GSE43241
A differential polarization of Th1, Th2 and Treg immune response determines resistance and susceptibility of sheep breeds to Teladorsagia circumcincta infection
Gastrointestinal nematode (GIN) is a major economic and health concern is sheep farming. Sheep breeds such as Texel are relatively resistant to GIN than the Suffolk. With the objective to understand the underlying genetic mechanism of resistance and susceptibility at the transcriptomic level, two groups of animal from both the breed were artificially (orally) infected with 30,000 L3 larvae of prominent GIN Teladorsagia circumcincta. Subgroups of animals from each breed were slaughtered on day 0, 3, 7, 14 and 21 of post infection (p.i.). Transcriptomic profiling of abomasal lymph node was performed using RNA-seq. The perturbations in gene expression profiles in both the breeds were evident and Texel showed a more tightly regulated immune response than the Suffolk.  The number of differentially expressed (DE) genes between the breeds was highest (437) on un-infected control (day 0) and lowest (173) on day 7 p.i.. Pathway analysis of DE genes identified 3 significant pathways, which involved only more highly expressed genes of Suffolk breed on day 0 and only more highly expressed genes of Texel (with one exception) on day 7 p.i.. The Th1, Th2 and Treg response was evident in response to GIN in Texel and was synchronized, while in Suffolk Th1 response was reduced after infection and pronounced Th2 and Treg was not evident. The study suggests maximum level of transcriptional activity in both breeds on day 7 p.i. and there was a shift of transcriptional activity from Suffolk on day 0 to Texel on day 7 p.i.. Suffolk had a reduced Th1 response with less pronounced Th2 and Treg immune response, while Texel had an active and synchronized Th1/Th2/Treg immune response in response to GIN infection. Overall design: Abomasal lymph node tissue was taken from control (n=10) and experimentally infected (with T. circumcincta) lambs (n=36) from Texel and Suffolk breed on day 0, 3, 7, 14 and 21 post infection.