Identification and characterization of Tu88, an antigenic gene from Theileria uilenbergi

Theileria uilenbergi is a pathogen that causes ovine theileriosis. Prevention and control of theileriosis relies on its diagnosis at early stages of occurrence and requires understanding of proteins with antigenic properties from the pathogen. Despite its prevalence in China, only a few molecules with antigenic properties have been characterized from T. uilenbergi. In this study, we identified a cDNA named Tu88 by immunoscreening a T. uilenbergi merozoite cDNA library with T. uilenbergi-positive sera from infected sheep. Recombinant Tu88 (rTu88) expressed in bacteria reacted strongly with the positive sera of T. uilenbergi in western blot analysis indicating its potential as an antigen. Southern blot analysis showed that it is a single copy gene. Protein localization by immunostaining blood smears from an infected sheep demonstrated the presence of native Tu88 in merozoites. These findings suggest that Tu88 is a potential candidate antigen for the development of a sero-diagnostic tool.