Development of Novel Recombinant Vaccine Models Against Infectious Salmon Anemia Virus (ISA)

Description

Infectious salmon anemia virus (ISAV) is an important virus pathogen of salmonids and causes mass mortalities. It remains a recurrent problem in Eastern Canada and Maine since the initial epizootics of 1996. A commercial heat-inactivated virus vaccine is available, however, with the current management of ISAV requiring depopulation at first signs of disease, vaccination may not get wide acceptance until it provides total protection from the disease.

Recombinant DNA vaccines are based on the expression of biological constructs encoding proteins from specific viral pathogens. They are made of protein or glycoprotein subunits synthesized in the laboratory using recombinant DNA technology. Heat Shock Proteins (HSPs) abound in normal cells, where they are involved in protein conformation, chaperoning, shuffling, etc. Whenever a cell is stressed, HSPs are produced. When cells rupture, such as during viral infections, HSP-peptide complexes are released. Some of these complexes can be detected by specialized cells that present the antigenic peptide at their surface, thus activating the cytotoxic T cell response, as part of an effective immune response.

This study is taking a novel approach using recombinant ISAV protein subunits combined in vivo to fish HSPs. It was demonstrated in various studies that antigenic recombinant peptides are more effective when combined with HSPs. In this approach, we will transfect fish cell lines with recombinant expression vectors. Once recombinant ISAV proteins are produced in these cells, necrosis (unplanned cell death) will be induced. Necrosis conditions will be selected such as to obtain the highest level of HSPs production before cell burst, and release of recombinant ISAV proteins associated with HSPs.

Program Name

Aquaculture Collaborative Research and Development Program (ACRDP)

Year(s)

2007 to 2009

Ecoregion(s)

Atlantic: Gulf of St. Lawrence, St. Lawrence Estuary

Principal Investigator(s)

Nellie Gagné
Email: Nellie.Gagne@dfo-mpo.gc.ca