title: Tiger shrimp (Penaeus monodon) penaeidin possesses cytokine features to promote integrin-mediated granulocyte and semi-granulocyte adhesion.
abstract: Recent studies indicated that antimicrobial peptides (AMPs) play multiple roles in both innate and adaptive immune functions. The penaeidin of tiger shrimp Penaeus monodon shows an antimicrobial activity against Gram-positive bacteria and filamentous fungi. To study immunomodulation functions of the penaeidin, we transfected shrimp hemocytes in primary culture with penaeidin-specific small interfering RNA (siRNA-3) and observed a concomitant 20% reduction in adhesive hemocytes compared with mock-transfected cells. The addition of biosynthesized or chemically synthesized penaeidin or penaeidin proline-rich domain (PRD) to the culture medium of penaeidin knock-down hemocytes led to a full recovery in the number of adhesive hemocytes. The effect of penaeidin knock-down on the expression of tiger shrimp cell adhesion-associated molecules was examined using real-time Q-PCR. Results demonstrated 91% and 64% decreases in the expression of integrin-beta and collagen, respectively, and a 396% increase in the expression of collagenase. The addition of chemically synthesized penaeidin after penaeidin knock-down hemocytes normalized the expression of these genes. The addition of the integrin-beta ligand competitor RGDS to mock-transfected hemocytes decreased the number of adhesive hemocytes similar to penaeidin knock-down. In conclusion, penaeidin possesses an integrin-beta-mediated cytokine feature that promotes shrimp granulocyte and semi-granulocyte adhesion. This is the first report about functional shrimp cytokine.
authors.affiliation: Institute of Zoology, National Taiwan University, Taipei 106, Taiwan.
authors.forename: Ching-Yu
authors.initials: CY
authors.lastname: Li
authors.forename: Hong-Young
authors.initials: HY
authors.lastname: Yan
authors.forename: Yen-Ling
authors.initials: YL
authors.lastname: Song
mesh_terms: D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000502:physiology*; D002448:Cell Adhesion / Q000502:physiology; D003094:Collagen / Q000096:biosynthesis; D016207:Cytokines / Q000502:physiology*; D004591:Electrophoresis, Polyacrylamide Gel; D055785:Gene Knockdown Techniques; D006098:Granulocytes / Q000276:immunology* / Q000502:physiology; D006434:Hemocytes / Q000276:immunology; D015151:Immunoblotting; D056747:Immunomodulation / Q000502:physiology; D039641:Integrin beta Chains / Q000096:biosynthesis; D033561:Penaeidae / Q000276:immunology* / Q000502:physiology; D016133:Polymerase Chain Reaction; D055232:Proline-Rich Protein Domains / Q000502:physiology; D034741:RNA, Small Interfering / Q000378:metabolism
chemical_list: D023181:Antimicrobial Cationic Peptides; D016207:Cytokines; D039641:Integrin beta Chains; D034741:RNA, Small Interfering; D003094:Collagen