The effect of Quil A adjuvant on the course of experimental
Veterinary Sciences Centre, School of Agriculture, Food Science and Veterinary Medicine, College of Life Sciences, University College Dublin, Belfield, Dublin 4, Ireland. Vaccine
(Impact Factor: 3.62).
10/2008; 27(1):45-50. DOI: 10.1016/j.vaccine.2008.10.035
Fasciola hepatica infection causes significant clinical disease in ruminants. Current control methods, based on flukicidal drugs, are becoming less useful because of resistance in fluke populations. Vaccination would be a viable alternative, but as yet no vaccine to protect ruminants against liver fluke infection has been commercialised. Adjuvants can be used to enhance and promote protective immune responses by vaccines. In previous vaccination trials, we have observed a distinct adjuvant effect, or a degree of protection, in animals administered adjuvant alone in the absence of any specific F. hepatica antigen. Understanding this effect will be important for continuing efforts to develop vaccines effective against fasciolosis. This study investigated the effects of three adjuvants (Quil A, Freund's Incomplete and TiterMax Gold) on the course of experimental F. hepatica infection in 6-month-old sheep (n=33). At completion of the trial, all animals were necropsied to determine fluke burden and fluke weight. Quil A administration led to a significant reduction in faecal egg count (P<0.0001) and significantly higher parasite-specific serum antibody activity for all isotypes measured (P<0.01). This suggests that Quil A, which promotes a Th1 response, may be useful as an adjuvant in anti-Fasciola vaccines. Furthermore, it reinforces the results of our previous studies indicating that enhanced Th1 responsiveness to vaccine antigens is required to achieve protection against challenge by F. hepatica.
Available from: Ahmet Tarik Baykal
- "Observation of liver flukes in the bile ducts confirmed the chronic phase of fasciolosis  . "
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ABSTRACT: Fasciola hepatica is a trematode helminth causing a damaging disease, fasciolosis, in ruminants and humans. Comprehensive proteomic studies broaden our knowledge of the parasite's protein profile, and provide new insights into the development of more effective strategies to deal with fasciolosis. The objective of this study was to generate a comprehensive profile of F. hepatica proteins expressed during the chronic stage of infection in cattle by building on previous efforts in this area. The approach included an improved sample preparation procedure for surface and internal layers of the parasite, the application of nanoUPLC-ESI-qTOF-MS (nano ultra performance liquid chromatography and electrospray ionization quadrupole time-of-flight mass spectrometry) integrated with different acquisition methods, and in silico database search against various protein databases and a transcript database including a new assembly of publically available expressed sequence tags. Of a total of 776 identified proteins, 206 and 332 were specific to the surface and internal layers of the parasite, respectively. Furthermore, 238 proteins were common to both layers, with comparative differences of 172 proteins detected. Specific proteins not previously identified in F. hepatica, but shown to be immunomodulatory or potential drug targets for other parasites, are discussed.This article is protected by copyright. All rights reserved
Available from: Maria Martínez-Valladares
- "Although GGT showed above normal levels in all groups, in C2, the increase was more pronounced beginning at 42 dpi. GGT remained elevated in the final half of the trial, as previously reported (Martínez-Valladares et al. 2010a; Haçariz et al. 2009; Buffoni et al. 2010; McConville et al. 2009). This suggests that bile duct damage was lower in animals treated with IMM, possibly as a consequence of smaller adult flukes. "
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ABSTRACT: The effects of the lipopolysaccharide (LPS) from Ochrobactrum intermedium was evaluated in sheep experimentally infected with Fasciola hepatica. Animals were divided into four groups: two treated with the LPS (T1/T2) and two controls (C1/C2). T1/C1 were slaughtered at 30 days postinfection (dpi) and T2/C2 at 85 dpi. Body weight and body condition were found higher in T1 and T2 than in controls, although differences were not significant. Treated sheep showed lower cumulative fecal egg count than controls (p < 0.01). Levels of red blood cells (RBC), white blood cells, hemoglobin, and hematocrit (HCT) were higher in T1 and T2. Significant differences (p < 0.05) in RBC and HCT were found between groups at 84 dpi. More severe macrocytic and hypochromic anemia was observed in C1 and C2 than in treated groups. Total protein and albumin values were higher in T1 and T2 (p < 0.01) until 29 dpi. At the end of the trial, no significant differences were observed in hepatic enzymes, although gamma-glutamyl transferase and aspartate aminotransferase values were higher in C2, and alanine aminotransferase was higher in T2. At necropsy, the mean weight of liver, fibrosis in portal triads, and ganglion size were similar in all groups. The number and size of flukes was greater in C2 than in T2 (p < 0.05). The histological examinations revealed a higher degree of parenchymatous fibrosis in T2 compared to C2 (p < 0.05). The administration of LPS from O. intermedium increased the nonspecific resistance against F. hepatica in experimentally infected sheep.
Available from: Abel Villa-Mancera
- "Serum was stored at À80 °C until use. Antibody responses were analyzed by ELISA as described by Haçariz et al. (2009), with minor modifications. The wells of microtiter plates (Nunc-Immuno , MaxiSorp) were coated with specific phage clones (1 Â 10 10 pfu) incubated in 100 lL of PBS overnight at 4 °C with gentle shaking. "
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ABSTRACT: Fluke burdens, liver fluke size and biomass, fecal eggs counts, serum levels of hepatic enzymes and immune response were assessed in sheep immunized with peptide mimotopes of cathepsin L1 and challenged with Fasciola hepatica metacercariae. Twenty sheep were randomly allocated to four groups of five animals each; groups 1 and 2 were immunized at weeks 0 and 2 with mimotopes YVYRWVEAECVA and FSPAYLRDAALK, respectively; group 3 was immunized with wild-type M13KE phage and the control group received phosphate-buffered saline (PBS). All groups were challenged with 300 metacercariae at week 6 and slaughtered 16weeks later. Groups 1 and 2 showed a reduction in fluke burden of 51.7% and 35.9%, respectively, when compared to the control group, but only the former was significant at the 5% level. Vaccinated animals showed a significant reduction in fluke length and width, wet weights and egg output. A significant diminution in the total biomass of parasites recovered was also observed in group 1. Levels of anti-phage total IgG increased rapidly within 2weeks of the first immunization and were always significantly higher in groups 1 and 2 than in the infected control group. The fluke burden in group 1 was significantly correlated with IgG1 and total IgG. The vaccinated sheep with phage clones produced significantly high titres of IgG1 and IgG2 antibodies indicating a mixed Th1/Th2 response.
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