Subolesin vaccination inhibits blood feeding and reproduction of Haemaphysalis longicornis in rabbits

Abstract

Background Ticks can transmit numerous tick-borne pathogens and cause a huge economic loss to the livestock industry. Tick vaccines can contribute to the prevention of tick-borne diseases by inhibiting tick infestation or reproduction. Subolesin is an antigenic molecule proven to be a potential tick vaccine against different tick species and even some tick-borne pathogens. However, its effectivity has not been verified in Haemaphysalis longicornis, which is a widely distributed tick species, especially in East Asian countries. Therefore, the purpose of this study was to evaluate the effectivity of subolesin vaccination against H. longicornis in a rabbit model. Methods Haemaphysalis longicornis (Okayama strain, female, adult, parthenogenetic strain) and Japanese white rabbits were used as the model tick and animal, respectively. The whole open reading frame of H. longicornis subolesin (HlSu) was identified and expressed as a recombinant protein using E. coli. The expression was verified using sodium dodecyl sulfate polyacrylamide gel electrophoresis, and the immunogenicity of rHlSu against anti-H. longicornis rabbit serum was confirmed using Western blotting. After vaccination of rHlSu in rabbits, experimental infestation of H. longicornis was performed. Variables related to blood-feeding periods, pre-oviposition periods, body weight at engorgement, egg mass, egg mass to body weight ratio, and egg-hatching periods were measured to evaluate the effectiveness of subolesin vaccination. Results The whole open reading frame of HlSu was 540 bp, and it was expressed as a recombinant protein. Vaccination with rHlSu stimulated an immune response in rabbits. In the rHlSu-vaccinated group, body weight at engorgement, egg mass, and egg mass to body weight ratio were statistically significantly lower than those in the control group. Besides, egg-hatching periods were extended significantly. Blood-feeding periods and pre-oviposition periods were not different between the two groups. In total, the calculated vaccine efficacy was 37.4%. Conclusions Vaccination of rabbits with rHlSu significantly affected the blood-feeding and reproduction in H. longicornis. Combined with findings from previous studies, our findings suggest subolesin has the potential to be used as a universal tick vaccine.

Co-Immunization Efficacy of Recombinant Antigens against Rhipicephalus microplus and Hyalomma anatolicumTick Infestations

“…The TPM antigen induced predominantly IgG over IgG1 and IgG2 on the 15th day PPI, whereas on the 75th and 120th day PPI, a higher level of IgG2 than IgG and IgG2was noted, as reported in [ 37 ]. Isotype switching is heavily influenced by cytokines in the immediate micro-environment of the activated B-cells [ 80 ]. Therefore, after challenges due to tick salivary secretion, it might be changed in the cytokine profile of the host.…”

Evaluation on two types of paramyosin vaccines for the control of Haemaphysalis longicornis infestations in rabbits

“…This may be because DNA inoculation only produces low antigen expression in the range from picograms to nanograms, and the immunogenicity of DNA vaccines is low compared with that of protein vaccines [ 33 ]. However, the calculated vaccination efficacy of the rPmy (60.37%) was higher than 37.4% efficacy of subolesin from H. longicornis [ 34 ]. The results are attributed to different functions of rPmy and subolesin, and the antibodies they induced affect the development of ticks to different degrees.…”

Cross-species immunoprotective antigens (subolesin, ferritin 2 and P0) provide protection against Rhipicephalus sanguineus sensu lato

“…The results of the present study support those of previous experiments in showing the protective effects of these proteins when used separately and in different combinations against different tick species [ 2 , 7 , 10 , 28 , 49 , 51 ]. For example, anti-tick vaccine efficacy for rSUB against tick infestations with homologous and heterologous tick strains ranged between 37.4% and 97% [ 3 , 49 , 63 , 64 ], and for rFER2, the anti-tick vaccine efficiency ranged between 49 and 98% [ 7 , 48 , 51 ], depending on differences in the experimental conditions, such as tick species, developmental stages, hosts and/or adjuvant composition [ 64 ].…”