dsRNA provides sequence-dependent protection against infectious myonecrosis virus in Litopenaeus vannamei.
Viral diseases are significant impediments to the sustainability of shrimp aquaculture. In addition to endemic disease, new viral diseases continue to emerge and cause significant impact on the shrimp industry. Disease caused by infectious myonecrosis virus (IMNV) has caused tremendous losses in farmed Pacific white shrimp (Litopenaeus vannamei) since it emerged in Brazil and translocated to Indonesia. There are no existing antiviral interventions, outside of pathogen exclusion, to mitigate disease in commercial shrimp operations. Here, we describe an iterative process of panning the genome of IMNV to discover RNA interference trigger sequences that initiate a robust and long-lasting protective response against IMNV in L. vannamei. Using this process, a single, low dose (0.02 µg) of an 81 or 153 bp fragment, with sequence corresponding to putative cleavage protein 1 in ORF1, protected 100 % of animals from disease and mortality caused by IMNV. Furthermore, animals that were treated with highly efficacious dsRNA survived an initial infection and were resistant to subsequent infections over 50 days later with a 100-fold greater dose of virus. This protection is probably sequence dependent, because targeting the coding regions for the polymerase or structural genes of IMNV conferred lesser or no protection. Interestingly, non-sequence specific dsRNA did not provide any degree of protection to animals as had been described for other shrimp viruses. Our data indicate that the targeted region for dsRNA is a crucial factor in maximizing the degree of protection and lowering the dose required to induce a protective effect against IMNV infection in shrimp.
Harrisvaccines, Inc., 1102 S. Hills Drive, Suite 101, Ames, IA 50010, USA.|Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA 50011, USA.|Department of Animal Science, Room 11 Kildee Hall, Iowa State University, Ames, IA 50011, USA.
J Dustin
JD
Loy
Harrisvaccines, Inc., 1102 S. Hills Drive, Suite 101, Ames, IA 50010, USA.|Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA 50011, USA.
Mark A
MA
Mogler
Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA 50011, USA.|Department of Animal Science, Room 11 Kildee Hall, Iowa State University, Ames, IA 50011, USA.
Duan S
DS
Loy
Department of Veterinary Diagnostic and Production Animal Medicine, 1657 Veterinary Medicine, Iowa State University, Ames, IA 50011, USA.
Bruce
B
Janke
Harrisvaccines, Inc., 1102 S. Hills Drive, Suite 101, Ames, IA 50010, USA.|Department of Animal Science, Room 11 Kildee Hall, Iowa State University, Ames, IA 50011, USA.
Kurt
K
Kamrud
ART Biologics, Ames, IA 50010, USA.
Edward D
ED
Scura
Department of Veterinary Diagnostic and Production Animal Medicine, 1657 Veterinary Medicine, Iowa State University, Ames, IA 50011, USA.|Harrisvaccines, Inc., 1102 S. Hills Drive, Suite 101, Ames, IA 50010, USA.|Department of Animal Science, Room 11 Kildee Hall, Iowa State University, Ames, IA 50011, USA.
D L Hank
DLH
Harris
Department of Entomology, 442 Science Hall II, Iowa State University, Ames, IA 50011, USA.
Lyric C
LC
Bartholomay
D000818:Animals; D017756:Aquaculture / Q000379:methods; D033561:Penaeidae / Q000821:virology*; D016133:Polymerase Chain Reaction / Q000662:veterinary; D034622:RNA Interference; D012327:RNA Virus Infections / Q000517:prevention & control / Q000662:veterinary*; D012330:RNA, Double-Stranded / Q000235:genetics / Q000627:therapeutic use*; D019196:Totiviridae / Q000235:genetics*
D012330:RNA, Double-Stranded