Characterisation of a cysteine protease from poultry red mites and its potential use as a vaccine for chickens.

Shiro Murata,Ayaka Taniguchi,Takuya Ito,Masayoshi Isezaki,Eishi Sakai,Tomohiro Okagawa,Kazuhiko Ohashi,Sotaro Fujisawa,Akira Taneno,Osamu Ichii,Satoru Konnai,Naoya Maekawa

doi:10.1051/parasite/2021005

Shiro Murata, Ayaka Taniguchi + Show 10 more

Open Access

https://doi.org/10.1051/parasite/2021005

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Abstract

Poultry red mites (PRMs, Dermanyssus gallinae) are ectoparasites that negatively affect farmed chickens, leading to serious economic losses worldwide. Acaricides have been used to control PRMs in poultry houses. However, some PRMs have developed resistance to acaricides, and therefore different approaches are required to manage the problems caused by PRMs. Vaccination of chickens is one of the methods being considered to reduce the number of PRMs in poultry houses. In a previous study, a cysteine protease, Deg-CPR-1, was identified as a candidate vaccine against PRMs distributed in Europe. In this study, we investigated the characteristics of Deg-CPR-1. A phylogenetic analysis revealed that Deg-CPR-1 is closely related to the digestive cysteine proteases of other mite species, and it was classified into a cluster different from that of chicken cathepsins. Deg-CPR-1 of PRMs in Japan has an amino acid substitution compared with that of PRMs in Europe, but it showed efficacy as a vaccine, consistent with previous findings. Deg-CPR-1 exhibited cathepsin L-like enzyme activity. In addition, the Deg-CPR-1 mRNA was expressed in the midgut and in all stages of PRMs that feed on blood. These results imply that Deg-CPR-1 in the midgut may have important functions in physiological processes, and the inhibition of its expression may contribute to the efficacy of a Deg-CPR-1-based vaccine. Further research is required to fully understand the mechanisms of vaccine efficacy.

Highlights

The poultry red mite (PRM), Dermanyssus gallinae (De Geer 1778), one of the major haematophagous ectoparasites in poultry farming, causes severe economic loses, mainly to the laying hen sector [23]
We investigated the characteristics of Deg-CPR-1, a cysteine protease, from PRMs
An amino acid substitution was observed within Deg-CPR-1 when European and Japanese PRMs were compared

Summary

Introduction

The poultry red mite (PRM), Dermanyssus gallinae (De Geer 1778), one of the major haematophagous ectoparasites in poultry farming, causes severe economic loses, mainly to the laying hen sector [23]. Pesticide-resistant PRMs are difficult to control, and other management strategies are required to ensure animal welfare and to reduce the economic losses in poultry farming [23]. The vaccine efficacy of both these cysteine proteases has been assessed; the results revealed a significant decrease in the survival rate of PRMs when they were fed heparinised blood of chickens immunised with Deg-CPR-1 [4]. These results suggest that Deg-CPR-1 could be developed as an anti-PRM vaccine. To further investigate the potential of Deg-CPR-1 as a vaccine antigen, in this study, we further characterised its genetic characteristics, enzyme activity, and gene expression

Materials and methods

Discussion

Findings

Conflict of interest