CAREER: The roles of amphibian macrophages in susceptibility and immunological resistance to the Frog Virus 3 ranavirus

职业：两栖动物巨噬细胞在青蛙病毒 3 型蛙病毒易感性和免疫抵抗中的作用

• 批准号: 1749427
• 负责人: Leon Grayfer
• 金额: $ 77.1万
• 依托单位: George Washington University
• 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: 2018-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1749427&HistoricalAwards=false
• 关键词: CAREER; roles; amphibian; macrophages; susceptibility

Frog populations around the globe are declining with almost two-thirds of all frog species threatened with extinction. Viral infections, such as Frog Virus 3, are significant contributors to these declines. Tadpoles are far more susceptible to viruses than adult frogs. There is a need to better understand the immune mechanisms that dictate susceptibility and resistance to Frog Virus 3. Such knowledge could be used to prevent further decline in frog populations. In this respect, it is notable that immune cells known as 'macrophages' are important both for the virus to infect the frog and for the frog's immune response against the infection. This award will define how distinct populations of macrophages found in the tadpole and adult frog serve either as immune barriers to this virus or as gateways for Frog Virus 3 entry, dissemination to other parts of the body, persistence and spread to other frogs. This work will broaden understanding of how vertebrates, including humans, resist viral infections and potentially lead to new therapies against viral diseases in humans. In addition, it will increase knowledge of conservation issues in the local community and provide educational opportunities to students, including underrepresented minorities, at all educational levels.The differentiation of nearly all vertebrate macrophages studied to date depends on the macrophage colony-stimulating factor (M-CSF) receptor. It is activated by both the M-CSF ligand and the interleukin34 (IL-34) cytokine. In Xenopus laevis, macrophages derived by M-CSF exacerbate Frog Virus 3 infections in the tadpole and adult frog whereas macrophages derived by IL-34 confer anti-viral resistance. In, Xenopus laevis, as in other vertebrates, the major antiviral effectors of IL-34-stimulated macrophages appear to be interferons. Interestingly, amphibians possess an expanded repertoire of interferons. Different subsets of these interferons are stimulated in tadpoles and adult frogs, in response to Frog Virus 3 infection, suggesting that different subsets of macrophages respond differently to Frog Virus 3. This award will (1) elucidate the roles played by M-CSF-stimulated and IL-34-stimulated macrophages in susceptibility and resistance to Frog Virus 3, (2) characterize the anti-Frog Virus 3 capacities of the distinct interferon subsets produced by the two macrophage populations. This work could foster development of measures to counteract amphibian declines by enhancing frog resistance to viral infections or using interferon treatment to prevent Frog Virus 3 replication. Moreover, as there are many parallels between the amphibian and mammalian immune systems, this research could deepen the understanding of how the human immune system evolved and lead to new ways for treating human viral infections. This award supports outreach aimed at raising public awareness of amphibian conservation. It provides hands-on laboratory experience to local high school and undergraduates, including underrepresented minorities, and mentors graduate students and postdoctoral fellows.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.

全球青蛙数量正在减少，几乎三分之二的青蛙物种面临灭绝的威胁。病毒感染，如青蛙病毒3型，是造成这些下降的重要原因。蝌蚪比成年青蛙更容易感染病毒。有必要更好地了解决定对青蛙病毒3的易感性和抵抗力的免疫机制。这些知识可以用来防止青蛙种群的进一步下降。在这方面，值得注意的是，被称为“巨噬细胞”的免疫细胞对于病毒感染青蛙和青蛙对感染的免疫反应都是重要的。该奖项将确定在蝌蚪和成年青蛙中发现的不同的巨噬细胞群体如何作为这种病毒的免疫屏障，或作为青蛙病毒3进入、传播到身体其他部位、持久和传播到其他青蛙的门户。这项工作将扩大对包括人类在内的脊椎动物如何抵抗病毒感染的理解，并可能导致针对人类病毒疾病的新疗法。此外，它还将增加对当地社区保护问题的认识，并为所有教育水平的学生提供教育机会，包括代表性不足的少数族裔。迄今为止研究的几乎所有脊椎动物巨噬细胞的分化依赖于巨噬细胞集落刺激因子(M-CSF)受体。它被M-CSF配体和白介素34(IL-34)细胞因子激活。在非洲爪哇，由M-CSF产生的巨噬细胞加剧了蝌蚪和成年青蛙对青蛙病毒3的感染，而由IL-34产生的巨噬细胞则具有抗病毒抗性。在非洲爪哇，和其他脊椎动物一样，IL-34刺激的巨噬细胞的主要抗病毒效应似乎是干扰素。有趣的是，两栖动物拥有更多的干扰素。这些干扰素的不同亚群在蝌蚪和成年青蛙中被刺激，以响应青蛙病毒3型感染，这表明不同亚群的巨噬细胞对青蛙病毒3型的反应不同。这一奖项将(1)阐明M-CSF刺激和IL-34刺激的巨噬细胞在对青蛙病毒3型的易感性和抵抗力中所起的作用，(2)表征由这两个巨噬细胞群产生的不同干扰素亚群的抗蛙病毒3型的能力。这项工作可能会促进通过提高青蛙对病毒感染的抵抗力或使用干扰素治疗来防止青蛙病毒3复制来对抗两栖动物衰退的措施的发展。此外，由于两栖动物和哺乳动物的免疫系统之间有许多相似之处，这项研究可能会加深对人类免疫系统如何进化的理解，并导致治疗人类病毒感染的新方法。该奖项支持旨在提高公众对两栖动物保护意识的宣传活动。它为当地高中和本科生，包括少数族裔，以及研究生和博士后导师提供实践实验室经验。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Class A Scavenger Receptors Are Used by Frog Virus 3 During Its Cellular Entry

• DOI: 10.3390/v11020093
• 发表时间: 2019-01
• 期刊: Viruses
• 作者: N. T. Vo;M. Guerreiro;Amulya Yaparla;Leon Grayfer;S. DeWitte-Orr

The amphibian (Xenopus laevis) colony-stimulating factor-1 and interleukin-34-derived macrophages possess disparate pathogen recognition capacities

两栖动物（非洲爪蟾）集落刺激因子 1 和白细胞介素 34 衍生的巨噬细胞具有不同的病原体识别能力

• DOI: 10.1016/j.dci.2019.04.011
• 发表时间: 2019
• 期刊: Developmental & Comparative Immunology
• 影响因子: 2.9
• 作者: Yaparla, Amulya;Docter-Loeb, Hannah;Melnyk, Mattie L.S.;Batheja, Aashish;Grayfer, Leon
• 通讯作者: Grayfer, Leon

Myelopoiesis of the amphibian Xenopus laevis is segregated to the bone marrow, away from their hematopoietic peripheral liver.

两栖动物非洲爪蟾的骨髓生成被分离到骨髓，远离其造血外周肝脏。

• DOI: 10.3389/fimmu.2019.03015
• 发表时间: 2020
• 期刊: Frontiers in immunology
• 影响因子: 7.3
• 作者: Yaparla A, Reeves P