Role of type I interferon signaling in Zika virus infection of the brain

寨卡病毒(ZIKV)是一种昆虫传播的黄病毒，直到最近才在赤道狭窄的地带被发现 从非洲到亚洲。ZIKV已在全球范围内出现，并已达到大流行水平，传播到 墨西哥、中美洲、加勒比海和南美洲。虽然寨卡病毒通常会引起轻微的疾病，但感染 的孕妇被怀疑导致出生时患有小头畸形症的婴儿显著增加 巴西，从2015年底开始，被认为是经胎盘感染，这是一条以前未知的途径 感染。ZIKV与胎儿大脑发育异常之间的联系得到了 最近检测到ZIKV RNA序列和抗原以及流产胎儿和 出生后不久就死亡的婴儿。因此，我们必须尽可能多地了解ZIKV是如何复制和 与宿主相互作用，包括在中枢神经系统的细胞中。I型干扰素应答是一种早期有效的抗病毒药物 对病毒入侵的反应可以对限制病毒传播产生重大影响，这一点就是明证 显著增加了病毒复制和快速死亡率，以及器官趋向性障碍的丧失 缺乏I型干扰素信号的小鼠。中枢神经系统表达低水平的干扰素信号基因 外周器官提示中枢神经系统可能对限制病毒入侵的准备较少。此外，病毒 抑制或逃避宿主免疫反应，以促进它们在宿主内的复制并引起 因此编码具有宿主干扰素拮抗剂活性的蛋白质。因此，感染的后果 取决于宿主免疫防御和病毒编码的毒力因素的平衡，这可能会有所不同 在病毒和组织类型中。我们已经对干扰素信号反应进行了广泛的研究 神经毒力的小鼠冠状病毒在体外的各种细胞类型以及在中枢神经系统和小鼠的外周。 我们建议利用我们的专业知识和收集的信息，以及我们最近的数据显示 ZIKV在人A549细胞中的复制，激活OAS-核糖核酸酶L途径 小鼠神经细胞和神经胶质细胞培养，以检验细胞类型和组织特异性差异在 ZIKV诱导的I型干扰素应答可能与胎脑对ZIKV诱导的易感性有关 病理学。在目标1中，我们将研究ZIKV感染人A549细胞过程中干扰素的信号转导途径。 CRIPSR/Cas9工程基因敲除A549细胞以及原代小鼠神经元和神经胶质细胞培养。在……里面 目的研究ZIKV在胚胎和新生小鼠体内的复制和干扰素应答。vt.在.的基础上 完成这些目标，我们将获得对I型干扰素在体外对ZIKV的反应的了解 人类细胞和小鼠中枢神经系统细胞。我们还将更多地了解发育中小鼠体内的干扰素信号。 ZIKV的胚胎和感染母亲的传播。这两种方法结合起来将有助于理解 干扰素信号对ZIKV感染和传播的影响及更长期的靶点确定 开发治疗ZIKV引起的疾病的治疗策略。

Zika virus (ZIKV) is an insect borne flavivirus which until recently was found within a narrow equatorial belt from Africa to Asia. ZIKV has emerged across the globe and has reached pandemic levels, spreading to Mexico, Central America, the Caribbean and South America. While ZIKV usually causes mild disease, infection of pregnant women has been suspected to cause a significant increase in babies born with microcephaly in Brazil, starting in late 2015, presumed to have become infected transplacentally a previously unknown route of infection. The association of ZIKV with abnormal brain development in the fetus has been supported by the recent detection of ZIKV RNA sequences and antigens along with neurodegeneration in aborted fetuses and babies that died soon after birth. Thus it is vital that we learn as much as possible of how ZIKV replicates and interacts with its host, including in cells of the CNS. The type I IFN response is an early potent antiviral response to viral invasion that can have a major impact on restricting virus spread as evidenced by significantly increased virus replication and rapid mortality as well as loss of organ tropism barriers observed in mice lacking type I IFN signaling. The CNS expresses low levels of interferon signaling genes compared to peripheral organs suggesting the CNS may be less prepared to restrict viral invasion. In addition, viruses suppress or evade the host immune response in order to facilitate their replication within a host and cause disease and therefore encode proteins with host IFN antagonist activities. The outcome of infection therefore depends on the balance of host immune defenses and virus encoded virulence factors and this can differ among viruses and tissue types. We have carried out extensive studies of IFN signaling responses to neurovirulent murine coronavirus in various cell types in vitro as well as in the CNS and the periphery of mice. We propose to use our expertise as well as information gathered, along with our recent data demonstrating robust replication of ZIKV in human A549 cells where it activates the OAS-RNase L pathway and in primary murine neuronal and glial cell cultures to test the hypothesis that cell type and tissue specific differences in the type I IFN response to ZIKV may contribute to susceptibility of the fetal brain to ZIKV-induced pathology. In Aim 1 we will investigate the IFN signaling pathways during ZIKV infected human A549 cells and CRIPSR/Cas9 engineered knockout A549 cells as well as primary murine neuronal and glial cell cultures. In Aim 2 we will investigate ZIKV replication and IFN response in vivo in embryonic and neonatal mice. Upon completion of these aims we will have gained an understanding of the type I IFN response to ZIKV in vitro in human cells as well as murine CNS cells. We will also know more about IFN signaling in the developing mouse embryo and spread of ZIKV from infected mothers. These two approaches combined will aid in understanding the impact of IFN signaling on ZIKV infection and spread and in the more long term identify targets for the development of therapeutic strategies to treat ZIKV-induced disease.