Nuttall P A, Paesen G C, Lawrie C H, Wang H
CEH Institute of Virology and Environmental Microbiology, Oxford, UK.
J Mol Microbiol Biotechnol. 2000 Oct;2(4):381-6.
Tick-borne spirochetes include borreliae that cause Lyme disease and relapsing fever in humans. They survive in a triangle of parasitic interactions between the spirochete and its vertebrate host, the spirochete and its tick vector, and the host and the tick. Until recently, the significance of vector-host interactions in the transmission of arthropod-borne disease agents has been overlooked. However, there is now compelling evidence that the pharmacological activity of tick saliva can have a profound effect on pathogen transmission both from infected tick to uninfected host, and from infected host to uninfected tick. The salivary glands of ticks provide a pharmacopoeia of anti-inflammatory, anti-haemostatic and anti-immune molecules. These include bioactive proteins that control histamine, bind immunoglobulins, and inhibit the alternative complement cascade. The effect of these molecules is to provide a privileged site at the tick-host interface in which borreliae and other tick-borne pathogens are sheltered from the normal innate and acquired host immune mechanisms that combat infections. Understanding the key events at the tick vector-host interface, that promote spirochete infection and transmission, will provide a better understanding of the epidemiology and ecology of these important human pathogens.
蜱传播的螺旋体包括可导致人类莱姆病和回归热的疏螺旋体。它们在螺旋体与其脊椎动物宿主、螺旋体与其蜱虫媒介以及宿主与蜱虫之间的寄生相互作用三角关系中生存。直到最近，节肢动物传播的病原体传播过程中媒介 - 宿主相互作用的重要性一直被忽视。然而，现在有确凿证据表明，蜱唾液的药理活性对病原体从受感染蜱虫传播到未感染宿主以及从受感染宿主传播到未感染蜱虫都能产生深远影响。蜱的唾液腺提供了一系列具有抗炎、抗止血和抗免疫作用的分子。这些分子包括控制组胺、结合免疫球蛋白以及抑制替代补体级联反应的生物活性蛋白。这些分子的作用是在蜱 - 宿主界面提供一个特殊位点，疏螺旋体和其他蜱传播的病原体在其中免受宿主对抗感染的正常先天性和获得性免疫机制的影响。了解蜱虫媒介 - 宿主界面促进螺旋体感染和传播的关键事件，将有助于更好地理解这些重要人类病原体的流行病学和生态学。
