Identification and Characterization of Immunogenetic Parameters Associated with Resistance/Susceptibility to Haemonchus contortus in Malpura Sheep

A study was conducted to identify and characterize immune molecules associated with resistance/susceptibility to Haemonchus contortus in Malpura sheep. The intensity of H. contortus infection, eosinophil count, packed cell volume and immune molecule expressions like Th1 cytokines (IFN-α, IL-8), Th2 cytokines (IL-4, IL-10), TNF-α, TLRs (TLR2, TLR4, TLR5, TLR8) and chemokines (CCR9, CCR10) were evaluated in Malpura sheep. For molecular study, six male sheep (3 from the R-line and 3 from the S-line) were selected on the basis of faecal egg counts. R-line had considerably lower mean FECs (P<0.001) and eosinophil count (P<0.001) and higher PCV (P<0.01) than the S-line. Real-time PCR results showed significant (P<0.05) down-regulated expression of TLR-2, TLR-4, TLR-5, TLR-8, CCR9, CCR10, IL-10, TNF-α genes and up-regulated expression of IL-8 and the IFN-α gene in R-line as compared to S-line. It was concluded that lower FEC, higher PCV and eosinophil count in R-line suggest their resistance to H. contortus as compared to S-line. The variable expression of immune molecules in divergent lines suggests their utility for further research on the identification of molecular markers for the detection of H. contortus resistant animals.