Recombinant infectious hematopoietic necrosis virus and viral hemorrhagic septicemia virus glycoprotein epitopes expressed in Aeromonas salmonicida induce protective immunity in rainbow trout (Oncorhynchus mykiss)

Abstract

Fragments of the glycoprotein genes of viral hemorrhagic septicemia virus (VHSV) and infectious hematopoietic necrosis virus (IHNV) were cloned into a bacterial broad-host-range expression vector under the control of the plac promoter. Western blot (immunoblot) analysis with monoclonal antibodies specific to the glycoproteins demonstrated the inducible expression of the fusion proteins in Escherichia coli. Aeromonas salmonicida is the causative agent of furunculosis in salmonid fish. It was confirmed that an avirulent strain of A. salmonicida, A440, which contains a deletion in the structural gene for the paracrystalline surface protein array, will provide protective immunity against furunculosis when used as a live attenuated vaccine. The plasmid-encoded viral epitopes were then mobilized into A440 for use as a shuttle system for the expression of fragments of the glycoprotein genes of IHNV and VHSV. Vaccination of rainbow trout with A440 containing the viral epitopes resulted in the development of protective immunity against both VHSV and IHNV. This indicates that the use of cloned fragments of the glycoproteins and the use of A. salmonicida as a shuttle system constitute a feasible approach to fish vaccine development.

Inactivated infectious haematopoietic necrosis virus (IHNV) vaccines

“…In general, three vaccine types have been investigated for the control of IHNV: (i) inactivated IHNV (Amend 1976; Nishimura, Sasaki, Ushiyama, Inoue, Suzuki, Ikeya, Tanaka, Suzuki, Kohara, Arai, Shimna & Sano 1985), (ii) attenuated IHNV (Fryer, Rohovec, Tebbit, McMichael & Pilcher 1976; Tebbit 1976) and (iii) recombinant IHNV (Gilmore, Engelking, Manning & Leong 1988; Oberg, Wirkkula, Mourich & Leong 1991; Emmenegger, Huang, Landolt, LaPatra & Winton 1995; Noonan, Enzmann & Trust 1995; Anderson, Mourich, Fahrenkrug, LaPatra, Shepard & Leong 1996; Winton 1997; Boudinot, Blanco, de Kinkelin & Benmansour 1998; Cain, LaPatra, Shewmaker, Jones, Byrne & Ristow 1999; Corbeil, LaPatra, Anderson, Jones, Vincent, Hsu & Kurath 1999; Simon, Nomellini, Chiou, Bingle, Thornton, Smit & Leong 2001). The latter includes the DNA or nucleic acid vaccines, N and G subunit vaccines synthesized in prokaryotic or eukaryotic organisms and synthetic peptide vaccines.…”

Cyprinid viral diseases and vaccine development

“…The effect of a bacterial live vector vaccine is mainly concentrated on whether it can express a sufficient amount of protein to cause the host immune responses and produce a protective immune response [179]. The initial report of living-vehicle vaccine in aquatic organism was in 1995, preventing Salmonella in salmon [180]. Subsequently, the application of livingvehicle vaccine was reported to prevent Streptococcus [181], Edwardsiella tarda, A. hydrophila [182] and CCV [183].…”

Molecular approaches to fish vaccines

“…These exciting results provide convincing evidence of the ability of recombinant virus vectors to stimulate a significant immune response in fish and pave the way for a multivalent vaccine for channel cat fish. Noonan et al (1995) developed a recombinant vector using a strain of Acroriionus sobnonicidu that had been attenuated by deletion of a 1410 base-pair segment of the wpA gene coding for the paracrystalline surface protein array (A-layer). Fragments of the glycoprotein genes of VHSV and IHNV were cloned into a bacterial expression vector under control of the pluc promoter and immunoblots revealed inducible expression in E. coli.…”