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

项目摘要 转化中的人类伽马疱疹病毒EBV和KSHV在B细胞中建立稳定的潜伏感染， 提供了一个终生的病毒储存库，可能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是至关重要的 预防疾病。伽马疱疹病毒在人体内的研究因困难而受到严重限制。 在自然宿主中工作。小鼠伽马疱疹病毒68与EB病毒和KSHV的相关性及致病原因 小鼠淋巴瘤和淋巴增生性疾病提供了一种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，MHV68也表现出多种形式 其在感染过程中的功能和发病机制在很大程度上是未知的。与大多数人不同 伽马疱疹病毒蛋白编码基因、伽马疱疹病毒ncRNAs在体内大量表达。 在淋巴增生性疾病的慢性感染和增生性病变中，提示这些ncRNAs 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，我们已经证明了 MHV68TMER4和EBV EBER1在血行播散中具有保守功能，在体内 抑制保守的miRNA靶标会增加B细胞的潜伏期。此外，我们新的初步发现表明， 小ncRNAs和miRNAs在病毒诱导的B细胞淋巴瘤发生发展中的作用因此，我们 假设伽马疱疹病毒利用广泛的ncRNAs形成关键的B细胞信号通路 从而促进病毒的传播、潜伏和肿瘤的形成。目标1(与项目2合作 在核心C和D的支持下，我们将定义伽马疱疹病毒小RNA 促进受感染B细胞的外流和扩散，促进B细胞在外围部位的潜伏，并推动 淋巴增生症的关键阶段。目标2(与项目2和项目3合作，并得到核心的支持 B、C和D)我们将定义伽马疱疹病毒miRNA对宿主mRNAs和lncRNAs的抑制作用 与B细胞潜伏期和淋巴肿大有关。该计划的高度协作性，以及系统化 体内分析携带EBV或KSHV基因的ncRNA突变体和重组病毒，提供了一种 非常强大的手段来确定ncRNAs参与的特定分子机制 伽马疱疹病毒潜伏期与肿瘤发生。

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.