Interferon Gene Expression in VSV-Infected Cells

病毒感染通常会触发抗病毒基因的转录，包括1型干扰素(干扰素)。新产生的干扰素从细胞中释放出来，并激活信号转导级联，诱导许多干扰素反应基因的转录，这些基因的产物在未感染的邻近细胞中建立抗病毒状态。许多病毒已经进化到对抗这种宿主防御机制，从而允许病毒复制。这项研究的总体重点是调查宿主诱导抗病毒干扰素反应的能力和水疱性口炎病毒(VSV)阻断该系统诱导的能力之间的平衡。细胞毒性VSV基质(M)蛋白抑制宿主定向转录并限制干扰素基因 在VSV感染细胞中表达。该项目的目的是根据M蛋白抑制宿主转录的能力，确定M蛋白是否单独负责抑制干扰素基因的表达，或者是否存在VSV调节干扰素基因表达的特定机制。我们的初步数据表明，后者是正确的。我们已经证明，作为干扰素基因表达的上游激活因子，核因子-kappaB的激活在感染干扰素诱导株和干扰素抑制株的VSV感染细胞中受到不同的调节。我们认为，病毒的第二个功能是抑制核因子-kappaB的激活。因此，这种病毒成分将发挥至关重要的作用。 诱导干扰素基因表达。为了验证这一假说，需要解决的具体目标是：(1)通过克隆和测定每个病毒基因的序列来表征VSV印第安纳州VSV干扰素抑制株和干扰素诱导株的HR基因。(2)为了确定导致核因子-kappaB激活的病毒成分，我们将研究感染重组M-缺陷VSV株的细胞中的核因子-kappaB的激活，以及在转染了编码其中一个病毒基因的表达载体的细胞中，是否抑制了核因子-kappaB的激活。(3)为了了解病毒调节NF-kappaB活化的机制，我们将确定IkappaB是否已被降解，并研究 VSV感染和转染细胞中IkappaB激酶的磷酸化状态。这个项目完成后，我们将对病毒对宿主干扰素反应的调节有新的见解。对这种对病毒感染的细胞反应的详细了解可能有助于开发新的抗病毒和抗癌疗法。

Viral infections commonly trigger the transcription of antiviral genes, including type 1 interferon (IFN). Newly produced IFNs are released from the cell, and activate a signal transduction cascade that induces the transcription of many interferon responsive genes whose products set up an antiviral state in uninfected neighboring cells. Many viruses have evolved to counteract this host defense mechanism, allowing virus replication to occur. The overall focus of this research is to investigate the balance between the ability of the host to induce the antiviral IFN response, and the ability of vesicular stomatitis virus (VSV) to block induction of this system. The cytotoxic VSV matrix (M) protein inhibits host-directed transcription and limits IFN gene expression in VSV-infected cells. The goal of this project is to determine if M protein is solely responsible for suppression of IFN gene expression based on its ability to inhibit host transcription, or if there is a specific mechanism by which VSV regulates IFN gene expression. Our preliminary data suggest that the later is true. We've demonstrated that NF-kappaB activation, an upstream activator of IFN gene expression, is regulated differently in cells infected with an IFN-inducing and IFN-suppressing strains of VSV. We propose that a second viral function inhibits NF-kappaB activation. This viral component would therefore play a crucial role in induction of IFN gene expression. To test this hypothesis, the specific aims to be addressed are: (1) To characterize the VSV Indiana Hr genes from an IFN-suppressing and IFN-inducing strain of VSV by cloning and determining the sequence of each viral gene. (2) To identify the viral component responsible for activation of NF-kappaB, we will investigate NF-kappaB activation in cells infected with recombinant M-defective strains of VSV, as well as determining if activation of NF-kappaB is suppressed in cells transfected with an expression vector encoding one of the viral genes. (3) To understand the mechanism by which the virus regulates NF-kappaB activation, we will determine if IkappaB has been degraded and investigate the phosphorylation status of the IkappaB Kinase in VSV-infected and transfected cells. Upon completion of this project, we will gain new insights into virus modulation of the host interferon response. Detailed knowledge of this cellular response to viral infection could be useful to the development of new antiviral and anticancer therapies.