Roles of Macrophages in Immunity to Ranavirus, and in Viral Persistence and Dissemination

巨噬细胞在蛙病毒免疫以及病毒持续和传播中的作用

• 批准号: 1754274
• 负责人: Jacques Robert
• 金额: $ 71.35万
• 依托单位: University of Rochester
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-04-01 至 2023-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1754274&HistoricalAwards=false
• 关键词: Roles; Macrophages; Immunity; Ranavirus; Viral; Roles; Macrophages; Immunity; Ranavirus; Viral

Macrophages are a type of immune cells that are indispensable to vertebrate host immunity and homeostasis. Thus, they often become targets of viral pathogens as a means of immune evasion and mechanisms of dissemination. Ranaviruses, which infect amphibians, are increasing in both prevalence and in the range of host species infected. This raises pressing concerns for biodiversity and aquaculture, and poses fundamental issues related to evolution of host/pathogen interactions. Indeed, the remarkable emerging features of ranavirus infections appear intimately linked to controlling immune responses in many host species, and growing evidence hints at macrophages as critical for their infection strategy. The goal of this research is to elucidate the complex roles of distinct amphibian adult and tadpole macrophage populations in orchestrating host immune defenses against ranavirus, while serving as reservoirs for ranavirus immune evasion and dissemination. The hypothesis addressed is that the ranavirus Frog virus 3 (FV3) targets macrophages to evade host immune defenses towards viral persistence and dissemination in the frog Xenopus laevis. The specific aims are to determine the phenotypes and fates of tadpole and adult macrophage subsets targeted by FV3; define molecular and cellular interactions of FV3 with tadpole and adult macrophages; and elucidate the roles of macrophages in host defenses and asymptomatic infections. The work will involve training of students at all levels, as well as public engagement through development of interactive programs at a local science museum. The researcher will also continue to develop and manage a resource for Xenopus immunobiology reagents and training. Macrophages are both at the forefront of immune defenses against ranavirus (Iridoviridae) pathogens and part of ranavirus infection strategies, which is unique among large DNA viruses. The dramatic worldwide increases in ranges of populations and species infected raise alarming concerns for biodiversity and aquaculture, and pose fundamental issues related to evolution of host/pathogen interactions. The overall goal of this proposed research is to elucidate the complex roles of distinct amphibian adult and tadpole macrophage populations in orchestrating host immune defenses, while serving as reservoirs for immune evasion and dissemination. The project will take advantage of the extensively characterized Xenopus/FV3 model system that permits reverse genetic as well as mechanistic experimental approaches from the molecular and cellular levels to the whole organism level. The guiding hypothesis is that FV3 targets amphibian macrophages to evade host immune defenses towards viral persistence and dissemination. The specific aims are (1) to determine the phenotypes and fates of larval and adult macrophage subsets targeted by FV3; (2) to define molecular and cellular interactions of FV3 with larval and adult macrophages; and (3) to elucidate the roles of macrophages in host defenses and asymptomatic infections. These aims will utilize technologies developed during the past NSF funding period, including RNAi-based and CRISPR/Cas9-mediated loss-of-function by transgenesis; traceable recombinant FV3 and FV3 knockout mutants deficient for virulence/immunomodulatory genes; adoptive macrophage transfer into inbred recipients; Xenopus macrophage cultures; macrophage depletion; and the use of specific Abs against Xenopus macrophages and FV3.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

巨噬细胞是一种免疫细胞，对于脊椎动物宿主免疫和稳态是必不可少的。因此，它们通常成为病毒病原体的靶标，作为免疫逃避和传播机制的一种手段。感染两栖动物的Ranaviruses的患病率和感染宿主物种的范围都在增加。这引起了人们对生物多样性和水产养殖的迫切关注，并提出了与宿主/病原体相互作用进化有关的基本问题。确实，兰纳瓦病毒感染的显着新兴特征似乎与控制许多宿主物种的免疫反应密切相关，并且越来越多的证据暗示巨噬细胞对其感染策略至关重要。这项研究的目的是阐明独特的两栖动物成年和t骨巨噬细胞种群在策划宿主免疫防御侵害兰纳韦病毒方面的复杂作用，同时充当用于兰纳维病毒免疫逃避和传播的储层。提到的假设是，雷纳韦病毒蛙病毒3（FV3）靶向巨噬细胞，以逃避宿主的免疫防御剂，以朝着青蛙xenopus laevis中的病毒持久性和传播。具体的目的是确定the的表型和命运和FV3靶向的成年巨噬细胞子集；定义FV3与t和成年巨噬细胞的分子和细胞相互作用；并阐明巨噬细胞在宿主防御和无症状感染中的作用。这项工作将涉及各个级别的学生培训，以及通过在当地科学博物馆开发互动计划的公众参与。研究人员还将继续开发和管理用于Xenopus免疫生物学试剂和培训的资源。 巨噬细胞既是针对兰纳维病毒（虹膜科）病原体的免疫防御措施的最前沿，也是兰纳维病毒感染策略的一部分，这在大型DNA病毒中是独一无二的。在全球范围内，人口和物种感染物种的范围急剧增加，引起了人们对生物多样性和水产养殖的令人震惊的关注，并提出了与宿主/病原体相互作用的进化有关的基本问题。这项拟议的研究的总体目标是阐明两栖动物成年和t的巨噬细胞种群在策划宿主免疫防御措施中的复杂作用，同时充当免疫逃避和传播的储层。该项目将利用广泛表征的Xenopus/FV3模型系统，该系统允许逆转遗传以及机械实验方法从分子和细胞水平到整个生物体水平。指导假设是，FV3靶向两栖动物巨噬细胞，以逃避宿主的免疫防御能力，以降低病毒持久性和传播。 具体目的是（1）确定由FV3靶向的幼虫和成年巨噬细胞亚集的表型和命运； （2）定义FV3与幼虫和成年巨噬细胞的分子和细胞相互作用； （3）阐明巨噬细胞在宿主防御和无症状感染中的作用。这些目标将利用在过去的NSF资金期间开发的技术，包括基于RNAi的和CRISPR/CAS9介导的转基因功能丧失；可追溯的重组FV3和FV3基因敲除突变体缺乏毒力/免疫调节基因；收养巨噬细胞转移到近交接受者中；武士巨噬细胞培养物；巨噬细胞耗尽；以及针对Xenopus巨噬细胞和FV3的特定ABS的使用。该奖项反映了NSF的法定任务，并且使用基金会的知识分子优点和更广泛的影响审查标准，被认为值得通过评估来获得支持。