Influence of CyHV-3 on the nonspecific defense mechanisms in common carp (Cyprinus carpio) and other species – in vitro and in vivo study

Objective: The herpes-like agents, referred to as CyHV-3, have been isolated and identified from common carp and induced mass mortality in many countries. Several species cultivated with common carp: tench (Tinca tinca) or sheatfish (Silurus glanis) did not present any symptoms of disease and were found to be fully resistant to it. This study reports the preliminary results of the in vitro effects of CyHV-3 on the spleen phagocytes activity and interleukin 1–like protein (IL-1-like) and interleukin 6–like protein (IL-6-like) production by mitogen-stimulated spleen phagocytes in carp, tench and sheatfish. Method & Materials: The spleen was isolated and cell cultures were performed from 10 healthy carps, tench and sheatfish. The phagocytic ability of spleen phagocytes were analysed by the respiratory burst activity (RBA) and potential killing activity (PKA) after stimulation with Aeromonas hydrophila. The cell suspensions isolated from carp, tench and sheatfish were incubated with CyHV-3 virus for 30 min at C. In the second part of this study a range of immunoassays have been applied°20 to study the in vivo influence of CyHV-3 on the nonspecific defence mechanisms and mortality after challenge test in carp. Results & Conclusion: The results showed that CyHV-3 significantly decreased (P<0.05) the spleen phagocyte activity in carp compared to the control and to the spleen phagocyte activity from the sheatfish and tench. In the sheatfish and tench we did not observe the immunosuppressive effect compared to the carp. The IL-1-like protein and IL-6-like protein were generated by ConA-stimulated or virus-stimulated cells but not by non-stimulated cells. Analysis of the results showed significant differences in production (P<0.05) of IL-1 and IL-6-like protein between cells isolated from carp, sheatfish and tench. The lowest levels of IL-1 and IL-6-like protein were observed in carp. The CyHV-3 significantly (P<0.05) reduced the cytokines production by spleen leukocytes stimulated by ConA in carp. The in vivo study demonstrated that CyHV-3 decreased cellular and humoral defence mechanisms in carp and induced high mortality, compared to the tench where we did not observe any mortality at the end of experimental study.

کلیدواژه ها:

CyHV-3 ، common carp ، sheatfish ، tench