Innate cell-mediated immune response and peripheral leukocyte populations in Atlantic salmon, Salmo salar L., to a live Cryptobia salmositica vaccine

Abstract

The effects of a live Cryptobia salmositica (Kinetoplastida) vaccine on the humoral and cellular immune response, and changes in the peripheral leukocyte populations of Salmo salar were investigated. The vaccine produced detectable parasitemia in the blood which peaked at 5 weeks post-vaccination (w.p.v). Antibodies were detectable at 4 w.p.v. and the antibody titer increased as parasitemia declined. Respiratory burst activity in vaccinated fish was significantly higher than in control fish; the highest activity occurred with rising parasitemia and lower activity with declining parasitemia. There was a significant increase in the proportion of granulocytes (to total leukocytes) at 4 w.p.v. At 6 w.p.v., the proportion of lymphocytes and monocytes increased significantly and remained elevated. These results demonstrate innate (respiratory burst activity and an increase in the proportion of granulocytes corresponding to rising parasitemia) and adaptive (antibody production and increases in the proportion of monocytes and lymphocytes corresponding to declining parasitemia) immune responses to the live vaccine.

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

“…Our result is in agreement with an earlier report by Chin and Woo [47] who observed after vaccination of salmon with live Cryptobia salmositica a significant increase in the proportion of blood granulocytes and significant increase in the proportion of lymphocytes and monocytes at 4 and 6 weeks post-vaccination, respectively. Oil-adjuvanted vaccines are known to induce inflammation at the site of injection leading to migration of phagocytes [48e51].…”

Injection of xenogeneic cells into teleost fish elicits systemic and local cellular innate immune responses

“…For example, in seabream, acidophils are mobilized from the head-kidney to other tissues after pathogenic bacteria (Vibrio anguillarum) or parasite (Enteromyxum leei) challenge (Chaves-Pozo et al 2005, unpublished). Similar redistributions have also been observed in other teleost fish challenged with different agents (Graves et al 1985;Vicha and Schmale 1994;Chin and Woo 2005); the general pattern seems to be that acidophils are the first fish leucocytes mobilized to the infection site, followed by monocyte-macrophages.…”

Contribution of food deprivation to the immune response in rainbow trout ( Oncorhynchus mykiss ) vaccinated against Cryptobia salmositica and Aeromonas salmonicida

“…A disadvantage of this nonspecific assay is that it may be somewhat subjective in interpretation. As described earlier (Anderson et al, 1992;Chin and Woo, 2005), neutrophil activity is increased upon antigen stimulation in rainbow trout.…”

“…Nitroblue tetrazolium (NBT) is a differential stain that changes colour from a yellow soluble substance to insoluble dark blue granules of formazan in the cell cytoplasm in the presence of oxygen radicals. This is an assay for nonspecific immune response of the host against microorganisms (Anderson et al, 1992;Chin and Woo, 2005).…”