title: Influence of immunoprotection on genetic variability of cysteine proteinases from Haemonchus contortus adult worms.
abstract: The limitations associated with the use of anthelmintic drugs in the control of gastrotintestinal nematodosis, such as the emergence of anthelmintic resistance, have stimulated the study of the immunological control of many parasites. In the case of Haemonchus contortus, several vaccination trials using native and recombinant antigens have been conducted. A group of antigens with demonstrated immunoprotective value are cathepsin B - like proteolytic enzymes of the cysteine proteinase type. These enzymes, which have been observed in both excretory-secretory products and somatic extracts of H. contortus, may vary among different geographic isolates and on strains isolated from different hosts, or even from the same host, as has been demonstrated in some comparative studies of genetic variability. In the present study, we evaluated the genetic variability of the worms that fully developed their endogenous cycle in immunised sheep and goat in order to identify the alleles of most immunoprotective value. To address these objectives, groups of sheep and goats were immunised with PBS soluble fractions enriched for cysteine proteinases from adult worms of H. contortus from either a strain of H. contortus isolated from goats of Gran Canaria Island (SP) or a strain isolated from sheep of North America (NA). The results confirmed the immunoprophylactic value of this type of enzyme against haemonchosis in both sheep and goats in association with increased levels of specific IgG. The genetic analysis demonstrated that the immunisation had a genetic selection on proteinase-encoding genes. In all the immunised animals, allelic frequencies were statistically different from those observed in non-immunised control animals in the four analysed genes. The reduction in the allelic frequencies suggests that parasites expressing these proteases are selectively targeted by the vaccine, and hence they should be considered in any subunit vaccine approach to control haemonchosis in small ruminants.
authors.affiliation: Parasitology Unit, Department of Animal Pathology, Faculty of Veterinary Medicine, University of Las Palmas de Gran Canaria, Trasmontaña s/n, 35413 Arucas, Las Palmas, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Martín
authors.affiliation: Parasitology Unit, Department of Animal Pathology, Faculty of Veterinary Medicine, University of Las Palmas de Gran Canaria, Trasmontaña s/n, 35413 Arucas, Las Palmas, Spain. Electronic address: josemanuel.molina@ulpgc.es.
authors.forename: J M
authors.initials: JM
authors.lastname: Molina
authors.affiliation: Parasitology Unit, Department of Animal Pathology, Faculty of Veterinary Medicine, University of Las Palmas de Gran Canaria, Trasmontaña s/n, 35413 Arucas, Las Palmas, Spain.
authors.forename: Y I
authors.initials: YI
authors.lastname: Hernández
authors.affiliation: Parasitology Unit, Department of Animal Pathology, Faculty of Veterinary Medicine, University of Las Palmas de Gran Canaria, Trasmontaña s/n, 35413 Arucas, Las Palmas, Spain.
authors.forename: O
authors.initials: O
authors.lastname: Ferrer
authors.affiliation: Parasitology Unit, Department of Animal Pathology, Faculty of Veterinary Medicine, University of Las Palmas de Gran Canaria, Trasmontaña s/n, 35413 Arucas, Las Palmas, Spain.
authors.forename: Ma C
authors.initials: MC
authors.lastname: Muñoz
authors.affiliation: Parasitology Unit, Department of Animal Pathology, Faculty of Veterinary Medicine, University of Las Palmas de Gran Canaria, Trasmontaña s/n, 35413 Arucas, Las Palmas, Spain.
authors.forename: A
authors.initials: A
authors.lastname: López
authors.affiliation: Parasitology Unit, Department of Animal Pathology, Faculty of Veterinary Medicine, University of Las Palmas de Gran Canaria, Trasmontaña s/n, 35413 Arucas, Las Palmas, Spain.
authors.forename: L
authors.initials: L
authors.lastname: Ortega
authors.affiliation: Parasitology Unit, Department of Animal Pathology, Faculty of Veterinary Medicine, University of Las Palmas de Gran Canaria, Trasmontaña s/n, 35413 Arucas, Las Palmas, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Ruiz
mesh_terms: D000483:Alleles; D000818:Animals; D000909:Antibodies, Helminth / Q000032:analysis; D000941:Antigens / Q000235:genetics / Q000494:pharmacology; D001483:Base Sequence; D002401:Cathepsin B / Q000494:pharmacology; D057056:Cysteine Proteases / Q000235:genetics* / Q000276:immunology*; D018509:DNA, Helminth / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D005260:Female; D005787:Gene Frequency; D014644:Genetic Variation; D015511:Goat Diseases / Q000097:blood / Q000276:immunology / Q000469:parasitology; D006041:Goats; D006188:Haemonchiasis / Q000097:blood / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary; D006189:Haemonchus / Q000201:enzymology* / Q000235:genetics* / Q000276:immunology; D008297:Male; D018807:Polymorphism, Single-Stranded Conformational; D016052:Protozoan Vaccines / Q000737:chemistry / Q000302:isolation & purification; D012756:Sheep; D012757:Sheep Diseases / Q000097:blood / Q000276:immunology / Q000469:parasitology
chemical_list: D000909:Antibodies, Helminth; D000941:Antigens; D018509:DNA, Helminth; D021903:DNA, Ribosomal Spacer; D016052:Protozoan Vaccines; D057056:Cysteine Proteases; D002401:Cathepsin B
keywords: Cysteine proteinases; Genetic variation; Goats; Haemochus contortus; Immunoprotection; Sheep