Suppression of PmRab7 by dsRNA Inhibits WSSV or YHV Infection in Shrimp

Abstract

Viral entry into host cells requires endocytosis machineries of the host for viral replication. PmRab7, a Penaeus monodon small GTPase protein, was investigated for its function in vesicular transport during viral infection. The double-stranded RNA of Rab7 was injected into a juvenile shrimp before challenging with white spot syndrome virus (WSSV) or yellow head virus (YHV). PmRab7 mRNA was specifically decreased at 48 h after dsRNA-Rab7 injection. Silencing of PmRab7 dramatically inhibited WSSV-VP28 mRNA and protein expression. Unexpectedly, the silencing of PmRab7 also inhibited YHV replication in the YHV-infected shrimp. These results suggested that PmRab7 is a common cellular factor required for WSSV or YHV replication in shrimp. Because PmRab7 should function in the endosomal trafficking pathway, its silencing prevents successful viral trafficking necessary for replication. Silencing of PmRab7 could be a novel approach to prevent both DNA virus (WSSV) and RNA virus (YHV) infection of shrimp.

Molecular cloning, characterization, and expression of Rab5B, Rab6A, and Rab7 from Litopenaeus vannamei (Penaeidae)

“…Previous studies revealed that the P. monodon Rab7 (PmRab7) protein can combine with a viral envelope, VP28, of the WSSV to avoid lysosomal digestion (Sritunyalucksana et al, 2006). Several studies also demonstrated that silencing of PmRab7 by injecting double-stranded RNA corresponding to PmRab7 (dsRNA-PmRab7) can effectively prevent WSSV, TSV, or yellow head virus infection, suggesting that Rab7 is involved in the endosomal trafficking pathway of virus infected penaeid shrimp (Ongvarrasopone et al, 2008(Ongvarrasopone et al, , 2011Thagun et al, 2012). The results in the present study provide further evidence that LvRab7 is involved in the antiviral activity of penaeid shrimp against IHHNV and WSSV infection.…”

Role of PmRab7 Regulation in WSSV Infection and Functional Validation of Small Molecule as PmRab7 GTPase Inhibitor

“…Although white spot syndrome remains a serious global problem in sea food production (shrimp) due to high mortality and less define immune system, till the date several groups are working to develop a potential drug (herbal, antibody, gene silencing and suppression of receptor gene (PmRab7) expression by dsRNA [20]. There is concurrent agreement that new antiviral drug is needed to shorten or simplify treatment by focusing the structural orientation, active site and week interaction of amino acid of PmRab7.…”

Anti-lipopolysaccharide factor isoform 3 from Penaeus monodon (ALFPm3) exhibits antiviral activity by interacting with WSSV structural proteins

“…The WSSV infection in shrimp causes a 100% mortality rate within 7-10 d and results in enormous economic losses in the shrimp farming industry (Flegel, 1997). Thus, several preventive and curative measures have been developed, such as vaccination (Rout et al, 2007;Satoh et al, 2008), immunostimulants (Chotigeat et al, 2004;Balasubramanian et al, 2008), direct neutralization by antiviral proteins (Dupuy et al, 2004;Tharntada et al, 2009) and RNAi (Ongvarrasopone et al, 2008), although they have not been successfully implemented in shrimp farms. In addition, the innate immunity in shrimp has been studied intensively in order to understand the response of shrimp to viral infections, including to WSSV .…”