Protein profiling in the gut of Penaeus monodon gavaged with oral WSSV-vaccines and live white spot syndrome virus.

White spot syndrome virus (WSSV) is a pathogen that causes considerable mortality of the farmed shrimp, Penaeus monodon. Candidate 'vaccines', WSSV envelope protein VP28 and formalin-inactivated WSSV, can provide short-lived protection against the virus. In this study, P. monodon was orally intubated with the aforementioned vaccine candidates, and protein expression in the gut of immunised shrimps was profiled. The alterations in protein profiles in shrimps infected orally with live-WSSV were also examined. Seventeen of the identified proteins in the vaccine and WSSV-intubated shrimps varied significantly compared to those in the control shrimps. These proteins, classified under exoskeletal, cytoskeletal, immune-related, intracellular organelle part, intracellular calcium-binding or energy metabolism, are thought to directly or indirectly affect shrimp's immunity. The changes in the expression levels of crustacyanin, serine proteases, myosin light chain, and ER protein 57 observed in orally vaccinated shrimp may probably be linked to immunoprotective responses. On the other hand, altered expression of proteins linked to exoskeleton, calcium regulation and energy metabolism in WSSV-intubated shrimps is likely to symbolise disturbances in calcium homeostasis and energy metabolism.

Evaluation of immune and apoptosis related gene responses using an RNAi approach in vaccinated Penaeus monodon during oral WSSV infection.

In the present study RNA interference was used to elucidate the connection between two endogenous genes [Penaeus monodon Rab7 (PmRab7) or P. monodon inhibitor of apoptosis (PmIAP)], and selected immune/apoptosis-related genes in orally 'vaccinated' shrimp after white spot syndrome virus (WSSV) infection. P. monodon were vaccinated by feeding them with formalin inactivated WSSV-coated feed. Thereafter, PmRab7 or PmIAP genes were silenced by injecting the shrimps with their respective dsRNA. The resulting groups of shrimps, Rab7 and IAP, were orally infected with WSSV and the expression of three immune-relevant genes in Rab7 group and five apoptosis-related genes in IAP group was evaluated. In the Rab7 group, PmToll, PmPPAE 2 and Pm penaeidin genes were down-regulated. The IAP-silenced shrimps were characterized by down-regulation of Pm caspase, PmERp57, Pm14-3-3 ε, Pm ald, and up-regulation of PmSTAT. Thus, silencing of PmRab7/PmIAP has provided important clues on their relationship with selected immune/apoptosis genes in orally vaccinated P. monodon during WSSV infection.