Relationship between susceptibility of Blackface sheep to Teladorsagia circumcincta infection and an inflammatory mucosal T cell response

Histopathology showed only minor changes in resistant animals with a low level lymphocyte infiltration; but in susceptible lambs, major pathological changes were associated with extensive infiltration of lymphocytes, eosinophils and neutrophils.Absolute quantitative RT-qPCR assays on the abomasal lymph node (ALN) revealed a significant positive correlation between IL6, IL21 and IL23A transcript levels with adult worm count and FEC. IL23A was also negatively correlated with IgA antibody levels. Significantly positive correlation of TGFB1 levels with adult worm count and FEC were also seen in the abomasal mucosa. These data are consistent with the hypothesis that the inability to control L3 larval colonization, adult worm infection and egg production is due to the activation of the inflammatory Th17 T cell subset.