"Project 3" Defining the in vivo function of ncRNAs during MHV68 latency and lymphomagenesis

项目摘要 转化的人γ疱疹病毒EBV和KSHV在B细胞中建立稳定的潜伏感染， 提供了一个终身的病毒库，可以有助于恶性疾病的发展。因此，定义 控制长期潜伏期和肿瘤发生的机制对于设计合理的策略至关重要， 预防疾病。人类γ疱疹病毒的体内研究受到了严重的限制， 在自然宿主中工作。鼠γ疱疹病毒68（MHV 68）与EBV和KSHV相关， 淋巴瘤和淋巴增生性疾病，提供了一个易于操作的小动物模型， 体内病毒/宿主关系的机制研究。与EBV和KSHV一样，MHV 68表达多种形式 在感染和发病过程中的功能在很大程度上是未知的ncRNA。与大多数 在γ疱疹病毒蛋白编码基因中，γ疱疹病毒ncRNA在体内大量表达， 慢性感染和淋巴增生性疾病期间的增生性病变，表明这些ncRNA 可能在潜伏期和肿瘤发生中起关键的保守作用。为了支持这一点，我们已经证明， MHV 68 TMER 4和EBV EBER 1在血行播散中具有保守的功能， 抑制保守的miRNA靶促进B细胞潜伏期。此外，我们新的初步发现表明 小ncRNA和miRNA在病毒诱导的B细胞淋巴瘤的发生和发展中的作用。因此我们 假设γ疱疹病毒利用广泛ncRNA来形成关键B细胞信号传导途径 从而促进病毒传播、潜伏和肿瘤发生。目标1（与项目2合作 在核心C和D的支持下，我们将定义γ疱疹病毒小RNA 促进受感染的B细胞的流出和扩散，促进外周部位的B细胞潜伏，并驱动 淋巴瘤形成的关键阶段在目标2中（与项目2和3合作，并得到核心小组的支持 B、C和D）我们将定义γ疱疹病毒miRNA抑制宿主mRNA和lncRNA的作用 到B细胞潜伏期和淋巴瘤发生。该计划的高度协作性，沿着系统化的 对携带EBV或KSHV基因的ncRNA突变体和重组病毒的体内分析，提供了一种 这是一种非常强大的手段，可以确定ncRNA参与的特定分子机制， γ疱疹病毒潜伏期和肿瘤发生。

Project Summary The transforming human gammaherpesviruses EBV and KSHV establish stable latent infections in B cells, providing a lifelong reservoir of virus that can contribute to the development of malignant disease. Thus, defining the mechanisms that govern long-term latency and tumorigenesis is critical for designing rational strategies to prevent disease. In vivo studies of gammaherpesviruses in humans have been severely limited by the difficulties of working in the natural host. Murine gammaherpesvirus 68 (MHV68) is related to EBV and KSHV and causes lymphomas and lymphoproliferative disease in mice, providing a readily manipulatable small animal model for mechanistic studies of the virus/host relationship in vivo. Like EBV and KSHV, MHV68 expresses multiple forms of ncRNAs whose functions during infection and pathogenesis are largely unknown. In contrast to most gammaherpesvirus protein-coding genes, gammaherpesvirus ncRNAs are abundantly expressed in vivo during chronic infection and in hyperplastic lesions during lymphoproliferative disease, suggesting that these ncRNAs may play key conserved roles in latency and tumorigenesis. In support of this, we have demonstrated that MHV68 TMER4 and EBV EBER1 share a conserved function in hematogenous dissemination, and that in vivo suppression of a conserved miRNA target promotes B cell latency. Further, our new preliminary findings implicate both small ncRNAs and miRNAs in the genesis and progression of virus-induced B cell lymphoma. Thus, we hypothesize that gammaherpesviruses utilize a broad array of ncRNAs to shape critical B cell signaling pathways and thereby promote virus dissemination, latency and tumorigenesis. In Aim 1 (in collaboration with Project 2 and with support from Cores C and D), we will define the mechanisms by which gammaherpesvirus small RNAs promote the egress and dissemination of infected B cells, facilitate B cell latency at peripheral sites, and drive key stages of lymphomagenesis. In Aim 2 (in collaboration with Projects 2 and 3, and with support from Cores B, C and D) we will define the contribution of gammaherpesvirus miRNA repression of host mRNAs and lncRNAs to B cell latency and lymphomagenesis. The highly collaborative nature of this program, along with the systematic in vivo analyses of ncRNA mutants and recombinant viruses carrying EBV or KSHV genes, provides an extremely powerful means to determine the specific molecular mechanisms by which ncRNAs contribute to gammaherpesvirus latency and tumorigenesis.