title: Recombinant baculovirus mediates dsRNA specific to rr2 delivery and its protective efficacy against WSSV infection.
abstract: White spot syndrome virus (WSSV) is a major causative agent in shrimp farming. Consequently, RNAi technology is an effective strategy to prevent WSSV infection in shrimp especially dsRNA targeting to rr2 of WSSV. In an effort to develop dsRNA expression in shrimp for control of WSSV infection, we developed a recombinant baculovirus expressing recombinant VP28 as the gene delivery system to carry a gene encoding dsRNA specific to rr2 for triggering the RNAi process in shrimp. The results showed that the recombinant baculovirus harboring VP28 was able to express VP28 indicated by Western blot with polyclonal antibody specific to VP28. VP28 transcript was detected in shrimp hemocytes after co-culture hemocytes with the recombinant baculovirus displaying VP28. In addition, we found that shrimp injected with the recombinant baculovirus displaying VP28 and encoding dsRNA synthetic gene specific to rr2 (Bac-VP28-dsrr2) showed the lowest cumulative mortality (33%) at 14days post infection (dpi) when compared to shrimp injected with baculovirus displaying VP28 (Bac-VP28) (64% cumulative mortality) (p<0.05). According to the results, shrimp injected with Bac-VP28-dsrr2 also showed significantly lower WSSV copies than shrimp injected with Bac-VP28 (p<0.05) along with the down-regulation of rr2 expression at 1, 3 and 7dpi. In conclusion, the Bac-VP28-dsrr2 was effective in prevention of WSSV infection. Therefore, the results obtained here can be applied to the prevention of WSSV infection by mixing the recombinant baculovirus with shrimp feed in the future.
authors.affiliation: Department of Microbiology, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand. Electronic address: triwit.rat@kmutt.ac.th.
authors.forename: Triwit
authors.initials: T
authors.lastname: Rattanarojpong
authors.affiliation: Department of Microbiology, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand.
authors.forename: Suthiwat
authors.initials: S
authors.lastname: Khankaew
authors.affiliation: Department of Microbiology, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand.
authors.forename: Pongsak
authors.initials: P
authors.lastname: Khunrae
authors.affiliation: Department of Anatomy, Faculty of Science, Mahidol University, Bangkok 10400, Thailand; Center of Excellence for Shrimp Molecular Biology and Biotechnology (Centex Shrimp), Mahidol University, Bangkok 10400, Thailand.
authors.forename: Rapeepun
authors.initials: R
authors.lastname: Vanichviriyakit
authors.affiliation: School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkok 10150, Thailand. Electronic address: kanokwan.poo@kmutt.ac.th.
authors.forename: Kanokwan
authors.initials: K
authors.lastname: Poomputsa
mesh_terms: D000818:Animals; D016367:Baculoviridae / Q000235:genetics*; D002478:Cells, Cultured; D033561:Penaeidae / Q000821:virology; D034622:RNA Interference; D012330:RNA, Double-Stranded / Q000235:genetics*; D019444:Vaccines, DNA / Q000235:genetics*; D014764:Viral Proteins / Q000235:genetics*; D046848:White spot syndrome virus 1 / Q000235:genetics*
chemical_list: D012330:RNA, Double-Stranded; D019444:Vaccines, DNA; D014764:Viral Proteins
keywords: Baculovirus; RNAi technology; VP28; White spot syndrome virus; rr2