Some experimental studies used this approach against

tick infestations [16], [17], [18], [19], [20], [21], [22] and [23]; however, in most cases, this strategy resulted in a statistical significant but slightly improvement in protection level. Although tick infestation inhibitors experiments using bovines in confined indoors can indicate vaccine efficacy, field trials http://www.selleckchem.com/products/pci-32765.html are necessary to evaluate vaccine performance under real husbandry conditions [24]. However, most of the protocols used in experiments to evaluate bovine vaccination against ticks employ confined bovines, a more practical and cost-saving approach, compared to field experiments which demand laborious handling of cattle and the availability of a large area [16] and [25]. Our research group has been studying several R. microplus molecules in order to find antigens that could be used in an anti-tick vaccine. In previous studies, immunizations of cattle with native or recombinant forms of an aspartic protease named BoophilusYolk pro-cathepsin (BYC) induced overall protections selleck chemical (measured

by the reproductive potential, including reduction in number and weight of engorging ticks and in egg weight and hatchability) around 30% [26] and [27]. Also, immunization with a R. microplus cysteine endopeptidase (VTDCE), involved in vitellin digestion [28] and [29], elicited an immunoprotection of 21% in vaccinated cattle [30]. More recently, an overall protective efficacy of 57% against R. microplus was achieved using a

recombinant Haemaphysalis longicornis GST (rGST-Hl) [31]. In this work, we evaluated a multi-antigenic vaccine composed by BYC, VTDCE and GST-Hl recombinant proteins against R. microplus infestation in cattle. Vaccine efficiency was evaluated under field conditions, based on semi-engorged female tick numbers and weight gain differences between vaccinated and control cattle groups. rGST-Hl, rBYC, and rVTDCE were expressed and purified as previously described [32], [33] and [34]. Briefly, rBYC and rGST-Hl were expressed in Escherichia (-)-p-Bromotetramisole Oxalate coli strain AD494 (DE3) pLysS. Recombinant VTDCE was expressed in E. coli strain BL21 (DE3) Star. The insoluble forms of rBYC and rVTDCE were solubilized with 6 M guanidine hydrochloride (GuHCl) and purified using a nickel-chelating Sepharose column (GE Healthcare, Uppsala, Sweden). The soluble form of recombinant GST-Hl was purified through affinity chromatography using GSTrap FF column (GE Healthcare, Uppsala, Sweden). Protein concentrations were determined by the Bradford method [35] and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) using bovine serum albumin as standard.