Cell-mediated immunity in yellow forms of rainbow trout.

The aim of the present study was to investigate possible pleiotropic effects of the genotypes controlling the palomino and albino coloration on blood phagocyte and lymphocyte activity. The results showed that the wild coloured trout has a higher metabolic and potential killing activity of blood phagocytes, compared to albino and palomino coloured trout. The proliferative response of blood lymphocytes stimulated by ConA or LPS indicated a similar pattern. The results showed that lymphocyte proliferation was statistically significantly higher in wild coloured trout, compared to albino and palomino trout.

In vitro immunomodulating influence of methisoprinol on the head kidney phagocyte and lymphocyte activity after suppression induced by VHSV in rainbow trout (Oncorhynchus mykiss).

The aim of this study was to evaluate the in vitro influence of methisoprinol on head kidney phagocyte and lymphocyte activity after suppression induced by VHSV. The VHSV statistically significantly decreased the respiratory burst activity of head kidney phagocytes and the proliferative response of lymphocytes stimulated by ConA. The results of our study showed that methisoprinol at a concentration of 100 microl/ml modulated and restored the phagocyte and lymphocyte activity suppressed by VHSV.

Influence of methisoprinol on the replication of rhabdoviruses isolated from carp (Cyprinus carpio) and catfish (Ictalurus melas): in vitro study.

Rhabdoviruses constitute one of the most pathogenic viruses isolated from rainbow trout and carp culture. Several viruses were also isolated from other species of fish. These viruses are mostly associated with epizootics and heavy losses. Spring viraemia of carp virus (SVCV) and pike fry rhabdovirus (PFRV) have been the most extensively studied, due to their significant economic impact. Significant progress has been made towards controlling the major bacterial fish diseases using vaccines, but this approach has not yet been successful in preventing viral diseases in fish culture. However, for an effective therapeutic approach, specific drugs should be developed to selectively inhibit virus replication and/or stimulate antiviral protection. In this investigation we examined the in vitro influence of methisoprinol on the SVCV and virus isolated from catfish (Ictalurus melas) replication by measuring their RNA synthesis. The viruses were propagated in EPC cells and cell cultures containing methisoprinol were followed by infection with SVCV or catfish rhabdovirus suspension containing 10(7) TCID50/ml. Methisoprinol (Polfa, Poland) at concentrations of 0, 100, 200, 300, 400 and 500 microg/ml of medium (Glasgow MEM) was used in this study. The results of this study show the strong inhibition of incorporation (cpm) of [3H]-uridine into SVCV and catfish rhabdovirus RNA in cell culture exposed to methisoprinol at various concentrations. The highest percent of inhibition of viral RNA at 72 h after infection with two rhabdoviruses were observed in doses of 400 and 500 microg/ml of methisoprinol in medium. The results of this in vitro study showed that methisoprinol inhibits the rhabdoviruses isolated from carp and catfish.