title: Induction of immunity in sheep to Fasciola hepatica with mimotopes of cathepsin L selected from a phage display library.
abstract: An M13 phage random 12-mers peptide library was used to screen cathepsin L mimotopes of Fasciola hepatica and to evaluate their immunogenicity in sheep. Seven clones showed positive reactivity to a rabbit anti-cathepsin L1/L2 antiserum in ELISA, and their amino acid sequences deduced by DNA sequencing were tentatively mapped on the protein. Twenty sheep were randomly allocated into 4 groups of 5 animals each, for immunization with 1x10(14) phage particles of clones 1, 20, a mixture of 7 clones and PBS, without adjuvant at the beginning, and 4 weeks later. All groups were challenged with 300 metacercariae at week 6 and slaughtered 16 weeks later. The mean worm burdens after challenge were reduced by 47.61% and 33.91% in sheep vaccinated with clones 1 and 20, respectively; no effect was observed in animals inoculated with the clone mixture. Also, a significant reduction in worm size and burden was observed for those sheep immunized with clone 1. Animals receiving clone 20, showed a significant reduction in egg output. Immunization induced a reduction of egg viability ranging from 58.92 to 82.11%. Furthermore, vaccinated animals produced clone-specific antibodies which were boosted after challenge with metacercariae of F. hepatica.
authors.affiliation: Departamento de Parasitología, Facultad de Medicina Veterinaria y Zootecnia, UNAM, México D.F. 04510.
authors.forename: A
authors.initials: A
authors.lastname: Villa-Mancera
authors.forename: H
authors.initials: H
authors.lastname: Quiroz-Romero
authors.forename: D
authors.initials: D
authors.lastname: Correa
authors.forename: F
authors.initials: F
authors.lastname: Ibarra
authors.forename: M
authors.initials: M
authors.lastname: Reyes-Pérez
authors.forename: H
authors.initials: H
authors.lastname: Reyes-Vivas
authors.forename: G
authors.initials: G
authors.lastname: López-Velázquez
authors.forename: K
authors.initials: K
authors.lastname: Gazarian
authors.forename: T
authors.initials: T
authors.lastname: Gazarian
authors.forename: R A
authors.initials: RA
authors.lastname: Alonso
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D056668:Cathepsin L; D002403:Cathepsins / Q000737:chemistry / Q000276:immunology*; D003546:Cysteine Endopeptidases / Q000737:chemistry / Q000276:immunology*; D005210:Fasciola hepatica; D005211:Fascioliasis / Q000517:prevention & control / Q000662:veterinary*; D005243:Feces / Q000469:parasitology; D008969:Molecular Sequence Data; D010270:Parasite Egg Count; D019151:Peptide Library; D012756:Sheep; D012757:Sheep Diseases / Q000276:immunology* / Q000469:parasitology; D014612:Vaccines / Q000276:immunology
chemical_list: D019151:Peptide Library; D014612:Vaccines; D002403:Cathepsins; D003546:Cysteine Endopeptidases; D056668:Cathepsin L