title: The broad pattern recognition spectrum of the Toll-like receptor in mollusk Zhikong scallop Chlamys farreri.
abstract: Toll-like receptors (TLRs) are among the most studied pattern recognition receptors (PRRs) playing essential roles in innate immune defenses. In the present study, the basic features of CfTLR in mollusk Zhikong scallop Chlamys farreri, including sequence homology, tissue distribution, subcellular localization and ligands spectrum, were investigated to elucidate its pattern recognition. The elements of extracellular domains (ECD) in CfTLR displayed high homology to the corresponding parts of the ECDs in TLRs from Homo sapiens. CfTLR protein was detected in hemocytes, mantle, gills, hepatopancreas, kidney and gonad of the scallops, and it was localized in both the plasma membranes and the lysosomes in HEK293T cells. CfTLR could activate NFκB in response to multiple HsTLR ligands including Pam3CSK4, glucan (GLU), peptidoglycan (PGN), polyriboinosinic:polyribocytidylic acid (poly I:C), Imiquimod and three types of CpG. Additionally, the scallop serum could enhance the induction of NFκB in the CfTLR expressing cells elicited by most PAMPs, including GLU, PGN, Imiquimod and four types of CpG. It could be concluded that this primitive mollusk TLR shared a hybrid function in pattern recognition and could recognize broader ligands than mammalian TLRs, and its mosaic capability of pathogen associated molecular pattern (PAMP) recognition might be based on the basic features of its structure, ligand properties and the assistance of some components in scallop serum.
authors.affiliation: The Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Rd., Qingdao 266071, China.
authors.forename: Mengqiang
authors.initials: M
authors.lastname: Wang
authors.affiliation: The Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Rd., Qingdao 266071, China.
authors.forename: Lingling
authors.initials: L
authors.lastname: Wang
authors.affiliation: The Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Rd., Qingdao 266071, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Guo
authors.affiliation: The Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Rd., Qingdao 266071, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Sun
authors.affiliation: The Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Rd., Qingdao 266071, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Yue
authors.affiliation: The Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Rd., Qingdao 266071, China.
authors.forename: Qilin
authors.initials: Q
authors.lastname: Yi
authors.affiliation: The Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Rd., Qingdao 266071, China; Dalian Ocean University, Dalian 116023, China. Electronic address: lshsong@dlou.edu.cn.
authors.forename: Linsheng
authors.initials: L
authors.lastname: Song
mesh_terms: D000818:Animals; D057809:HEK293 Cells; D006801:Humans; D007113:Immunity, Innate; D008024:Ligands; D008070:Lipopolysaccharides / Q000494:pharmacology; D008974:Mollusca / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology; D046709:Pattern Recognition, Physiological; D021381:Protein Transport; D017386:Sequence Homology, Amino Acid; D051193:Toll-Like Receptors / Q000502:physiology*; D015533:Transcriptional Activation / Q000276:immunology; D014733:Vibrio / Q000276:immunology
chemical_list: D008024:Ligands; D008070:Lipopolysaccharides; D051193:Toll-Like Receptors
keywords: Chlamys farreri; Innate immunity; Pattern recognition; Toll-like receptor