Immunoprotective potential of a Rhipicephalus (Boophilus) microplus metalloprotease

Abstract

Ticks have serious impacts on animal and human health, causing significant economic losses in cattle breeding. Besides damage due to the hematophagous behavior, they transmit several pathogens. Low cost and environmental safety have made vaccines a promising alternative control method against tick infestation. Metalloproteases (MPs) have been shown to be essential for diverse biological functions in hematophagous organisms, inhibiting blood clotting, degrading extracellular matrix proteins, and inhibiting host tissue repair via anti-angiogenic activity. In this study, we analyzed the immunoprotective potential of a recombinant MP against Rhipicephalus (Boophilus) microplus infestation. First, a cDNA encoding R. microplus amino acids sequence with highly conserved regions of the metzincin (reprolysin) group of MP was identified (BrRm-MP4). After expression and purification, recombinant BrRm-MP4 was used as a vaccinal antigen against R. microplus infestation in cattle (Bos taurus taurus). All vaccinated bovines developed immune response to the antigen, resulting in increased antibody level throughout the immunization protocol. Immunization with rBrRm-MP4 reduced tick feeding success, decreasing the number of engorged females and their reproduction potential, representing a 60% overall protection. These results show that rBrRm-MP4 provides protection against tick infestation, placing it is a potential candidate for an anti-tick vaccine.

An insight into the sialome of Hyalomma excavatum

“…Notice that clade XIV, with three sub clades is the only one to contain sequences from the predatory mite Metaseiulus occidentalis , and may represent the ancestral gene that in ticks generated the other clades by gene or genome duplications. Proteins of this family have been targeted as anti-tick vaccines providing partial protection (Ali et al, 2015). …”

The Distinct Transcriptional Response of the Midgut of Amblyomma sculptum and Amblyomma aureolatum Ticks to Rickettsia rickettsii Correlates to Their Differences in Susceptibility to Infection

“…Importantly, the knockdown of both reprolysins and astacins leaded to a reduction of both oviposition and egg weight, demonstrating that those proteins correspond to promising targets for development of strategies to protect the cattle against ticks (Barnard et al, 2012). Indeed, the immunization of bovines with the reprolysin BrRm-MP4 diminished the feeding and reproductive rates of R. microplus females (Ali et al, 2015), strengthening the potential of metalloproteinases as vaccine candidates. Among the metalloproteinases from A. aureolatum , six are reprolysins and two are astacins, while 14 of the metalloproteases of A. sculptum are reprolysins and only one is astacin.…”

The Essential Role of Tick Salivary Glands and Saliva in Tick Feeding and Pathogen Transmission

“…Moreover, this strategy may also cause tick rejection and thus abolish or limit pathogen transmission, which typically occurs many hours or even days after tick attachment for hard ticks. Indeed, encouraging results have been obtained for several tick species including H. longicornis (Mulenga et al, 1999; Imamura et al, 2005; Zhang et al, 2011; Anisuzzaman et al, 2012), R. appendiculatus (Imamura et al, 2006), O. moubata and O. erraticus (Astigarraga et al, 1995; Garcia-Varas et al, 2010), A. americanum (de la Fuente et al, 2010b), R. (B) microplus (Andreotti et al, 2002; Merino et al, 2013; Ali et al, 2015), and I. ricinus (Prevot et al, 2007; Decrem et al, 2008b). Finally, anti-tick vaccination may also target salivary proteins directly implicated in TBP transmission.…”