassembly property, broad target of various shrimp tissues and immune enhancement. •MrNv VLPs are excellent nanocontainers that carry negatively charged dsRNA.•MrNv VLPs target to multiple tissues in shrimp and deliver active substances therein.•dsRNA against WSSV can be loaded and delivered into shrimp tissues by VLPs to protect shrimp against WSSV.