Vaccination with recombinant actin from scab mites and evaluation of its protective efficacy against Psoroptes cuniculi infection

Abstract

The mite Psoroptes cuniculi is globally widespread and has a serious impact on commercial rabbit breeding. Current treatment methods are based on chemotherapy. Because of the disadvantages of these methods, alternative measures are required, and vaccination is one of the most promising strategies. Here, we cloned and expressed the recombinant P. cuniculi actin gene (rPc-act). Antiserum levels against rPc-act in rabbits were used to locate actin distribution in mite sections. Challenge trials were carried out to evaluate the immunity protection of rPc-act in rabbits, with antibody levels determined by ELISA. Sequence analysis of this gene fragment showed 89·26% and 84·91% identity to Sarcoptes scabiei and Mayetiola destructor sequences, respectively. Immunohistochemistry showed rPc-act to locate widely throughout the mites, especially in feet and muscle tissues. Recombinant P. cuniculi actin with QuliA adjuvant was used to immunize six rabbits. Each animal was challenge-infested with 25-50 adult mites. Although IgE levels showed no significant difference to controls, IgG levels were significantly higher, and clinical development showed no significantly different severity of lesions in vaccinated rabbits than in the controls. This study showed that rPc-act is a muscular isotype actin and has no clinical protective efficacy against P. cuniculi.

Preliminary analysis of Psoroptes ovis transcriptome in different developmental stages

“…In particular, we characterized putative P. ovis allergen genes and analyzed differences in in gene expression between larval and adult/nymph stages, which lays the foundations for research into the pathogenic properties of these two mite stages. At present, only eight allergen genes have been studied in-depth in P. ovis : pso2 [48], actin [49], pso1 [50], pso10 [51], pso11 [51], vitellogenin [52], gst [53], and troponin C [31]. In this study, comparisons of P. ovis DEGs against allergen protein sequences resulted in 188 predicted allergen genes.…”

New salivary anti-haemostatics containing protective epitopes from Ornithodoros moubata ticks: Assessment of their individual and combined vaccine efficacy

“…With the exception of actin, these proteins might have also contributed to the protective responses induced by the SGE and the purified Om44 antigen, so they could also be regarded as candidate antigens for vaccine development. Actin was excluded as a potential vaccine antigen owing to its high degree of conservation between ticks and mammals and to the lack of protective effects observed by us in a preliminary vaccine trial (unpublished) and by other authors using actin in vaccine trials against other parasites (Zheng et al, 2013).…”