Project description:Human babesiosis, especially caused by the cattle derived Babesia divergens parasite, is on the increase, resulting in renewed attentiveness to this potentially life threatening emerging zoonotic disease. The molecular mechanisms underlying the pathophysiology and intra-erythrocytic development of these parasites are poorly understood. This impedes concerted efforts aimed at the discovery of novel anti-babesiacidal agents. By applying sensitive cell biological and molecular functional genomics tools, we describe the intra-erythrocytic development cycle of B. divergens parasites from immature, mono-nucleated ring forms to bi-nucleated paired piriforms and ultimately multi-nucleated tetrads that characterizes zoonotic Babesia spp. This is further correlated for the first time to nuclear content increases during intra-erythrocytic development progression, providing insight into the part of the life cycle that occurs during human infection. High-content temporal evaluation elucidated the contribution of the different stages to life cycle progression. Moreover, molecular descriptors indicate that B. divergens parasites employ physiological adaptation to in vitro cultivation. Additionally, differential expression is observed as the parasite equilibrates its developmental stages during its life cycle. Together, this information provides the first temporal evaluation of the functional transcriptome of B. divergens parasites; information that could be useful in identifying biological processes essential to parasite survival for future anti-babesiacidal discoveries.
Project description:Protozoan parasites of the genus Babesia are considered a serious threat to humans and animals worldwide. Babesia parasites are naturally transmitted by ticks and infect the erythrocytes or red blood cells (RBCs) of many vertebrates causing babesiosis. Infectious species include B. divergens, which causes asymptomatic to fatal babesiosis in humans and red water fever in cattle in Europe. To better understand the biology of B. divergens and to develop diagnostic and control strategies for babesiosis, we studied the extracellular vesicles (EVs) released into the environment by B. divergens-infected red blood cells (iRBCs). B. divergens parasites were cultured in human erythrocytes in vitro in a complete medium containing low human vesicle (LHV) serum. Uninfected erythrocytes (uRBC) were also maintained in the LHV complete medium. Bd-derived EVs and uRBC-derived EVs were collected and purified from the supernatants of B. divergens and uRBC cultures, respectively. Proteins were extracted from Bd-derived EVs and uRBC-derived EVs.