title: The use of melatonin as a vaccine agent.
abstract: Molecules with immunomodulatory properties determine the magnitude and quality of immune responses specific for the coadministered antigen. Melatonin is considered a biological-response modifier of the immune system with broad application in veterinary medicine. In seasonally-breeding animals, the indolamine is able to improve reproductive performance. With the purpose of expanding new advantageous roles for melatonin, we investigated the effect of subcutaneous slow-release melatonin implants in the humoral response after a vaccination. We reported here a new feature of melatonin as an adjuvant-like system towards Dichelobacter nodosus (A1 and C serotypes)--the bacterium which cause ovine footrot--the most important cause of lameness in sheep. Antibody titres determined by both agglutination and ELISA techniques were substantially higher and were sustained for a longer duration than non-implanted animals. Remarkably, the effect of melatonin was completely dependent on the presence of aluminium hydroxide. The finding that melatonin enhances a defined immune response in vivo opens new perspectives for the improvement of Th2-biased immune responses by alum adjuvants.
authors.affiliation: Section of Histology, Department of Veterinary Medicine, The University of Extremadura Veterinary School, Avda de la Universidad, 10071 Cáceres, Spain.
authors.forename: Sergio
authors.initials: S
authors.lastname: Regodón
authors.forename: Pedro
authors.initials: P
authors.lastname: Martín-Palomino
authors.forename: Rafael
authors.initials: R
authors.lastname: Fernández-Montesinos
authors.forename: Juan Luis
authors.initials: JL
authors.lastname: Herrera
authors.forename: M Pilar
authors.initials: MP
authors.lastname: Carrascosa-Salmoral
authors.forename: Segundo
authors.initials: S
authors.lastname: Píriz
authors.forename: Santiago
authors.initials: S
authors.lastname: Vadillo
authors.forename: Juan M
authors.initials: JM
authors.lastname: Guerrero
authors.forename: David
authors.initials: D
authors.lastname: Pozo
mesh_terms: D000276:Adjuvants, Immunologic; D000372:Agglutination Tests; D000536:Aluminum Hydroxide / Q000494:pharmacology; D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis / Q000096:biosynthesis; D000917:Antibody Formation / Q000187:drug effects*; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology*; D001428:Bacterial Vaccines / Q000276:immunology*; D004343:Drug Implants; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005535:Foot Rot / Q000276:immunology / Q000517:prevention & control; D006090:Gram-Negative Bacteria / Q000276:immunology; D016905:Gram-Negative Bacterial Infections / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary; D008550:Melatonin / Q000008:administration & dosage / Q000494:pharmacology*; D012756:Sheep; D012757:Sheep Diseases / Q000276:immunology / Q000517:prevention & control; D014611:Vaccination
chemical_list: D000276:Adjuvants, Immunologic; D000907:Antibodies, Bacterial; D000975:Antioxidants; D001428:Bacterial Vaccines; D004343:Drug Implants; D000536:Aluminum Hydroxide; D008550:Melatonin