How relevant are in vitro culture models for study of tick-pathogen interactions?

ABSTRACT

Although tick-borne infectious diseases threaten human and animal health worldwide, with constantly increasing incidence, little knowledge is available regarding vector–pathogen interactions and pathogen transmission. In vivo laboratory study of these subjects using live, intact ticks is expensive, labor-intensive, and challenging from the points of view of biosafety and ethics. Several in vitro models have been developed, including over 70 continuous cell lines derived from multiple tick species and a variety of tick organ culture systems, facilitating many research activities. However, some limitations have to be considered in the translation of the results from the in vitro environment to the in vivo situation of live, intact ticks, and vertebrate hosts. In this review, we describe the available in vitro models and selected results from their application to the study of tick-borne viruses, bacteria, and protozoa, where possible comparing these results to studies in live, intact ticks. Finally, we highlight the strengths and weaknesses of in vitro tick culture models and their essential role in tick-borne pathogen research.

KEYWORDS:

• Ticks
• tick cell lines
• organ culture
• tick-borne
• in vitro model
• virus
• bacteria
• protozoa

Acknowledgments

CS is funded by the University of Padua. SM’s research is supported by the French Agency for Food, Environmental and Occupational Health & Safety (ANSES). HA is funded by the National Institute for Agriculture, Food and Environment (INRAE). LBS is funded by the United Kingdom Biotechnology and Biological Sciences Research Council grant number BB/P024270/1.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

CS drafted section 1; LBS drafted section 2; SM and CS drafted section 3; LD and LBS drafted section 4; EZ drafted section 5; HA drafted section 6; CS and LBS drafted section 7; LBS edited all sections and all authors revised and agreed to the final version of the manuscript.

Additional information

Funding

This work was supported by the Agence Nationale de Sécurité Sanitaire de l’Alimentation, de l’Environnement et du Travail; Biotechnology and Biological Sciences Research Council [BB/P024270/1]; Institut National de Recherche en Sciences et Technologies pour l’Environnement et l’Agriculture; Università degli Studi di Padova [DOR2020-DOR2021].