Analysis and Professional Designing of COBRA (Computationally Optimized Broadly Reactive Antigen) Vaccine for Bm86 midgut Protein of R. microplus and R. annulatus Ticks

Introduction: The cattle tick Rhipicephalus spp. causes significant economic losses due to diseases in animals and human. Bm86 is a midgut protein and vaccine candidate, which its sequences among the isolates of Ripsephalus spp are geographically separated, variable, and are the main reason for reducing effectiveness, and subsequently, the failure of the recombinant vaccines. Method: In this bioinformatics study, the sequences of R. microplus and R. annulatus were retrieved, aligned, and edited. Then, the variation plot and phylogenetic tree were constructed. Afterwards, grouping and taxa marking for designing evolutionary vaccine, COBRA antigen, center of tree and ancestral were done. Also, over COBRA vaccine sequences, modeling analysis and superimpose test were done. Results: In both R. microplus and R. annulatus, the most variable region were residues 177-181, 270-276, and 351-352, respectively. 6 sequences were selected as appropriate sequences for design of evolutionary vaccine, and 12 for the realignment of and achieving sequences for design of COBRA antigen. On the other hand, R. annulatus sequences were in sister branches and more similar to each other compared to Bm86 protein sequences in R. microplus except ADQ19687. The sequences selected for vaccine design based on the center of tree and ancestral, were AJE29931, AJE29932, and ATW75472, and ATW5476, ADM86722, ACZ55133 sequences, respectively. Conclusion: Anti-tick COBRA-based vaccines of Bm86 could be more cost-effective and better alternative with broader spectrum, compared to the commonly used recombinant vaccines.