| Participant(s):
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Forfatter:
Scapigliati, G.
Dipartimento di Scienze Ambientali, Largo dell'Università
Forfatter:
Buonocore, F.
Dipartimento di Scienze Ambientali, Largo dell'Università
Forfatter:
Randelli, E.
Dipartimento di Scienze Ambientali, Largo dell'Università
Forfatter:
Casani, D.
Dipartimento di Scienze Ambientali, Largo dell'Università
Forfatter:
Meloni, S.
Dipartimento di Scienze Ambientali, Largo dell'Università
Forfatter:
Zarletti, G.
Dipartimento di Scienze Ambientali, Largo dell'Università
Forfatter:
Tiberi, M.
Dipartimento di Scienze Ambientali, Largo dell'Università
Forfatter:
Pietretti, D.
Dipartimento di Scienze Ambientali, Largo dell'Università
Forfatter:
Boschi, I.
Dipartimento di Scienze Ambientali, Largo dell'Università
Forfatter:
Manchado, M.
Centro IFAPA, Junta de Andalucia, El Torufio, Càdiz, Spain
Forfatter:
Martin-Antonio, B.
Centro IFAPA, Junta de Andalucia, El Torufio, Càdiz, Spain
Forfatter:
Jimenez-Cantizano, R.
Centro IFAPA, Junta de Andalucia, El Torufio, Càdiz, Spain
Forfatter:
Bovo, G.
Istituto Zooprofilattico Spermentale delle Venezie, Italy
Forfatter:
Borghesan, F.
Istituto Zooprofilattico Spermentale delle Venezie, Italy
Technical University of Denmark
Email:
Technical University of Denmark
Forfatter:
Adams, S.
Aquatic Diagnostics, UK
Forfatter:
Thompson, K.
Aquatic Diagnostics, UK
Forfatter:
Alonso, C.
University of Malaga, Spain
Forfatter:
Bejar, J.
University of Malaga, Spain
Forfatter:
Borrego, J.J.
University of Malaga, Spain
Forfatter:
Alvarez, M.C.
University of Malaga, Spain
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| Abstract:
|
Naïve sea bass juveniles (38.4 ± 4.5 g) were intramuscularly infected with a sublethal dose of betanodavirus isolate 378/I03, followed after 43 days by a similar boosting. This infection resulted in an overall mortality of 7.6%. At various intervals, sampling of fish tissues was performed to investigate: i) B and T lymphocyte content in organs and tissues; ii), proliferation of leucocytes re-stimulated in vitro with inactivated virus; iii) presence of serum antibody specific for betanodavirus; iv) expression of genes coding for the following immunoregulatory molecules involved in innate and acquired responses: type I IFN, Mx, IL-1, Cox-2; IL-10, TGF-β, TCRβ, CD4, CD8α, IgM, by using a quantitative PCR array system developed for sea bass.
The obtained results showed a detectable increase of T cells and B cells in PBL during betanodavirus infection. Furthermore, leucocytes obtained from blood, head kidney, and gills showed a detectable “in vitro” increase in viability upon addition of inactivated viral particles, as determined by measuring intracellular ATP concentration. ELISA analysis of sera showed that exposure to nodavirus induced a low, but specific antibody titer measured 43 days after infection, despite the presence of measurable levels of natural antibody. Finally, a strong upregulation of genes coding for type I IFN, Mx, and IgM was identified after both infection and boosting. Interestingly, an upregulation of Cox-2 until boosting, and of TGF-β and IL-10 after boosting was also observed, while the other tested genes did not show any significant variations with respect to mock-treated fish. Overall, our work represents a first comprehensive analysis of cellular and molecular immune parameters in a fish species exposed to a pathogenic virus. |