Determining how a Werner helicase (WRN) tumor suppressor complex regulates the human papillomavirus 16 life cycle

确定维尔纳解旋酶 (WRN) 肿瘤抑制复合物如何调节人乳头瘤病毒 16 生命周期

• 批准号: 10408136
• 负责人: Iain Morgan
• 金额: $ 55.11万
• 依托单位: VIRGINIA COMMONWEALTH UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-06-01 至 2026-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10408136
• 关键词: Anogenital cancer; Biological Assay; CRISPR/Cas technology; Cell Death; Cell Line; Cell Proliferation; Cells; Cervical; Collaborations; Complex; DNA; DNA Damage; DNA Double Strand Break; DNA Repair; DNA biosynthesis; DNA replication fork; Data; Deoxyribonuclease I; Disease; Enzymes; Gene Activation; Gene Expression; Genetic Recombination; Genome; Goals; Head and Neck Cancer; Human Papillomavirus; Human papilloma virus 31; Human papillomavirus 16; Immune Response Genes; Immunotherapy; Innate Immune Response; Integration Host Factors; Knowledge; LacZ Genes; Lesion; Life Cycle Stages; Malignant Neoplasms; Measures; Modeling; Mutagenesis; Outcome; Pathogenicity; Pathway interactions; Phenotype; Publishing; Regulation; Reporting; Retinoblastoma Protein; Role; SIRT1 gene; Stimulator of Interferon Genes; System; TP53 gene; Testing; Time; Tumor Suppressor Proteins; Viral; Viral Genome; Virus; Virus Diseases; Virus Replication; adaptive immune response; burden of illness; endonuclease; enzyme activity; helicase; homologous recombination; human disease; innate immune mechanisms; keratinocyte; malignant mouth neoplasm; member; new therapeutic target; novel; novel strategies; novel therapeutic intervention; recruit; replication stress; response; targeted treatment; therapeutic target; transcriptome sequencing

Human papillomaviruses (HPV) are causative agents in ano-genital and head and neck cancers. Our long-term goal is to identify, and develop, novel approaches for targeting these viral diseases; to do this we must enhance our understanding of the viral life cycle and how it interacts with the host. HPV activates the DNA damage response (DDR) during the viral life cycle and uses homologous recombination (HR) to replicate its genome. The Morgan lab has identified several HR factors involved in HPV replication including TopBP1, BRD4, SIRT1 and WRN. We have demonstrated that these factors regulate the levels and fidelity of HPV16 E1-E2 DNA replication in C33a cells. Following WRN depletion, E1-E2 replication switches from high fidelity mechanisms to break induced replication (BIR). BIR is highly mutagenic and occurs when a paused fork is unable to be resolved by WRN. In the absence of WRN there is excess recruitment of MUS81 to E1-E2 replicating DNA, an endonuclease that causes DNA double strand breaks at paused forks in the absence of WRN. This resolves the fork and allows BIR to continue replication, albeit with low fidelity. We present data demonstrating that WRN is a restriction factor for the HPV16 life cycle; in the absence of WRN there is increased cell proliferation, DNA damage and viral replication in organotypic raft cultures. We observed a similar phenotype following SAMHD1 depletion, another HR factor. WRN and SAMHD1 are in the same cellular complex along with other DDR factors involved in HPV life cycles. Our first objective is to determine the roles of the WRN-SAMHD1 complex in controlling HPV life cycles. The central hypothesis is that this complex controls high fidelity replication during the viral life cycle, and that targeting components of this complex along with MUS81 may block HPV replication. Using a novel HPV16 genome, we will investigate the levels and the fidelity of viral replication during the viral life cycle. Our second objective is to determine whether there are altered host DNA replication forks in HPV16 positive cells. The central hypothesis is that differences can be exploited for differential targeting of HPV positive cells. This will be done in association with Pietro Pichierri, a WRN and DNA replication and repair expert; Morgan and Pichierri have already published together. Our third objective is to investigate the activation of the innate immune response (IIR) in HPV16 cells depleted for WRN and SAMHD1. The central hypothesis is that depletion of WRN or SAMHD1 in the presence of the active DDR in HPV16 cells results in excess cytoplasmic DNA fragments that activate the IIR. The outcomes are crucial for achieving our long-term goals. For example, targeting of WRN enzyme activities could boost the IIR in HPV16 positive cells, assisting the adaptive immune response (and immunotherapy) to eliminate HPV positive cells. If there are different factors replicating host DNA in the presence of HPV, these could be targeted to preferentially kill HPV positive cells. Double targeting of WRN and MUS81 in HPV positive cells may block viral replication resulting in cell death following E6/E7 depletion and reactivation of p53/pRb pathways.

人乳头瘤病毒（HPV）是肛门生殖器癌和头颈癌的病原体。我们的长期目标是确定和开发针对这些病毒性疾病的新方法;要做到这一点，我们必须加强对病毒生命周期及其如何与宿主相互作用的理解。HPV在病毒生命周期中激活DNA损伤反应（DDR），并利用同源重组（HR）复制其基因组。摩根实验室已经确定了几个参与HPV复制的HR因子，包括TopBP 1，BRD 4，SIRT 1和WRN。我们已经证明，这些因素调节C33 a细胞中HPV 16 E1-E2 DNA复制的水平和保真度。在WRN耗尽后，E1-E2复制从高保真机制切换到中断诱导复制（BIR）。BIR具有高度致突变性，当WRN无法解决暂停的分叉时会发生。在不存在WRN的情况下，存在MUS 81向E1-E2复制DNA的过量募集，E1-E2复制DNA是一种在不存在WRN的情况下在暂停叉处引起DNA双链断裂的内切核酸酶。这解决了分叉问题，并允许BIR继续复制，尽管保真度较低。我们目前的数据表明，WRN是HPV 16生命周期的限制因素，在没有WRN的情况下，有增加的细胞增殖，DNA损伤和病毒复制的器官型筏文化。我们观察到一个类似的表型SAMHD 1耗尽后，另一个HR因素。WRN和SAMHD 1与其他参与HPV生命周期的DDR因子一起沿着在相同的细胞复合体中。我们的第一个目标是确定WRN-SAMHD 1复合物在控制HPV生命周期中的作用。中心假设是该复合物在病毒生命周期期间控制高保真复制，并且该复合物的靶向组分沿着MUS 81可以阻断HPV复制。使用一种新的HPV 16基因组，我们将研究在病毒生命周期中病毒复制的水平和保真度。我们的第二个目标是确定是否有改变的宿主DNA复制叉在HPV 16阳性细胞。中心假设是差异可以用于HPV阳性细胞的差异靶向。这将与WRN和DNA复制和修复专家Pietro Pichierri合作完成; Morgan和Pichierri已经一起发表了文章。我们的第三个目标是研究在去除WRN和SAMHD 1的HPV 16细胞中先天免疫应答（IIR）的激活。核心假设是，在HPV 16细胞中存在活性DDR的情况下，WRN或SAMHD 1的缺失导致过量的细胞质DNA片段激活IIR。这些成果对于实现我们的长期目标至关重要。例如，靶向WRN酶活性可以增强HPV 16阳性细胞中的IIR，帮助适应性免疫应答（和免疫疗法）消除HPV阳性细胞。如果在HPV存在的情况下有不同的因子复制宿主DNA，则这些因子可以被靶向以优先杀死HPV阳性细胞。HPV阳性细胞中WRN和MUS 81的双重靶向作用可阻断病毒复制，导致E6/E7耗竭和p53/pRb途径再激活后的细胞死亡。