Infectious hematopoietic necrosis virus (IHNV), is a negative-sense single-stranded RNA virus that is a member of the Rhabdoviridae family, and from the genus Novirhabdovirus. It causes the disease known as infectious hematopoietic necrosis in salmonid fish like trout and salmon. IHNV is commonly found in the Pacific Coast of Canada and the USA, and has also been found in Europe and Japan. The first reported epidemics of IHNV occurred in the United States at the Washington and the Oregon fish hatcheries during the 1950s. IHNV is transmitted following shedding of the virus in the feces, urine, sexual fluids, and external mucus and by direct contact or close contact with surrounding water. The virus gains entry into fish at the base of the fins.
Clinical signs of infection with IHNV include abdominal distension, bulging of the eyes, skin darkening, anemia and fading of the gills. Infected fish commonly hemorrhage in several areas; the mouth and behind the head, the pectoral fins, muscles near the anus, and (in fry) the yolk sac. Diseased fish weaken eventually floating “belly-up” on the surface of the water. Necrosis is common in the kidney and spleen, and sometimes in the liver (Wiki: Infectious Hematopoietic Necrosis Virus).
Molecule Role Annotation :
The DNA vaccine pIHNw-G encodes the glycoprotein of the fish rhabdovirus infectious hematopoietic necrosis virus (IHNV). Vaccine performance in rainbow trout was measured 3, 6, 13, 24, and 25 months after vaccination. At three months all fish vaccinated with 0.1 microg pIHNw-G had detectable neutralizing antibody (NAb) and they were completely protected from lethal IHNV challenge with a relative percent survival (RPS) of 100% compared to control fish (Kurath et al., 2006).
>gi|9628087|ref|NP_042680.1| non-virion protein [Infectious hematopoietic necrosis virus]
MDHRDINTNMEALREALRYKNEVAGHGFSFDDGDLVWREEDDATWRRLCDVVNALISSKRMQRVLYMDLS
ITKGEGHLLLVDLQGTKNRLYKEPRFRRHLILIEDFLAYPR
Molecule Role :
Virmugen
Molecule Role Annotation :
A mutation in the non-virion protein of IHNV causes attenuated growth in rainbow trout and is able to provide significant protection from subsequent challenge with wild type IHNV (Thoulouze et al., 2004).
Immune Response:
The G protein expressed by the DNA vaccine construct did confer significant protection in fry up to 80 days post-immunization and induced protective neutralizing antibodies (Corbeil et al., 1999).
Efficacy:
Cumulative percent mortality in fish immunized with pCDNA-G ranged from 0 to 2% whereas mortality in fish immunized with DNA vaccines that contained other proteins or were left unhandled ranged from 36 to 76%. Significant protection was elicited up to 80 days post-immunization, and the vaccine also induced protective neutralizing antibodies (Corbeil et al., 1999).
Immune Response:
Fish injected with the glycoprotein-encoding plasmid pCMV4-G, either alone or in combination with the nucleoprotein-encoding plasmid pCMV4-N, generated glycoprotein-specific and virus-neutralizing antibody responses (Anderson et al., 1996).
Efficacy:
The vaccinated fish were protected from subsequent IHNV challenge (Anderson et al., 1996).
4. IHNV DNA vaccine pCMV4-N encoding the nucleoprotein
Efficacy:
Challenge experiments revealed that immunity established shortly after vaccination was cross-protective between IHNV and VHSV whereas no increased survival was found upon challenge with bacterial pathogens. Within two months after vaccination, the cross-protection disappeared while the specific immunity to homologous virus remained high (Lorenzen et al., 2002).
Description:
The open reading frame of the G gene of IHNV WRAC strain was amplifed by reverse transcriptase-polymerase chain reaction using sequence-specic primers and cloned into the pT7-blue vector (Novagen, Madison, WI). The gene was then subcloned downstream of the immediate-early enhancer-promoter sequences of human cytomegalovirus (CMV) of the pCDNA 3.1 vector (Invitrogen). The resulting plasmid was designated pIHNw-G (previously pCDNA-G) (Corbeil et al., 2000).
Vaccination Protocol:
Fish from cohort 1 were used for viral challenge experiments, serological analyses, histology, and passive transfer experiments 1 and 2. For these studies two groups of 500 juvenile rainbow trout from cohort 1 (mean weight 2.5 g) were anaesthetized by immersion in 100 μg/ml tricaine methane sulfonate (MS-222; Argent Chemical Laboratories, Redmond, WA) and vaccinated by i.m. injection with 0.1 μg of either pIHNw-G or pLuc in a total volume of 50 μl phosphate buffered saline (PBS). A group of 200 fish was left unhandled, and all fish were maintained at 12 °C for the entire study period (Kurath et al., 2006).
Challenge Protocol:
. At 25 months post-vaccination a challenge experiment was done with three subgroups of 18 fish per treatment. For each experiment duplicate groups of pIHNw-G vaccinated fish were i.p. injected with IHNV as described above, and the third group was injected with 200 μl MEM without virus. Similarly, two groups of pLuc vaccinated fish were challenged with IHNV, and the third group was mock-challenged (Kurath et al., 2006).
Efficacy:
The DNA vaccine pIHNw-G encodes the glycoprotein of the fish rhabdovirus infectious hematopoietic necrosis virus (IHNV). Vaccine performance in rainbow trout was measured 3, 6, 13, 24, and 25 months after vaccination. At three months all fish vaccinated with 0.1 microg pIHNw-G had detectable neutralizing antibody (NAb) and they were completely protected from lethal IHNV challenge with a relative percent survival (RPS) of 100% compared to control fish (Kurath et al., 2006).
Efficacy:
An NV mutant induces significant protection in rainbow trout from challenge with wild type IHNV (Thoulouze et al., 2004).
IV. References
1. Anderson et al., 1996: Anderson ED, Mourich DV, Fahrenkrug SC, LaPatra S, Shepherd J, Leong JA. Genetic immunization of rainbow trout (Oncorhynchus mykiss) against infectious hematopoietic necrosis virus. Molecular marine biology and biotechnology. 1996; 5(2); 114-122. [PubMed: 8680524].
2. Corbeil et al., 1999: Corbeil S, Lapatra SE, Anderson ED, Jones J, Vincent B, Hsu YL, Kurath G. Evaluation of the protective immunogenicity of the N, P, M, NV and G proteins of infectious hematopoietic necrosis virus in rainbow trout oncorhynchus mykiss using DNA vaccines. Diseases of aquatic organisms. 1999; 39(1); 29-36. [PubMed: 11407402].
3. Corbeil et al., 2000: Corbeil S, LaPatra SE, Anderson ED, Kurath G. Nanogram quantities of a DNA vaccine protect rainbow trout fry against heterologous strains of infectious hematopoietic necrosis virus. Vaccine. 2000; 18(25); 2817-2824. [PubMed: 10812224].
4. Einer-Jensen et al., 2009: Einer-Jensen K, Delgado L, Lorenzen E, Bovo G, Evensen Ø, Lapatra S, Lorenzen N. Dual DNA vaccination of rainbow trout (Oncorhynchus mykiss) against two different rhabdoviruses, VHSV and IHNV, induces specific divalent protection. Vaccine. 2009; 27(8); 1248-1253. [PubMed: 19118593].
5. Kurath et al., 2006: Kurath G, Garver KA, Corbeil S, Elliott DG, Anderson ED, LaPatra SE. Protective immunity and lack of histopathological damage two years after DNA vaccination against infectious hematopoietic necrosis virus in trout. Vaccine. 2006; 24(3); 345-354. [PubMed: 16154239].
6. Lorenzen et al., 2002: Lorenzen N, Lorenzen E, Einer-Jensen K, LaPatra SE. Immunity induced shortly after DNA vaccination of rainbow trout against rhabdoviruses protects against heterologous virus but not against bacterial pathogens. Developmental and comparative immunology. 2002; 26(2); 173-179. [PubMed: 11696382].
7. Thoulouze et al., 2004: Thoulouze MI, Bouguyon E, Carpentier C, Brémont M. Essential role of the NV protein of Novirhabdovirus for pathogenicity in rainbow trout. Journal of virology. 2004; 78(8); 4098-4107. [PubMed: 15047826].
