Theileria are tick-borne protozoan parasites which in their mammalian hosts successively utilise leukocytes and erythrocytes for completion of their life cycle. The parasites are found predominantly in ruminants. In domestic cattle, there are two species, namely T. annulata and T. parva, which cause economically important diseases. T. parva occurs throughout a large part of East and Central Africa where it causes an acute, usually fatal disease known as East Coast fever (ECF) (W.I. Morrison et al. 1986; Irvin and Morrison 1987). Control of the disease relies largely on regular application of acaricides to prevent tick infestation. This practice is costly, time consuming and can lead to selection of acaricide-resistant ticks. Thus an effective method of imunising against the disease would have a major impact on cattle production in ECF-endemic areas. To this end, studies have been undertaken to define the host immune responses involved in immunity against T. parva with the aim of identifying protentially protective antigens. These studies have yielded evidence that major histocompatibility complex (MHC) restricted cytotoxic T cells are important in mediating immunity.
- Clone Cells
- Host-Parasite Interactions
- Immunity, Active/immunology
- Major Histocompatibility Complex/genetics
- Major Histocompatibility Complex/immunology
- T-Lymphocytes, Cytotoxic/immunology
- T-Lymphocytes, Helper-Inducer/immunology