title: Oral administration of recombinant epinecidin-1 protected grouper (Epinephelus coioides) and zebrafish (Danio rerio) from Vibrio vulnificus infection and enhanced immune-related gene expressions.
abstract: Immunostimulatory effects of the oral administration of the recombinant epinecidin-1 protein from BL21 Escherichia coli (containing the pET28a-epinecidin-1-dsRed plasmid) were studied in grouper (Epinephelus coioides) and zebrafish (Danio rerio). For this purpose, fish were fed diets for 30 days containing the recombinant epinecidin-1 protein from BL21 E. coli (containing the pET28a-epinecidin-1-dsRed plasmid) at different bacterial numbers (10(4), 10(6), 10(8), and 10(10) colony-forming units (cfu) of BL21 E. coli in 50 ml of LB medium) mixed with 50 g of eel powder as fodder. After 30 days of feeding, immune-related gene expressions for bacterial-infection responses and disease resistance against Vibrio vulnificus (204) were determined. The V. vulnificus (204) injected into the fish abdominal cavity mimicked gram-negative bacterial infections in culture ponds. Experimental results assessed whether the recombinant epinecidin-1 protein from BL21 E. coli (containing the pET28a-epinecidin-1-dsRed plasmid) has up- (or down-) regulation immune-related genes expression. Results indicated that the recombinant epinecidin-1 protein from BL21 E. coli administered as a feed supplement significantly enhanced expressions several immune-related genes such as tumor necrosis factor (TNF)-1 in grouper and Toll-like receptor (TLR)4, interleukin (IL)-1β, nitric oxide synthase (NOS)2, and nuclear factor (NF)-κB in zebrafish. After being challenged with V. vulnificus (204) for 24, 48, 72, or 96 h, the percentage mortality was significantly reduced in treated fish, which indicated that the recombinant epinecidin-1 protein from BL21 E. coli administered as a feed supplement could bring about downregulation of TNF-1 expression and functioned like an antagonist for binding TLR4, which reduced the signal transduction pathway for inhibiting TNF and IL-1β expressions while reducing binding of the transcription factor, NF-κB, to TNF and the IL-1β promoter region. The experimental results indicated that dietary intake of the recombinant epinecidin-1 protein from BL21 E. coli modulated immune-related gene expressions and disease resistance of grouper and zebrafish after a V. vulnificus (204) infection.
authors.affiliation: Marine Research Station, Institute of Cellular and Organismic Biology, Academia Sinica, Jiaushi, Ilan 262, Taiwan.
authors.forename: Chieh-Yu
authors.initials: CY
authors.lastname: Pan
authors.forename: Tsui-Chin
authors.initials: TC
authors.lastname: Huang
authors.forename: Yi-Da
authors.initials: YD
authors.lastname: Wang
authors.forename: Yu-Chih
authors.initials: YC
authors.lastname: Yeh
authors.forename: Cho-Fat
authors.initials: CF
authors.lastname: Hui
authors.forename: Jyh-Yih
authors.initials: JY
authors.lastname: Chen
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage*; D000284:Administration, Oral; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000008:administration & dosage* / Q000235:genetics / Q000276:immunology; D004926:Escherichia coli / Q000235:genetics; D005393:Fish Diseases / Q000276:immunology / Q000517:prevention & control*; D029941:Fish Proteins / Q000008:administration & dosage* / Q000235:genetics / Q000276:immunology; D005786:Gene Expression Regulation / Q000187:drug effects*; D010473:Perciformes / Q000235:genetics / Q000276:immunology*; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D014735:Vibrio Infections / Q000517:prevention & control / Q000662:veterinary*; D015027:Zebrafish / Q000235:genetics / Q000276:immunology*
chemical_list: D000276:Adjuvants, Immunologic; D023181:Antimicrobial Cationic Peptides; D029941:Fish Proteins; D011994:Recombinant Proteins; C521392:epinecidin-1, Epinephelus coioides