Dermacentor marginatus is a widespread tick species and a vector of many pathogens in Eurasia. Due to the medical importance of D. marginatus, control measures are needed for this tick species. Currently tick control approaches rely mostly on acaricide application, whereas wrong and irrational acaricide use may result in drug resistance and residue problems. Vaccination as an alternative approach for tick control has been proven to be effective towards some tick species. However, immunization against D. marginatus has not yet reached satisfactory protection. The effort of in silico based analysis could predict antigenicity and identify candidates for anti-tick vaccine development. We carried out an in silico analysis of D. marginatus glutathione S-transferases (DmGSTs) in order to identify blood-feeding induced GSTs as antigens that can be used in anti-tick vaccine development. Phylogenetic analysis, linear B-cell epitope prediction, homology modeling, and conformational B-cell epitope mapping on the GST models were performed to identify highly antigenic DmGSTs. Relative gene expressions of the seven GSTs were profiled through real-time quantitative PCR (RT-qPCR) to outline GSTs up-regulated during blood feeding. The phylogenetic analysis indicated that the seven GSTs belonged to four classes of GST, including one in epsilon-class, one in zeta-class, one in omega-class, and four in mu-class. Linear B-cell epitope prediction revealed mu-class GSTs share similar conserved antigenic regions. The conformational B-cell epitope mapped on the homology model of the GSTs displayed that GSTs of mu-class showed stronger antigenicity than that of other classes. RT-qPCR revealed DmGSTM1 and DmGSTM2 were positively related to blood feeding. In sum, the data suggest that DmGSTM1 and DmGSTM2 could be tested for potential anti-tick vaccine trials.

Dermacentor marginatus是一种广泛分布的蜱物种，也是欧亚大陆许多病原体的载体。由于D. marginatus的医学重要性，需要对这种蜱物种采取控制措施。目前蜱虫控制方法主要依赖于杀螨剂的应用，而错误和不合理的杀螨剂使用可能会导致耐药性和残留问题。疫苗接种作为控制蜱的替代方法已被证明对某些蜱物种有效。然而，针对D. marginatus的免疫接种尚未达到令人满意的保护效果。基于计算机的分析工作可以预测抗原性并确定抗蜱疫苗开发的候选者。我们对D. marginatus进行了计算机分析谷胱甘肽 S-转移酶 (DmGSTs) 以将供血诱导的 GSTs 鉴定为可用于抗蜱疫苗开发的抗原。对 GST 模型进行系统发育分析、线性 B 细胞表位预测、同源性建模和构象 B 细胞表位作图，以鉴定高抗原性 DmGST。通过实时定量 PCR (RT-qPCR) 对七种 GST 的相对基因表达进行分析，以概述在血液喂养期间上调的 GST。系统发育分析表明，7个GST属于4类GST，其中ε类1个，zeta类1个，omega类1个，mu类4个。线性 B 细胞表位预测显示 mu 类 GST 具有相似的保守抗原区域。GSTs同源模型上的构象B细胞表位显示，mu类的GSTs比其他类的GSTs具有更强的抗原性。RT-qPCR 显示 DmGSTM1 和 DmGSTM2 与血液喂养呈正相关。总之，数据表明 DmGSTM1 和 DmGSTM2 可以用于潜在的抗蜱疫苗试验。