TY - JOUR
T1 - Immune Gene Expression in Trout Cell Lines Infected with the Fish Pathogenic Oomycete Saprolegnia Parasitica
AU - Bruijn, Irene de
AU - Belmonte, Rodrigo
AU - Anderson, Vicky L.
AU - Saraiva, Marcia
AU - Wang, Tiehui
AU - West, Pieter van
AU - Secombes, Christopher J
N1 - Copyright © 2012. Published by Elsevier Ltd.
PY - 2012/9
Y1 - 2012/9
N2 - The oomycete Saprolegnia parasitica causes significant losses in the aquaculture industry, mainly affecting salmon, trout and catfish. Since the ban of malachite green, effective control measures are currently not available prompting a re-evaluation of the potential for immunological intervention. In this study, the immune response of salmonid cells is investigated at the transcript level, by analysis of a large set of immune response genes in four different rainbow trout cell lines (RTG-2, RTGill, RTL and RTS11) upon infection with S. parasitica. Proinflammatory cytokine transcripts were induced in all four cell lines, including IL-1ß1, IL-8, IL-11, TNF-a2, as well as other components of the innate defences, including COX-2, the acute phase protein serum amyloid A and C-type lectin CD209a and CD209b. However, differences between the four cell lines were found. For example, the fold change of induction was much higher in the epithelial RTL and macrophage-like RTS11 cell lines compared to the fibroblast cell lines RTG-2 and RTGill. Several antimicrobial peptides (AMPs) were also up-regulated in response to Saprolegnia infection, including hepcidin and cathelicidin 1 (rtCATH1) and 2 (rtCATH2). An rtCATH2 peptide was synthesised and tested for activity and whilst it showed no killing activity for zoospores, it was able to delay sporulation of S. parasitica. These results demonstrate that particular immune genes are up-regulated in response to S. parasitica infection and that AMPs may play a crucial role in the first line of defence against oomycetes in fish.
AB - The oomycete Saprolegnia parasitica causes significant losses in the aquaculture industry, mainly affecting salmon, trout and catfish. Since the ban of malachite green, effective control measures are currently not available prompting a re-evaluation of the potential for immunological intervention. In this study, the immune response of salmonid cells is investigated at the transcript level, by analysis of a large set of immune response genes in four different rainbow trout cell lines (RTG-2, RTGill, RTL and RTS11) upon infection with S. parasitica. Proinflammatory cytokine transcripts were induced in all four cell lines, including IL-1ß1, IL-8, IL-11, TNF-a2, as well as other components of the innate defences, including COX-2, the acute phase protein serum amyloid A and C-type lectin CD209a and CD209b. However, differences between the four cell lines were found. For example, the fold change of induction was much higher in the epithelial RTL and macrophage-like RTS11 cell lines compared to the fibroblast cell lines RTG-2 and RTGill. Several antimicrobial peptides (AMPs) were also up-regulated in response to Saprolegnia infection, including hepcidin and cathelicidin 1 (rtCATH1) and 2 (rtCATH2). An rtCATH2 peptide was synthesised and tested for activity and whilst it showed no killing activity for zoospores, it was able to delay sporulation of S. parasitica. These results demonstrate that particular immune genes are up-regulated in response to S. parasitica infection and that AMPs may play a crucial role in the first line of defence against oomycetes in fish.
KW - oomycete
KW - Saprolegnia parasitica
KW - cathelicidin
KW - trout
KW - salmon
U2 - 10.1016/j.dci.2012.03.018
DO - 10.1016/j.dci.2012.03.018
M3 - Article
C2 - 22522286
SN - 0145-305X
VL - 38
SP - 44
EP - 54
JO - Developmental and Comparative Immunology
JF - Developmental and Comparative Immunology
IS - 1
ER -