Leishmania RNA virus (LRV) infectivity and host responses

利什曼原虫 RNA 病毒 (LRV) 感染性和宿主反应

• 批准号: 8664035
• 负责人: Stephen M Beverley
• 金额: $ 49.25万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-06-01 至 2014-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8664035
• 关键词: Animal Model; Biology; Cutaneous; Data; Development; Disease; Double Stranded RNA Virus; Double-Stranded RNA; Exhibits; Experimental Animal Model; Family; Gene Expression; Generations; Genetic; Genome; Goals; Human; Immune response; Infection; Inflammatory Response; Knock-out; Knowledge; Leishmania; Leishmania leishmania; Leishmania viannia; Leishmaniavirus; Link; Mammals; Mediating; Methods; Modeling; Molecular Virology; Mucocutaneous leishmaniasis; Mus; Nature; Neoplasm Metastasis; Parasites; Pathology; Pathway interactions; Phenotype; Population; Process; RNA; RNA Interference; RNA Interference Pathway; RNA Viruses; Reporter Genes; Research; Role; Severities; Severity of illness; Signal Pathway; Small Interfering RNA; TLR3 gene; Testing; Totiviridae; Totivirus; Viannia; Viral; Virulence; Virulence Factors; Virus Diseases; Visceral; base; genome sequencing; improved; interest; mouse model; novel diagnostics; novel strategies; response

DESCRIPTION (provided by applicant): Infections with the protozoan parasite Leishmania exhibit a variety of disease pathologies, ranging from mild cutaneous to fatal visceral to disfiguring mucocutaneous disease. The basis for this diversity is not understood; differences amongst strains or species of Leishmania have been implicated as well as differences in the human host genetic background. Mucocutaneous leishmaniasis (MCL) is especially debilitating, associated primarily with infections by species within the Viannia subgenus. In experimental animal models the presence of a dsRNA virus infecting some strains of Leishmania confers elevated pathology and metastasis, mediated by a TLR3-dependent inflammatory response. LRV is the only proven virulence factor associated with increased disease severity and metastasis, two hallmarks relevant to human MCL, caused primarily by L. braziliensis (Lbr). Recently we used genome sequence data to identify a L. braziliensis clade manifesting both LRV and MCL, and consistent with the Leishmania LRV-disease hypothesis, an LRV+ isolate exhibited greatly elevated virulence. This clade will thus be the focus of detailed studies of the role(s) and responses to LRV in L. braziliensis. Clonal LRV+ and LRV- lines will be generated and their infectivity and metastatic potential defined, making use of a new mouse model for Leishmania metastasis. We will exploit an exciting new approach for generating isogenic LRV- lines to dissect the roles of and response to LRVs, utilizing RNAi targeting of the LRV dsRNA genome . In Aim 2 we focus on the mammalian host response to LRV-infected Leishmania, including a detailed characterization of the immune response to LRV+ vs. LRV- L. braziliensis and L. guyanensis. Recent data implicate the RNA interference pathway in L. braziliensis infectivity, which will be tested in L. guyanensis using RNAi-null Argonaute (AGO1) knockouts. Our studies suggest the possibility of a mechanistic link in either or both species between LRV and RNAi. This will be confirmed and explored mechanistically through the use of mice bearing alterations in relevant dsRNA signaling pathways, challenged with parasites of varying LRV or RNAi status. Lastly we will focus on the Leishmania response to LRV, including changes in gene expression, modulation of RNAi activity by LRV or of viral siRNA formation by the RNAi pathway, and siRNA biology. We will explore the possibility of generating an infectious LRV clone, which would radically improve our ability to dissect the role of LRV in Leishmania biology.

描述（由申请方提供）：原生动物寄生虫利什曼原虫感染表现出多种疾病病理，从轻度皮肤到致命内脏到毁容粘膜皮肤疾病。这种多样性的基础尚不清楚;利什曼原虫株或种之间的差异以及人类宿主遗传背景的差异都有牵连。皮肤粘膜利什曼病（MCL）尤其使人衰弱，主要与Viannia亚属内的物种感染有关。在实验动物模型中，感染某些利什曼原虫株的dsRNA病毒的存在赋予由TLR3依赖性炎症反应介导的升高的病理学和转移。LRV是唯一被证实与疾病严重程度和转移增加相关的毒力因子，这两个标志与人类MCL相关，主要由L。braziliensis（Lbr）.最近，我们使用基因组序列数据来鉴定L。巴西利什曼原虫分支表现出LRV和MCL，并与利什曼原虫LRV-疾病假说一致，LRV+分离株表现出大大提高的毒力。因此，该分支将是详细研究LRV在L.巴西。利用利什曼原虫转移的新小鼠模型，将产生克隆LRV+和LRV-系，并确定其感染性和转移潜力。我们将利用RNAi靶向LRV dsRNA基因组，开发一种用于产生等基因LRV系的令人兴奋的新方法，以剖析LRV的作用和对LRV的响应。在目标2中，我们关注哺乳动物宿主对LRV感染的利什曼原虫的反应，包括对LRV+与LRV-L的免疫反应的详细表征。braziliensis和L. guyanensis。最近的研究表明，L.巴西乳杆菌的感染性，将在L. guyanensis中使用RNAi无效Argonaute（AGO1）敲除。我们的研究表明，LRV和RNAi之间的一个或两个物种的机械链接的可能性。这将通过使用在相关dsRNA信号传导途径中具有改变的小鼠，用不同LRV或RNAi状态的寄生虫攻击来进行机制上的证实和探索。最后，我们将集中在利什曼原虫对LRV的反应，包括基因表达的变化，LRV或RNAi途径的病毒siRNA形成的RNAi活性的调制，和siRNA生物学。我们将探索产生感染性LRV克隆的可能性，这将从根本上提高我们解剖LRV在利什曼原虫生物学中的作用的能力。