Protein Biomarkers for a New Human Polyomavirus in AIDS-related Malignancies

艾滋病相关恶性肿瘤中新型人类多瘤病毒的蛋白质生物标志物

• 批准号: 7691836
• 负责人: PATRICK S. MOORE
• 金额: $ 34.09万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-25 至 2011-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7691836
• 关键词: AIDS related cancer; Acquired Immunodeficiency Syndrome; Antibodies; Antibody Formation; Antigens; Baculoviruses; Biological Assay; Biological Markers; Blood; Blood Tests; Carcinoma; Cell Line; Cells; Cercopithecus pygerythrus; Clinical; Common Neoplasm; Diagnostic tests; Early Diagnosis; Elderly; Ensure; Enzyme-Linked Immunosorbent Assay; Epitope Mapping; Etiology; Funding; Gene Expression Profile; Generations; Genome; Human; Human Virus; Immune; Immunocompromised Host; Immunological Diagnosis; Infection; Laboratories; Malignant Epithelial Cell; Malignant Neoplasms; Mammalian Cell; Measures; Merkel cell carcinoma; Methods; Monoclonal Antibodies; Mutate; Oncogenic Viruses; Patients; Pattern; Peptide Library; Peptide Mapping; Persons; Pharmaceutical Preparations; Polyomavirus; Polyomavirus Infections; Population; Preventive; Proteins; Reagent; Research Personnel; Role; Screening procedure; Serum; Skin Cancer; Southern Blotting; Specificity; Staining method; Stains; Techniques; Time; Tissue Microarray; Tissues; Transplantation; Vaccines; Viral; Viral Antigens; Viral Genome; Viral Proteins; Viral Tumor Antigens; Virus; Virus-like particle; Viviparous-1 protein; advanced disease; base; cross reactivity; digital; immunosuppressed; mortality; neoplastic cell; novel; patient population; sialosyl-T antigen; tumor

DESCRIPTION (provided by applicant): Merkel cell carcinoma (MCC) is a neuroectodermal, AIDS-related cancer suspected to have a viral etiology. MCC is 13 times more common than expected among AIDS patients and occurs in post-transplant and other immunosuppressed patient populations. While rare, it is the most aggressive skin cancer and only 50% of patients with advanced disease survive 9 months or longer. There are no early detection markers and it is frequently misdiagnosed with other small round cell tumors. We identified a novel polyomavirus in MCC using digital transcriptome subtraction (DTS). This agent, Merkel carcinoma polyomavirus (MCPyV), is most closely related to African green monkey lymphotropic polyomavirus (LPyV). Between 15-30% of persons have antibodies to LPyV, which has led investigators to speculate on the existence of a closely related but undiscovered human virus. MCPyV has a 5387 bp genome and expresses T antigen proteins in MCC tumors. Most MCC are positive for an integrated MCPyV that is readily detected by PCR and by Southern blotting. In contrast only 8-16% of control tissues harbor detectable viral genome. On Southern blotting, the majority of MCPyV positive tumors show a monoclonal somatic insertion pattern suggesting that the virus contributes to clonal cell expansion. We have developed reagents required to study this new virus including infected cell lines, specific antibodies and an overlapping peptide library for the VP1 protein. Preliminary studies suggest that MCPyV is a common but not ubiquitous infection that contributes to MCC when the virus mutates and integrates into the host genome. Identification of specific biomarkers for MCPyV infection is essential to determine MCPyV's role in human cancers. We propose to develop screening blood tests for MCPyV infection using established polyomavirus immunodiagnostic techniques as well as new immunodiagnostic methods. We will identify and characterize human antibody responses to MCPyV infection using cell-based IFA, MCPyV peptide mapping and virus-like particle ELISA with sera from well-defined populations. These assays will be vetted for cross-reactivity to known human polyomaviruses to ensure assay specificity. We also propose generating specific monoclonal antibodies to be used to detect viral antigens in tissue microarrays so that common tumors can be screened for infection. Expression of viral proteins can also be correlated with cellular protein biomarker expression to determine clinical course and responsiveness to treatment. This is the first proposal for funding to study a new human tumor virus found in our laboratory, MCPyV, likely to cause Merkel cell carcinoma. Merkel cell carcinoma is a cancer of the elderly, AIDS, transplant and other immunosuppressed persons. It has the highest overall mortality rate among skin cancers and there are no specific preventive measures or diagnostic tests for MCPyV infection. If funded, this proposal will develop accurate blood assays to measure antibody proteins marking MCPyV infection and to measure viral proteins in tissues. These are required to understand human infection with this virus and to develop effective vaccines and drugs against MCPyV.

描述（由申请人提供）：默克尔细胞癌（MCC）是一种神经外胚层、艾滋病相关癌症，怀疑有病毒病因。MCC在艾滋病患者中的发病率是预期的13倍，发生在移植后和其他免疫抑制患者人群中。虽然罕见，但它是最具侵袭性的皮肤癌，只有50%的晚期患者存活9个月或更长时间。没有早期检测标志物，它经常被误诊为其他小圆细胞肿瘤。我们使用数字转录组减法（DigitalTranscriptome Subtraction，简称RT-PCR）在MCC中鉴定了一种新型多瘤病毒。这种病原体，默克尔癌多瘤病毒（MCPyV），与非洲绿色猴嗜淋巴多瘤病毒（LPyV）最密切相关。15-30%的人有LPyV抗体，这使得研究人员推测存在一种密切相关但未被发现的人类病毒。MCPyV具有5387 bp的基因组，并在MCC肿瘤中表达T抗原蛋白。大多数MCC对通过PCR和Southern印迹容易检测到的整合的MCPyV呈阳性。相比之下，只有8-16%的对照组织具有可检测的病毒基因组。在Southern印迹上，大多数MCPyV阳性肿瘤显示单克隆体细胞插入模式，表明病毒有助于克隆细胞扩增。我们已经开发了研究这种新病毒所需的试剂，包括感染的细胞系，特异性抗体和VP 1蛋白的重叠肽库。初步研究表明，MCPyV是一种常见但并非普遍存在的感染，当病毒突变并整合到宿主基因组中时，会导致MCC。鉴定MCPyV感染的特异性生物标志物对于确定MCPyV在人类癌症中的作用至关重要。我们建议使用已建立的多瘤病毒免疫诊断技术以及新的免疫诊断方法开发MCPyV感染的筛查血液检测。我们将使用基于细胞的IFA、MCPyV肽图谱和病毒样颗粒ELISA，用来自明确定义的人群的血清鉴定和表征对MCPyV感染的人抗体应答。将审查这些检测试剂与已知人多瘤病毒的交叉反应性，以确保检测试剂的特异性。我们还建议产生特异性单克隆抗体，用于检测组织微阵列中的病毒抗原，以便对常见肿瘤进行感染筛查。病毒蛋白的表达也可以与细胞蛋白生物标志物表达相关，以确定临床过程和对治疗的反应性。这是第一个资助研究我们实验室发现的一种新的人类肿瘤病毒MCPyV的提案，这种病毒可能导致默克尔细胞癌。默克尔细胞癌是一种老年人、艾滋病患者、移植者和其他免疫抑制者的癌症。它在皮肤癌中具有最高的总体死亡率，并且没有针对MCPyV感染的具体预防措施或诊断测试。如果获得资助，该提案将开发准确的血液检测试剂盒，以测量标记MCPyV感染的抗体蛋白并测量组织中的病毒蛋白。这些是了解人类感染这种病毒和开发有效的疫苗和药物对MCPyV所必需的。