Immunization with Fasciola hepatica thioredoxin glutathione reductase failed to confer protection against fasciolosis in cattle.
The liver fluke Fasciola hepatica remains an important agent of food-borne trematode disease producing great economic losses due to its negative effect on productivity of livestock grazing in temperate areas. The prevailing control strategy based on anthelmintic drugs is unsustainable due to widespread resistance hence vaccination appears as an attractive option to pursue. In this study we evaluate the effect of vaccination in calves with a functional recombinant thioredoxin glutathione reductase (rFhTGR) from liver fluke, a critical antioxidant enzyme at the crossroads of the thioredoxin and glutathione metabolism in flatworms. The recombinant enzyme produced in Escherichia coli was tested in two vaccination experiments; in the first trial rFhTGR was administered in combination with Freund́s Incomplete Adjuvant (FIA) in a three-inoculation scheme on weeks 0, 4 and 8; in the second trial rFhTGR was given mixed with Adyuvac 50 or Alum as adjuvants on weeks 0 and 4. In both cases calves were challenged with metacercariae (400 in the first and 500 in the second trial) 2 weeks after the last inoculation. Our results demonstrate that two or three doses of the vaccine induced a non-significant reduction in worm counts of 8.2% (FIA), 3.8% (Adyuvac 50) and 23.0% (Alum) compared to adjuvant controls indicating that rFhTGR failed to induce a protective immunity in challenged calves. All vaccine formulations induced a mixed IgG1/IgG2 response but no booster was observed after challenge. No correlations between antibody titres and worm burdens were found.
Unidad de Biología Parasitaria, Depto. de Biología Celular y Molecular, Facultad de Ciencias, Instituto de Higiene, Av. A. Navarro 3051, CP11600 Montevideo, Uruguay.
Gabriela
G
Maggioli
Unidad de Biología Parasitaria, Depto. de Biología Celular y Molecular, Facultad de Ciencias, Instituto de Higiene, Av. A. Navarro 3051, CP11600 Montevideo, Uruguay.
Gualberto
G
Bottini
Unidad de Biología Parasitaria, Depto. de Biología Celular y Molecular, Facultad de Ciencias, Instituto de Higiene, Av. A. Navarro 3051, CP11600 Montevideo, Uruguay; Laboratório de Genãmica Estrutural e Funcional, Laboratório de Biologia Molecular de Cestódeos, and Programa de Pós-Graduação em Biologia Celular e Molecular (PPGBCM), Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.
Tatiana
T
Basika
Campo Experimental, Instituto de Higiene, Ruta 11, Km 42, Empalme Olmos, Canelones, Uruguay.
Pablo
P
Alonzo
Cátedra de Inmunología, Facultad de Química, Instituto de Higiene, Avda. A. Navarro 3051, CP11600 Montevideo, Uruguay.
Gustavo
G
Salinas
Unidad de Biología Parasitaria, Depto. de Biología Celular y Molecular, Facultad de Ciencias, Instituto de Higiene, Av. A. Navarro 3051, CP11600 Montevideo, Uruguay. Electronic address: ccarmona@higiene.edu.uy.
Carlos
C
Carmona
D000276:Adjuvants, Immunologic; D000818:Animals; D000947:Antigens, Helminth / Q000276:immunology*; D002417:Cattle; D002418:Cattle Diseases / Q000517:prevention & control*; D005210:Fasciola hepatica / Q000201:enzymology / Q000276:immunology; D005211:Fascioliasis / Q000517:prevention & control / Q000662:veterinary*; D007114:Immunization / Q000592:standards / Q000662:veterinary*; D009097:Multienzyme Complexes / Q000276:immunology*; D009247:NADH, NADPH Oxidoreductases / Q000276:immunology*; D059208:Parasite Load; D011994:Recombinant Proteins / Q000276:immunology
D000276:Adjuvants, Immunologic; D000947:Antigens, Helminth; D009097:Multienzyme Complexes; D011994:Recombinant Proteins; D009247:NADH, NADPH Oxidoreductases; C466433:thioredoxin glutathione reductase
Fasciola hepatica; Thioredoxin glutathione reductase; Vaccine