DNA vaccines encoding the viral G
glycoprotein show the most successful protection capability against fish rhabdoviruses. Nowadays, the molecular mechanisms underlying the protective response remain still poorly understood. With the aim of shedding light on the protection conferred by the
DNA vaccines based in the G
glycoprotein of
viral haemorrhagic septicaemia virus (VHSV) in turbot (Scophthalmus maximus) we have used a specific microarray highly enriched in
antiviral sequences to carry out the transcriptomic study associated to VHSV
DNA vaccination/
infection. The differential gene expression pattern in response to empty plasmid (pMCV1.4) and
DNA vaccine (pMCV1.4-G860) intramuscular administration with regard to non-stimulated turbot was analyzed in head kidney at 8, 24 and 72 hours post-vaccination. Moreover, the effect of VHSV
infection one month after immunization was also analyzed in vaccinated and non-vaccinated fish at the same time points. Genes implicated in the
Toll-like receptor signalling pathway, IFN inducible/regulatory
proteins, numerous sequences implicated in apoptosis and cytotoxic pathways, MHC
class I antigens, as well as
complement and coagulation cascades among others were analyzed in the different experimental groups. Fish receiving the pMCV1.4-G860
vaccine showed transcriptomic patterns very different to the ones observed in pMCV1.4-injected turbot after 72 h. On the other hand, VHSV challenge in vaccinated and non-vaccinated turbot induced a highly different response at the transcriptome level, indicating a very relevant role of the acquired immunity in vaccinated fish able to alter the typical innate immune response profile observed in non-vaccinated individuals. This exhaustive transcriptome study will serve as a complete overview for a better understanding of the crosstalk between the innate and adaptive immune response in fish after
viral infection/vaccination. Moreover, it provides interesting clues about molecules with a potential use as
vaccine adjuvants,
antiviral treatments or markers for
vaccine efficiency monitoring.