Identification and functional characterization of Toll-like receptor 2–1 in geese

Abstract

BackgroundToll-like receptor 2 (TLR2), an important pattern recognition receptor, activates proinflammatory pathways in response to various pathogens. It has been reported in humans and chicken, but not in geese, an important waterfowl species in China. Since some vaccines stimulate robust immune responsesl in chicken but not in geeeses we speculated that their immune systems are different.ResultsIn this study, we cloned the goose TLR2-1 gene using rapid amplification of cDNA ends (RACE)and showed that geese TLR2-1 encoded a 793-amino-acid protein, containing a signal secretion peptide, an extracellular leucine-rich repeat domain, a transmembrane domain and a Toll/interleukin-1 receptor signaling domain deduced from amino acid sequence. TLR2-1 shared 38.4%–93.5% homology with its homologues in other species. Tissue expression of geese TLR2-1 varied markedly, and was higher in kidney, cloacal bursa, skin and brain compared to other organs/tissues. HEK293 cells transfected with plasmids carrying goose TLR2-1 and NF-κB-luciferase responded significantly to stimulation with Mycoplasma fermentans lipopeptide. Furthermore, geese infected with Mycoplasma gallisepticum (MG) and Salmonella enteritidis (SE) showed significant upregulation of TLR2-1 in both in vivo and in vitro.ConclusionGeese TLR2-1 is a functional homologue of TLR2 present in other species and plays an important role in bacterial recognition in geese.

Redox Homeostasis in Poultry: Regulatory Roles of NF-κB

“…It seems likely that there is a tissue-specific regulation of TLR expression in the process of orchestrating the immune response against bacterial pathogens [ 181 ]. Goose TLR2-1 was also shown to play an important role in the recognition of Mycoplasma fermentans lipopeptide, Mycoplasma gallisepticum (MG) and Salmonella enteritidis (SE), and it induced the activation of NF-κB [ 182 ]. Furthermore, in HEK293T cells, flagellin was shown to induce pigeon NF-κB via TLR5 activation.…”

Mycoplasmas–Host Interaction: Mechanisms of Inflammation and Association with Cellular Transformation

“…To this regard, a protein able to bind TLRs is the macrophage-activating lipopeptide-2 (MALP-2) from Mycoplasma fermentans [ 38 , 39 , 78 ]. Upon binding, nuclear factor NF-kB [ 79 ] is activated and induces the expression of pro-inflammatory mediators, such as TNF-α (tumor necrosis factor-α), IL-6 (interleukin 6), MIP-1β (macrophage inflammatory protein-1β), GRO-α (growth-regulated oncogene-α), MCP-1 (monocyte chemoattractant protein-1), MIP-1α (macrophage inflammatory protein-1α) [ 42 ], CXCL13 (chemokine CXCL13), CXL14 (chemokine CXL14), RANTES (Regulated-on-Activation-Normal-T-cell-Expressed-and-Secreted chemokine) [ 43 ], and MIP-2 (macrophage inflammatory protein-2) in monocytes [ 44 ]. Mycoplasma fermentans infection of monocyte/macrophages increase also MMP-12 levels, a metalloproteinase which is both a pro-inflammatory molecule and necessary for Monocyte Chemoattractant Protein-1 (MCP-1) cleavage into its active form [ 80 ].…”

Mycoplasma anserisalpingitidis sp. nov., isolated from European domestic geese (Anser anser domesticus) with reproductive pathology

“…1220. Toll-like receptors in geese also appear to play an important role in the recognition of pathogen-associated molecular patterns in bacteria, and in particular Mycoplasma species [67]. There is no information on the presence of this mycoplasma in other goose species of the genus Anser [68].…”