|REIF, KATHRYN - Kansas State University|
|BOHALIGA, GAMILA - Washington State University|
Submitted to: Journal of Proteome Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/2/2017
Publication Date: 2/9/2017
Citation: Johnson, W.C., Taus, N.S., Reif, K.E., Bohaliga, G., Kappmeyer, L.S., Ueti, M.W. 2017. Analysis of stage-specific protein expression during babesia bovis development within female rhipicephalus microplus. Journal of Proteome Research. 16(3):1327-1338.
Interpretive Summary: Disease-causing organisms called Apicomplexans are carried by ticks and have a complex life cycle that includes reproduction in the very different environments of mammalian red blood cells, called erythrocytes, and ticks. Apicomplexans transition between different forms that are specific to erythrocytes and ticks. This transition is critical for on-going transmission between mammalian hosts and tick vectors. Understanding how the transition occurs is crucial for developing control strategies, including drug treatment and immunization, to prevent spread of these organisms. In this study we describe a comparative analysis of the proteins expressed by the cattle Apicomplexan, Babesia bovis, during its development within erythrocytes and the tick circulatory system. Twelve B. bovis tick stage specific proteins were identified and antibodies against portions of four of these proteins confirmed that they were expressed on the tick stage, kinetes, but not on the mammalian blood stages. Interestingly, these kinete proteins correspond to proteins in closely related Apicomplexans. This is the first report of proteins expressed exclusively by kinetes. The proteins identified in this study could be critical for the development of novel strategies to control tick borne pathogens of veterinary and human importance.
Technical Abstract: Arthropod borne pathogens have a complex life cycle that includes asexual reproduction of haploid stages in mammalian erythrocytes and development of diploid stages in the vector. Transition of Apicomplexan pathogens between the mammalian host and the arthropod vector is critical for ongoing transmission. The ability of pathogens to invade, survive and replicate within distinct cell types is the requirement for transmission. Understanding the mechanism that mediates transmission is critical to the development of control strategies for preventing pathogen spread through chemotherapy or immunization. In this study, we described a comparative proteome analysis of a cattle pathogen, B. bovis, during its development within the erythrocytes and tick hemolymph. Cell-surface CyDye labeling was applied on B. bovis blood stages or transient B. bovis kinetes isolated from R. microplus female ticks to determine parasite stage specific proteins. B. bovis stage specific protein spots were identified using 2D-DIGE, picked and analyzed by liquid chromatography and tandem mass spectrometry. Stage specific protein expression during B. bovis life cycle in the tick vector was identified that includes 12 proteins exclusively expressed by B. bovis kinete. Antibodies against polypeptides from four proteins confirmed their expression by kinetes and absents in blood stages. Interestingly, these kinete proteins were found to be orthologs of other proteins from closely related arthropod borne Apicomplexan pathogens. These findings are the first report providing evidences of proteins exclusively expressed by kinetes, a specific tick stage of B. bovis. The proteins identified in this study may be critical for the development of novel strategies to control tick borne pathogens of veterinary and human importance.