Galectin secretion and binding to adult Fasciola hepatica during chronic liver fluke infection of sheep
- Authors: Young, Anna , Barcham, Garry , McWilliam, Hamish , Piedrafita, David , Meeusen, Els
- Date: 2012
- Type: Text , Journal article
- Relation: Veterinary Immunology and Immunopathology Vol. 145, no. 1-2 (2012), p. 362-367
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- Description: Galectins are increasingly recognised as important mediators of immune homeostasis and disease regulation, but comparatively little is known about their role in parasite infection. This study investigates the interaction between two ovine galectins, galectin-11 and galectin-14, and the parasitic liver fluke, F. hepatica. Galectin-14 was found in eosinophils infiltrating the tissue surrounding infected bile ducts and secreted in the connective tissue, while galectin-11 was specifically induced in epithelial cells of bile ducts from infected sheep. Strong nuclear staining was observed for galectin-11. Both galectins were found to be secreted into the bile fluid of parasite infected sheep, and were also detected in the excretory/secretory products of adult flukes, following their removal from the ovine host. Recombinant galectin-14, but not recombinant galectin-11, was found to bind specifically to the surface tegument of adult flukes in a carbohydrate dependent manner. This study shows for the first time that both galectin-14 and galectin-11 are produced in liver tissue after chronic liver fluke infection and that they can directly interact with the parasite in the bile ducts. Galectin-11 may also be involved in epithelial cell turnover and cancerogenesis.
The kinetics of local cytokine and galectin expression after challenge infection with the gastrointestinal nematode, Haemonchus contortus
- Authors: Robinson, Nicholas , Pleasance, Jill , Piedrafita, David , Meeusen, Els
- Date: 2011
- Type: Text , Journal article
- Relation: International Journal for Parasitology Vol. 41, no. 5 (2011 2011), p. 487-493
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- Description: Gastrointestinal nematode parasites undergo several developmental stages within their mammalian host, each presenting different antigenic challenges to the immune system. To examine the expression of different immune mediators over time, biopsy samples were collected from the cannulated abomasum (true stomach) of immune sheep at several times after a challenge infection with Haemonchus contortus L3s. IL-5 and IL-13 mRNA expression levels were significantly increased above saline-challenged control levels at 5 and 7 days post challenge, while IL-4 showed an earlier peak at day 2 post challenge. IL-5, IL-13 and IL-4, as well as IFN-
The relationship between the rapid rejection of Haemonchus contortus larvae with cells and mediators in abomasal tissues in immune sheep
- Authors: Kemp, Joanna , Robinson, Nicholas , Meeusen, Els , Piedrafita, David
- Date: 2009
- Type: Text , Journal article
- Relation: International Journal for Parasitology Vol. 39, no. 14 (2009), p. 1589-1594
- Full Text: false
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- Description: Rapid rejection or immune exclusion of challenge larvae is a well recognised phenomenon in sheep hypersensitised by repeated infection with gastrointestinal nematodes. While mast cells and globule leukocytes (GLs) are typically associated with this rapid rejection response, the exact mechanisms and mediators involved are not known. This study has adapted a recently developed ex vivo tissue explant model to examine in more detail the cells and mediators involved in preventing establishment of Haemonchus contortus L3s in abomasal tissue of sensitised sheep. Hypersensitisation of sheep by repeated larval infection resulted in a significant inhibition of larval establishment in abomasal tissue cultures and the extent of inhibition was dependent on the sensitisation dose. Both mast cells and GLs, but not eosinophils, were increased in abomasal tissues of hypersensitised sheep. Globule leucocyte numbers decreased significantly after 3 h of culture, independent of the addition of L3s. In contrast, mast cell numbers only decreased after addition of L3s to the tissue cultures and this was associated with an increased release of histamine in tissue washes after incubation with L3s. Although, there was no significant difference in the number of tissue eosinophils between the groups, there was a marked increase in the eosinophil-specific protein, galectin-14, in tissue washes of the hypersensitised sheep after culture, suggesting eosinophils and their products may play a hitherto unrecognised role in the rapid rejection response. Further studies using specific inhibitors in this ex vivo tissue explant model may delineate the relative role of each cell population and mediator in the rapid rejection process.