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Molecular mechanisms governing the ubiquitination signaling during KSHV cell entry and tumorigenesis

KSHV 细胞进入和肿瘤发生过程中泛素化信号传导的分子机制

基本信息

批准号：
10326475
负责人：
Noula Dattu Shembade
金额：
$ 47.14万
依托单位：
UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-07-01 至 2026-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10326475
关键词：
AIDS related cancer AIDS/HIV problem Acquired Immunodeficiency Syndrome Anti-Retroviral Agents Cell Adhesion Molecules Cell Proliferation Cell Survival Cells Chronic Complex Country DNA Data Development Drug Targeting Environment Etiology Florida Goals Guanine Nucleotide Exchange Factors HIV Herpesviridae Infections Human Herpesvirus 8 Incidence Individual Infection Inflammation Integration Host Factors Kaposi Sarcoma Libraries Link Lymphoma cell Lymphoproliferative Disorders Lysine Lytic Phase Malignant Neoplasms Mediating Molecular Monomeric GTP-Binding Proteins Multicentric Angiofollicular Lymphoid Hyperplasia Patients Pharmaceutical Preparations Pharmacology Play Polyubiquitination Post-Translational Protein Processing Production Proteins Proteomics Publishing Regulation Risk Role STAT3 gene Sampling Scanning Signal Pathway Signal Transduction Small Interfering RNA TIAM1 gene Testing Therapeutic Intervention Ubiquitin-Conjugating Enzymes Ubiquitination Virion Virus Xenograft Model base cellular targeting efficacy evaluation in vivo mouse model novel pathogenic virus patient derived xenograft model predictive modeling prevent primary effusion lymphoma screening small molecule small molecule inhibitor transcription factor tumor tumor xenograft tumorigenesis ubiquitin-protein ligase

项目摘要

Infection with Kaposi sarcoma herpesvirus (KSHV) has been shown to increase the risk of classic Kaposi's sarcoma (KS), AIDS-associated KS (AIDS-KS) and lymphoproliferative disorders, including primary effusion lymphoma (PEL) and multicentric Castleman disease (MCD) in HIV/AIDS. About 30-40% of AIDS-related cancers in HIV+ individuals treated with antiretroviral drugs are caused due to KSHV infection, and in many circumstances they are incurable. Emerging studies have indicated that chronic inflammation mediated by transcription factors, including STAT3 and NF-κB, in KSHV-infected cells plays critical role in the development of KSHV-associated malignancies in HIV (+) individuals. Protein ubiquitination, a post-translational modification, plays key roles in the regulation of NF-κB and STAT3 activation, pathogenic virus entry into target cells, and survival of virus infected cells. Using an unbiased Ubi-Scan proteomics approach, we have identified tumor specific CADM1 ubiquitination at lysine 437 (K437), which is essential for chronic activation of STAT3 and NF- κB and the proliferation and survival of PEL cells. CADM1-K63-Ubi is also critical for efficient KSHV entry into target cells after KSHV de novo infection. Using siRNA library-based screening we identified the E2 ubiquitin conjugating enzyme Ubc13 and the E3 ubiquitin ligase Mib1, as essential factors for CADM1 ubiquitination. In addition, we found that ubiquitinated CADM1 was required for the activation of the small GTPase Rac1 in KSHV- infected cells, which in turn was critical for chronic STAT3 and NF-κB activation and PEL cell proliferation and survival. Furthermore, using siRNA library-based screening of Guanine nucleotide exchange factors (GEFs), we have also determined that the GEF TIAM1 is required for Rac1 activation. Therefore, we hypothesize that KSHV de novo infection-induced rapid Ubc13 and Mib1-dependent CADM1-K63 ubiquitination leads to the activation of TIAM1/Rac1 and NF-κB and STAT3 essential for KSHV entry into target cells, KSHV latency establishment and KSHV lymphoma cells survival and proliferation. To test this hypothesis, we propose three specific Aims: 1) Mechanistic roles of CADM1-K63-Ubi and its associated molecules in KSHV entry into target cells after de novo infection, 2) Mechanistic roles of CADM1-K63-Ubi and its associated molecules in NF-κB and STAT3 activation after KSHV de novo infection, and 3) Examine the efficacy of small molecule inhibitors against CADM1-K63-Ubi and its associated molecules using PEL patient-derived xenograft (PDX) mouse model. Data obtained from this project will reveal the mechanisms of chronic STAT3 and NF-κB activation and efficient KSHV entry into target cells after KSHV de novo infection. These findings will pave the way for therapeutic intervention of KSHV- mediated highly aggressive AIDS associated malignancies, which are often seen throughout the US, particularly South Florida, which has one of the highest incidences of HIV in the country.

感染卡波西肉瘤疱疹病毒（KSHV）已被证明会增加经典卡波西的风险肉瘤（KS）、艾滋病相关KS（AIDS-KS）和淋巴组织增生性疾病，包括原发性积液淋巴瘤（PEL）和多中心Castleman病（MCD）的HIV/AIDS。大约30-40%的艾滋病相关在接受抗逆转录病毒药物治疗的HIV+个体中，癌症是由于KSHV感染引起的，在这种情况下，他们是无法治愈的。新兴的研究表明，慢性炎症介导的 KSHV感染细胞中的转录因子（包括STAT 3和NF-κB）在发育中发挥关键作用 KSHV相关的恶性肿瘤在HIV（+）个体中的发生率。蛋白质泛素化，一种翻译后修饰，在调节NF-κB和STAT 3活化、致病性病毒进入靶细胞以及病毒感染细胞的存活。使用无偏的Ubi-Scan蛋白质组学方法，我们已经确定了肿瘤特异性CADM 1在赖氨酸437（K437）的泛素化，这是STAT 3和NF-κ B慢性激活所必需的。 κB与PEL细胞增殖和存活的关系。CADM 1-K63-Ubi对于KSHV有效进入 KSHV从头感染后的靶细胞。使用基于siRNA文库的筛选，我们鉴定了E2泛素结合酶Ubc 13和E3泛素连接酶Mib 1，作为CADM 1泛素化的必需因子。在此外，我们发现泛素化的CADM 1是KSHV中小GTdR Rac 1激活所必需的。感染的细胞，这反过来又是慢性STAT 3和NF-κB活化和PEL细胞增殖的关键，生存此外，利用基于siRNA文库的鸟嘌呤核苷酸交换因子（GEFs）筛选，我们还确定了GEF TIAM 1是Rac 1激活所必需的。因此，我们假设KSHV 从头感染诱导的快速Ubc 13和Mib 1依赖性CADM 1-K63泛素化导致激活 TIAM 1/Rac 1和NF-κB和STAT 3对KSHV进入靶细胞、KSHV潜伏期建立至关重要和KSHV淋巴瘤细胞的存活和增殖。为了验证这一假设，我们提出了三个具体目标：1） CADM 1-K63-Ubi及其相关分子在KSHV从头感染后进入靶细胞中的作用 2）CADM 1-K63-Ubi及其相关分子在NF-κB和STAT 3活化中的机制作用 KSHV从头感染后，和3）检查小分子抑制剂对CADM 1-K63-Ubi的功效和其相关分子。数据来源于此本项目将揭示STAT 3和NF-κB的慢性激活以及KSHV有效进入靶点的机制 KSHV从头感染后的细胞。这些发现将为KSHV的治疗干预铺平道路- 介导的高度侵袭性的艾滋病相关恶性肿瘤，这是常见于整个美国，特别是南佛罗里达是全国艾滋病发病率最高的地区之一。