title: Cytotoxicity and antigenicity of antimicrobial synthesized peptides derived from the beetle Allomyrina dichotoma defensin in mice.
abstract: Synthetic peptides, peptides A (Arg-Leu-Tyr-Leu-Arg-Ile-Gly-Arg-Arg-NH(2)) and B (Arg-Leu-Arg-Leu-Arg-Ile-Gly-Arg-Arg-NH(2)), derived from the beetle Allomyrina dichotoma defensin, have antimicrobial activities. Immunotoxicological effect of these peptides was evaluated by cytotoxicity of mouse peritoneal macrophages. In addition, antigenicity of these peptides was studied by evaluating antibody responses in mice immunized with these peptides. The toxicity of peptide A toward mouse peritoneal cells was less than that of polymyxin B, when morphologically evaluated in a cytotoxicity test. Almost all of mice injected intraperitoneally (i.p.) with either peptide A or B at 50-150 mg/kg survived, whereas all mice injected i.p. with polymyxin B at the doses of more than 25 mg/kg died within 24 h. Interestingly, almost all of mice injected intravenously with these peptides at the doses of 10 and 25 mg/kg also survived. Furthermore, mice immunized with these peptides conjugated with keyhole limpet hemocyanin (KLH) showed little or negligible anti-peptide A or B antibody production, although anti-KLH antibody was significantly produced. The results indicated that peptides A and B were less cytotoxic than polymyxin B and also had poor antigenicity to produce specific antibody in mice.
authors.affiliation: National Institute of Animal Health, Tsukuba, Ibaraki, Japan.
authors.forename: Yukari
authors.initials: Y
authors.lastname: Koyama
authors.forename: Maki
authors.initials: M
authors.lastname: Motobu
authors.forename: Kenji
authors.initials: K
authors.lastname: Hikosaka
authors.forename: Manabu
authors.initials: M
authors.lastname: Yamada
authors.forename: Kikuyasu
authors.initials: K
authors.lastname: Nakamura
authors.forename: Hisako
authors.initials: H
authors.lastname: Saido-Sakanaka
authors.forename: Ai
authors.initials: A
authors.lastname: Asaoka
authors.forename: Minoru
authors.initials: M
authors.lastname: Yamakawa
authors.forename: Takashi
authors.initials: T
authors.lastname: Isobe
authors.forename: Kameo
authors.initials: K
authors.lastname: Shimura
authors.forename: Chung-Boo
authors.initials: CB
authors.lastname: Kang
authors.forename: Hideki
authors.initials: H
authors.lastname: Hayashidani
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Nakai
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Hirota
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000906:Antibodies / Q000276:immunology; D000941:Antigens / Q000276:immunology; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D001517:Coleoptera; D023082:Defensins / Q000737:chemistry*; D005260:Female; D006433:Hemocyanins / Q000276:immunology; D007114:Immunization; D017737:Macrophages, Peritoneal / Q000187:drug effects; D051379:Mice; D008807:Mice, Inbred BALB C; D009842:Oligopeptides / Q000276:immunology / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D000906:Antibodies; D000941:Antigens; D023082:Defensins; D009842:Oligopeptides; D006433:Hemocyanins; C032808:keyhole-limpet hemocyanin