Poster #RP222
Secreted antigens of the parasite Babesia bovis: a proteomic approach
Ana Patricia Yatsuda*, Frits F. Franssen**, Henk-Jan van den Ham**, Erik de Vries**
*University of São Paulo, Ribeirão Preto, Brazil; **Utrecht University, Utrecht, The Netherlands
Babesia bovis is a tick-transmitted parasite of bovines and closely related to malaria parasites. It induces severe pathology during the asexual cycle consisting of repeated steps of erythrocyte invasion and intracellular multiplication. Animals that have recovered from initial infection become a carrier for life and remain fully susceptible to reinfection but are protected from severe disease. When B. bovis is cultured in vitro it secretes a complex mixture of soluble protein antigens (SPA) into the medium. SPA can be used to immunize animals against severe disease but the protective components could not be identified by a trial and error approach of fractionation and immunization.
We aim to unravel the composition of SPA by 2D-PAGE and mass spectrometry to support rational vaccine development. To obtain functional insight it is crucial to reveal the origin of SPA components (e.g. secreted from invading free parasites; shed from parasite or infected erythrocyte membranes; secreted into the erythrocyte cytoplasm; non-specific leakage from damaged parasites). Comparative analysis of such fractions by 2D-PAGE image analysis has been initiated and the potential origin and applicability of ~10 SPA proteins that have been identified by MS will be discussed.