A novel crustin from Marsupenaeus japonicus promotes hemocyte phagocytosis

• Published in: Developmental and comparative immunology Vol. 49; no. 2; pp. 313 - 322
• Main Authors: Liu, Ning, Lan, Jiang-Feng, Sun, Jie-Jie, Jia, Wen-Ming, Zhao, Xiao-Fan, Wang, Jin-Xing
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 01.04.2015
• Subjects: Amino Acid Sequence; Animals; Anti-Bacterial Agents - pharmacology; Antimicrobial Cationic Peptides - genetics; Antimicrobial Cationic Peptides - metabolism; Antimicrobial Cationic Peptides - pharmacokinetics; Antimicrobial peptides (AMPs); Base Sequence; Cell Wall - metabolism; Crustin; Decapoda; Gene Expression; Hemocytes - immunology; Innate immunity; Lipopolysaccharides - metabolism; Marsupenaeus japonicus; Microbial Sensitivity Tests; Molecular Sequence Data; Penaeidae - genetics; Penaeidae - immunology; Penaeidae - metabolism; Peptidoglycan - metabolism; Phagocytosis; Phagocytosis - immunology; Protein Binding; Protein Structure, Tertiary; Recombinant Proteins - pharmacology; RNA Interference; RNA, Small Interfering; Sequence Analysis, DNA; Staphylococcus aureus; Staphylococcus aureus - immunology; Teichoic Acids - metabolism; Up-Regulation; Vibrio - immunology; Vibrio anguillarum; Whey acidic protein domain (WAP); Antimicrobial peptides (AMPs); Innate immunity; Crustin; Whey acidic protein domain (WAP); Phagocytosis; Marsupenaeus japonicus
• ISSN: 0145-305X; 1879-0089
• DOI: 10.1016/j.dci.2014.11.021

•A novel crustin, MjCru I, was identified in Marsupenaeus japonicus.•MjCru I is upregulated in the hemocytes of shrimp challenged with bacteria.•MjCru I exhibits binding activity to bacteria and has an antibacterial activity.•MjCru I increases the hemocyte phagocytosis against Vibrio anguillarum and Staphylococcus aureus. Crustins are cationic cysteine-rich antimicrobial peptides (AMPs) that contain multiple domains (glycine-rich, cysteine-rich, or proline-rich) at the N-terminus and whey acidic protein (WAP) domains at the C-terminus. Crustins have multiple functions, including protease inhibition and antimicrobial activity. Other functions of crustins need to be clarified. In this study, a novel crustin with a cysteine-rich region, and a single WAP domain, belonging to type I crustins, was identified in Marsupenaeus japonicus and designated as MjCru I-1. MjCru I-1 was expressed in various tissues. The expression of MjCru I-1 was upregulated in the hemocytes of shrimp challenged with bacteria. MjCru I-1 could bind to bacteria by binding to the cell wall molecules of the bacteria, such as lipopolysaccharide (LPS), peptidoglycan (PGN), and lipoteichoic acid (LTA). The synthesized WAP domain of MjCru I-1 but not synthesized Cys-rich domain has antibacterial and agglutinative activities. Scanning electron microscope assay showed that the bacterial cells treated with sMjCru I-1 appeared to be disrupted and cracked compared with those of the control samples. The knockdown of MjCru I-1 could reduce bacterial clearance and injection of MjCru I-1 could significantly increase the survival rate of shrimp infected with Vibrio anguillarum and Staphylococcus aureus compared with those of the control samples. Further study discovered that MjCru I-1 could increase the hemocyte phagocytosis against V. anguillarum and S. aureus. These results suggest that MjCru I-1 has dual functions, bactericidal and phagocytosis promoting activities, in the antibacterial immunity of shrimp.