Authors

Discussion

Human babesiosis is an emerging tick-borne disease and blood transfusion-transmitted infection. Babesia microti, the prevalent cause of babesiosis in humans is an apicomplexan parasite related to Plasmodium spp., the etiological agents of malaria, and parasites of the genus Theileria and Babesia that cause economically significant disease in livestock.

Babesia spp. invade and proliferate in erythrocytes.  During invasion, parasites are exposed to host antibodies and can be targeted by vaccines.   Currently, no B.microti invasion proteins or erythrocyte receptors have been identified and the cell-surface proteome is poorly characterised.

To identify invasion proteins, we have compiled a recombinant protein library comprising the cell surface receptor repertoire of the blood stage parasite.  Protein sequences corresponding to the ectodomain of the proteins were optimised for expression in a mammalian system.  Protein expression and integrity was determined by Western blotting and ELISA, with 70 % of the proteins expressed at detectable levels.   

These proteins will be used to examine host immune responses in an experimental vaccine model and identify receptors for parasite proteins on erythrocytes using AVEXIS, a systematic protein interaction assay designed to detect low affinity interactions.