Cattle Specific Immune Mechanisms used against the Protozoan Theileria annulata

Theileria annulata, the causative agent of tropical theileriosis, is an intracellular protozoan parasite transmitted by ticks of the genus Hyalomma. This tick-borne disease (TBD) exerts a high impact on livestock production in many developing tropical and subtropical countries. With an intricate life cycle and wide distribution around the world, many advances were made to restrict the impact and to control this TBD through the use of acaricides, chemotherapy and attenuated vaccines. However, an overreliance on these chemicals has meant new approaches for developing more effective vaccines are needed. Decades of studies support the idea that the humoral immune response elicited against the sporozoite stage of the tick life cycle may protect the host from infection. Further protective responses provided by cytotoxic T-cells, macrophages, and Natural Killer cells have also been identified as critically important during T. annulata infection. Here our focus will be the bovine immune response upon T. annulata infection, particularly the differential humoral and cellular immune responses. Our aim is to highlight the importance of the mechanisms potentially involved in protective immunity as well as significant findings, which may be incorporated into novel strategies for tropical theileriosis control.publishersversionpublishe