Crucian carp(Carassius auratus gibelio),an extensively cultivated freshwater fish,was one of the model species for the study of fish immunology.Polyclonal antibodies were advantageous molecular tools for studying tele...Crucian carp(Carassius auratus gibelio),an extensively cultivated freshwater fish,was one of the model species for the study of fish immunology.Polyclonal antibodies were advantageous molecular tools for studying teleost immune system.Specifically,polyclonal antibodies reacting with immunoglobulins(Ig)were used successfully in studies of the teleost fishes.In the present study,we produced polyclonal antibody against CH2 domains of crucian carp IgM,and measured the in vivo dynamics of IgM mRNA caused by CyHV-2 infection.The recombinant protein IgM with relative molecular weight about 53 KD was correctly expressed in prokaryotic cells.The specificity of the polyclonal antibody was evaluated by Western blotting and results revealed that the antibody not only specifically recognized crucian carp serum but also cross-reacted with grass carp serum.Quantitative RT-PCR analysis demonstrated the expression of IgM mRNA changed significantly after CyHV-2 infection.The expression of IgM in the kidney increased and reached a maximum at 6 h post-infection(hpi),while dropped to a low level at 5 days post-infection(dpi).In conclusion,the expression of IgM was significantly upregulated in the kidney of crucian carp infected with CyHV-2,indicating that IgM played a potential role in systemic immunity against viral infection.Polyclonal antibody against crucian carp IgM had certain clinical relevance,which might provide insight into the early stage of virus infection and prevention of the disease.展开更多
Neomycin belongs to the family of 2-deoxystreptamine-containing aminoglycoside antibiotics.It is widely used for bacterial infections,targeting most gram-negative and some gram-positive bacteria.Neomycin has also been...Neomycin belongs to the family of 2-deoxystreptamine-containing aminoglycoside antibiotics.It is widely used for bacterial infections,targeting most gram-negative and some gram-positive bacteria.Neomycin has also been reported to show antiviral activity.Here,we evaluated the toxicity of neomycin sulfate,and investigated its effect on non-specific immunity and viral infection in crucian carp(Carassius auratus gibelio).The safe concentration of neomycin sulfate for crucian carp was determined to be 102.9 mg/kg in vivo.In oxidative damage assays,neomycin sulfate increased superoxide dismutase and catalase activity and decreased malondialdehyde in the liver of crucian carp.In non-specific blood immune assays,the white blood cell count and complement 3 content significantly increased after neomycin sulfate treatment,while no significant changes were observed in antibacterial or lysozyme activity.In a challenge test,neomycin sulfate protected the crucian carp from cyprinid herpesvirus 2(CyHV-2)infection and inhibited CyHV-2 replication.In cytotoxicity assays,low concentrations of neomycin sulfate had no cytotoxicity on cells from the fins of crucian carp.The results of the present study indicate that oral administration of neomycin sulfate reduced oxidative damage,enhanced immunity and provided protection against CyHV-2 in crucian carp.展开更多
基金supported by the General Fund Project of China Shanghai Natural Science Foundation(Program No.22ZR1427200).
文摘Crucian carp(Carassius auratus gibelio),an extensively cultivated freshwater fish,was one of the model species for the study of fish immunology.Polyclonal antibodies were advantageous molecular tools for studying teleost immune system.Specifically,polyclonal antibodies reacting with immunoglobulins(Ig)were used successfully in studies of the teleost fishes.In the present study,we produced polyclonal antibody against CH2 domains of crucian carp IgM,and measured the in vivo dynamics of IgM mRNA caused by CyHV-2 infection.The recombinant protein IgM with relative molecular weight about 53 KD was correctly expressed in prokaryotic cells.The specificity of the polyclonal antibody was evaluated by Western blotting and results revealed that the antibody not only specifically recognized crucian carp serum but also cross-reacted with grass carp serum.Quantitative RT-PCR analysis demonstrated the expression of IgM mRNA changed significantly after CyHV-2 infection.The expression of IgM in the kidney increased and reached a maximum at 6 h post-infection(hpi),while dropped to a low level at 5 days post-infection(dpi).In conclusion,the expression of IgM was significantly upregulated in the kidney of crucian carp infected with CyHV-2,indicating that IgM played a potential role in systemic immunity against viral infection.Polyclonal antibody against crucian carp IgM had certain clinical relevance,which might provide insight into the early stage of virus infection and prevention of the disease.
基金This work was supported by the Earmarked Fund for China Agriculture Research System(grant number CARS-45-19).The authors report no conflicts of interest in this paper.
文摘Neomycin belongs to the family of 2-deoxystreptamine-containing aminoglycoside antibiotics.It is widely used for bacterial infections,targeting most gram-negative and some gram-positive bacteria.Neomycin has also been reported to show antiviral activity.Here,we evaluated the toxicity of neomycin sulfate,and investigated its effect on non-specific immunity and viral infection in crucian carp(Carassius auratus gibelio).The safe concentration of neomycin sulfate for crucian carp was determined to be 102.9 mg/kg in vivo.In oxidative damage assays,neomycin sulfate increased superoxide dismutase and catalase activity and decreased malondialdehyde in the liver of crucian carp.In non-specific blood immune assays,the white blood cell count and complement 3 content significantly increased after neomycin sulfate treatment,while no significant changes were observed in antibacterial or lysozyme activity.In a challenge test,neomycin sulfate protected the crucian carp from cyprinid herpesvirus 2(CyHV-2)infection and inhibited CyHV-2 replication.In cytotoxicity assays,low concentrations of neomycin sulfate had no cytotoxicity on cells from the fins of crucian carp.The results of the present study indicate that oral administration of neomycin sulfate reduced oxidative damage,enhanced immunity and provided protection against CyHV-2 in crucian carp.
