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.
Project description:Babesia parasites transition between a mammalian host, where they cause babesiosis, and the tick vector that transmits them. This transition provides an environmental signal resulting in altered gene expression allowing the completion of the parasite’s life cycle. A comparison of the different life stages that occur within mammalian and tick hosts can provide insight into the adaptation of Babesia to these different environments. In this study, we used RNA-Seq to compare gene expression between Babesia bovis blood stages and tick derived kinetes.
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. Two-condition experiment, Untreated vs.Treated B. divergens parasites, cultured in human erythrocytes. Treatment with a piperidinyl-benzimidizalone analogue. Biological replicates: 3 untreated (control) replicates, 3 treated replicates. The 6-sample dataset represents untreated(control) vs pooled_reference samples at various timepoints.
Project description:Bovine babesiosis is a tick-borne disease that poses a significant economic threat to cattle industries in tropical and subtropical areas, and Babesia bovis is the most virulent causative agent of bovine babesiosis. This apicomplexan parasite infects erythrocytes of cattle causing severe hemolytic disease, and animals that survive acute infections become persistently infected for life. Young cattle (< 6 months of age) are resistant to infection while adult cattle (>1 year of age) are highly susceptible and succumb to acute infection; however, the immunological mechanisms associated with the age-resistance remain unclear. Protective host immunity involves peripheral blood mononuclear cells (PBMCs) including natural killer (NK) and T cells, and activated macrophages that act to control the pathogen. In this study, we examined the transcriptional signatures of PBMCs from adult cattle (>1.5 years old) experimentally infected with the B. bovis virulent strain S74-T3Bo. Transcriptional signatures evident during the acute phase of babesiosis were categorized into immune-related and non-immune genes. We identified both upregulated and downregulated genes, with fold changes ranging from 2 to 263-fold. We discuss our findings in the context of immune responses to acute disease as a mechanism for adult host survival, with a focus on the molecular functions and biological processes involved in the response to B. bovis infection. In this RNA-Seq analysis, we identified genes related to the immune system, including cytokines and chemokines, complement, cell signaling pathways and surface molecules that may play a role in the recognition of pathogen-associated molecular patterns. In addition, non-immune genes potentially involved in cell proliferation, cell migration, development, energy production, protein-protein interactions, molecular transport, and flagella assembly were also identified.
Project description:Ticks, as obligate blood-feeding arthropod vectors of pathogenic viruses, bacteria, protozoa and helminths, are responsible for prevalent tick-borne diseases (TBDs) worldwide. This arthropod constitutes the second most common that transmit pathogens among humans, after mosquitoes, and the first vector in domestic animals. Vaccines constitute the safest and more effective approach to control tick and TBDs, but this is in constant research to identify new antigens and improve vaccines formulations. The tick antigen Subolesin is a well-known vaccine protective antigen with a highly conserved sequence at both gene and protein levels in the Ixodidae and among arthropods and vertebrates. In this study, RNAseq and proteomic analyses were carried out in wild type and Subolesin knockdown tick ISE6 cells in order to identify and characterize the functional implications of Subolesin in tick cells, demonstrating once again the importance of this antigen in vaccine development against tick and TBDs.
Project description:Lysine methylation on histone tails impacts genome regulation and cell fate determination in many developmental processes. Apicomplexa intracellular parasites cause major diseases and they have developed complex life cycles with fine-tuned differentiation events. Yet, apicomplexa genomes have few transcription factors and little is known about their epigenetic control systems. Tick-borne Theileria apicomplexa species have relatively small, compact genomes and a remarkable ability to transform leukocytes in their bovine hosts. Here we report enriched H3 lysine 18 monomethylation (H3K18me1) on the gene bodies of repressed genes in Theileria macroschizonts. Differentiation to merozoites (merogony) led to decreased H3K18me1 in parasite nuclei. Pharmacological manipulation of H3K18 acetylation or methylation impacted parasite differentiation and expression of stage-specific genes. Finally, we identified a parasite SET-domain methyltransferase (TaSETup1) that can methylate H3K18 and represses gene expression. Thus, H3K18me1 emerges as an important epigenetic mark which controls gene expression and stage differentiation in Theileria parasites.
Project description:Canine babesiosis, a tick-borne disease, is characterized by protozoan parasites invading red blood cells. It is rapidly expanding in many European countries. Examining extracellular vesicles (EVs) and their protein cargo has the potential to offer crucial insights into the response to Babesia canis infection, presenting opportunities for advancements in veterinary diagnostic and therapeutic strategies. In the present study, we have a) isolated small EVs (< 200 nm) from the serum of 15 healthy dogs and 15 dogs naturally infected with B. canis using size-exclusion chromatography (fraction 2 and 3 per each sample), (2) characterized isolated EVs by nanoparticle tracking analysis, transmission electron microscopy and Western blot (3) analysed the protein cargo of isolated EVs by mass spectrometry. We hypothesized that there will be a difference in EV characteristics (size, concentration, EV marker proteins) and profiles of luminal proteins between the two experimental groups. Our aim was to characterize proteins that can offer valuable insights into B. canis infection in dogs, thereby unravelling the complex mechanisms of B. canis infection.