Monitoraggio dell'espressione citochinica in corso di vaccinazione polivalente della spigola (Dicentrarchus labrax, L. 1758) contro Photobacterium damselae subsp. piscicida e Listonella anguillarum

Sea bass (Dicentrarchus labrax, L. 1758) is the most important fish species in the Mediterranean aquaculture and the fight against Vibriosis and Pasteurellosis is a prior objective for the economy in marine aquaculture. Vaccination would be an ideal tool to prevent these infectious diseases, but it still requires optimization. The study of the immune response induced by infection and vaccination is an important tool for evaluation of vaccine protocol efficacy. Cytokine expression analysis, in this respect, can provide a useful contribution to the study of the mechanisms involved in the immune response activated by infections and vaccinations. This research was aimed to develop an assay for absolute quantification of 3 seabass cytokines and to apply it during polyvalent vaccination against Photobacterium damselae subsp. piscicida (Phdp) and Listonella anguillarum to measure immune response. The method has proved to be sensitive, reproducible and accurate for the quantification of mRNA coding IL-1β, IL-6 and IL-8 seabass cytokines. The analysis of cytokine gene expression during polyvalent vaccination against Phdp and L. anguillarum showed a correlation between cytokine gene upregulation and the percentage of survival after challenge with L. anguillarum in subjects vaccinated intraperitoneally suggesting the involvement of these cytokines in the immune mechanisms protecting the fish against this infection. Upregulation of the three cytokines investigated was also observed in the seabass during Phdp infection in analogy with what has been previously observed in other species. Further studies will be necessary to identify effective methods for the administration of polyvalent vaccine other than intraperitoneal route.