Mangia Carlo, Vismarra Alice, Kramer Laura, Bell-Sakyi Lesley, Porretta Daniele, Otranto Domenico, Epis Sara, Grandi Giulio
Department of Veterinary Sciences, University of Parma, 43126, Parma, Italy.
The Pirbright Institute, Ash Road, Pirbright, Surrey GU24 0NF, Pirbright, UK.
Parasit Vectors. 2016 Apr 18;9:215. doi: 10.1186/s13071-016-1497-2.
Ticks are among the most important vectors of pathogens causing human and animal disease. Acaricides are used to control tick infestation, although there are increasing reports of resistance. Recently, over-expression of ATP-binding cassette (ABC) transporter proteins (P-glycoproteins, PgP) has been implicated in resistance to the acaricide ivermectin in the ticks Rhipicephalus (Boophilus) microplus and Rhipicephalus sanguineus sensu lato. Ixodid tick cell lines have been used to investigate drug resistance mechanisms. The aim of the present study was to evaluate expression of several PgPs in the Ixodes ricinus-derived cell line IRE/CTVM19 and to determine modulation of expression following treatment with ivermectin.
IRE/CTVM19 cells were treated with different concentrations of ivermectin (0, 11, 22 or 33 μM) and incubated for 10 days. Evaluation of viability and relative expression of ABCB1, ABCB6, ABCB8 and ABCB10 genes were carried out at day 10 post treatment. Cell viability ranged between 84% and 92% with no significant differences between untreated and treated cells. qRT-PCR showed that ABC pump expression was not significantly modulated by ivermectin treatment. Expression of the ABCB8 PgP subfamily revealed a biphasic trend, based on the ivermectin concentration. ABCB6 and ABCB10 gene expression was not modulated by ivermectin treatment and ABCB1 expression was not detected.
This is the first report of PgP expression in an I. ricinus-derived tick cell line. Development of an in vitro model for the study of acaricide resistance mechanisms would greatly facilitate screening for drug resistance in ticks.
蜱是导致人类和动物疾病的最重要病原体传播媒介之一。杀螨剂用于控制蜱虫侵扰，尽管关于耐药性的报道日益增多。最近，在微小牛蜱和广义血红扇头蜱中，ATP结合盒（ABC）转运蛋白（P-糖蛋白，PgP）的过表达与对杀螨剂伊维菌素的耐药性有关。硬蜱细胞系已被用于研究耐药机制。本研究的目的是评估蓖麻蜱来源的IRE/CTVM19细胞系中几种PgP的表达，并确定伊维菌素处理后表达的调节情况。
IRE/CTVM19细胞用不同浓度的伊维菌素（0、11、22或33 μM）处理，并孵育10天。在处理后第10天评估细胞活力以及ABCB1、ABCB6、ABCB8和ABCB10基因的相对表达。细胞活力在84%至92%之间，未处理和处理后的细胞之间无显著差异。定量逆转录聚合酶链反应（qRT-PCR）表明，伊维菌素处理未显著调节ABC转运蛋白的表达。基于伊维菌素浓度，ABCB8 PgP亚家族的表达呈现双相趋势。伊维菌素处理未调节ABCB6和ABCB10基因的表达，且未检测到ABCB1的表达。
这是关于蓖麻蜱来源的蜱细胞系中PgP表达的首次报道。开发用于研究杀螨剂耐药机制的体外模型将极大地促进蜱虫耐药性的筛选。
