Herpesviral hematopoietic necrosis disease caused by cyprinid herpesvirus 2(CyHV-2)results in huge economic losses for the gibel carp(Carassius auratus gibelio)aquaculture industry.A vaccination strategy is a feasible...Herpesviral hematopoietic necrosis disease caused by cyprinid herpesvirus 2(CyHV-2)results in huge economic losses for the gibel carp(Carassius auratus gibelio)aquaculture industry.A vaccination strategy is a feasible method to prevent CyHV-2 infection and the resulting economic losses.In this study,inactivators(includingβ-propiolactone,formaldehyde and binary ethylenimine)were used to prepare an inactivated vaccine.The optimal inactivated CyHV-2 vaccine(0.2%β-propiolactone inactivates CyHV-2 for 48 h)mixed withβ-glucan,anisodamine,chitosan,and astragalus polysaccharide(APS)adjuvants were injected into gibel carp.Theβ-glucan and APS combined with inactivated vaccine significantly improved the relative immune protection rate of gibel carp against CyHV-2 infection.The highest specific antibody levels inβ-glucan and APS groups were found in serum by ELISA assay and antibody neutralization titer.Furthermore,adjuvant addition groups produced better results for lysozyme,total superoxide dismutase,and complement C3 in serum.β-glucan and APS combined with vaccine treatment effectively enhanced mRNA expressions of important immune genes(IL-1β,IgM,IL-2 and IFN-γ2).Minimal tissue lesions(gill,spleen,and head kidney)and virus replication were seen in theβ-glucan and APS groups by histopathological examination and expression analysis of CyHV-2 TK gene.These results indicated that the combination of inactivated vaccine and adjuvantβ-glucan or APS is an effective method against CyHV-2 infection and provided a case study reference for prevention of fish viral diseases using inactivated vaccines.展开更多
Grass carp hemorrhagic disease caused by grass carp reovirus(GCRV)results in significant economic losses to the global grass carp aquaculture industry.Oral vaccination is an ideal choice for disease precaution in aqua...Grass carp hemorrhagic disease caused by grass carp reovirus(GCRV)results in significant economic losses to the global grass carp aquaculture industry.Oral vaccination is an ideal choice for disease precaution in aquaculture.However,oral vaccine can be degraded in the gut.Therefore,the selection of loading materials is essential.In this study,the S6 and S7 fragments(encoding the outer capsid protein VP4 and fibronectin VP56 of GCRV)and grass carp interferons(IFNs),including IFN1,IFN3,and IFNγ2 were used to create DNA vaccines and adjuvants based on pcDNA3.1,respectively.The oral DNA vaccine was encapsulated in poly(lactic-co-glycolic acid)(PLGA)and polyvinyl alcohol(PVA)with IFNs.The PLGA-PVA(PP)nano-microspheres were prepared by double emulsionsolvent evaporation technique.Using transmission electron microscopy and dynamic light scattering assays,it was determined the vaccines had a spherical structure with uniform particle size(643.5±35.3 nm).The nanomicrospheres possessed excellent encapsulation efficiency(81.6±2.6%)and loading rate(0.54±0.02%),and simultaneously exhibited negligible hemolytic activity and cell toxicity.The protection rate and tissue viral loads post-GCRV challenge in grass carp were assessed.The oral PP nano-microsphere with pVP4 t pIFN1(PP41)vaccine increased protection rate by 44%compared with the control group and was correlated with relatively low viral loads in the spleen,head kidney,and hindgut.Further,three crucial serum biochemical indexes,total superoxide dismutase(TSOD),complement C3(C3),and lysozyme(LZM),were also dramatically increased.Furthermore,mRNA expressions of representative immune-related genes(IgM,IFN1,IFNγ2,MHC-I,and CD8α)in the head kidney and spleen were significantly enhanced.In addition,mRNA expression of IgT was significantly boosted in the hindgut.The results indicate that DNA vaccine capsulated with PP is effective against GCRV infection.The present study provides insights into a prospective strategy for oral vaccine development in aquaculture.展开更多
基金supported by Fundamental Research Funds for the Central Universities (2662021SCPY006)National Key Research and Development Program of China (2018YFD0900504).
文摘Herpesviral hematopoietic necrosis disease caused by cyprinid herpesvirus 2(CyHV-2)results in huge economic losses for the gibel carp(Carassius auratus gibelio)aquaculture industry.A vaccination strategy is a feasible method to prevent CyHV-2 infection and the resulting economic losses.In this study,inactivators(includingβ-propiolactone,formaldehyde and binary ethylenimine)were used to prepare an inactivated vaccine.The optimal inactivated CyHV-2 vaccine(0.2%β-propiolactone inactivates CyHV-2 for 48 h)mixed withβ-glucan,anisodamine,chitosan,and astragalus polysaccharide(APS)adjuvants were injected into gibel carp.Theβ-glucan and APS combined with inactivated vaccine significantly improved the relative immune protection rate of gibel carp against CyHV-2 infection.The highest specific antibody levels inβ-glucan and APS groups were found in serum by ELISA assay and antibody neutralization titer.Furthermore,adjuvant addition groups produced better results for lysozyme,total superoxide dismutase,and complement C3 in serum.β-glucan and APS combined with vaccine treatment effectively enhanced mRNA expressions of important immune genes(IL-1β,IgM,IL-2 and IFN-γ2).Minimal tissue lesions(gill,spleen,and head kidney)and virus replication were seen in theβ-glucan and APS groups by histopathological examination and expression analysis of CyHV-2 TK gene.These results indicated that the combination of inactivated vaccine and adjuvantβ-glucan or APS is an effective method against CyHV-2 infection and provided a case study reference for prevention of fish viral diseases using inactivated vaccines.
基金supported by the National Key R&D Program of China(2022YFF1000302)Major Project of Hubei Hongshan Laboratory(2022hszd011).
文摘Grass carp hemorrhagic disease caused by grass carp reovirus(GCRV)results in significant economic losses to the global grass carp aquaculture industry.Oral vaccination is an ideal choice for disease precaution in aquaculture.However,oral vaccine can be degraded in the gut.Therefore,the selection of loading materials is essential.In this study,the S6 and S7 fragments(encoding the outer capsid protein VP4 and fibronectin VP56 of GCRV)and grass carp interferons(IFNs),including IFN1,IFN3,and IFNγ2 were used to create DNA vaccines and adjuvants based on pcDNA3.1,respectively.The oral DNA vaccine was encapsulated in poly(lactic-co-glycolic acid)(PLGA)and polyvinyl alcohol(PVA)with IFNs.The PLGA-PVA(PP)nano-microspheres were prepared by double emulsionsolvent evaporation technique.Using transmission electron microscopy and dynamic light scattering assays,it was determined the vaccines had a spherical structure with uniform particle size(643.5±35.3 nm).The nanomicrospheres possessed excellent encapsulation efficiency(81.6±2.6%)and loading rate(0.54±0.02%),and simultaneously exhibited negligible hemolytic activity and cell toxicity.The protection rate and tissue viral loads post-GCRV challenge in grass carp were assessed.The oral PP nano-microsphere with pVP4 t pIFN1(PP41)vaccine increased protection rate by 44%compared with the control group and was correlated with relatively low viral loads in the spleen,head kidney,and hindgut.Further,three crucial serum biochemical indexes,total superoxide dismutase(TSOD),complement C3(C3),and lysozyme(LZM),were also dramatically increased.Furthermore,mRNA expressions of representative immune-related genes(IgM,IFN1,IFNγ2,MHC-I,and CD8α)in the head kidney and spleen were significantly enhanced.In addition,mRNA expression of IgT was significantly boosted in the hindgut.The results indicate that DNA vaccine capsulated with PP is effective against GCRV infection.The present study provides insights into a prospective strategy for oral vaccine development in aquaculture.
