Membrane-cloaked nanoparticles as mucosal vaccines against giardiasis

项目摘要 蓝氏贾第鞭毛虫（Giardia lamblia）是一种CDC分类B类优先病原体，是引起腹泻病的重要病原体 全世界每年有数以亿计的病例在美国，G.兰布利亚是世界上 寄生虫病暴发的常见原因，流行率为1- 7%。贾第鞭毛虫病是 以腹泻、上腹痛、恶心、呕吐、吸收不良和营养不良为特征，尤其是在 孩子长期后遗症是常见的，即使治疗明显成功，也可能持续存在。 重要的是，感染可以通过摄入少于10个包囊来启动，这表明G。兰布利亚群岛 传染性很强，对公共供水安全和健康构成了可信的威胁。滋养体 致病形式的寄生虫，定殖于小肠腔并附着于上皮。 感染通常是自限性的，表明存在有效的免疫防御。尽管临床 G的重要性。lamblia，没有可用的预防性医疗策略。先前的临床前研究表明， 用单个表面抗原免疫可提供抗G.兰氏杆菌感染 小鼠和沙鼠，但保护作用不如先前感染寄生虫有效，这表明， 抗原可能不足以诱导最佳保护。多抗原免疫可以用活的 病原体疫苗，但没有达到必要的减毒G。可能不是 这可能是由于可预见的肠道定植能力受损。作为替代方案，我们建议 基于纳米颗粒的疫苗，从G. Lamblia菌株， 多抗原粘膜免疫，而无需担心由于活微生物暴露引起的副作用。 所得到的纳米颗粒疫苗提供了几个明显的优点： 存在于病原体表面上，ii）用于体内有效运输的稳定性和均匀尺寸，和 有效地摄取到抗原呈递细胞中，和iii）通过用以下物质负载核而可调的免疫学偏置 用于控制释放的合适佐剂。因此，我们的总体目标是发展G。兰氏膜- 包被的纳米颗粒作为针对贾第虫病的新型粘膜疫苗接种策略。我们将系统地 用天然病原体膜制造不同的纳米疫苗制剂，并测试它们的 免疫原性和保护能力。这个项目带来了新的想法 以及从纳米技术领域预防贾第虫病的方法，贾第虫病是一种高度传染性和 临床上重要但被忽视的乳腺癌。重要的是，我们的创新战略克服了 与鉴定单一保护性抗原或使用非天然的、化学修饰的 形式的目标病原体，从而大大提高诱导适应性免疫，以多种天然 寄生虫表面的蛋白质新策略对疫苗设计具有广泛的影响， 其他粘膜病原体，不仅包括原生动物，还包括细菌和病毒因子。

Project Summary Giardia lamblia, a protozoan CDC category B priority pathogen, is an important cause of diarrheal disease with hundreds of millions of annual cases worldwide. In the United States, G. lamblia is one of the two most common causes of outbreaks of parasitic disease, with prevalence rates of 1-7%. Symptomatic giardiasis is characterized by diarrhea, epigastric pain, nausea, vomiting, malabsorption and malnutrition, especially in children. Long-term sequelae are common and can persist despite apparently successful treatment. Importantly, infection can be initiated by ingestion of fewer than ten cysts, demonstrating that G. lamblia is highly contagious and a credible threat to the safety of public water supplies and health. Trophozoites, the disease-causing forms of the parasite, colonize the lumen of the small intestine and attach to the epithelium. Infection is typically self-limiting, indicating that effective immune defenses exist. Despite the clinical importance of G. lamblia, no preventive medical strategies are available. Prior preclinical studies have shown that immunization with individual surface antigens can confer partial protection against G. lamblia infection in mice and gerbils, but protection is not as effective as prior infection with the parasite, suggesting that single antigens may not be sufficient to induce optimal protection. Multi-antigen immunizations can be done with live pathogen vaccines, but the necessary attenuation has not been achieved for G. lamblia and may not be possible due to the predictably compromised ability to colonize the intestine. As an alternative, we propose a nanoparticle-based vaccine, constructed from the membranes of G. lamblia strains, which enables effective multi-antigen mucosal immunization without concerns about adverse effects due to live microbe exposure. The resulting nanoparticle vaccines offer several distinct advantages: i) delivery of multi-antigenic material present on the pathogen surface, ii) stability and homogeneous sizing for effective transport in vivo and efficient uptake into antigen-presenting cells, and iii) tunable immunological biasing by loading the core with suitable adjuvants for controlled release. Therefore, our overall objective is to develop G. lamblia membrane- coated nanoparticles as a novel mucosal vaccination strategy against giardiasis. We will systematically fabricate different nanovaccine formulations with native pathogen membranes and test them for immunogenicity and protective capacity in relevant animal models of giardiasis. This project brings new ideas and approaches from the field of nanotechnology to the prevention of giardiasis, a highly contagious and clinically important but largely neglected diarrheal disease. Importantly, our innovative strategy overcomes the challenges associated with identifying single protective antigens or with using non-native, chemically modified forms of the target pathogen, thereby greatly improving induction of adaptive immunity to multiple native proteins found on the live parasite surface. The new strategy has broad implications for vaccine design for other mucosal pathogens, including not only protozoan, but also bacterial and viral agents.