| Gibel carp(Carassius auratus gibelio)is one of the most important freshwater economic species in China.But massive outbreaks of hemorrhagic sepsis had made great damage to the gibel carp culture industry in recent years.CyHV-2 and A,veronii are important viral and bacterial pathogens responsible for the hemorrhagic sepsis,respectively.In this study.we analyzed the response mechanisms of gibel carp to CyHV-2 and A.veronii infections with RNA-seq,followed with comparing the differences between the two response profiles.The results showed that comparing with healthy gibel carp,there were 1053 and 11567 differentially expressed genes(DEGs)detected in the CyHV-2 and A.veronii infection kidney,respectively.Based on these DEGs,60 genes were identified to react to both CyHV-2 and A.veronii infections.Detail analysis results shown that 12 genes were co-up-regulated and enriched in 17 GO terms and 4 KEGG pathways;4 genes were co-up-regulated and enriched in 10 GO terms and 3 KEGG pathways;25 genes were up-regulated after CyHV-2 infection while down-regulated after A.veronii infection and enriched in 27 GO terms and 11 KEGG pathways;19 genes were up-regulated after CyHV-2 infection while down-regulated after A.veronii infection and enriched in 28 GO terms and 13 KEGG pathways.In addition,there were 487 and 506 genes which up-regulated and down-regulated specifically after CyHV-2 infection,respectively.Parallelly,there were 356 and 433 genes which up-regulated and down-regulated specifically after A.veronii infection,respectively.These results indicated obvious differences between responses of gibel carp to CyHV-2 infection and A.veronii infection.Vaccine immunization is the most ideal method to prevent fish from virus diseases,but the study of CyHV-2 vaccines is still immature.The subunit vaccine is the safest vaccine but with disadvantages such as easy loss of epitopes,complicated separation and purification steps.In faced with these problems,we constructed two recombinant viruses,BmNPV-D4ORF-VP3-polh and BmNPV-H1-D4ORF-polh,encapsulated the CyHV-2 multivalent subunit vaccine proteins into protein microcrystals with bio-recognition technology,and then evaluated the immune protection effects on CyHV-2 infection.The results shown that the recombinant vaccine proteins D4ORF-VP3 and H1-D4ORO were recruited and embedded in the protein microcrystals successfully.Three weeks after the injective immunizations,specific antibodies were detected in the D4ORF-VP3 and H1-D4 ORF immunized fish by the means of competitive-ELISA,and the antibody titer reached 6400 times.The challenge test demonstrated that,immunized with D4ORF-VP3 and H1-D4 ORF,the anti-infective rates against CyHV-2 were 64.7%and 58.82%,respectively.These results indicated that the D4ORF-VP3 and H1-D4ORF protein microcrystals prepared in this study were candidate for anti-CyHV-2 vaccine development. |
