TY - JOUR

T1 - Immunomodulation of rainbow trout (Oncorhynchus mykiss) fry by bath exposure to a β-glucan from Euglena gracilis

AU - Chettri, Jiwan Kumar

AU - Kania, Per Walter

AU - Buchmann, Kurt

PY - 2013

Y1 - 2013

N2 - Early developmental stages of fish mostly depend on innate immune factors for their protection. Augmenting these factors by application of different immunostimulatory substances may be beneficial for rearing and survival of the early life stages of fish. Bath administration of stimulants leads to a uniform exposure of fish independent of feed intake and reduces the individual handling. The present study demonstrates the immunostimulatory effectof beta-glucan (bath exposure) in rainbow trout fry at different dosages and exposure time. Rainbow trout fry (avg. wt. 770 mg; 87 days post hatch) wereexposed to three different concentrations of beta-glucan (10, 100 and 1000 microgram/mL) by bath exposure for 1 and 24 h. Expression of immune relatedgenes from pooled internal organ samples of individual fish were analysed using a real time qPCR assay. Expression of complement factors (C3 andfactor B) and acute phase proteins (hepcidin, precerebellin and transferrin) was significantly up-regulated after 24 h bath stimulation with beta-glucan (100 microgram/mL). These innate immune factors may play a vital role in clearance of pathogens. The expression of most of genes showed both a dose and time-dependent response. A medium dose (100 microgram/mL) induced a significant increase in expression of complement factors and acute phaseproteins mainly at 24 h exposure, whereas the highest dose of b-glucan (1000 microgram/mL) downregulated the expression of most of the studied genes. The result from the present study indicates that beta-glucan bath exposure could be applied for enhancing the innate immune factors even in fry.

AB - Early developmental stages of fish mostly depend on innate immune factors for their protection. Augmenting these factors by application of different immunostimulatory substances may be beneficial for rearing and survival of the early life stages of fish. Bath administration of stimulants leads to a uniform exposure of fish independent of feed intake and reduces the individual handling. The present study demonstrates the immunostimulatory effectof beta-glucan (bath exposure) in rainbow trout fry at different dosages and exposure time. Rainbow trout fry (avg. wt. 770 mg; 87 days post hatch) wereexposed to three different concentrations of beta-glucan (10, 100 and 1000 microgram/mL) by bath exposure for 1 and 24 h. Expression of immune relatedgenes from pooled internal organ samples of individual fish were analysed using a real time qPCR assay. Expression of complement factors (C3 andfactor B) and acute phase proteins (hepcidin, precerebellin and transferrin) was significantly up-regulated after 24 h bath stimulation with beta-glucan (100 microgram/mL). These innate immune factors may play a vital role in clearance of pathogens. The expression of most of genes showed both a dose and time-dependent response. A medium dose (100 microgram/mL) induced a significant increase in expression of complement factors and acute phaseproteins mainly at 24 h exposure, whereas the highest dose of b-glucan (1000 microgram/mL) downregulated the expression of most of the studied genes. The result from the present study indicates that beta-glucan bath exposure could be applied for enhancing the innate immune factors even in fry.

U2 - 10.1111/j.1365-2109.2012.03145.x

DO - 10.1111/j.1365-2109.2012.03145.x

M3 - Journal article

VL - 44

SP - 1407

EP - 1415

JO - Aquaculture Research

JF - Aquaculture Research

SN - 1355-557X

IS - 9

ER -