Protection of rainbow trout from infectious hematopoietic necrosis (IHN) by injection of infectious pancreatic necrosis virus (IPNV) or Poly(I:C)

• Published in: Diseases of aquatic organisms Vol. 83; no. 2; pp. 105 - 113
• Main Authors: KIM, Hyoung Jun, OSEKO, Norihisa, NISHIZAWA, Toyohiko, YOSHIMIZU, Mamoru
• Format: Journal Article
• Language: English
• Published: Oldendorf Inter-Research 12.02.2009
• Subjects: Animal aquaculture; Animal productions; Animals; Antibodies, Viral - blood; Antiviral Agents - pharmacology; Biological and medical sciences; Birnaviridae Infections - immunology; Birnaviridae Infections - prevention & control; Birnaviridae Infections - veterinary; Fish Diseases - immunology; Fish Diseases - prevention & control; Fundamental and applied biological sciences. Psychology; Infectious pancreatic necrosis virus - immunology; Oncorhynchus mykiss; Pisciculture; Poly I-C - pharmacology; Vertebrate aquaculture; Immunization; Infectious hematopoietic necrosis virus; Antiviral state; Poly(I:C); Vaccine; Birnaviridae; Injection; Aquabirnavirus; Oncorhynchus mykiss; Necrosis; Freshwater environment; Virus; Mononegavirales; Vertebrata; Rhabdoviridae; Pisces; Antiviral; Dual infection; Vaccine; Interferon; Protection; Infectious pancreatic necrosis virus; Immunization; Infectious hematopoietic necrosis virus; IHNV
• ISSN: 0177-5103; 1616-1580
• DOI: 10.3354/dao02000

It was recently reported that prophylaxis against infectious hematopoietic necrosis virus (IHNV) in fish was induced by pre-exposure to the infectious pancreatic necrosis virus (IPNV). Here the establishment of IHNV immunity in rainbow trout Oncorhynchus mykiss was investigated by IHNV challenge following non-lethal pre-infection with IPNV. Also, synthetic double-stranded RNA polyinosinic polycytidylic acid, Poly(I:C), an inducer for interferon (IFN), was evaluated as a substitute for IPNV induction of the non-specific antiviral state and subsequent IHNV-specific immunity in fish. Rainbow trout pre-infected with IPNV were protected from IHNV challenge 7 d later (relative percentage survival, RPS: 68.8%), and IHNV-specific antibodies were detected in sera from the survivors. Moreover, these surviving fish showed 91.6% RPS when re-challenged with IHNV 28 d after the primary IHNV challenge. Thus, fish appear to acquire IHNV-specific immunity through the IHNV challenge following pre-injection with IPNV. Fish pre-injected with Poly(I:C) were also highly protected from IHNV challenge 2 d later (RPS: 95.2%), and IHNV-specific antibodies were also detected amongst survivors. The survivors showed a 100% survival rate following re-challenge with IHNV both 21 and 49 d after the primary IHNV challenge. Thus, IHNV immunity in rainbow trout is induced by challenge with live IHNV following pre-injection with either IPNV or Poly(I:C). The use of Poly(I:C) to induce an anti-viral state protecting rainbow trout from an otherwise lethal vaccination dose of IHNV may have application to a wider range of fish species and fish pathogenic viruses.