Immune response related to Pelibuey sheep naturally infected with gastrointestinal nematodes in a tropical region of Mexico

We analysed the immune response involved in sheep naturally infected with gastrointestinal (GI) nematodes. Fifteen Pelibuey lambs were grazed in paddocks contaminated with GI nematodes for 13 weeks. To assess the infection, the number of eggs per gram (epg) and the percentage of packed cell volume (pcv) were evaluated. Blood and abomasal tissue samples were collected at week 8 post-infection to analyse the expression levels of IL-4, IL-5, IL-6, IL-8, IL-13, TGF-β and FCεR1A genes. The nematode Haemonchus contortus was the main species identified. In addition, two groups of lambs were classified based on the x ± SE of epg and pcv values: G-1, with 151 ± 28 and 29 ± 0.33%, respectively, and G-2, with 475 ± 59.5 and 26 ± 0.38%, respectively. For G-1, upregulation of IL-4, IL-8, IL-13, TGF-β and FCεR1A genes from 2.42- to 14.99-fold was observed in blood and abomasal tissue samples (p > .05), and IL-5, IL-8 and TGF-β genes had significant gene expression levels in blood (p .05), and the IL-5 gene presented significant gene expression in blood (p