Vaccines and molecular tools for the control of the emerging bunyavirus, severe fever with thrombocytopenia syndrome phlebovirus (SFTSV)

用于控制新出现的布尼亚病毒、严重发热伴血小板减少综合征白斑病毒 (SFTSV) 的疫苗和分子工具

• 批准号: BB/R019800/1
• 负责人: Alain Kohl
• 金额: $ 114.13万
• 依托单位: University of Glasgow
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FR019800%2F1
• 关键词: Vaccines; molecular; tools; control; emerging

Viruses in the newly formed order Bunyavirales are frequently arthropod-transmitted with many members capable of causing substantial human, animal and disease. The WHO has identified several bunyaviruses as key emerging pathogens, and this call entitled "One health approaches to accelerate vaccine development" also emphasizes interest in this group of viruses. This project focuses on severe fever with thrombocytopenia syndrome phlebovirus (SFTS phlebovirus; SFTSV) of the Phenuiviridae family of bunyaviruses which also includes significant emerging pathogens in both Asia and the USA (Heartland virus, HRTV). To date, over 2500 SFTSV cases have been reported in China, 172 cases in South Korea and 96 cases in Japan, with case fatality rates ranging from 8.2% to 32.6%. The annual incidence of reporting is increasing in all endemic countries, e.g. in China where 53 cases were reported in 2010, compared to 676 in 2013. To address the threat posed by novel, emerging bunyaviruses, scientists at the MRC-University of Glasgow Centre for Virus Research (CVR) have developed a "reverse genetics" system with which SFTSV can be manipulated, and which permit the rational design of rationally attenuated virus vaccine candidates. Such reverse genetics systems enable the rapid recovery of replication competent bunyaviruses from plasmids encoding cDNA copies of the viral genomic RNA. This technology facilitates the mapping of epitopes targeted by the humoral and cellular immune response as well as the identification and manipulation of virally-encoded virulence factors. The NSs proteins of many bunyaviruses are recognised as virulence factors due to their ability to counteract the mammalian innate immune responses. Hence, these reverse genetics-based strategies offer a realistic means to develop rational vaccine candidates for emerging bunyaviral diseases, as well as the development of viruses that help to further elucidate the immune responses mounted to infection and viral pathogenesis. We have now generated a recombinant NSs-deletant SFTSV (called SFTSVdelNSs) which is unable to antagonise type I interferon responses mounted in response to infection. This facilitates the studies into the role of innate immune responses in controlling SFTSV, as well as in vivo tissue tropism and pathogenesis in absence of the virulence factor NSs, leading to the evaluation of such potentially attenuated viruses as vaccine candidates. The strengths of reverse genetics-based approaches to producing recombinant bunyaviruses extends beyond the production of attenuated virus vaccine candidates. The system also allows the development and production of virus-like particles (VLPs). Both recombinant viruses and VLPs can be tested for their ability to induce immune responses in immunised animals as well as protective vaccine candidates. This proposal will bring together CVR and Beijing Institutes of Life Science (BIOLS) researchers to elucidate host immune responses to SFTSV infection and pathogenesis, the development of recombinant virus vaccine candidates and tools to further study SFTSV.Aim 1. To elucidate the contribution of SFTSV NSs to in vivo tissue tropism and pathogenesis. We will also assess a recombinant SFTSV (lacking NSs; SFTSVdelNSs) as vaccine candidate in comparison to VLPs.Aim 2. To produce novel neutralising antibodies against SFTSV for basic research and as potential therapeutic agents. We will investigate antibody responses using a novel SFTS viruses expressing reporter genes to study immune responses in both patient sera and infected animals. This will allow us to define the breadth of the neutralising antibody responses and to map antigenic determinants on the virion. Antigenic variation and escape from neutralisation of the SFTSV Gn structural protein (known target for antibody responses) will be investigated through mutational analysis. The project will also include training in reverse genetics technology for the partner BIOLS.

新形成的布尼亚病毒目中的病毒经常通过节肢动物传播，其中许多成员能够引起大量的人类、动物和疾病。世卫组织已经确定了几种布尼亚病毒作为关键的新兴病原体，这一题为“加速疫苗开发的一种健康方法”的呼吁也强调了对这组病毒的兴趣。该项目的重点是布尼亚病毒属的Phenuiviridae家族的严重发热伴血小板减少综合征静脉病毒（SFTS静脉病毒; SFTSV），其中还包括亚洲和美国的重要新兴病原体（Heartland病毒，HRTV）。迄今为止，中国已报告了超过2500例SFTSV病例，韩国报告了172例，日本报告了96例，病死率为8.2%至32.6%。所有流行国家的年度报告发生率都在增加，例如中国2010年报告了53例病例，而2013年为676例。为了解决新出现的布尼亚病毒所带来的威胁，格拉斯哥大学病毒研究中心（CVR）的科学家们开发了一种“反向遗传学”系统，利用该系统可以操纵SFTSV，并允许合理设计合理减毒的候选病毒疫苗。这种反向遗传学系统能够从编码病毒基因组RNA的cDNA拷贝的质粒中快速回收有复制能力的布尼亚病毒。该技术有助于定位体液和细胞免疫应答靶向的表位，以及鉴定和操纵病毒编码的毒力因子。许多布尼亚病毒的NS蛋白被认为是毒力因子，因为它们能够抵消哺乳动物的先天免疫应答。因此，这些基于反向遗传学的策略提供了一种现实的手段来开发用于新兴布尼亚病毒疾病的合理候选疫苗，以及开发有助于进一步阐明感染和病毒发病机制的免疫应答的病毒。我们现在已经产生了一种重组的NS缺失型SFTSV（称为SFTSVdelNS），它不能拮抗I型干扰素应答感染。这有助于研究先天免疫应答在控制SFTSV中的作用，以及在不存在毒力因子NS的情况下的体内组织嗜性和发病机理，从而评估此类潜在减毒病毒作为疫苗候选物。以反向遗传学为基础的生产重组布尼亚病毒的方法的优势超出了减毒病毒疫苗候选物的生产。该系统还允许开发和生产病毒样颗粒（VLP）。可以测试重组病毒和VLP在免疫动物以及保护性疫苗候选物中诱导免疫应答的能力。本项目将汇集CVR和北京生命科学研究院（BIOLS）的研究人员，阐明SFTSV感染的宿主免疫应答和发病机制，开发重组病毒候选疫苗和工具，以进一步研究SFTSV。阐明SFTSV NS在体内组织嗜性和致病性中的作用。我们还将评估与VLP相比作为疫苗候选物的重组SFTSV（缺乏NS; SFTSVdelNS）。生产针对SFTSV的新型中和抗体用于基础研究并作为潜在的治疗剂。我们将使用表达报告基因的新型SFTS病毒来研究抗体应答，以研究患者血清和感染动物中的免疫应答。这将使我们能够确定中和抗体反应的广度，并绘制病毒体上的抗原决定簇。将通过突变分析研究SFTSV Gn结构蛋白（抗体应答的已知靶标）的抗原变异和中和逃逸。该项目还将包括为伙伴BIOLS提供反向遗传学技术培训。

项目成果

Exploration of immunological responses underpinning severe fever with thrombocytopenia syndrome virus infection reveals IL-6 as a therapeutic target in an immunocompromised mouse model.

• DOI: 10.1093/pnasnexus/pgac024
• 发表时间: 2022-03
• 期刊: PNAS NEXUS
• 作者: Bryden, Steven R.;Dunlop, James I.;Clarke, Andrew T.;Fares, Mazigh;Pingen, Marieke;Wu, Yan;Willett, Brian J.;Patel, Arvind H.;Gao, George F.;Kohl, Alain;Brennan, Benjamin
• 通讯作者: Brennan, Benjamin