Role of type 1 IFN in eye infection

摘要 HSV-1感染是眼病和生殖器疱疹的主要原因，但尚未有HSV-1疫苗显示 对人类的功效。它只能引起部分保护性免疫反应，并能建立持续的潜伏期 神经细胞中的感染病毒。I型干扰素(IFN)的诱生是早期的、关键的宿主对大多数 限制病毒复制，诱导感染细胞的凋亡/自噬，并动员 其他免疫反应。尽管对干扰素反应的战略性规避是许多病毒的标志，但它 在HSV-1感染中还没有完全定义。用重组病毒剖析个体的角色 在细胞因子复杂的体内免疫反应环境下，我们产生了引人注目的 初步数据表明，规避1型干扰素反应在两种原发疾病中都起着关键作用 HSV-1感染和随后在小鼠眼部感染模型中潜伏期的诱导 HSV-1潜伏期相关转录本(LAT)在调节作用中的作用。干扰素和干扰素转录本为 眼部感染LAT(+)后野生型小鼠三叉神经节的表达显著下调 病毒与LAT(-)病毒比较。表达抗凋亡基因的HSV-1重组病毒 随后将LAT(+)存活表型恢复到IFNAR1/-感染更容易感染HSV-1小鼠 感染的小鼠比wt小鼠。LAT的这些活性被映射到LAT的811个碱基区域，该区域编码小的非 编码RNA(SncRNAs)。这些和其他数据表明了一种高度创新的假设模型，在该模型中，HSV-1 Lat促进HSV-1通过干扰素系统在原发性眼部感染和 通过：(I)抑制干扰素-2和/或干扰素的产生；和(Ii)限制凋亡，从而在TG中重新激活 干扰素产生的影响。这一假设将在小鼠模型中得到验证：(1)确定HSV-1是否下调- 干扰素2和干扰素的调节，而不是干扰素的调节，影响初次感染、潜伏期的建立和重新激活 在眼部HSV-1感染后的TG中；参与这些过程的LAT区域的精细定位；以及 体外结合干扰素-2和干扰素启动子的分析；(2)特异性鉴定 LAT通过诱导细胞凋亡和保护IFNAR1-/-小鼠抗感染作用的研究 对复制的干扰，以及对介导这些影响的LAT区域的精细定位；以及 (3)LAT依赖的干扰素-2和干扰素调节在潜伏期中的差异和联合作用分析。 使用干扰素-/-、干扰素2-/-和干扰素2-/-干扰素-/-小鼠重新激活和初次感染单纯疱疹病毒1型。结果是 将确定HSV-1用来逃避宿主干扰素系统的主要机制，并提供 为可用于预防感染和最大限度减少复发疾病的战略奠定基础。

ABSTRACT HSV-1 infection is a leading cause of eye disease and genital herpes but no HSV-1 vaccines have shown efficacy in humans. It elicits only a partially protective immune response and can establish persistent latent infections virus in neurons. Induction of type I interferons (IFNs) is an early, pivotal host response to most pathogenic viruses that limits viral replication, induces apoptosis/autophagy of infected cells, and mobilizes other immune responses. Although strategic circumvention of IFN responses is a hallmark of many viruses, it has not been fully defined in HSV-1 infections. Using recombinant viruses to dissect of the roles of individual cytokines in the context of the complex in vivo immune response environment, we have generated compelling preliminary data that indicate that circumvention of the type 1 IFN response plays a key role in both primary HSV-1 infection and subsequent induction of latency in mouse models of ocular infection and implicate the latency-associated transcript (LAT) of HSV-1 in modulation of the effects. IFN and IFN transcripts are significantly downregulated in the trigeminal ganglia (TG) of wild-type mice after ocular infection with LAT(+) virus as compared with LAT(-) virus. HSV-1 recombinant viruses expressing anti-apoptotic genes in place of LAT restore the LAT(+) survival phenotype to IFNAR1-/- infected mice, which are more susceptible to HSV-1 infection than wt mice. These activities of LAT map to an 811 bp region of LAT, which encodes small non- coding RNAs (sncRNAs). These and other data suggest a highly innovative hypothetical model in which HSV-1 LAT promotes HSV-1 evasion of clearance by the IFN system during both primary ocular infection and reactivation in the TG by: (i) Suppressing the production of IFN2 and/or IFN; and (ii) Limiting the apoptotic effects of IFN production. This hypothesis will be tested in mouse models by: (1) Determining if HSV-1 down- regulation of IFN2 and IFN, but not IFN, affects primary infection, establishment of latency, and reactivation in the TG after ocular HSV-1 infection; fine mapping of the regions of LAT involved in these processes; and analysis of the binding of the sncRNAs to IFN2 and IFN promoters in vitro; (2) Identification of the specific roles of LAT in protecting against infection in IFNAR1-/- mice through analysis of apoptosis induction and interference with replication together with fine-mapping of the regions of LAT that mediate these effects; and (3) Analysis of the differential and combinatorial roles of LAT-dependent IFN2 and IFN regulation in latency- reactivation and primary HSV-1 infection using IFN-/-, IFN2-/-, and IFN2-/-IFN-/- mice. The results generated will identify the primary mechanisms utilized by HSV-1 to evade the host IFN system and provide a basis for strategies that can be used to prevent infection and minimize recurrent disease.