title: A single-CRD C-type lectin from oyster Crassostrea gigas mediates immune recognition and pathogen elimination with a potential role in the activation of complement system.
abstract: C-type lectins (CTLs), serving as pattern recognition receptors (PRRs), are a superfamily of Ca(2+)-dependent carbohydrate-recognition proteins that participate in nonself-recognition and pathogen elimination. In the present study, a single carbohydrate-recognition domain (CRD) CTL was identified from oyster Crassostrea gigas (designated as CgCLec-2). There was only one CRD within the deduced amino acid sequence of CgCLec-2 consisting of 129 amino acid residues. A conserved EPN (Glu246-Pro247-Asn248) motif was found in Ca(2+)-binding site 2 of CgCLec-2. The CgCLec-2 mRNA could be detected in all the examined tissues at different expression levels in oysters. The mRNA expression of CgCLec-2 in hemocytes was up-regulated significantly at 6 h post Vibrio splendidus challenge. The recombinant CgCLec-2 (rCgCLec-2) could bind various Pathogen-Associated Molecular Patterns (PAMPs), including lipopolysaccharide, mannan and peptidoglycan, and displayed strong binding abilities to Vibrio anguillarum, V. splendidus and Yarrowiali polytica and week binding ability to Staphylococcus aureus. It could also enhance the phagocytic activity of oyster hemocytes to V. splendidus and exhibited growth suppression activity against gram-positive bacteria S. aureus but no effect on gram-negative bacteria V. splendidus. Furthermore, the interaction between rCgCLec-2 and rCgMASPL-1 was confirmed by GST Pull down. The results suggested that CgCLec-2 served as not only a PRR in immune recognition but also a regulatory factor in pathogen elimination, and played a potential role in the activation of complement system.
authors: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors: Hui
authors: H
authors: Li
authors: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
authors: Huan
authors: H
authors: Zhang
authors: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
authors: Shuai
authors: S
authors: Jiang
authors: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors: Weilin
authors: W
authors: Wang
authors: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors: Lusheng
authors: L
authors: Xin
authors: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
authors: Hao
authors: H
authors: Wang
authors: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
authors: Lingling
authors: L
authors: Wang
authors: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Dalian Ocean University, Dalian 116023, China. Electronic address: lshsong@dlou.edu.cn.
authors: Linsheng
authors: L
authors: Song
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western / Q000662:veterinary; D016000:Cluster Analysis; D003165:Complement System Proteins / Q000276:immunology*; D049896:Crassostrea / Q000235:genetics* / Q000276:immunology; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000096:biosynthesis; D005434:Flow Cytometry / Q000662:veterinary; D005786:Gene Expression Regulation / Q000276:immunology*; D006434:Hemocytes / Q000276:immunology; D037181:Lectins, C-Type / Q000235:genetics* / Q000276:immunology; D008957:Models, Genetic; D008969:Molecular Sequence Data; D000069452:Pathogen-Associated Molecular Pattern Molecules / Q000378:metabolism; D010587:Phagocytosis / Q000276:immunology; D010802:Phylogeny; D060888:Real-Time Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013211:Staphylococcus aureus / Q000276:immunology*
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; D037181:Lectins, C-Type; D000069452:Pathogen-Associated Molecular Pattern Molecules; D003165:Complement System Proteins
keywords: C-type lectin; Complement system; Crassostrea gigas; Growth suppression activity; Innate immunity; Opsonin; PRR