Evaluation of vaccine potential of 2-Cys peroxiredoxin from the hard tick Haemaphysalis longicornis
Evaluation of vaccine potential of 2-Cys peroxiredoxin from the hard tick Haemaphysalis longicornis
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长角血蜱硬蜱 2-Cys 过氧化还原蛋白的疫苗潜力评估
DOI：
10.1007/s10493-018-0209-3
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
T.
中科院分区：
文献类型：
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作者：
Kusakisako;K.;Miyata;T.;Tsujio;M.;Galay;R. L.;Talactac;M. R.;Hernandez;E. P.;Fujisaki;K. and Tanaka;T.
蜱在其整个生命周期中需要以脊椎动物的血液为食，并且还浓缩含铁的血液，导致高浓度的过氧化氢（H2O2）。高浓度的H2O2对生物体的危害是由于其对大分子的严重破坏。蜱有抗氧化酶，如过氧化物酶（Prxs），它能分解H2O2。Prxs可能在蜱吸血和产卵过程中对H2O2浓度的调节起重要作用。此外，Prxs被认为是其他寄生虫（如利什曼原虫和片形吸虫）的潜在疫苗候选者。在本研究中，评估了蜱Prx（HlPrx2）作为疫苗候选抗原的功效。首先，在大肠杆菌中表达重组HlPrx 2（rHlPrx 2），然后在给药前确认其纯度和内毒素水平。rHlPrx2蛋白具有高纯度，具有可接受的低内毒素水平。第二，评价rHlPrx2施用刺激小鼠免疫的能力。rHlPrx2蛋白在有无佐剂的情况下均能刺激小鼠产生免疫应答，尤其是Th2免疫应答中的IgG1。利用Western blot分析，我们还观察了rHlPrx2免疫小鼠血清是否可以识别天然蜱中肠蛋白中的HlPrx2蛋白。Western印迹分析表明，rHlPrx2给药的小鼠血清可以检测到天然HlPrx2。最后，使用蜱若虫研究rHlPrx2免疫在小鼠中的效果。虽然rHlPrx2免疫对攻毒蜱不产生影响，但由于其高免疫原性，rHlPrx2仍可能被认为是抗蜱的候选疫苗。
Ticks require blood feeding on vertebrate animals throughout their life cycle, and also concentrate the iron-containing blood, resulting in a high concentration of hydrogen peroxide (H2O2). High concentrations of H2O2are harmful to organisms, due to their serious damage of macromolecules. Ticks have antioxidant enzymes, such as peroxiredoxins (Prxs), that scavenge H2O2. Prxs may have important roles in regulating the H2O2concentration in ticks during blood feeding and oviposition. Moreover, Prxs are considered potential vaccine candidates in other parasites, such asLeishmaniaandFasciola. In the present study, the efficacy of a tick Prx (HlPrx2) as a vaccine candidate antigen was evaluated. First, recombinant HlPrx2 (rHlPrx2) was expressed inEscherichia coli, and then, its purity and endotoxin levels were confirmed prior to administration. The rHlPrx2 proteins were of high purity with acceptably low endotoxin levels. Second, the ability of rHlPrx2 administration to stimulate mouse immunity was evaluated. The rHlPrx2 protein, with or without an adjuvant, could stimulate immunity in mice, especially the IgG1 of Th2 immune response. Using Western blot analysis, we also observed whether rHlPrx2-immunized mice sera could recognize native HlPrx2 protein in crude tick midgut proteins. Western blot analysis demonstrated that rHlPrx2-administrated mouse sera could detect the native HlPrx2. Finally, the effects of rHlPrx2 immunization in mice were studied using nymphal ticks. Although the challenged ticks were not affected by rHlPrx2 immunization, rHlPrx2 still might be considered as a vaccine candidate against ticks because of its high immunogenicity.