AUTHOR=Guo Mengjiao , Li Rong , Xiao Qianqian , Fan Xiuxiu , Li Ning , Shang Yingli , Wei Liangmeng , Chai Tongjie 

TITLE=Protective Role of Rabbit Nucleotide-Binding Oligomerization Domain-2 (NOD2)-Mediated Signaling Pathway in Resistance to Enterohemorrhagic Escherichia coli Infection

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=8

YEAR=2018

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2018.00220

DOI=10.3389/fcimb.2018.00220

ISSN=2235-2988

ABSTRACT=<p>Nucleotide-binding oligomerization domain 2 (NOD2), a member of the NOD-like receptors (NLRs) family that is well-known to play a key role in innate immune responses and is involved in innate antibacterial responses. In this study, rabbit NOD2 (rNOD2) was cloned from rabbit kidney (RK) cells. It was distributed in various tissues, and the highest level of <italic>rNod2</italic> was detected in spleen. Moreover, the expression of <italic>rNod2</italic> was significantly upregulated in the heart, liver, and spleen induced by enterohemorrhagic <italic>Escherichia coli</italic> (EHEC). Overexpression of rNOD2 induced the expression of pro-inflammatory cytokine, including <italic>Il1</italic>β, <italic>Il6, Ifn-</italic>γ, and <italic>Tnf</italic>, as well as defensins, including <italic>Defb124, Defb125</italic>, and <italic>Defb128</italic> through the nuclear factor (NF)-κB signaling pathway. Furthermore, overexpression of rNOD2 inhibited the growth of EHEC, and knockdown of rNOD2 or inhibition of the NF-κB pathway promoted its replication. In addition, our results suggest that rNOD2 can significantly activate NF-κB signaling and trigger antibacterial defenses to increase the expression of pro-inflammatory cytokine and defensins after stimulation by EHEC. These findings are useful to further understanding the innate immune system of rabbits and providing a new perspective for the prevention of bacterial diseases in rabbits.</p>