Chitosan nanoparticles encapsulating pva-pre-miR-11881 for RNA therapy against white spot syndrome virus in the Pacific white shrimp

Abstract

Several studies have highlighted the significant roles of microRNAs (miRNAs) in shrimp antiviral defense. The precursor miRNA (pre-miRNA) of pva-miR-11881 from Pacific white shrimp (Penaeus vannamei) called “pva-pre-miR-11881”, has been found to be highly effective in enhancing the shrimp immune response to white spot syndrome virus (WSSV) infection. Although pre-miRNA molecules have higher stability than miRNA, pre-miRNA still faces the risk of nuclease degradation before reaching the target cell cytoplasm. In the current work, the pva-pre-miR-11881 was encapsulated within chitosan nanoparticles called ‘pva-pre-miR-11881 CNP’. These nanoparticles, averaging 545.2 nm in size with a 43.6 mV surface charge, demonstrated optimal stability at 4 °C. Functional assays revealed that co-injection of pva-pre-miR-11881 CNPs with WSSV effectively inhibited viral gene expression, reduced viral load, modulated hemocyte programmed cell death and autophagy, and enhanced immune responses, including phenoloxidase activity. Notably, shrimp treated with pva-pre-miR-11881 CNPs showed significantly higher survival rates post-WSSV infection compared to those treated with naked pva-pre-miR-11881. Furthermore, incorporating pva-pre-miR-11881 CNPs as a feed supplement yielded a 62 % survival rate in WSSV-infected shrimp, whereas the controls did not survive the infection. These findings highlight the potential of pva-pre-miR-11881 CNPs as a promising RNA-based therapeutic against WSSV in shrimp aquaculture.