title: Intranasal immunization of lambs with serine/threonine phosphatase 2A against gastrointestinal nematodes.
abstract: Seven 3-month-old, female, helminth-free lambs were immunized intranasally with three doses (1 mg total) of a recombinant part of the catalytic region of the serine/threonine phosphatase 2A (PP2Ar) (group 1 [G1]). In addition, four lambs were used as an adjuvant control group (G2), four as unimmunized, infected controls (G3), and four as unimmunized, uninfected controls (G4). Fifteen days after the last immunization, lambs from G1, G2, and G3 were challenged with 10,000 larval stage 3 (L3) organisms in a plurispecific nematode infection composed of ca. 40% Trichostrongylus colubriformis, 40% Haemonchus contortus, and 20% Teladorsagia circumcincta. All the lambs were clinically monitored throughout the experiment. Parasitological (fecal egg output and immunological response), biopathological (packed-cell volume and leukocyte and eosinophil counts), and zootechnical (live-weight gain) analyses were conducted. On day 105 of the experiment, all the animals were slaughtered and the adult worm population in their abomasa examined. Intranasal administration of PP2Ar with bacterial walls as an adjuvant elicited a strong immune response in the immunized lambs, as evidenced by their humoral immune response. Immunized animals and animals receiving the adjuvant shed significantly (P < 0.001) fewer numbers of parasites' eggs in their feces. The immunization significantly reduced the helminth burden in the abomasa by the end of the experiment (>68%), protection being provided against both Haemonchus and Teladorsagia. Live-weight gain in the immunized lambs was similar to that in the uninfected controls versus the infected or adjuvanted animal groups. Our results suggest that heterologous immunization of ruminants by intranasal administration may be efficacious in the struggle to control gastrointestinal helminths in these livestock.
authors.affiliation: Departmento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: Elshaima
authors.initials: E
authors.lastname: Mohamed Fawzi
authors.forename: Teresa
authors.initials: T
authors.lastname: Cruz Bustos
authors.forename: Mercedes
authors.initials: M
authors.lastname: Gómez Samblas
authors.forename: Gloria
authors.initials: G
authors.lastname: González-González
authors.forename: Jenifer
authors.initials: J
authors.lastname: Solano
authors.forename: María Elena
authors.initials: ME
authors.lastname: González-Sánchez
authors.forename: Luis Miguel
authors.initials: LM
authors.lastname: De Pablos
authors.forename: María Jesús
authors.initials: MJ
authors.lastname: Corral-Caridad
authors.forename: Montserrat
authors.initials: M
authors.lastname: Cuquerella
authors.forename: Antonio
authors.initials: A
authors.lastname: Osuna
authors.forename: José María
authors.initials: JM
authors.lastname: Alunda
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage; D000281:Administration, Intranasal; D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood; D000947:Antigens, Helminth / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D001419:Bacteria / Q000737:chemistry; D001835:Body Weight; D002473:Cell Wall / Q000378:metabolism; D005243:Feces / Q000469:parasitology; D005260:Female; D006373:Helminthiasis / Q000517:prevention & control; D007410:Intestinal Diseases / Q000517:prevention & control / Q000662:veterinary*; D007411:Intestinal Diseases, Parasitic; D009348:Nematoda / Q000201:enzymology* / Q000235:genetics / Q000276:immunology*; D009349:Nematode Infections / Q000517:prevention & control / Q000662:veterinary*; D010270:Parasite Egg Count; D054648:Protein Phosphatase 2 / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D012756:Sheep; D014611:Vaccination / Q000379:methods*
chemical_list: D000276:Adjuvants, Immunologic; D000909:Antibodies, Helminth; D000947:Antigens, Helminth; D011994:Recombinant Proteins; D054648:Protein Phosphatase 2