Fecundity in adult Haemonchus contortus parasites is correlated with abomasal tissue eosinophils and gamma-delta T cells in resistant Canaria Hair Breed sheep
- Authors: Gonzalez, Jorge , Hernandez, Alvaro , Meeusen, Els , Rodríguez, Francisco , Molina, Jose , Jaber, Jose , Raadsma, Herman , Piedrafita, David
- Date: 2011
- Type: Text , Journal article
- Relation: Veterinary Parasitology Vol. 178, no. 3-4 (2011), p. 286-292
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- Description: Canaria Hair Breed (CHB) sheep are more resistant than Canaria sheep (CS) to experimental Haemonchus contortus infection. Protective responses appear effective against the adult stage of the parasite, not as commonly reported in other breeds against the larval stages. In this study we have quantified several abomasal immune cells and correlated these with parasitological variables for each breed. A significant negative correlation between CD4+ T cell numbers and worm burden or length at 28 dpi was seen only in CS sheep. Significant negative correlations for both abomasal eosinophils and
Modulation of Haemonchus contortus infection by depletion of γδ+ T cells in parasite resistant Canaria Hair Breed sheep
- Authors: Hernández, Julia , Meeusen, Els , Stear, Michael , Rodríguez, Francisco , Piedrafita, David , Gonzalez, Jorge
- Date: 2017
- Type: Text , Journal article
- Relation: Veterinary Parasitology Vol. 237, no. (2017), p. 57-62
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- Description: Canaria Hair Breed (CHB) sheep display resistance against the adult stage of the nematode, Haemonchus contortus. Previous studies have suggested significant correlations between γδ+ T lymphocytes and fecundity of female adult worms, suggesting a novel role in immune modulation by these cells. The largest proportion of γδ+ T lymphocytes in sheep are the subpopulation of γδ+/WC1+ T cells. The aim of this study was to evaluate the effect of γδ+/WC1+ T cell depletion via infusion of anti-γδ/WC1 monoclonal antibody (mAb) on the subsequent immune response of CHB sheep infected with H. contortus. Significantly lower γδ+ T cell levels in both peripheral blood and in the basal layers of the abomasal tissue resulted following anti-γδ/WC1 mAb infusion of CHB sheep compared to control animals. Worms recovered from the anti-γδ/WC1 mAb treated CHB sheep had significantly longer female worms with correspondingly more eggs in utero than the saline control group. Significant correlations between eosinophils and worm length and fecundity were no longer apparent in the anti-γδ/WC1 mAb treated CHB sheep. These results support the notion that γδ+ T cells in CHB sheep play a critical role in fecundity regulation (length and eggs in utero) of H. contortus adult female worms, and highlights a new mechanism of modulation by this lymphocyte population, possibly involving eosinophil activation. © 2017 Elsevier B.V.
Increased susceptibility to Haemonchus contortus infection by interleukin-5 modulation of eosinophil responses in sheep
- Authors: Hernández, Julia , Meeusen, Els , Rodríguez, Francisco , Piedrafita, David , González, Jorge
- Date: 2020
- Type: Text , Journal article
- Relation: Parasite Immunology Vol. 42, no. 1 (2020), p.
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- Description: Eosinophils are prominent effector cells in immune responses against gastrointestinal nematode infections in ruminants, but their in vivo role has been hard to establish in large animals. Interleukin-5 is a key cytokine in the induction and stimulation of anti-parasitic eosinophil responses. This study attempted to modulate the eosinophil response in sheep through vaccination with recombinant interleukin-5 (rIL-5) and determine the effect on subsequent Haemonchus contortus infection. Nematode-resistant Canaria Hair Breed (CHB) sheep vaccinated with rIL-5 in Quil-A adjuvant, had lower blood eosinophil counts and higher mean worm burdens than control sheep vaccinated with Quil-A adjuvant alone. In addition, adult worms in IL-5-vaccinated sheep were significantly longer with higher eggs in utero in female worms, supporting an active role of eosinophils against adult parasites in CHB sheep. These results confirm that eosinophils can play a direct role in effective control of H contortus infection in sheep and offer a new approach to study immune responses in ruminants. © 2019 John Wiley & Sons Ltd