PAMP induced expression of immune relevant genes in head kidney leukocytes of rainbow trout (Oncorhynchus mykiss)

TY - JOUR

T1 - PAMP induced expression of immune relevant genes in head kidney leukocytes of rainbow trout (Oncorhynchus mykiss)

AU - Chettri, Jiwan Kumar

AU - Raida, Martin Kristian

AU - Holten-Andersen, Lars

AU - Kania, Per Walter

AU - Buchmann, Kurt

PY - 2011/4

Y1 - 2011/4

N2 - Host immune responses elicited by invading pathogens depend on recognition of the pathogen by specific receptors present on phagocytic cells. However, the reactions to viral, bacterial, parasitic and fungal pathogens vary according to the pathogen-associated molecular patterns (PAMPs) on the surface of the invader. Phagocytic cells are known to initiate a respiratory burst following an exposure to the pathogen, but the underlying and associated specific elements are poorly elucidated in fish. The present study describes the differential response of head kidney leukocytes from rainbow trout (Oncorhynchus mykiss) to different PAMPs mimicking viral (poly I:C), bacterial (flagellin and LPS) and fungal infections (zymosan and β-glucan). Transcript of cytokines related to inflammation (IL-1β, IL-6, IL-10 and TNF-α) was highly up-regulated following LPS exposure whereas flagellin or poly I:C induced merely moderate reactions. In contrast, IFN-γ expression was significantly higher in the poly I:C stimulated group compared to the LPS group. When head kidney cells were exposed to zymosan or β-glucan, genes encoding IL-1β, TNF-α, IL-6 and IL-10 became up-regulated. Their level of up-regulation was comparable to LPS but the kinetics differed. In particular, TNF-α induction was considerably slower when stimulated with zymosan or β-glucan. The gene encoding the COX-2 enzyme, a central element during initiation of inflammatory reactions, was significantly higher in stimulated cells although a depressing effect of high concentrations of LPS and zymosan became evident after 4. h exposure. This study suggests that rainbow trout leukocytes respond differently to viral, bacterial and fungal PAMPs, which may reflect activation of specific signaling cascades eventually leading to activation of different immune effector molecules.

AB - Host immune responses elicited by invading pathogens depend on recognition of the pathogen by specific receptors present on phagocytic cells. However, the reactions to viral, bacterial, parasitic and fungal pathogens vary according to the pathogen-associated molecular patterns (PAMPs) on the surface of the invader. Phagocytic cells are known to initiate a respiratory burst following an exposure to the pathogen, but the underlying and associated specific elements are poorly elucidated in fish. The present study describes the differential response of head kidney leukocytes from rainbow trout (Oncorhynchus mykiss) to different PAMPs mimicking viral (poly I:C), bacterial (flagellin and LPS) and fungal infections (zymosan and β-glucan). Transcript of cytokines related to inflammation (IL-1β, IL-6, IL-10 and TNF-α) was highly up-regulated following LPS exposure whereas flagellin or poly I:C induced merely moderate reactions. In contrast, IFN-γ expression was significantly higher in the poly I:C stimulated group compared to the LPS group. When head kidney cells were exposed to zymosan or β-glucan, genes encoding IL-1β, TNF-α, IL-6 and IL-10 became up-regulated. Their level of up-regulation was comparable to LPS but the kinetics differed. In particular, TNF-α induction was considerably slower when stimulated with zymosan or β-glucan. The gene encoding the COX-2 enzyme, a central element during initiation of inflammatory reactions, was significantly higher in stimulated cells although a depressing effect of high concentrations of LPS and zymosan became evident after 4. h exposure. This study suggests that rainbow trout leukocytes respond differently to viral, bacterial and fungal PAMPs, which may reflect activation of specific signaling cascades eventually leading to activation of different immune effector molecules.

U2 - 10.1016/j.dci.2010.12.001

DO - 10.1016/j.dci.2010.12.001

M3 - Journal article

C2 - 21147161

SN - 0145-305X

VL - 35

SP - 476

EP - 482

JO - Developmental and Comparative Immunology

JF - Developmental and Comparative Immunology

IS - 4

ER -