KSHV latent infection replication

KSHV潜伏感染复制

• 批准号: 8936822
• 负责人: Kenneth M Kaye
• 金额: $ 44.31万
• 依托单位: BRIGHAM AND WOMEN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-04-01 至 2020-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8936822
• 关键词: Acquired Immunodeficiency Syndrome; Africa South of the Sahara; Architecture; Binding; Binding Sites; Biology; Cell Cycle; Cell Nucleus; Cell Survival; Cells; Complex; DNA; DNA biosynthesis; DNA-Directed DNA Polymerase; Daughter; Development; Dominant-Negative Mutation; Epidemic; Episome; Epstein-Barr Virus Infections; Genome; HIV; Herpesviridae; Herpesviridae Infections; Human; Human Herpesvirus 4; Human Herpesvirus 8; Image; Immune; Kaposi Sarcoma; Link; Malignant Neoplasms; Mediating; Multicentric Angiofollicular Lymphoid Hyperplasia; Oral cavity; Organ; Outcome; Persons; Plasmids; Polymerase; Process; Proliferating; Proteins; Reagent; Recruitment Activity; Resolution; Role; Saliva; Site; Solutions; Structure; Terminal Repeat Sequences; Testing; Therapeutic; Validation; Viral; Viral Genome; Virus; Virus Diseases; Virus Latency; Virus Replication; Visceral; Work; antigen binding; cell type; co-infection; daughter cell; inhibitor/antagonist; latency-associated nuclear antigen; latent infection; neoplastic cell; prevent; primary effusion lymphoma; public health relevance; research study; segregation; single molecule; small molecule; therapeutic target; tumor; viral DNA

 DESCRIPTION (provided by applicant): Kaposi's sarcoma (KS)-associated herpesvirus (KSHV or HHV8) is the causative agent of KS, primary effusion lymphoma (PEL) and multicentric Castleman's disease. KSHV is spread person to person through saliva. KSHV tumors occur primarily in AIDS and other immune compromised states. There are no available specific therapies for these tumors. KS is the leading AIDS malignancy and is epidemic in sub Saharan Africa where coinfection with HIV is common. KS often involves the oral cavity and visceral organs. KSHV latently infects tumor cells. During latent infection viral genomes persist as multiple copy, extrachromosomal, circular episomes (plasmids). To persist in proliferating cells, episomes must replicate with each cell cycle and efficiently segregate to daughter nuclei. The latency-associated nuclear antigen (LANA) mediates KSHV episome persistence and is strictly required for viral latency and KSHV survival in proliferating cells. Episome maintanence is comprised of two components: replication of KSHV DNA, and segregation of replicated episomes to daughter cell nuclei. LANA is responsible for both these functions. To replicate KSHV DNA, LANA binds viral terminal repeat (TR) DNA. Since no KSHV DNA replication proteins are expressed during latent infection, LANA is responsible for recruiting host cell replication machinery. Although LANA interacts with several cell replication factors, little is known regarding the underlying mechanisms through which LANA mediates replication. We recently found that LANA recruits the DNA polymerase clamp loader to mediate efficient replication and viral persistence. Loss of this recruitment greatly inhibited LANA's ability to mediate DNA replication and resulted in loss of virus infection. These findings suggested that clamp loading is a rate-limiting step in DNA replication that is incompatible with virus survival. LANA enhancement of clamp loading enables KSHV replication, persistence, and survival. The overarching hypothesis of this application is that LANA's recruitment of the clamp loader is a fundamental component of KSHV replication biology that is an ideal target for potential therapeutic inhibition. Experiments will test this hypothesis. Work will assess the mechanism by which LANA enhances clamp loading. Experiments will investigate the architecture of the LANA-clamp loader complex. In addition, experiments will target the LANA-clamp loader complex for inhibition. The expected outcome of this work is a detailed understanding of the mechanism through which LANA acts on the clamp loader and validation of this interaction as a potential therapeutic target for KSHV malignancy.

 描述（由申请方提供）：卡波西肉瘤（KS）相关疱疹病毒（KSHV或HHV 8）是KS、原发性渗出性淋巴瘤（PEL）和多中心Castleman病的病原体。KSHV通过唾液在人与人之间传播。KSHV肿瘤主要发生在艾滋病和其他免疫受损状态。对于这些肿瘤没有可用的特异性疗法。KS是主要的艾滋病恶性肿瘤，在撒哈拉以南非洲流行，那里与艾滋病毒合并感染很常见。KS常累及口腔和内脏器官。KSHV潜伏感染肿瘤细胞。在潜伏感染期间，病毒基因组以多拷贝、染色体外、环状附加体（质粒）的形式存在。为了在增殖细胞中持续存在，附加体必须在每个细胞周期中复制并有效地分离到子细胞核。潜伏相关核抗原（拉娜）介导KSHV附加体持续存在，并且是增殖细胞中病毒潜伏和KSHV存活的严格要求。附加体的维持由两部分组成：KSHV DNA的复制和复制的附加体分离到子细胞核。拉娜负责这两项职能。为了复制KSHV DNA，拉娜结合病毒末端重复（TR）DNA。由于在潜伏感染期间不表达KSHV DNA复制蛋白，因此拉娜负责募集宿主细胞复制机器。虽然拉娜与几种细胞复制因子相互作用，但关于拉娜介导复制的潜在机制知之甚少。我们最近发现，拉娜招募DNA聚合酶钳装载介导有效的复制和病毒的持久性。这种募集的丧失极大地抑制了拉娜介导DNA复制的能力，并导致病毒感染的丧失。这些发现表明，钳加载是DNA复制中的限速步骤，与病毒存活不相容。拉娜增强钳负载使得KSHV能够复制、持久和存活。本申请的首要假设是，拉娜募集的钳装载物是KSHV复制生物学的基本组成部分，是潜在治疗抑制的理想靶标。实验将检验这一假设。工作将评估拉娜增强夹钳载荷的机制。实验将调查的LANA钳加载器复杂的体系结构。此外，实验将靶向LANA-夹装载复合物用于抑制。这项工作的预期结果是详细了解拉娜作用于夹钳加载器的机制，并验证这种相互作用作为KSHV恶性肿瘤的潜在治疗靶点。