title: Titration in cattle of infectivity and immunogenicity of autologous cell lines infected with Theileria parva.
abstract: Cell lines infected with Theileria parva were derived by infection of bovine peripheral blood lymphocytes with sporozoites in vitro. Cattle were inoculated with doses of autologous infected cells ranging from 1 X 10(1) to 1 X 10(8). Infection became established in animals which received 1 X 10(2) or more cells. While 1 X 10(2) cells resulted in sub-patent infection with development of immunity to challenge with sporozoites, larger doses of cells gave rise to patent infections of increasing severity. Thus, doses of 1 X 10(5) and 1 X 10(6) cells sometimes produced lethal infections and with 1 X 10(7) and 1 X 10(8) the outcome was invariably lethal. Based on the previous observation that induction of immunity by allogeneic cells requires transfer of infection into the recipient-host cells, a comparison of the infections produced by autologous and allogeneic cells indicated that the transfer of infection from allogeneic cells occurs at a frequency of maximally 1 X 10(-5). Two pairs of cattle were identified as being mutually non-reactive in the mixed leukocyte reaction (MLR). Doses of 1 X 10(6) and 1 X 10(7) cells of cell lines derived from 1 animal of each pair were inoculated into the autologous host, the non-reactive partner and an animal which was shown to be strongly reactive to the donor in the MLR. In each instance, the reaction in the MLR non-reactive recipient was not significantly different from that of the MLR reactive recipient, but was markedly different from that of the autologous recipient.
mesh_terms: D000818:Animals; D016782:Apicomplexa / Q000276:immunology; D002417:Cattle; D002460:Cell Line; D007109:Immunity; D008198:Lymph Nodes / Q000469:parasitology; D008214:Lymphocytes / Q000469:parasitology; D008285:Major Histocompatibility Complex; D013801:Theileriasis / Q000276:immunology / Q000469:parasitology*