Differential expression of three members of the multidomain adhesion CCp family in Babesia bigemina, Babesia bovis and Theileria equi.
Authors: Bastos Reginaldo G, Suarez Carlos E, Laughery Jacob M, Johnson Wendell C, Ueti Massaro W, Knowles Donald P
Journal: PloS one
Summary
# Editorial Summary: CCp Protein Expression in Equine and Bovine Blood Parasites Babesia and Theileria parasites cause economically significant diseases in horses and cattle worldwide, yet transmission-blocking vaccine targets remain poorly characterised. This research investigated three members of the CCp adhesion protein family across *Babesia bigemina*, *Babesia bovis* and *Theileria equi*, drawing parallels with successful malaria transmission-blocking strategies that exploit similar proteins in *Plasmodium*. Using in vitro culture of *B. bigemina* and in vivo blood sampling from naturally infected horses and cattle, the team assessed mRNA and protein expression across different parasite life stages, revealing a markedly differential expression pattern: all three CCp genes produced transcripts and proteins in *B. bigemina* sexual stages, whilst *T. equi* blood stages expressed all three transcripts but no detectable proteins, and *B. bovis* showed only CCp3 transcription without corresponding protein production. These findings suggest that CCp proteins are regulated distinctly across species and life stages, potentially reflecting different transmission strategies or vector adaptation mechanisms. For equine and bovine practitioners, this work opens promising avenues for developing transmission-blocking interventions that could interrupt parasite cycling through arthropod vectors, though further investigation into the functional roles of these proteins and their immunogenicity will be essential before vaccine development can proceed.
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Practical Takeaways
- •This research identifies novel vaccine targets that could eventually reduce transmission of economically important parasitic diseases in cattle and horses
- •The species-specific and stage-specific expression patterns of CCp proteins suggest that any future vaccine approach would need to be tailored to the target parasite and life stage
- •Understanding parasite biology at the molecular level may lead to new control strategies beyond current tick management and treatment approaches
Key Findings
- •Three CCp family members (CCp1, CCp2, CCp3) were identified and characterized in B. bigemina, B. bovis, and T. equi parasites
- •Differential expression patterns observed across species: B. bigemina showed expression of all three CCp genes and proteins in sexual stages; T. equi showed transcript expression in blood stages; B. bovis showed CCp3 transcripts only
- •No protein expression was detected in T. equi blood stages, B. bovis blood stages, or B. bovis tick stages despite transcript presence
- •CCp proteins represent potential targets for transmission-blocking vaccines similar to their role in Plasmodium parasites