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

Abstract

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.