Enhancement of shrimp immunity against white spot syndrome virus by Macrobrachium rosenbergii nodavirus-like particle encapsulated VP28 double-stranded RNA

We investigated the efficiency and downstream effects of Macrobrachium rosenbergii nodavirus-like particle (MrNv-VLP) encapsulated VP28 double-stranded RNA against white spot syndrome virus (WSSV) in shrimp. Our results showed that the VP28 gene of WSSV was significantly silenced at 72 h post-viral challenge in group pre-treated with the VLP encapsulated VP28 dsRNA. At 24 h post-treatment, the amount of VP28 dsRNA was significantly higher (two-fold) in encapsulated VP28 dsRNA-VLP pre-treated shrimp compared with non-encapsulated VP28 dsRNA pre-treated shrimp. Using quantitative real time polymerase chain reaction (PCR), we found higher and longer expression of RNA-induced silencing complex (RISC) and immune-related genes in shrimp pre-treated with encapsulated VP28 dsRNA compared to the control groups. Increasing expression of apoptotic-related genes was also associated with the encapsulated VP28 dsRNA-VLP pretreatment group at 24 h post-WSSV challenge. These results indicate thatMrNv-VLP was able to efficiently deliver VP28 dsRNA into shrimp tissues, which in turn, triggered a better anti-viral response. This may represent a novel strategy for aquaculture disease management. Statement of relevance: This study developed methods for WSSV protection. (C) 2015 Elsevier B.V. All rights reserved.