Moderate protection is induced by a chimeric protein composed of leucine aminopeptidase and cathepsin L1 against Fasciola hepatica challenge in sheep.
Vaccine
; 37(24): 3234-3240, 2019 05 27.
Article
em En
| MEDLINE
| ID: mdl-31036453
ABSTRACT
Leucine aminopeptidase (FhLAP) and cathepsin L1 (FhCL1) of Fasciola hepatica play a critical role in parasite feeding, migration through host tissue, and immune evasion. These antigens have been tested for immune protection as single components with variable degrees of success. The chimeric-protein approach could improve protection levels against fasciolosis. Previously, we reported the design and construction of a chimeric protein composed of antigenic sequences of FhLAP and FhCL1 of F. hepatica. The goal of the present study was to express and evaluate the immune-protective capacity of this chimeric protein (rFhLAP-CL1) in sheep. Animals were randomly allocated into five groups with five animals in each group. Groups 1, 2 and 3 were immunized twice with 100⯵g, 200⯵g and 400⯵g of rFhLAP-CL1 emulsified with Quil A adjuvant, whereas groups 4 and 5 were the adjuvant control and infection control groups, respectively. The animals were then challenged with 200 metacercariae two weeks after the rFhLAP-CL1 booster. The fluke burden was reduced by 25.5%, 30.7% (pâ¯<â¯0.05) and 46.5% (pâ¯<â¯0.01) in sheep immunized with 100⯵g, 200⯵g and 400⯵g of chimeric protein, respectively, in comparison to the infection control group. There was a reduction of 22.7% (pâ¯<â¯0.05) and 24.4% (pâ¯<â¯0.01) in fecal egg count in groups 2 and 3, respectively, compared to the infection control group. Sheep immunized with chimeric protein produced F. hepatica excretion-secretion product-specific total IgG antibody, which were increased after challenge. Moreover, the levels of rFhLAP-CL1-specific IgG1 and IgG2 isotypes in immunized sheep increased rapidly two weeks after the first immunization and were significantly more elevated than those of the control groups, indicating a mixed Th1/Th2 response. This is a preliminary evaluation of the chimeric protein rFhLAP-CL1 as a possible immunogen against F. hepatica infection in sheep.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Doenças dos Ovinos
/
Anticorpos Anti-Helmínticos
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Fasciolíase
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Catepsina L
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Leucil Aminopeptidase
Limite:
Animals
Idioma:
En
Revista:
Vaccine
Ano de publicação:
2019
Tipo de documento:
Article