Biological effect of vaccination can be assessed directly from diluted whole blood of rainbow trout using homologous blood phagocytes as immunosensors

Multiple whole bacterial antigens in polyvalent vaccine may result in inhibition of specific responses in rainbow trout (Oncorhynchus mykiss)

“…Respiratory burst (RB) activity of experimental fish was measured as luminol-amplified CL from diluted whole blood of each fish [23]. The RB activity of blood phagocytes was induced with bacterial strains A. salmonicida MT004, L. anguillarum serotype 01 and with F6A/00 (serotype Fd), P13-4/96 (serotype Th) and L5/00 (serotype Fp T ;Th) strains of Fl.…”

“…psychrophilum P13-4/96 in the plasma samples as described previously [23]. Formalin-killed bacterial cells (w1 Â 10 8 cells) in carbonate buffer, pH 9.0, was added to microplate wells (MaxiSorp, Nunc) and incubated overnight at 4 C. Unbound bacteria were removed by washing twice with 0.25% Tween-20 in PBS.…”

“…We recently showed that the increased level and biological function of specific antibodies against A. salmonicida following vaccination can be determined directly from diluted whole blood of fish by inducing the respiratory burst (RB) activity of blood phagocytes with A. salmonicida cells in the presence of homologous plasma [23]. Because the vaccines used contained multiple whole bacterial antigens, we induced the RB activity of phagocytes with the same bacterial strains as used in the vaccines.…”

“…Hence, the effect of Fd and Th serotypes on the antibody response of trout was investigated in polyvalent vaccines. Because the conventional serological tests do not provide much information about the biological function of antibodies and particularly, give no information about the role of SCS in antibody-dependent opsonophagocytosis, we investigated the biological function of antibodies using the blood monocytes and granulocytes as immunosensors [23]. We also aimed to determine whether the plasma antibody level was associated with magnitude of opsonophagocytosis in fish.…”

Respiratory burst activity of Atlantic cod (Gadus morhua L.) blood phagocytes differs markedly from that of rainbow trout

“…Recent studies have shown that the ingestion of bacteria can be measured directly from highly diluted blood of trout by the CL emission of blood phagocytes [7]. Additionally, the enhancing effect of specific antibodies, if present, on the ingestion of bacteria can also be determined by the CL measurements [8].…”