title: Scavenger receptor B protects shrimp from bacteria by enhancing phagocytosis and regulating expression of antimicrobial peptides.
abstract: Scavenger receptors (SRs) are involved in innate immunity through recognizing pathogen-associated molecular patterns (PAMPs) and in pathogenesis of diseases through interactions with damage-associated molecular patterns (DAMPs). The roles of SRs in invertebrate innate immunity still need to be elucidated. Here we identify a class B scavenger receptor from kuruma shrimp, Marsupenaeus japonicus, designated MjSR-B1. The recombinant MjSR-B1 agglutinated bacteria in a calcium dependent manner and bound lipopolysaccharide and lipoteichoic acid. After knockdown of MjSR-B1, both the bacterial clearance and phagocytotic ability of M. japonicus against V. anguillarum and S. aureus were impaired, and several phagocytosis related genes were downregulated. The expression levels of antimicrobial peptides were also downregulated. Overexpression of MjSR-B1 led to enhanced bacterial clearance, phagocytosis rate and upregulation of phagocytosis-related and antimicrobial peptide genes. However, overexpression of mutant MjSR-B1ΔC, which lacks the carboxyl tail of MjSR-B1, had none of these effects. Our results indicate that MjSR-B1 can protect shrimp from bacteria by promoting phagocytosis and by enhancing the expression of antimicrobial peptides.
authors.affiliation: Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan 250100, China.
authors.forename: Wen-Jie
authors.initials: WJ
authors.lastname: Bi
authors.affiliation: Biotechnology Department, School of Biological Sciences and Biotechnology, University of Jinan, Jinan 250022, China.
authors.forename: Dian-Xiang
authors.initials: DX
authors.lastname: Li
authors.affiliation: Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan 250100, China.
authors.forename: Yi-Hui
authors.initials: YH
authors.lastname: Xu
authors.affiliation: Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan 250100, China.
authors.forename: Sen
authors.initials: S
authors.lastname: Xu
authors.affiliation: Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan 250100, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.affiliation: Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan 250100, China.
authors.forename: Xiao-Fan
authors.initials: XF
authors.lastname: Zhao
authors.affiliation: Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan 250100, China. Electronic address: jxwang@sdu.edu.cn.
authors.forename: Jin-Xing
authors.initials: JX
authors.lastname: Wang
mesh_terms: D000371:Agglutination; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000235:genetics / Q000378:metabolism*; D058491:Bacterial Load / Q000235:genetics; D001483:Base Sequence; D003001:Cloning, Molecular; D005786:Gene Expression Regulation / Q000235:genetics; D055785:Gene Knockdown Techniques; D007113:Immunity, Innate / Q000235:genetics; D008070:Lipopolysaccharides / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D033561:Penaeidae / Q000276:immunology*; D010587:Phagocytosis / Q000235:genetics; D010802:Phylogeny; D011485:Protein Binding; D051122:Scavenger Receptors, Class B / Q000235:genetics / Q000378:metabolism*; D013203:Staphylococcal Infections / Q000276:immunology*; D013211:Staphylococcus aureus / Q000276:immunology*; D013682:Teichoic Acids / Q000378:metabolism; D014733:Vibrio / Q000276:immunology*; D014735:Vibrio Infections / Q000276:immunology*
chemical_list: D023181:Antimicrobial Cationic Peptides; D008070:Lipopolysaccharides; D051122:Scavenger Receptors, Class B; D013682:Teichoic Acids; C009900:lipoteichoic acid
keywords: Bacteria; Innate immunity; Marsupenaeus japonicus; Phagocytosis; Scavenger receptors