title: Validation of the protective Ostertagia ostertagi ES-thiol antigens with different adjuvantia.
abstract: Intramuscular immunization of calves with an excretory-secretory antigen fraction enriched for cysteine proteinase activity (ES-thiol) and QuilA as adjuvant induces a protective immune response against the abomasal nematode Ostertagia ostertagi. The objectives of the present study were to confirm the protective capacity of ES-thiol in combination with QuilA, to test Al(OH)(3) as adjuvant for vaccination against O. ostertagi and to look for correlations between protection and immunological effector responses. Calves(seven animals/group) were vaccinated three times intramuscularly with 100 micro g antigen and/or adjuvant (ES-thiol with QuilA, ES-thiol with Al(OH)(3), QuilA alone and Al(OH)(3) alone) and subsequently challenged with a trickled oral infection of 25 000 infective larvae in total over 25 days. Faecal egg counts in the ES-thiol QuilA group were reduced by 56% during the two-month period of the trial compared to the QuilA control group (P < 0.002). Calves immunized with ES-thiol QuilA had significantly smaller adult worms (P < 0.002) and less eggs/female worm (P < 0.05) compared to the QuilA control group. No differences in egg output, worm counts or parameters of worm fitness were observed in the ES-thiol Al(OH)(3) group compared to the Al(OH)(3) control group. Although the protective immune mechanism against O. ostertagi remains unknown, protection in the ES-thiol QuilA group was associated with high levels of parasite-specific antibodies in the abomasal mucosa.
authors.affiliation: Laboratory of Parasitology, Faculty of Veterinary Medicine, Ghent University, Belgium. geldp@mri.sari.ac.uk
authors.forename: P
authors.initials: P
authors.lastname: Geldhof
authors.forename: I
authors.initials: I
authors.lastname: Vercauteren
authors.forename: J
authors.initials: J
authors.lastname: Vercruysse
authors.forename: D P
authors.initials: DP
authors.lastname: Knox
authors.forename: W
authors.initials: W
authors.lastname: Van Den Broeck
authors.forename: E
authors.initials: E
authors.lastname: Claerebout
mesh_terms: D000018:Abomasum / Q000276:immunology; D000276:Adjuvants, Immunologic; D000536:Aluminum Hydroxide / Q000276:immunology; D000818:Animals; D000909:Antibodies, Helminth / Q000032:analysis; D000947:Antigens, Helminth / Q000276:immunology*; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology / Q000469:parasitology / Q000517:prevention & control*; D003543:Cysteamine; D003546:Cysteine Endopeptidases / Q000276:immunology; D005243:Feces / Q000469:parasitology; D007070:Immunoglobulin A / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D008297:Male; D009092:Mucous Membrane / Q000276:immunology; D010028:Ostertagia / Q000276:immunology*; D010029:Ostertagiasis / Q000276:immunology / Q000469:parasitology / Q000517:prevention & control / Q000662:veterinary*; D010270:Parasite Egg Count; D062605:Quillaja Saponins; D012503:Saponins / Q000276:immunology; D014611:Vaccination / Q000662:veterinary
chemical_list: D000276:Adjuvants, Immunologic; D000909:Antibodies, Helminth; D000947:Antigens, Helminth; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D062605:Quillaja Saponins; D012503:Saponins; D000536:Aluminum Hydroxide; D003543:Cysteamine; C046386:Quil A; D003546:Cysteine Endopeptidases