Advances in tick vaccinology in Brazil: from gene expression to immunoprotection.

Rhipicephalus (Boophilus) microplus has substantial economic impact on the cattle breeding industry and, chemical control and tick resistance development are the major concern. There is a worldwide search for new options, and control using vaccines has been the main focus nowadays. Studies performed in Brazil found that Bm86-based immunization of bovines reduced the infestation of R. (B.) microplus of vaccinated bovines by 45% to 60%. Native Boophilusmicroplus tripsin inhibitors (BmTIs) with trypsin-, kallikrein-, and elastase-inhibiting activities have been used as immunogens in bovines reaching 72.8.% of efficacy. The reverse vaccinology approach has also been used for antigen search using transcriptome analysis to identify and characterize potential antigens. Study has generated more than 600 million sequences using RNA-seq of larvae, nymphs, salivary glands, intestines, and ovaries of the tick R. (B) microplus. Based on the set of transcripts obtained using this strategy, a total of 20,326 protein sequences have been identified. A pipeline analysis built in house identified the protein sequences that were most likely to be immunogenic based on the overall structural characteristic analysis.