Mining a differential sialotranscriptome of Rhipicephalus microplus guides antigen discovery to formulate a vaccine that reduces tick infestations

Background: ticks cause massive damage to livestock and vaccines are one sustainable substitute for the acaricides currently heavily used to control infestations. to guide antigen discovery for a vaccine that targets the gamut of parasitic strategies mediated by tick saliva and enables immunological memory,we exploited a transcriptome constructed from salivary glands from all stages of rhipicephalus microplus ticks feeding on genetically tick-resistant and susceptible bovines. results: different levels of host anti-tick immunity affected gene expression in tick salivary glands; we thus selected four proteins encoded by genes weakly expressed in ticks attempting to feed on resistant hosts or otherwise abundantly expressed in ticks fed on susceptible hosts; these sialoproteins mediate four functions of parasitism deployed by male ticks and that do not induce antibodies in naturally infected,susceptible bovines. we then evaluated in tick-susceptible heifers an alum-adjuvanted vaccine formulated with recombinant proteins. parasite performance (i.e. weight and numbers of females finishing their parasitic cycle) and titres of antigen-specific antibodies were significantly reduced or increased,respectively,in vaccinated versus control heifers,conferring an efficacy of 73.2%; two of the antigens were strong immunogens,rich in predicted t-cell epitopes and challenge infestations boosted antibody responses against them. conclusion: mining sialotranscriptomes guided by the immunity of tick-resistant hosts selected important targets and infestations boosted immune memory against salivary antigens. © 2017 the author(s).