title: A transmembrane C-type lectin receptor mediates LECT2 effects on head kidney-derived monocytes/macrophages in a teleost, Plecoglossus altivelis.
abstract: Leukocyte cell-derived chemotaxin 2 (LECT2) is a multifunctional cytokine involved in many diseases in which immune dysfunction is present. Ayu LECT2 (PaLECT2), which interacts with a C-type lectin receptor (PaCLR), was shown to activate ayu head kidney-derived monocytes/macrophages (MO/MΦ) to improve the outcomes of fish upon bacterial infections. However, it is not known if PaCLR mediates PaLECT2 effects on ayu MO/MΦ. In this study, we determined the role of PaCLR in signal transduction of PaLECT2 on ayu MO/MΦ. We expressed the PaCLR ectodomain in Escherichia coli and produced a refolded recombinant protein (rPaCLR) that was then used to produce the anti-PaCLR IgG (anti-PaCLR) for neutralization. Addition of the refolded PaLECT2 mature peptide (rPaLECT2m) to ayu MO/MΦ cultures, increased cytokine expression, induced chemotaxis, and enhanced phagocytosis and bactericidal activity of these cells were observed. When we added anti-PaCLR to block the ectodomain of PaCLR, these effects were significantly inhibited. Based on our previous works and the data presented here, we conclude that PaCLR mediates the immunomodulatory effects of PaLECT2 on ayu MO/MΦ, thus defining a mechanism by which LECT2 protects fish against pathogens.
authors.affiliation: Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Ningbo 315211, China.
authors.forename: Hai-Ling
authors.initials: HL
authors.lastname: Ma
authors.affiliation: Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Ningbo 315211, China.
authors.forename: Yu-Hong
authors.initials: YH
authors.lastname: Shi
authors.affiliation: Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Ningbo 315211, China.
authors.forename: Xue-Heng
authors.initials: XH
authors.lastname: Zhang
authors.affiliation: Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Ningbo 315211, China.
authors.forename: Ming-Yun
authors.initials: MY
authors.lastname: Li
authors.affiliation: Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Ningbo 315211, China; Collaborative Innovation Center for Zhejiang Marine High-efficiency and Healthy Aquaculture, Ningbo University, Ningbo 315211, China. Electronic address: jchen1975@163.com.
authors.forename: Jiong
authors.initials: J
authors.lastname: Chen
mesh_terms: D000818:Animals; D002633:Chemotaxis; D004926:Escherichia coli / Q000235:genetics; D029941:Fish Proteins / Q000235:genetics* / Q000378:metabolism; D060226:Head Kidney / Q000378:metabolism; D007113:Immunity, Innate; D056747:Immunomodulation; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics* / Q000378:metabolism; D037102:Lectins / Q000235:genetics* / Q000378:metabolism; D037181:Lectins, C-Type / Q000235:genetics* / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism; D009000:Monocytes / Q000378:metabolism; D030781:Organisms, Genetically Modified / Q000235:genetics; D036441:Osmeriformes / Q000235:genetics* / Q000276:immunology / Q000378:metabolism
chemical_list: D029941:Fish Proteins; D036341:Intercellular Signaling Peptides and Proteins; D037102:Lectins; D037181:Lectins, C-Type
keywords: Antibody neutralization; Bacterial killing; C-type lectin receptor; Chemotaxis; Cytokine expression; LECT2; Monocyte/macrophage; Phagocytosis