PHENOTYPIC ANALYSIS OF BOVINE LEUKOCYTE CELL-LINES INFECTED WITH THEILERIA-ANNULATA

Six cell lines that were infected with Theileria annulata were compare d for expression of a range of surface molecules. Immunofluorescence s taining with the panel of monoclonal antibodies formulated for the Sec ond Workshop was analysed by flow cytometry. Four lines generated from bovine peripheral blood mononuclear cells by exposure to sporozoites in vitro and one line generated in vivo from an infected calf were phe notypically similar. Phenotypic analysis of those lines did not demons trate a monocyte or B cell origin, but indicated they were not derived from T cells. An uncloned line generated in vivo from an infected cal f was CD3+ and gamma/delta TCR+. The results indicate that a wider ran ge of host cell types may be infected in vivo than suspected hitherto and that some of the cells may express an abnormal pattern of surface molecules. Both could have profound consequences for the pathogenesis of T. annulata infection.