Arbovirus midgut escape mechanisms

虫媒病毒中肠逃逸机制

• 批准号: 8237879
• 负责人: ROLLIE J CLEM
• 金额: $ 66.98万
• 依托单位: KANSAS STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-12-01 至 2015-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8237879
• 关键词: Address; Aedes; Affect; Alphavirus; Apoptosis; Apoptotic; Arboviruses; Arthropod Vectors; Arthropods; Baculoviruses; Basal lamina; Biochemical; Biochemical Reaction; Biological Assay; Biology; Blood; Bypass; Candidate Disease Gene; Caspase; Cell Death; Cells; Cleaved cell; Culicidae; DNA; Dengue; Dengue Virus; Development; Ensure; Epithelium; Exhibits; Female; Fibroblast Growth Factor; Gene Silencing; Gene Targeting; Genes; Genetic Recombination; Health; Immune; Immunohistochemistry; In Vitro; Induction of Apoptosis; Infection; Ingestion; Insect Vectors; Insecta; Invaded; Lead; Measures; Metalloproteases; Methods; Microscopy; Midgut; Organ; Pathway interactions; Peptide Hydrolases; Phenotype; Physical condensation; Play; Process; Production; Proteins; RNA Interference; Regulator Genes; Research Personnel; Role; Salivary Glands; Secondary to; Signal Transduction; Sindbis Virus; Site; System; Systemic infection; TdT-Mediated dUTP Nick End Labeling Assay; Techniques; Testing; Tissues; Trachea; Transgenic Organisms; Transmission Electron Microscopy; Up-Regulation; Viral; Virus; Virus Diseases; Virus Replication; West Nile virus; Work; Yellow Fever; chikungunya; gain of function; human morbidity; human mortality; in vitro testing; in vivo; inhibitor/antagonist; interest; novel; overexpression; research study; success; transmission process; vector; vector mosquito

DESCRIPTION (provided by applicant): Arboviruses cause a significant world-wide health burden, with well over 100 million people becoming infected each year with viruses such as dengue, West Nile, yellow fever, and chikungunya, among others. Arboviruses are transmitted by arthropod vectors such as mosquitoes that become infected after ingestion of a viremic blood meal from a vertebrate host. Transmission to a new host requires that the arbovirus replicate in the midgut cells of the vector and then spread to secondary tissues eventually reaching the salivary glands. Once the latter are infected, the arthropod is able to transmit the virus to a new host. A long standing question in the field of vector biology is how arboviruses escape from the midgut, bypassing barriers such as basal laminae as well as host immune mechanisms. In some cases, arboviruses are able to infect and replicate in midgut epithelium but are not able to disseminate to other organs. The existence of this so-called midgut escape barrier implies that virus midgut escape is an active process. However, the mechanisms involved in midgut escape by arboviruses are almost completely unknown. This proposal addresses the signaling mechanisms used by the mosquito-borne viruses dengue, chikungunya, and Sindbis viruses to escape the midgut. Previous work by the investigators has defined a novel mechanism used by baculovirus to escape the midgut of their insect host. Baculoviruses use an elegant mechanism that signals a stepwise cascade of protease activation, wherein matrix metalloproteases become activated and in turn activate effector caspases, which directly cleave components of the basal lamina. This leads to remodeling of the basal lamina which lines tracheal cells associated with the midgut and culminates in the establishment of efficient systemic infections. The hypothesis underlying this proposal is that mosquito-borne arboviruses utilize this same pathway for midgut escape, and preliminary results support this hypothesis. Specifically, (1) it will be determined whether the mechanisms used by baculoviruses to remodel the midgut barrier are also utilized by arboviruses, including activation of matrix metalloproteases and caspases; (2) the contribution of candidate genes involved in midgut escape will be evaluated by RNA interference, arbovirus transducing systems, and transgenic Aedes aegypti mosquitoes by silencing or overexpressing target genes; and (3) the contribution of apoptosis and key apoptotic regulatory genes to arbovirus midgut escape will be tested. The results of these studies will contribute important new information to the understanding of arbovirus-vector interactions and potentially lead to new strategies for control of arbovirus transmission in the field. PUBLIC HEALTH RELEVANCE: Arthropod-borne viruses such as dengue, West Nile and yellow fever infect over 100 million people per year and cause significant human morbidity and mortality. After an insect vector is exposed to a virus by taking a blood meal, the virus must disseminate from the midgut to the salivary glands in order to be transmitted to a new host. The specific mechanisms of how these viruses escape from the midgut are not known. The proposed studies will determine the mechanisms used by three mosquito-vectored viruses to escape the midgut and may lead to the development of new strategies to control the transmission of viruses vectored by mosquitoes.

描述（由申请人提供）：Arboviruses造成了全球范围内的重大健康负担，每年有超过1亿人被登革热，西尼罗河，黄热病和奇肯古尼亚等病毒感染。 arbovirus是由节肢动物载体（如蚊子）传播的，这些蚊子在脊椎动物宿主摄入病毒血液粉后感染。向新宿主的传播要求arbovirus在载体的中肠细胞中复制，然后扩散到二次组织最终到达唾液腺。一旦感染了后者，节肢动物就会能够将病毒传播到新宿主。矢量生物学领域的一个长期存在的问题是，arbovirus是如何从中肠逃脱的，绕过基底层薄片和宿主免疫机制等障碍。在某些情况下，Arbovirus能够在中肠上皮感染和复制，但无法传播到其他器官。这种所谓的中肠逃逸屏障的存在意味着病毒中肠逃生是一个积极的过程。然而，几乎完全未知，arbovirus涉及的中肠逃生的机制几乎是完全未知的。该提案介绍了蚊子传播病毒登革热，基孔肯亚和信德氏症病毒逃脱中肠的信号传导机制。研究人员的先前工作定义了杆状病毒用来逃避其昆虫宿主中间的一种新型机制。杆状病毒使用一种优雅的机制，该机制向逐步激活的逐步级联反应，其中矩阵金属蛋白酶被激活，进而激活效应子胱天蛋白酶，该caspase直接裂解基底层的成分。这导致了基底层的重塑，该层是与中肠和高效系统感染建立的气管细胞线条。该提议的基础假设是，蚊子 - 纳博病毒利用这种相同的途径进行中肠逃生，而初步结果支持了这一假设。具体而言，（1）将确定杆菌病毒用于重塑中肠屏障的机制是否也是由arbovires使用的，包括激活基质金属蛋白酶和胱天蛋白酶； （2）将通过RNA干扰，Arbovirus转导系统和转基因埃及埃及蚊子通过沉默或过表达靶基因来评估参与中肠逃脱的候选基因的贡献； （3）将测试细胞凋亡和关键凋亡调节基因对Arbovirus Midgut逃生的贡献。这些研究的结果将为理解Arbovirus-vector相互作用的理解提供重要的新信息，并有可能导致控制该领域弧病毒传播的新策略。 公共卫生相关性：每年超过1亿人感染登革热，西尼罗河和黄热病等节肢动物传播的病毒，并引起大量的人类发病率和死亡率。在昆虫载体通过血餐暴露于病毒之后，病毒必须从中肠传播到唾液腺，以便将其传播到新宿主。这些病毒如何从中肠逃脱的特定机制尚不清楚。拟议的研究将确定三种蚊子载体病毒逃脱中肠的机制，并可能导致开发新策略，以控制蚊子载体的传播。