Towards a vaccine against Fasciola hepatica using FhSAP2 as an antigen

使用 FhSAP2 作为抗原研制肝片形吸虫疫苗

基本信息

批准号：
8435474
负责人：
ANA M ESPINO
金额：
$ 21.15万
依托单位：
UNIVERSITY OF PUERTO RICO MED SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-03-01 至 2014-08-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8435474
关键词：
Address Adjuvant Adverse effects Affect Agreement Agriculture Animals Antibodies Antigens Bacterial DNA Biological Assay Cattle Cells Characteristics Chronic Chronic Phase Dendritic Cells Disease Drug Formulations Drug resistance Effectiveness Eosinophilia Epitopes Equilibrium Fasciola Fasciola hepatica Fascioliasis Food Freund&apos s Adjuvant Funding Future Goals Goat Hand Health Helminths Hepatica Human ISCOMs IgE IgG1 Immune Immune response Immunity Infection Interleukin-12 Interleukin-4 Lead Link Measures Mediating Memory Modeling Morbidity - disease rate Mus NK-lysin Oils Oryctolagus cuniculus Outcome Parasites Pharmaceutical Preparations Production Protein Family Proteins Research Research Personnel Role Ruminants Saposins Sheep T-Lymphocyte Testing Time Treatment Cost Trematoda Vaccinated Vaccination Vaccines base bile duct cytokine disorder control food security immunogenic improved liver injury macrophage mouse model neglect novel pathogen polypeptide protective effect response theories triclabendazole vaccine efficacy

项目摘要

DESCRIPTION (provided by applicant): The helminth parasite Fasciola hepatica causes liver fluke disease or fascioliasis, thereby affecting the health of humans, as well as sheep, cattle and goats, among others mammalians. Fascioliasis causes losses in agriculture estimated at >US3.2billion per year. Fascioliasis is also a major zoonotic disease and it is estimated that 17 million people worldwide are infected. The flukicide triclabendazole is the most effective drug to control fascioliasis; however, the cost of treatment and the emergence of drug resistance in sheep infected with F. hepatica suggest a need to develop sustainable strategies, such as vaccination for the control of this disease. However, despite the long-standing research, a vaccine against Fasciola hepatica has not yet been developed. We have identified a novel F. hepatica antigen termed FhSAP2 that when delivered subcutaneously (SC) in Freund's complete adjuvant (FCA) is able to induce partial immunity (>60% reduction in parasite burden and significant reduction of liver damage) in rabbits and mice challenged with F. hepatica metacercariae. FhSAP2 is an 11.5kDa polypeptide belonging to the F. hepatica saposin-like / NK-lysin protein family. We also demonstrated that the immunity induced by the FhSAP2-FCA formulation is associated with high levels of IgG2a antibodies and high levels of IFN3, which are signatures of a Th1 immune response. These results led us to hypothesize that the protection induced by FhSAP2 is mediated by a mechanism linked to CD4+ Th1 cells, which is a new concept in the field of fascioliasis since F. hepatica, like most helminthes, is traditionally associated to Th2 immune responses. The goal of the present study is to study the modulation of T-helper 1, T- helper 2 responses and the protective effect against F. hepatica induced by FhSAP2 with these formulations in the mouse model of fascioliasis. To address this goal we propose to fulfill two specific aims in the 3-year funding period. In specific aim-1 we will study the protective effect of FhSAP2 when delivered SC in adjuvants containing immunostimulatory sequences. Specifically, we will ascertain whether the prime-boost strategy of naove C57BL/6 (H-2b) mice with FhSAP2 in MontanideTM ISM 1312 and ISA 70M or trapped into ISCOMs co- administered with IL-12 or CpG-ODN could mimic or enhance the protection levels obtained with FhSAP2 in CFA. This will lead to an optimization of the vaccine formulation for future studies. In the specific aim-2 we will study how the vaccine formulations used in the aim-1 modulate the T helper 1(Th1)-T helper 2 (Th2) responses. We will look at the Th1/Th2 cytokine profile, the levels of antibody subclasses as well as the activation status of B- and T-cells, macrophages (MX) and dendritic cells (DCs) elicited in naove mice and these parameters will be correlated with the levels of protection obtained in specific aim-1. The outcome will allow us to test our hypothesis of the protective role of Th1 responses in fascioliasis. If the proposed aims are achieved, we not only would have in hand an optimized vaccine formulation to be assayed in ruminants but we will also put forward a new concept of how to induce protection against F. hepatica, which will open the door to further studies to elucidate the immune mechanisms that make possible the Th1 immune responses which are effective against a multicellular fluke like F. hepatica. Moreover, these studies might serve as the basis for the application of this concept in the study of other neglected diseases caused by human liver fluke pathogens. The main objective of PI with this SC1 application is to make a transition to a non-SCORE support mechanism and in doing so establish herself as an independent competitive investigator.

描述（由申请人提供）：蠕虫寄生虫肝片形吸虫引起肝吸虫病或片形吸虫病，从而影响人类以及绵羊、牛和山羊等哺乳动物的健康。片形吸虫病每年造成的农业损失估计超过 32 亿美元。片形吸虫病也是一种主要的人畜共患病，估计全世界有 1700 万人受到感染。杀吸虫剂三氯苯达唑是控制片形吸虫病最有效的药物；然而，治疗费用和感染肝镰刀菌的羊出现的耐药性表明需要制定可持续的策略，例如通过疫苗接种来控制这种疾病。然而，尽管进行了长期的研究，但针对肝片形吸虫的疫苗尚未开发出来。我们已经鉴定出一种名为 FhSAP2 的新型肝镰状菌抗原，当在弗氏完全佐剂 (FCA) 中皮下 (SC) 递送时，能够在兔子和小鼠中诱导部分免疫（寄生虫负荷减少 60% 以上，并显着减少肝损伤）受到肝囊蚴杆菌攻击。 FhSAP2 是一种 11.5kDa 的多肽，属于 F. hepatica saposin 样/NK 溶素蛋白家族。我们还证明，FhSAP2-FCA 制剂诱导的免疫与高水平的 IgG2a 抗体和高水平的 IFN3 相关，这是 Th1 免疫反应的特征。这些结果使我们推测 FhSAP2 诱导的保护是由与 CD4+ Th1 细胞相关的机制介导的，这是片形吸虫病领域的一个新概念，因为肝片形吸虫与大多数蠕虫一样，传统上与 Th2 免疫反应相关。本研究的目的是研究 FhSAP2 在片形吸虫病小鼠模型中使用这些制剂对 T 辅助细胞 1、T 辅助细胞 2 反应的调节以及对 FhSAP2 诱导的肝片吸虫的保护作用。为了实现这一目标，我们建议在三年资助期内实现两个具体目标。在特定的目标 1 中，我们将研究 FhSAP2 在含有免疫刺激序列的佐剂中皮下注射时的保护作用。具体来说，我们将确定在 MontanideTM ISM 1312 和 ISA 70M 中使用 FhSAP2 或与 IL-12 或 CpG-ODN 共同施用的 ISCOM 中的 FhSAP2 的 naove C57BL/6 (H-2b) 小鼠的初免-加强策略是否可以模拟或增强CFA 中使用 FhSAP2 获得的保护级别。这将为未来的研究优化疫苗配方。在具体的目标 2 中，我们将研究目标 1 中使用的疫苗配方如何调节辅助性 T 细胞 1 (Th1)-辅助性 T 细胞 2 (Th2) 反应。我们将研究 Th1/Th2 细胞因子谱、抗体亚类的水平以及 B 细胞和 T 细胞、巨噬细胞 (MX) 和树突状细胞 (DC) 在新生小鼠中的激活状态，并且这些参数将相互关联与特定目标 1 中获得的保护级别。这一结果将使我们能够检验关于 Th1 反应在片形吸虫病中的保护作用的假设。如果实现了所提出的目标，我们不仅将拥有可在反刍动物中进行检测的优化疫苗配方，而且还将提出如何诱导针对肝镰刀菌的保护的新概念，这将为进一步研究打开大门阐明使 Th1 免疫反应成为可能的免疫机制，该免疫反应可有效对抗肝片吸虫等多细胞吸虫。此外，这些研究可能作为这一概念在人类肝吸虫病原体引起的其他被忽视疾病的研究中应用的基础。 PI 使用此 SC1 应用程序的主要目标是过渡到非 SCORE 支持机制，并在此过程中确立自己作为独立竞争性调查员的地位。