Department of Biochemistry, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719, Olsztyn, Poland.
Global Health and Tropical Medicine, GHTM, Associate Laboratory in Translation and Innovation Towards Global Health, LA-REAL, Instituto de Higiene e Medicina Tropical, IHMT, Universidade NOVA de Lisboa, UNL, Rua da Junqueira 100, 1349-008, Lisboa, Portugal.
Dev Comp Immunol. 2024 Nov;160:105231. doi: 10.1016/j.dci.2024.105231. Epub 2024 Jul 21.
The immune system of ticks, along with that of other invertebrates, is comparatively simpler than that of vertebrates, relying solely on innate immune responses. Direct antimicrobial defence is provided by the synthesis of antimicrobial peptides (AMPs), including defensins. The aim of this study was to investigate the differences in defensin genes expression between questing and engorged Ixodes ricinus (def1 and def2) and Dermacentor reticulatus (defDr) ticks, in the presence of selected pathogens: Borrelia spp., Rickettsia spp., Babesia spp., Anaplasma phagocytophilum, and Neoehrlichia mikurensis in the natural environment. After pathogen screening by PCR/qPCR, the expression of defensin genes in pathogen positive ticks and ticks without any of the tested pathogens, was analysed by reverse transcription qPCR. The results showed an increased expression of defensin genes in I. ricinus ticks after blood feeding and I. ricinus and D. reticulatus ticks during in cases of co-infection. In particular, the expression of defensins genes was higher in questing D. reticulatus than in questing and engorged I. ricinus ticks, when borreliae were detected. This study contributes to uncovering the expression patterns of defensin genes in the presence of several known tick pathogens, the occurrence of these pathogens and possible regulatory mechanisms of defensins in tick vector competence.
蜱的免疫系统与其他无脊椎动物的免疫系统相比相对简单，仅依赖于先天免疫反应。抗菌肽 (AMPs) 的合成提供了直接的抗菌防御，包括防御素。本研究旨在研究在自然环境中存在选定病原体（伯氏疏螺旋体、立克次体、巴贝斯虫、嗜吞噬细胞无形体和新立克次体）时，游离和饱血的硬蜱（def1 和 def2）和扇头蜱（defDr）中防御素基因表达的差异。通过 PCR/qPCR 进行病原体筛选后，通过逆转录 qPCR 分析了防御素基因在携带病原体的蜱和未携带任何测试病原体的蜱中的表达。结果表明，硬蜱和扇头蜱在饱血后以及在合并感染时，防御素基因的表达增加。特别是，当检测到伯氏疏螺旋体时，游离的扇头蜱中的防御素基因表达高于游离和饱血的硬蜱。本研究有助于揭示在存在几种已知蜱病原体的情况下防御素基因的表达模式，这些病原体的发生以及防御素在蜱媒介能力中的可能调控机制。
