A conserved Toll-like receptor-to-NF-κB signaling pathway in the endangered coral Orbicella faveolata

• Published in: Developmental and comparative immunology 2018-02, Vol.79, p.128-136
• Main Authors: Williams, Leah M., Fuess, Lauren E., Brennan, Joseph J., Mansfield, Katelyn M., Salas-Rodriguez, Erick, Welsh, Julianne, Awtry, Jake, Banic, Sarah, Chacko, Cecilia, Chezian, Aarthia, Dowers, Donovan, Estrada, Felicia, Hsieh, Yu-Hsuan, Kang, Jiawen, Li, Wanwen, Malchiodi, Zoe, Malinowski, John, Matuszak, Sean, McTigue, Thomas, Mueller, David, Nguyen, Brian, Nguyen, Michelle, Nguyen, Phuong, Nguyen, Sinead, Njoku, Ndidi, Patel, Khusbu, Pellegrini, William, Pliakas, Tessa, Qadir, Deena, Ryan, Emma, Schiffer, Alex, Thiel, Amber, Yunes, Sarah A., Spilios, Kathryn E., Pinzón C, Jorge H., Mydlarz, Laura D., Gilmore, Thomas D.
• Format: Article
• Language: English
• Subjects: Animals; Anthozoa - immunology; Biological Evolution; Conserved Sequence - genetics; Coral; Evolution; Humans; I-kappa B Kinase - metabolism; Immunity, Innate; Innate immunity; Lipopolysaccharides - immunology; Myeloid Differentiation Factor 88 - metabolism; NF-kappa B - metabolism; NF-kappaB; Orbicella faveolata; Phosphorylation; Protein Binding; Signal Transduction; Toll-like receptor; Toll-Like Receptor 4 - genetics; Toll-Like Receptors - genetics; Toll-Like Receptors - metabolism
• ISSN: 0145-305X; 1879-0089
• DOI: 10.1016/j.dci.2017.10.016

Herein, we characterize the Toll-like receptor (TLR)-to-NF-κB innate immune pathway of Orbicella faveolata (Of), which is an ecologically important, disease-susceptible, reef-building coral. As compared to human TLRs, the intracellular TIR domain of Of-TLR is most similar to TLR4, and it can interact in vitro with the human TLR4 adapter MYD88. Treatment of O. faveolata tissue with lipopolysaccharide, a ligand for mammalian TLR4, resulted in gene expression changes consistent with NF-κB pathway mobilization. Biochemical and cell-based assays revealed that Of-NF-κB resembles the mammalian non-canonical NF-κB protein p100 in that C-terminal truncation results in translocation of Of-NF-κB to the nucleus and increases its DNA-binding and transcriptional activation activities. Moreover, human IκB kinase (IKK) and Of-IKK can both phosphorylate conserved residues in Of-NF-κB in vitro and induce C-terminal processing of Of-NF-κB in vivo. These results are the first characterization of TLR-to-NF-κB signaling proteins in an endangered coral, and suggest that these corals have conserved innate immune pathways. •A Toll-like receptor to NF-κB pathway is present in the coral Orbicella faveolata.•Activities of O. faveolata TLR and NF-κB proteins are characterized.•LPS treatment of coral tissue activated an NF-κB gene expression profile.