Adjuvant activity of fish type I interferon shown in a virus DNA vaccination model
Permanent lenke
https://hdl.handle.net/10037/9002Dato
2015-04-09Type
Journal articleTidsskriftartikkel
Peer reviewed
Sammendrag
There is a need for more efficient vaccines to combat viral diseases of Atlantic salmon and other farmed
fish. DNA vaccines are highly effective against salmonid rhabdoviruses, but have shown less effect against
other viruses. In the present work we have studied if type I IFNs might be used as adjuvants in fish
DNA vaccines. For this purpose we chose a DNA vaccine model based on the hemagglutinin-esterase
(HE) gene of infectious salmon anemia virus (ISAV) as antigen. Salmon presmolts were injected with a
plasmid encoding HE alone or together with a plasmid encoding Atlantic salmon type I IFN (IFNa1, IFNb
or IFNc). Sera were harvested after 7–10 weeks for measurements of antibody against ISAV and the fish
were challenged with ISAV to measure protective effects of the vaccines. The results showed that all
three IFN plasmids delivered together with HE plasmid potently enhanced protection of salmon against
ISAV mediated mortality and stimulated an increase in IgM antibodies against the virus. In contrast,
HE plasmid alone gave low antibody titers and a minor protection against ISAV. This demonstrates that
type I IFNs stimulate adaptive immune responses in fish, which may be a benefit also in other fish DNA
vaccines. Quantitative RT-PCR studies showed that the salmon IFNs caused an increased influx of B-cells
and cytotoxic T-cells at the muscle injection site, which may in part explain the adjuvant effect of the
IFNs.
Beskrivelse
Published version also available at http://dx.doi.org/10.1016/j.vaccine.2015.03.093