Influence of HMB (?-hydroxy-?-methylbutyrate) on antibody secreting cells (ASC) after in vitro and in vivo immunization with the anti-Yersinia ruckeri vaccine of rainbow trout (Oncorhynchus mykiss)

Abstract

-In practice, protection of fish against disease by immunization is of limited effectiveness. Therefore, research is concentrated on how to improve the potency and efficacy of vaccines and how to optimally activate the cell-mediated immunity and the specific antibody response. In the present study, the influence of HMB (β-Hydroxy-β-methylbutyrate) on the antibody secreting cells (ASC) after both in vitro and in vivo immunization of rainbow trout (Oncorhynchus mykiss) with the anti-Yersiniose vaccine was studied. For in vitro immunization, the spleens from 160 fish were sampled and placed each in 35 mm sterile wells with medium containing HMB at concentrations of 0, 0.1, 1, 5, 10, 25, 50 or 100 µg/mL of medium. The spleens from 80 fish were injected with the vaccine and incubated at 14°C for 10 days. For the in vivo study, fish were fed pellets containing HMB at doses of 0, 10, 25 and 50 mg/kg bw per day. After 2 weeks of HMB supplementation, the fish were immunized by intraperitoneal injection of the vaccine. At 7, 14, 18, 21, 28 and 35 days after immunization, pronephros were taken from 10 fish in each group for testing. When analyzed by the ELISPOT assay, HMB increased the number of splenic ASC after in vitro immunization at concentrations between 10 and 100 µg/mL (P < 0.05). Dietary HMB also increased the number of total and specific ASC when the fish were vaccinated in vivo. In conclusion, the results of the present study showed that HMB increases the levels of specific ASC after both in vitro and in vivo immunization of rainbow trout with the anti-Yersinia ruckeri vaccine.HMB / rainbow trout / anti-Yersiniose vaccine / antibody secreting cells Vet. Res. 32 (2001) [491][492][493][494][495][496][497][498] 491

The effect of feeding the leucine metabolite beta-hydroxy-beta-methylbutyrate (HMB) on cell-mediated immunity and protection against Yersinia ruckeri in pikeperch (Sander lucioperca)

“…The results of this part of the study are evidence that HMB in the diet had an immunostimulating influence on phagocyte and lymphocyte activity in pikeperch. Similar immunomodulating effects of HMB on nonspecific cellular defence mechanisms in rainbow trout have been observed in our previous studies (Siwicki et al 2001, 2003). These studies strongly suggested that supplemental HMB acts as an immunomodulator, and that at doses between 10 and 50 mg kg −1 of the feed it stimulated phagocyte activity examined through the phagocytic ability and potential killing activity, and lymphocyte activity analysed through the proliferative response induced by mitogens.…”

“…Previously, Siwicki and colleagues, in cooperation with Department of Animal Sciences, Iowa State University, USA examined the role of leucine and leucine catabolites in the activity of nonspecific defence mechanisms in rainbow trout ( Oncorhynchus mykiss (Walbaum)). The results showed that HMB, applied in the diet, activated cellular and humoral defence mechanisms and provided protection against diseases in intensive rainbow trout culture (Siwicki, Morand, Fuller, Nissen, Kazun & Glompski 2001; Siwicki, Morand, Fuller, Nissen, Goryczko, Ostaszewski, Kazun & Glompski 2003).…”

Yersinia ruckeri infections in salmonid fish

“…Leucocyte phagocytosis is an important reaction activated in Y. ruckeri ‐vaccinated fish as well as antibody production (Cossarini‐Dunier 1986) and lymphocyte proliferation (Siwicki & Dunier 1993; Siwicki, Morand, Fuller, Nissen, Kazun & Glombski 2001). Enzyme‐linked immunosorbent assays (ELISA) have been developed for the detection of many fish pathogens.…”

Effects of Levamisole on Phagocytic Activity of Rainbow Trout (Oncorhynchus mykiss W.)

“…Several promising adjuvants, natural and synthetic drugs and biological modifiers have been tested in fish in vivo and in vitro. The substances, such as chitosan, β-glucan, muramyl dipeptide, trace mineral and vitamin combinations as well as various products derived from plants and animals, are effective in stimulating or modulating non-specific defence mechanism, and offer protection against viral and bacterial diseases in fish (Siwicki et al 1994;Siwicki et al 2001;Kodama et al 1993;Mulero et al 1998a;Cuesta et al 2002a).…”