The Tick Cell Biobank: A global resource for in vitro research on ticks, other arthropods and the pathogens they transmit

Abstract

Tick cell lines are increasingly used in many fields of tick and tick-borne disease research. The Tick Cell Biobank was established in 2009 to facilitate the development and uptake of these unique and valuable resources. As well as serving as a repository for existing and new ixodid and argasid tick cell lines, the Tick Cell Biobank supplies cell lines and training in their maintenance to scientists worldwide and generates novel cultures from tick species not already represented in the collection. Now part of the Institute of Infection and Global Health at the University of Liverpool, the Tick Cell Biobank has embarked on a new phase of activity particularly targeted at research on problems caused by ticks, other arthropods and the diseases they transmit in less-developed, lower- and middle-income countries. We are carrying out genotypic and phenotypic characterisation of selected cell lines derived from tropical tick species. We continue to expand the culture collection, currently comprising 63 cell lines derived from 18 ixodid and argasid tick species and one each from the sand fly Lutzomyia longipalpis and the biting midge Culicoides sonorensis, and are actively engaging with collaborators to obtain starting material for primary cell cultures from other midge species, mites, tsetse flies and bees. Outposts of the Tick Cell Biobank will be set up in Malaysia, Kenya and Brazil to facilitate uptake and exploitation of cell lines and associated training by scientists in these and neighbouring countries. Thus the Tick Cell Biobank will continue to underpin many areas of global research into biology and control of ticks, other arthropods and vector-borne viral, bacterial and protozoan pathogens.

Hard ticks as research resources for vector biology: from genome to whole-body level

“…Pathogen-free tick colonies are essential as references in studies on tick-pathogen interactions (Battsetseg et al, 2001;Fujisaki, 1978;Ikadai et al, 2007;Patel et al, 2016;Tonetti et al, 2015;Umemiya-Shirafuji et al, 2017). In addition to tick colonies, the Tick Cell Biobank was established in 2009, covers 30 collaborating institutes in Asia, Africa, the Americas and Europe, and the cell lines it distributes have become essential auxiliary tools for promotion of tick research (Bell-Sakyi et al, 2018). The cell lines of hard ticks are derived from genera Amblyomma, Dermacentor, Hyalomma, Ixodes, Rhipicephalus and subgenus Boophilus, but there is no cell line of genus Haemaphysalis at present (Nakao, 2019).…”

“…Some cell lines have been subjected to studies on genomics, biology and physiology, innate immunity, tick-borne pathogens and microbiome. The genome of I. ricinus and I. scapularis cell lines have been sequenced (Bell-Sakyi et al, 2018;Murgia et al, 2019). Although the cell lines are excellent tools for tick research, in vitro experiments using the cells sometimes cause difficulty to extrapolate experimental results and apply to natural conditions.…”

Tick Cell Lines in Research on Tick Control

“…Tick cell lines have an invaluable role to play in many aspects of tick and TBP research including tick biology, hostvector-pathogen relationships, genetic manipulation, genomics and proteomics (Bell-Sakyi et al, 2007). In addition, tick cell lines play a major role as essential tools in in vitro studies to examine and assess the impact of chemical molecules and vaccines against ticks and TBPs, as well as to investigate the mechanisms of resistance and tick metabolism which can lead to the development of novel approaches to control ticks and TBPs (Bell-Sakyi et al, 2018). While >60 continuous cell lines have now been established from 16 ixodid and three argasid tick species (Bell-Sakyi et al, 2018), studies on tick and pathogen control have predominantly centered around cell lines derived from, not surprisingly, R. microplus.…”

“…In addition, tick cell lines play a major role as essential tools in in vitro studies to examine and assess the impact of chemical molecules and vaccines against ticks and TBPs, as well as to investigate the mechanisms of resistance and tick metabolism which can lead to the development of novel approaches to control ticks and TBPs (Bell-Sakyi et al, 2018). While >60 continuous cell lines have now been established from 16 ixodid and three argasid tick species (Bell-Sakyi et al, 2018), studies on tick and pathogen control have predominantly centered around cell lines derived from, not surprisingly, R. microplus. A smaller number of studies have used cell lines derived from other tropical Rhipicephalus species of veterinary importance, from Ixodes ricinus, a European tick that feeds on a wide range of domestic and wild animal hosts as well as attacking humans, and from the medically important North American species Ixodes scapularis (Table 1).…”

A tick cell line as a powerful tool to screen the antimicrobial susceptibility of the tick-borne pathogen Anaplasma marginale

“…Therefore, we established an in vitro assay using the embryonic cell line ISE6 of I. scapularis( 21 ), which is easy to maintain in laboratory conditions( 21 ). Indeed, in the last years, tick cell lines have been shown to be a potent tool for the study of parasite biology and parasite-host relationship( 22 ). These models allow not only a great control of the experimental conditions, but also the evaluation of molecular interactions between ticks and the pathogens transmitted by them without involving the use of vertebrate animals.…”