The role of basophils in acquired protective immunity to tick infestation.

Soichiro Yoshikawa,Kensuke Miyake,Hajime Karasuyama,Atsunori Kamiya

doi:10.1111/pim.12804

Soichiro Yoshikawa, Kensuke Miyake + Show 2 more

Open Access

https://doi.org/10.1111/pim.12804

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Abstract

Ticks are blood‐feeding ectoparasites that transmit a variety of pathogens to host animals and humans, causing severe infectious diseases such as Lyme disease. In a certain combination of animal and tick species, tick infestation elicits acquired immunity against ticks in the host, which can reduce the ability of ticks to feed on blood and to transmit pathogens in the following tick infestations. Therefore, our understanding of the cellular and molecular mechanisms of acquired tick resistance (ATR) can advance the development of anti‐tick vaccines to prevent tick infestation and tick‐borne diseases. Basophils are a minor population of white blood cells circulating in the bloodstream and are rarely observed in peripheral tissues under steady‐state conditions. Basophils have been reported to accumulate at tick‐feeding sites during re‐infestation in cattle, rabbits, guinea pigs and mice. Selective ablation of basophils resulted in a loss of ATR in guinea pigs and mice, illuminating the essential role of basophils in the manifestation of ATR. In this review, we discuss the recent advance in the elucidation of the cellular and molecular mechanisms underlying basophil recruitment to the tick‐feeding site and basophil‐mediated ATR.

Highlights

Ticks (Acari: Ixodidae) are haematophagous and obligate ectoparasites that feed on blood of animals and humans
It has been reported that acquired tick resistance (ATR) can be induced in some animal species after experiencing a single or multiple tick infestation(s),[4,5,6] despite that ticks inject saliva substances, including immunosuppressive and anti-inflammatory factors, into the host during blood feeding to facilitate their blood feeding.[7,8,9,10]
It remained unclear whether either mast cells or basophils or both are important for ATR in mice

Summary

Introduction

Ticks (Acari: Ixodidae) are haematophagous and obligate ectoparasites that feed on blood of animals and humans. Steeves et al discovered the infiltration of basophils at the tick-feeding site of mice re-infested with D. variabilis larvae by using electron microscopy which can definitely identify mouse basophils.[29] Mast cell-deficient WBB6F1-W/Wv mice were able to develop acquired resistance to the infestation with larval D. variabilis, unlike the observation in mice infested with H. longicornis.[29] it remained unclear whether either mast cells or basophils or both are important for ATR in mice.

Results

Conclusion