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Understanding the immune mechanism of host disease resistance and development of marker vaccines and DIVA tests for Peste des Petits Ruminants (PPR)

了解宿主抗病的免疫机制以及针对小反刍兽疫 (PPR) 标记疫苗和 DIVA 检测的开发

基本信息

批准号：
BB/L004801/1
负责人：
Satya Parida
金额：
$ 45.12万
依托单位：
The Pirbright Institute
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2014
资助国家：
英国
起止时间：
2014 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=BB%2FL004801%2F1
关键词：
Understanding immune mechanism host disease

项目摘要

Peste des petits ruminants (PPR), also known as 'goat plague', is a highly contagious viral disease of sheep and goats. The direct economic losses of this disease have been estimated to be INR 1800 million (US$ 39 million) annually in India alone, whilst globally, >60% of the small ruminant population is considered at risk. However little is known about the pathogenesis of PPRV. Importantly, the primary site of viral replication has yet to be properly defined and the mechanism of the contrasting host specific disease resistance to PPR is unknown. Effective live attenuated vaccines are available to control PPR and a c-ELISA kit, to monitor the antibody response against the H protein, has been developed at IVRI and Pirbright. However, the critical drawback of these vaccines and associated c-ELISA kits is their inability to differentiate infection in vaccinated animals (DIVA) that slows down the implementation of PPR control through vaccination. We hypothesise that PPRV infects immune cells of the respiratory mucosa, which then migrate to T-cell-rich areas of local lymphoid organs, from which virus enters the general circulation. We aim to develop a recombinant live attenuated DIVA vaccine that will be aerosolised to the primary viral replication site and is capable of generating a rapid and appropriate immune response including mucosal immunity. By further characterising the immune mechanisms underlying the differential susceptibility of sheep, goats and large ruminants to PPRV infection we aim to enhance our understanding of disease resistance mechanisms that will enable the development of better vaccines for the control of PPRV.Aims and objectives: Three complementary research objectives are necessary to advance the ability to control and eradicate PPR: 1) understand PPRV pathogenesis in the pre-viraemic stage to identify the primary site of virus replication as a target for vaccination; 2) further characterise the immune response to PPR in small and large ruminants to understand differential disease resistance; and 3) develop appropriate PPR marker vaccines with associated DIVA tests to provide effective and targeted PPR control, ultimately leading to eradication from India. Research approaches: Similar to our Nigeria75/1 GFP vaccine virus rescue, a virulent recombinant PPR virus containing the GFP gene will be constructed and rescued. This virus will be aerosolised to infect goats. Tissues will be collected from respiratory mucosa and associated lymph nodes and the primary viral replication site will be located by auto fluorescence of GFP and by IHC in tissues. Subsequent vaccinations will use the intranasal route if we define the primary replication site of PPRV during the pre-viremic stage. Using reverse genetics techniques we will develop two negative marker vaccines against Indian PPRV (Sungri 96- goat origin and Arasur 1987- sheep origin). Epitope deletion of a region of the H protein critical for monoclonal antibody binding will allow serological differentiation between vaccinated and naturally infected animals using the current cH-ELISA. For simple and rapid field diagnosis, we intend to develop loop mediated isothermal amplification assay (LAMP) and a lateral flow device. Real-time RT-PCR assay and biosensor assay development and validation in India will help the PPR control programme. Interrogation of the immune mechanisms that underlie the differential susceptibility of species / breeds of small and large ruminants to PPRV will be carried forward using an unbiased transcriptomics approach. Increasing our knowledge on early pathogenesis, using a marker vaccine to generate an appropriate immune response and the ability to differentiate infection from vaccination, in combination with a deeper understanding of immune function will enable the control of PPRV. This project will help in delivering PPR control in India and elsewhere by bringing together major players in PPR research in India and the UK.

小反刍兽疫（PPR），又称“山羊疫”，是绵羊和山羊的一种高度传染性病毒性疾病。据估计，仅在印度，每年这种疾病的直接经济损失就达18亿印度卢比（3900万美元），而在全球范围内，超过60%的小型反刍动物种群被认为处于危险之中。然而，对PPRV的发病机制知之甚少。重要的是，病毒复制的主要位点尚未被正确定义，并且对比宿主对PPR的特异性疾病抗性的机制尚不清楚。有效的减毒活疫苗可用于控制PPR，IVRI和Pirbright已开发出用于监测针对H蛋白的抗体反应的c-ELISA试剂盒。然而，这些疫苗和相关的c-ELISA试剂盒的关键缺点是它们不能区分接种动物中的感染（DIVA），这减缓了通过接种疫苗实施PPR控制。我们假设PPRV感染呼吸道粘膜的免疫细胞，然后迁移到局部淋巴器官的T细胞丰富的区域，病毒从那里进入全身循环。我们的目标是开发一种重组DIVA减毒活疫苗，该疫苗将被雾化到主要病毒复制位点，并且能够产生快速和适当的免疫应答，包括粘膜免疫。通过进一步表征绵羊、山羊和大型反刍动物对PPRV感染的不同易感性的免疫机制，我们旨在提高我们对疾病抗性机制的理解，这将使我们能够开发更好的疫苗来控制PPRV。目的和目标：三个互补的研究目标是必要的，以提高控制和根除PPR的能力：1）了解PPRV在病毒血症前阶段的发病机制，以确定病毒复制的主要位点作为疫苗接种的靶点; 2）进一步研究小型和大型反刍动物对PPR的免疫应答，以了解不同的抗病性;和3）开发适当的PPR标记疫苗，并进行相关的DIVA试验，以提供有效和有针对性的PPR控制，最终导致从印度根除。研究方法：类似于我们的PPR 75/1 GFP疫苗病毒拯救，将构建并拯救含有GFP基因的毒性重组PPR病毒。这种病毒会被雾化感染山羊。将从呼吸道粘膜和相关淋巴结收集组织，并通过GFP的自体荧光和组织中的IHC定位主要病毒复制位点。如果我们在病毒血症前阶段确定了PPRV的主要复制位点，则随后的疫苗接种将使用鼻内途径。利用反向遗传学技术，我们将开发两种针对印度PPRV的阴性标记疫苗（Sungri 96-山羊源和Arasur 1987-绵羊源）。对单克隆抗体结合至关重要的H蛋白区域的表位缺失将允许使用当前的cH-ELISA在接种疫苗的动物和自然感染的动物之间进行血清学区分。为了简便、快速地进行现场诊断，我们打算开发环介导等温扩增法（LAMP）和侧流装置。印度的实时RT-PCR检测和生物传感器检测的开发和验证将有助于PPR控制方案。将使用无偏转录组学方法对小型和大型反刍动物物种/品种对PPRV的不同易感性的免疫机制进行调查。增加我们对早期发病机制的了解，使用标记疫苗产生适当的免疫应答以及区分感染和疫苗接种的能力，结合对免疫功能的更深入了解，将使PPRV得到控制。该项目将通过汇集印度和英国PPR研究的主要参与者，帮助在印度和其他地方提供PPR控制。

项目成果

期刊论文数量（10）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Serological Detection of Antibodies to Peste des Petits Ruminants Virus in Large Ruminants.

DOI：
10.1111/tbed.12392
发表时间：
2017-04
期刊：
Transboundary and emerging diseases
影响因子：
4.3
作者：
Abubakar M;Mahapatra M;Muniraju M;Arshed MJ;Khan EH;Banyard AC;Ali Q;Parida S
通讯作者：
Parida S

Persistence of Lineage IV Peste-des-petits ruminants virus within Israel since 1993: An evolutionary perspective

自 1993 年以来以色列境内第四代小反刍兽疫病毒的持续存在：进化视角