Our previous study showed that the haplotype of MHC MvaIbc-SacIIab-Hin1Iab, was associated with cystic echinococcosis (CE) resistance in Kazakh sheep. The present study described here was designed to analyze the system immune response in the very early stage of Echinococcus granulosus (E. granulosus) infection in sheep with CE resistant haplotype. Fourteen healthy Kazakh sheep were divided into two groups: seven sheep with CE resistant haplotype referred to group A, while the others without this haplotype constituted group B. These sheep were all experimentally infected with E. granulosus eggs. Blood samples were collected on day 0 (prior to infection), hours 2, 3, 4, and 9 post-infection as well as days 1, 2, 3, and 7 post-infection, respectively. ELISA assay was used to measure serum levels of antibodies (IgE and IgM), cytokines (Th1:TNF-α and IFN-γ; Th2: IL-4 and IL-10) and chemokines (Th1:CXCL-9; Th2: CCL17) at different time points of E. granulosus infection in the two groups. Results showed that, in the early stage of E. granulosus infection, antibodies like IgM and IgE, Th1 cytokines such as IFN-γ and TNF-α, as well as Th1 chemokines CXCL-9 were predominant in group A, especially for IgE and Th1 cytokines, which were significantly higher, most were at or began from 4h post-infection, as compared with group B. Our findings revealed that the influence of the host’s genetic background on the immunopathology of E. granulosus infection in the early stage could be partially mediated by Th1-type cytokines and IgE.

Key words: E. granulosus infection, Immune response, Kazakh sheep, MHC haplotype