IL10 and infection: Data on small ruminant nematodes are lacking, although it has been shown that PBMC from sheep experimentally infected with T. circumcincta produce reduced levels of IFNγ and increased levels of IL-10 in response to mitogenic stimulation during later stages of infection, suggesting that infection with this nematode may result in a generalised suppression of Th1 immunity and establishment of more regulatory immune responses [52].