scholarly journals Long-Term Protection and Serologic Response of European Sea Bass Vaccinated with a Betanodavirus Virus-Like Particle Produced in Pichia pastoris

Vaccines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 447
Author(s):  
Sofie Barsøe ◽  
Anna Toffan ◽  
Francesco Pascoli ◽  
Ansgar Stratmann ◽  
Tobia Pretto ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
High Titer ◽  
Dicentrarchus Labrax ◽  
Sea Bass ◽  
Nervous Necrosis Virus ◽  
European Sea Bass ◽  
Post Vaccination ◽  
Serologic Response ◽  
Viral Nervous Necrosis ◽  
Virus Like Particle

Viral Nervous Necrosis (VNN) causes high mortality and reduced growth in farmed European sea bass (Dicentrarchus labrax) in the Mediterranean. In the current studies, we tested a novel Pichia-produced virus-like particle (VLP) vaccine against VNN in European sea bass, caused by the betanodavirus “Red-Spotted Grouper Nervous Necrosis Virus” (RGNNV). European sea bass were immunized with a VLP-based vaccine formulated with different concentrations of antigen and with or without adjuvant. Antibody response was evaluated by ELISA and serum neutralization. The efficacy of these VLP-vaccine formulations was evaluated by an intramuscular challenge with RGNNV at different time points (1, 2 and 10 months post-vaccination) and both dead and surviving fish were sampled to evaluate the level of viable virus in the brain. The VLP-based vaccines induced an effective protective immunity against experimental infection at 2 months post-vaccination, and even to some degree at 10 months post-vaccination. Furthermore, the vaccine formulations triggered a dose-dependent response in neutralizing antibodies. Serologic response and clinical efficacy, measured as relative percent survival (RPS), seem to be correlated with the administered dose, although for the individual fish, a high titer of neutralizing antibodies prior to challenge was not always enough to protect against disease. The efficacy of the VLP vaccine could not be improved by formulation with a water-in-oil (W/O) adjuvant. The developed RGNNV-VLPs show a promising effect as a vaccine candidate, even without adjuvant, to protect sea bass against disease caused by RGNNV. However, detection of virus in vaccinated survivors means that it cannot be ruled out that survivors can transmit the virus.

scholarly journals Sea Bass Immunization to Downsize the Betanodavirus Protein Displayed in the Surface of Inactivated Repair-Less Bacteria

Vaccines ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 94
Author(s):  
Lama ◽  
Pereiro ◽  
Novoa ◽  
Coll
Keyword(s):  
Culture Media ◽  
Dicentrarchus Labrax ◽  
Sea Bass ◽  
Surface Expression ◽  
Environmental Safety ◽  
Nervous Necrosis Virus ◽  
Necrosis Virus ◽  
European Sea Bass ◽  
Viral Nervous Necrosis ◽  
Casein Hydrolysates

: This work describes immunization of European sea bass (Dicentrarchus labrax) juveniles against viral nervous necrosis virus (VNNV), a betanodavirus causing worldwide mortalities in many fish species. Protection was obtained with the so-called spinycterin vehicles consisting of irreversibly DNA-damaged DNA-repair-less Escherichia coli displaying at their surface a downsized VNNV coat antigen. In this work we have i) maximized bacterial expression levels by downsizing the coat protein of VNNV to a fragment (frgC91–220) containing most of its previously determined antigenicity, ii) developed a scalable autoinduction culture media for E.coli based in soy-bean rather than in casein hydrolysates, iii) enriched surface expression by screening different anchors from several prokaryotic sources (anchor + frgC91–220 recombinant products), iv) preserved frgC91–220 antigenicity by inactivating bacteria by irreversible DNA-damage by means of Ciprofloxacin, and v) increased safety using a repair-less E.coli strain as chassis for the spinycterins. These spinycterins protected fish against VNNV challenge with partial (Nmistic + frgC91–220) or total (YBEL + frgC91–220) levels of protection, in contrast to fish immunized with frgC91–220 spinycterins. The proposed spinycterin platform has high levels of environmental safety and cost effectiveness and required no adjuvants, thus providing potential to further develop VNNV vaccines for sustainable aquaculture.

scholarly journals Sea Bass Immunization to Downsized Betanodavirus Protein Displayed in The Surface of Dna-Damaged Repair-Less Bacteria

2019 ◽  
Author(s):  
Raquel Lama ◽  
Patricia Pereiro ◽  
Beatriz Novoa ◽  
Julio Coll
Keyword(s):  
Dicentrarchus Labrax ◽  
Sea Bass ◽  
Surface Expression ◽  
Environmental Safety ◽  
Small Fish ◽  
Nervous Necrosis Virus ◽  
Necrosis Virus ◽  
European Sea Bass ◽  
C Protein ◽  
Viral Nervous Necrosis

This work describes practical immunization of European sea bass (Dicentrarchus labrax) juveniles against viral nervous necrosis virus (VNNV), a betanodavirus causing worldwide mortalities in many fish species. Protection was obtained with the so called spinycterin vehicles consisting in irreversibly DNA-damaged DNA-repair-less E.coli displaying at their surface a downsized antigen. In this work we, i) maximized bacterial expression levels by downsizing the C protein to a fragment (frgC91-220) containing most of its antigenicity, ii) developed an scalable autoinduction bacterial media based in soy-bean increasing membrane display and reproducibility, iii) enriched surface expression by screening different anchors from several prokaryotic origins (anchor+frgC91-220), iv) preserved frgC91-220 antigenicity by inactivating bacteria by irreversible DNA-damage by means of Ciprofloxacin, and v) increased safety using a repair-less E.coli strain as spinycterin chassis. These second generation of spinycterins protected fish against VNNV challenge with partial (Nmistic+frgC91-220) or 100 % (YBEL+frgC91-220 ) protection, in contrast to those fish immunized with frgC91-220 spinycterins. The proposed spinycterin platform has high levels of environmental safety and cost effectiveness, thus providing potential for small fish vaccines for sustainable aquaculture.

scholarly journals Nervous Necrosis Virus-like Particle (VLP) Vaccine Stimulates European Sea Bass Innate and Adaptive Immune Responses and Induces Long-Term Protection against Disease

Pathogens ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1477
Author(s):  
Sofie Barsøe ◽  
Kerstin Skovgaard ◽  
Dagoberto Sepúlveda ◽  
Ansgar Stratmann ◽  
Niccolò Vendramin ◽  
...  
Keyword(s):  
Gene Expression ◽  
Immune Response ◽  
Expression Analysis ◽  
Gene Expression Analysis ◽  
Sea Bass ◽  
Nervous Necrosis Virus ◽  
Necrosis Virus ◽  
European Sea Bass ◽  
Post Vaccination ◽  
Virus Like Particle

The rapidly increasing Mediterranean aquaculture production of European sea bass is compromised by outbreaks of viral nervous necrosis, which can be recurrent and detrimental. In this study, we evaluated the duration of protection and immune response in sea bass given a single dose of a virus-like particle (VLP)-based vaccine. Examinations included experimental challenge with nervous necrosis virus (NNV), serological assays for NNV-specific antibody reactivity, and immune gene expression analysis. VLP-vaccinated fish showed high and superior survival in challenge both 3 and 7.5 months (1800 and 4500 dd) post-vaccination (RPS 87 and 88, OR (surviving) = 16.5 and 31.5, respectively, p < 0.01). Although not providing sterile immunity, VLP vaccination seemed to control the viral infection, as indicated by low prevalence of virus in the VLP-vaccinated survivors. High titers of neutralizing and specific antibodies were produced in VLP-vaccinated fish and persisted for at least ~9 months post-vaccination as well as after challenge. However, failure of immune sera to protect recipient fish in a passive immunization trial suggested that other immune mechanisms were important for protection. Accordingly, gene expression analysis revealed that VLP-vaccination induced a mechanistically broad immune response including upregulation of both innate and adaptive humoral and cellular components (mx, isg12, mhc I, mhc II, igm, and igt). No clinical side effects of the VLP vaccination at either tissue or performance levels were observed. The results altogether suggested the VLP-based vaccine to be suitable for clinical testing under farming conditions.

A BIVALENT INACTIVATED VACCINE OF VIRAL NERVOUS NECROSIS VIRUS AND GROUPER IRIDOVIRUS APPLIED TO GROUPER BROODFISH (EPINEPHELUS COIOIDES) REDUCES THE RISK OF VERTICAL TRANSMISSION

2017 ◽  
Vol 43 (03) ◽  
pp. 171-176 ◽  
Author(s):  
Sue-Min Huang ◽  
Jin-Hua Cheng ◽  
Chien Tu ◽  
Tzyy-Ing Chen ◽  
Chun-Ta Lin ◽  
...  
Keyword(s):  
Vertical Transmission ◽  
Neutralizing Antibodies ◽  
High Titer ◽  
Serum Antibody ◽  
Pcr Analysis ◽  
Nervous Necrosis Virus ◽  
Epinephelus Coioides ◽  
Necrosis Virus ◽  
Viral Nervous Necrosis ◽  
Level 1

Forty-one broodfish of orange-spotted groupers (Epinephelus coioides) were selected to evaluate the effectiveness of a viral nervous necrosis virus (VNNV) and grouper iridovirus (GIV) inactivated bivalent vaccine in grouper broodfish. Real-time quantitative PCR analysis showed that a detection rate of 10.5% (2/19) was found in egg specimens of VNNV and GIV, which carried approximately 1780 copies of GIV viral DNA in the egg specimens from broodfish before vaccination. This confirmed the vertical transmission route of GIV in broodfish. A significant increase of the anti-VNNV serum antibody titer was more than 50% in the high titer level (1:1810 to 1:5120) and 45% in the moderate titer level (1:452 to 1:1280), which were higher than those of the anti-GIV display, with 50% (10/20) in a titer of 1:57 to 1:320 and 40% (8/20) in a titer of 1:452 to 1:1280 one month after the vaccination. This result showed that the VNNV is a highly antigenic virus and can effectively induce neutralizing antibodies better than GIV. In addition, the VNNV and GIV viral copy numbers were 97.1 and 1780 copies per [Formula: see text]g host egg DNA from the broodfish before vaccination, respectively. One month after the vaccination, the viral genomes of VNNV and GIV were undetectable in egg specimens. The results show that immunization can induce the production of specific protective neutralizing antibodies, and the infective antigens can thereby be eliminated by the immunity. The results demonstrate that the specific antibodies of GIV and VNNV induced by vaccination can reduce the risk of vertical transmission of VNNV and GIV in grouper broodfish.

scholarly journals Induction of a Protective Immune Response against Viral Nervous Necrosis in the European Sea Bass Dicentrarchus labrax by Using Betanodavirus Virus-Like Particles

2006 ◽  
Vol 80 (20) ◽  
pp. 10201-10207 ◽  
Author(s):  
R. Thiéry ◽  
J. Cozien ◽  
J. Cabon ◽  
F. Lamour ◽  
M. Baud ◽  
...  
Keyword(s):  
Immune Response ◽  
Expression System ◽  
Dicentrarchus Labrax ◽  
Sea Bass ◽  
Baculovirus Expression System ◽  
Single Type ◽  
European Sea Bass ◽  
Virus Like Particles ◽  
Viral Nervous Necrosis ◽  
Baculovirus Expression

ABSTRACT Betanodaviruses are causative agents of viral nervous necrosis (VNN), a devastating disease of cultured marine fish worldwide. Virus particles contain a single type of coat protein that spontaneously assembles into virus-like particles (VLPs) when expressed in a baculovirus expression system. In the present study, the immunogenicity of betanodavirus VLPs and the protection they confer against VNN in the European sea bass Dicentrarchus labrax were investigated. Enzyme-linked immunosorbent assay and seroneutralization tests performed on plasma from fish vaccinated intramuscularly with doses as low as 0.1 μg of VLPs indicated that the VLPs elicited the synthesis of specific antibetanodavirus antibodies with neutralizing activity. Moreover, fish vaccinated with VLPs were protected from challenge with live virus. Both the immune response and the protective effect against viral challenge were dose dependent. Reverse transcription-PCR data indicated that higher doses of vaccine also reduced the number of fish containing detectable quantities of betanodavirus RNA on day 30 after challenge. Taken together these data strongly support the hypothesis that VLPs obtained in the baculovirus expression system may represent an effective vaccine against VNN.

scholarly journals Different survival of three populations of European sea bass (Dicentrarchus labrax) following challenge with two variants of nervous necrosis virus (NNV)

2021 ◽  
Vol 19 ◽  
pp. 100621
Author(s):  
Sofie Barsøe ◽  
François Allal ◽  
Alain Vergnet ◽  
Marc Vandeputte ◽  
Niels Jørgen Olesen ◽  
...  
Keyword(s):  
Dicentrarchus Labrax ◽  
Sea Bass ◽  
Nervous Necrosis Virus ◽  
Necrosis Virus ◽  
European Sea Bass

scholarly journals Resistance to viral nervous necrosis in European sea bass (Dicentrarchus labrax L.): heritability and relationships with body weight, cortisol concentration, and antibody titer

2021 ◽  
Vol 53 (1) ◽  
Author(s):  
Sara Faggion ◽  
Daniela Bertotto ◽  
Massimiliano Babbucci ◽  
Giulia Dalla Rovere ◽  
Rafaella Franch ◽  
...  
Keyword(s):  
Body Weight ◽  
Antibody Titer ◽  
Selective Breeding ◽  
Dicentrarchus Labrax ◽  
Sea Bass ◽  
Cortisol Concentration ◽  
European Sea Bass ◽  
Testing Procedures ◽  
Viral Nervous Necrosis ◽  
Highest Posterior Density

Abstract Background Susceptibility of European sea bass (Dicentrarchus labrax L.) to viral nervous necrosis (VNN) is well-known. Interest towards selective breeding as a tool to enhance genetic resistance in this species has increased sharply due to the major threat represented by VNN for farmed sea bass and limitations concerning specific therapeutical measures. A sea bass experimental population (N = 650) was challenged with nervous necrosis virus (NNV) to investigate genetic variation in VNN mortality. In addition, relationships of this trait with serum cortisol concentration after stress exposure, antibody titer against NNV antigens, and body weight at a fixed age were studied to identify potential indicator traits of VNN resistance. Results The estimate of heritability for VNN mortality was moderate and ranged from 0.15 (HPD95%, 95% highest posterior density interval: 0.02, 0.31) to 0.23 (HPD95%: 0.06, 0.47). Heritability estimates for cortisol concentration, antibody titer, and body weight were 0.19 (HPD95%: 0.07, 0.34), 0.36 (HPD95%: 0.16, 0.59) and 0.57 (HPD95%: 0.33, 0.84), respectively. Phenotypic relationships between traits were trivial and not statistically significant, except for the estimated correlation between antibody titer and body weight (0.24). Genetic correlations of mortality with body weight or antibody titer (− 0.39) exhibited a 0.89 probability of being negative. A negligible genetic correlation between mortality and cortisol concentration was detected. Antibody titer was estimated to be positively correlated with body weight (0.49). Conclusions Antibody titer against NNV offers the opportunity to use indirect selection to enhance resistance, while the use of cortisol concentration as an indicator trait in breeding programs for VNN resistance is questionable. The estimate of heritability for VNN mortality indicates the feasibility of selective breeding to enhance resistance to NNV and raises attention to the development of genomic prediction tools to simplify testing procedures for selection candidates.

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