title: The antimicrobial peptide, epinecidin-1, mediates secretion of cytokines in the immune response to bacterial infection in mice.
abstract: Epinecidin-1, an antimicrobial peptide which encodes 21 amino acids, was isolated from a marine grouper (Epinephelus coioides). In this study, we investigated its immunomodulatory functions in mice co-injected with Pseudomonas aeruginosa. In vivo results showed that the synthetic epinecidin-1 peptide induced significant secretion of immunoglobulin G1 (IgG1) in mice co-injected with P. aeruginosa. Moreover, after injection of 40, 100, 200, or 500 μg epinecidin-1/mouse, we detected IgM, IgG, IgG1, and IgG2a in mice treated for 1, 2, 3, 7, 14, 21, and 28 days. Results showed that there were no significant differences in IgM, IgG, or IgG2a between mice injected with epinecidin-1 alone. IgG1 increased to a peak at 24 h, 7 days, and 28 days after an epinecidin-1 (40 μg/mouse) injection. Injection of 500 μg epinecidin-1/mouse increased IgG1 to peaks at 2 and 3 days; injection of 100 μg epinecidin-1/mouse increased IgG1 to a peak at 21 days. This supports epinecidin-1 being able to activate the Th2 cell response (enhance IgG1 production) against P. aeruginosa infection. Treatment with different concentrations of epinecidin-1 in mice elevated plasma interleukin (IL)-10 to initial peaks at 24 and 48 h, and it showed a second peak at 16 days. In RAW264.7 cells, treatment with epinecidin-1 alone did not produce significant changes in tumor necrosis factor (TNF)-α protein secretion at 1, 6, or 24h after treatment with 3.75, 7.5, or 15 μg/ml epinecidin-1 compared to the lipopolysaccharide group.
authors.affiliation: Marine Research Station, Institute of Cellular and Organismic Biology, Academia Sinica, Jiaushi, Ilan 262, Taiwan.
authors.forename: Shang-Chun
authors.initials: SC
authors.lastname: Lee
authors.forename: Chieh-Yu
authors.initials: CY
authors.lastname: Pan
authors.forename: Jyh-Yih
authors.initials: JY
authors.lastname: Chen
mesh_terms: D000410:Alanine Transaminase / Q000097:blood; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000907:Antibodies, Bacterial / Q000097:blood; D057134:Antibodies, Neutralizing / Q000097:blood; D000938:Antigen-Presenting Cells / Q000187:drug effects / Q000502:physiology; D023181:Antimicrobial Cationic Peptides / Q000494:pharmacology*; D001219:Aspartate Aminotransferases / Q000097:blood; D049109:Cell Proliferation; D016207:Cytokines / Q000097:blood / Q000235:genetics / Q000378:metabolism*; D029941:Fish Proteins / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects; D007113:Immunity, Innate / Q000187:drug effects*; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007136:Immunoglobulins; D059413:Intraabdominal Infections / Q000188:drug therapy* / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D011552:Pseudomonas Infections / Q000188:drug therapy* / Q000276:immunology; D011550:Pseudomonas aeruginosa / Q000276:immunology; D013154:Spleen / Q000187:drug effects / Q000276:immunology / Q000473:pathology
chemical_list: D000900:Anti-Bacterial Agents; D000907:Antibodies, Bacterial; D057134:Antibodies, Neutralizing; D023181:Antimicrobial Cationic Peptides; D016207:Cytokines; D029941:Fish Proteins; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007136:Immunoglobulins; C521392:epinecidin-1, Epinephelus coioides; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase