Cloning of two rainbow trout nucleotide-binding oligomerization domain containing 2 (NOD2) splice variants and functional characterization of the NOD2 effector domains.
Nucleotide-binding oligomerization domain 2 (NOD2) is a cytoplasmic pattern recognition receptor (PRR), which is involved in innate antibacterial and antiviral responses. Here, two NOD2 splice variants, trNOD2a and trNOD2b, are reported in rainbow trout Oncorhynchus mykiss, that share 63% and 61% similarity with human NOD2, respectively. These two trout NOD2 splice variants were shown to be constitutively expressed in thymus, gills, skin, muscle, liver, spleen, head kidney, intestine, heart, and brain, with the expression of trout NOD2 (trNOD2) mainly contributed by trNOD2a in all the examined tissues. PolyI:C transfection up-regulated the expression of trNOD2a and trNOD2b in RTG-2 cells. The expression of trNOD2a/b was modulated by the inflammatory stimulant interferon-γ (IFN-γ) or interleukin-1β (IL-1β). Overexpression of trout NOD2 effector domains resulted in induced expression of proinflammatory cytokines including IL-1β, tumor necrosis factor-α (TNF-α), IL-6 and IL-8, the antibacterial peptide cathelicidin-2, a variety of caspases including caspase-2, -6, -7, -8, -9, and type I and type II IFN. These results suggest that fish NOD2 functions in inflammatory events, possibly via NF-κB activation, regulation of apoptosis, and triggering of antibacterial and antiviral defences.
Chang
Mingxian
M
Scottish Fish Immunology Research Centre, University of Aberdeen, Aberdeen AB24 2TZ, UK.
Wang
Tiehui
T
Nie
Pin
P
Zou
Jun
J
Secombes
Christopher J
CJ
D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis / Q000502:physiology; D001483:Base Sequence; D020169:Caspases / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism; D005786:Gene Expression Regulation; D007249:Inflammation / Q000378:metabolism; D008969:Molecular Sequence Data; D053473:Nod2 Signaling Adaptor Protein / Q000235:genetics* / Q000378:metabolism*; D017686:Oncorhynchus mykiss / Q000378:metabolism*; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000662:veterinary; D020033:Protein Isoforms / Q000235:genetics*; D017434:Protein Structure, Tertiary
D016207:Cytokines; D053473:Nod2 Signaling Adaptor Protein; D020033:Protein Isoforms; D020169:Caspases