The response of Bos taurus and Bos indicus cattle types to inoculation of lymphoblastoid cell lines infected with Theileria parva schizonts.

In a preliminary experiment eight Bos indicus type cattle were inoculated with 10(9) cells of a Bos taurus lymphoblastoid cell line infected with Theileria parva schizonts. Four cattle showed patent infections and one died of theileriosis. On challenge of the surviving cattle with a tick derived stabilate of the same stock of T. parva no animal died of theileriosis. To test the susceptibility of Bos taurus and Bos indicus cattle to cell lines of both cattle types infected with T. parva of the same stock, 10(9) cells of each cattle type were inoculated into five cattle of each type. Bos taurus cattle had a higher susceptibility to infection regardless of the origin of the donor cells. Two Bos taurus type cattle receiving Bos taurus cells died of theileriosis while none receiving Bos indicus cattle died. Both cattle types were more susceptible to infection with cells derived from their own cattle type. All surviving Bos indicus and Bos taurus cattle were immune to lethal stabilate challenge. The possibility that the histocompatibility type of the donor cells influences the success of the immunization is discussed.