Abstract：
Babesia gibsoni is an intraerythrocytic apicomplexan parasite transmitted by Haemaphysalis longicornis and causes canine babesiosis. Within the tick, the Babesia parasite undergoes sexual conjugation and the sporogony process of its life cycle. To control B. gibsoni infection, prompt and effective treatment of acute infections and curing chronic carriers are urgently needed. Gene disruption of Plasmodium CCps resulted in blocking the transition of sporozoites from the mosquito midgut to the salivary glands, showing that these proteins are potential targets for the development of a transmission-blocking vaccine. In this study, we described the identification and characterization of three members of the CCp family in B. gibsoni, named CCp1, CCp2, and CCp3. The B. gibsoni sexual stages were induced in vitro by exposing parasites to xanthurenic acid (XA), dithiothreitol (DTT), and tris (2-carboxyethyl) phosphine (TCEP) at serial concentrations. Among them, 100 µM XA-exposed and cultured at 27 °C without CO2B. gibsoni presented diverse morphologies, including parasites with long projections, gradually increased free merozoites, and aggregated and round forms, indicative of sexual stage induction. Then, the expression of CCp proteins of induced parasites was confirmed by real-time reverse transcription PCR, immunofluorescence, and western blot. The results showed that BgCCp genes were highly significantly increased at 24 h post-sexual stage induction (p < 0.01). The induced parasites were recognized by anti-CCp mouse antisera and anti-CCp 1, 2, and 3 antibodies weakly reacted with sexual stage proteins of expected molecular weights of 179.4, 169.8, and 140.0 KDa, respectively. Our observations on morphological changes and confirmation of sexual stage protein expression will advance elemental biological research and lay the foundation for the development of transmission-blocking vaccines against canine babesiosis.
摘要：
gibsoni巴贝斯虫是一种由长钩血丝传播的红细胞内尖丛寄生虫，可引起犬巴贝斯虫病。在滴答内，巴贝虫寄生虫经历了性结合和其生命周期的孢子病过程。为了控制GibsoniB.感染,迫切需要迅速有效地治疗急性感染和治愈慢性携带者。疟原虫CCps的基因破坏导致子孢子从蚊子中肠向唾液腺的过渡被阻断,表明这些蛋白质是开发阻断传播疫苗的潜在靶标。在这项研究中,我们描述了B.gibsoni中CCp家族的三个成员的鉴定和表征，命名为CCp1、CCp2和CCp3。通过将寄生虫暴露于xanthurenic酸（XA）在体外诱导了B.gibsoni性阶段，二硫苏糖醇(DTT),和连续浓度的三(2-羧乙基)膦(TCEP)。其中,暴露于100μMXA并在27°C培养，无CO2B。Gibsoni呈现了不同的形态，包括长突起的寄生虫，逐渐增加的自由裂殖子，以及聚合和圆形形式，表明性阶段诱导。然后，通过实时逆转录PCR证实了诱导寄生虫CCp蛋白的表达，免疫荧光，和westernblot.结果表明，BgCCp基因在性阶段诱导后24h高度显着增加（p<0.01）。诱导的寄生虫被抗CCp小鼠抗血清和抗CCp1、2和3抗体识别，与预期分子量为179.4、169.8和140.0KDa的性阶段蛋白弱反应，分别。我们对形态学变化和性阶段蛋白表达的确认的观察将促进元素生物学研究，并为开发针对犬巴贝斯虫病的传播阻断疫苗奠定基础。
