背景:蜱是具有不同宿主特异性的采血外寄生虫,能够传播病原体。铁调节蛋白(IRP)在脊椎动物的铁稳态中起着至关重要的作用。然而,它们在蜱中的功能仍然知之甚少。本研究的目的是调查这些特征,功能,分子机制,以及IRP在硬蜱长骨干中的疫苗效力。
结果:长尾血囊IRP的全长互补DNA(HlIRP)为2973bp,包括一个2772bp的开放阅读框。它在三个发育阶段表达(幼虫,若虫,和成年女性)和各种组织(唾液腺,卵巢,中肠,和Malpighian小管)。通过原核表达系统获得了重组的长尾血栓素IRP(rHlIRP),并表现出乌头酸酶,铁螯合,自由基清除,和体外溶血活性。RNA干扰介导的IRP敲低降低蜱充血重量,卵巢重量,鸡蛋质量重量,卵孵化率,和卵巢卵黄蛋白含量,以及延长卵子的潜伏期。蛋白质组学显示IRP可能通过蛋白酶体途径影响蜱的繁殖和发育,核糖体,生殖相关,和铁代谢相关的蛋白质.对兔进行的一项针对成虫长齿血丝感染的试验表明,rHlIRP疫苗可以显着降低充血体重(减少10%),蜱的蛋质量重量(16%)和蛋孵化率(22%)。使用rHlIRP对成年女性的总体免疫效力为41%。
结论:IRP可限制长尾血齿的繁殖和发育,HlIRP被确认为候选疫苗抗原,可损害蜱铁代谢并保护宿主免受蜱感染。©2024化学工业学会。
BACKGROUND: Ticks are blood-feeding ectoparasites with different host specificities and are capable of pathogen transmission. Iron regulatory proteins (IRPs) play crucial roles in iron homeostasis in vertebrates. However, their functions in ticks remain poorly understood. The aim of the present study was to investigate the characteristics, functions, molecular mechanisms, and the vaccine efficacy of IRP in the hard tick Haemaphysalis longicornis.
RESULTS: The full-length complementary DNA of IRP from Haemaphysalis longicornis (HlIRP) was 2973 bp, including a 2772 bp open reading frame. It is expressed throughout three developmental stages (larvae, nymphs, and adult females) and in various tissues (salivary glands, ovaries, midgut, and Malpighian tubules). Recombinant Haemaphysalis longicornis IRP (rHlIRP) was obtained via a prokaryotic expression system and exhibited aconitase, iron chelation, radical-scavenging, and hemolytic activities in vitro. RNA interference-mediated IRP knockdown reduced tick engorgement weight, ovary weight, egg mass weight, egg hatching rate, and ovary vitellin content, as well as prolonging the egg incubation period. Proteomics revealed that IRP may affect tick reproduction and development through proteasome pathway-associated, ribosomal, reproduction-related, and iron metabolism-related proteins. A trial on rabbits against adult Haemaphysalis longicornis infestation demonstrated that rHlIRP vaccine could significantly decrease engorged weight (by 10%), egg mass weight (by 16%) and eggs hatching rate (by 22%) of ticks. The overall immunization efficacy using rHlIRP against adult females was 41%.
CONCLUSIONS: IRP could limit reproduction and development in Haemaphysalis longicornis, and HlIRP was confirmed as a candidate vaccine antigen to impair tick iron metabolism and protect the host against tick infestation. © 2024 Society of Chemical Industry.