In vitro infection with Theileria parva is associated with IL10 expression in all bovine lymphocyte lineages.
The patterns of cytokine mRNA expressed by 19 bulk and cloned Theileria parva-infected lymphoblast cell lines were investigated using a multiplex PCR system. Considerable variation was observed in the cytokine profiles of these lines and only IL-10 was universally expressed. Investigation of cloned lines representing the major bovine lymphocyte populations failed to reveal a lineage-specific pattern of cytokine mRNA expression that could be associated with infection. However, analysis of a CD4+ T cell clone before and after transformation with the parasite indicated that infection does alter the pattern of cytokine expression, with apparent upregulation of IL-10. It is suggested that IL-10 derived from infected cells may influence the immune responses of naive cattle to challenge.