Syrian Hamster as a Permissive Model for Testing Anti-Adenovirus Drugs

叙利亚仓鼠作为测试抗腺病毒药物的许可模型

• 批准号: 7327485
• 负责人: WILLIAM SM WOLD
• 金额: $ 22.27万
• 依托单位: VIRRX, INC
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-15 至 2008-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7327485
• 关键词: Adenovirus Infections; Adenoviruses; Allogenic; Animal Model; Applications Grants; Biodistribution; Biological Assay; Blood; Bone Marrow Stem Cell; Cessation of life; Chemistry; Child; Childhood; Cidofovir; Classification; Clinical Trials; Condition; Controlled Clinical Trials; Controlled Study; Cultured Cells; Cyclophosphamide; Development; Dose; Drug Approval; Effectiveness; Evaluation; Goals; Hamsters; Hematology; Hepatocyte; Histopathology; Human; Human Adenoviruses; Immune system; Immunocompetent; Immunocompromised Host; Immunohistochemistry; Immunosuppression; Infection; Injection of therapeutic agent; Lead; Liver; Liver neoplasms; Lung; Maximum Tolerated Dose; Mesocricetus auratus; Modeling; Oncogenes; Oncolytic; Organ; Patients; Pharmaceutical Preparations; Phase; Proteins; Ribavirin; Safety; Schedule; Serotyping; Serum; Small Business Technology Transfer Research; Staining method; Stains; Stem cell transplant; Systemic infection; Testing; Therapeutic immunosuppression; Toxic effect; Toxicology; Transplant Recipients; Viral; Virion; Virus; Virus Replication; base; day; gene therapy; immunosuppressed; in vivo; interest; intravenous injection; latent virus activation; leukemia; member; oncolytic vector; research study; success; tissue culture; tumor; vector

DESCRIPTION (provided by applicant): Human adenoviruses (Ads) are a significant problem in immunosuppressed humans, especially in children undergoing allogeneic stem cell transplants. About 20% of these pediatric patients develop disseminated Ad infections and about half of the patients die. There are no anti-viral drugs approved to treat these Ad infections. Cidofovir and ribavirin are used in some cases, but it is not known whether they are effective because they have not been studied in a systematic controlled manner. Development of anti-Ad drugs has been hindered because there is no animal model for replicating human Ads. This is because Ads are highly species-specific. We are developing the Syrian hamster as a tumor model to study the efficacy, replication, toxicity, and biodistribution of oncolytic Ad vectors. We showed that human Ad serotype 5 (Ad5) and Ad5-based oncolytic vectors replicate well in hamster tumors, livers, lungs, and other organs following intratumoral or intravenous injection. Of great interest, immunosuppression of the hamsters using cyclophosphamide (CP) leads to much higher levels of replication of the viruses. Replication continues at high levels in tumors and livers for at least 42 days (the end of the experiment) following administration of the virus. Based on these observations, we propose to use CP-immunosuppressed Syrian hamsters as a new animal model to evaluate the efficacy and toxicology of anti-Ad drugs on disseminated Ad infections in immunocompromised patients. To obtain initial proof-of-principle for this model, we will evaluate the anti-Ad efficacy and toxicology of hexadecyloxypropyl-cidofovir (HDP-CDV). In Specific Aim 1 we will examine HDP- CDV inhibition of Ad5 (a member of human Ad Species C) replication in the liver of hamsters immunosuppressed by CP. Ad5 replication in the liver and blood will be determined by qPCR, a tissue culture infectious dose assay 50 (TCID50 assay), and immunohistochemistry for an Ad virion protein. Toxicity will be assessed based on histopathology of the liver and serum chemistry. In Aim 2 we will determine whether serotypes in human Ad Species A, B, D, E, and F replicate in the liver of hamsters immunosuppressed by CP. If they do replicate, then we will determine whether HDP-CDV inhibits their replication in cultured cells. When humans become severely immunosuppressed, for example when children with leukemia have their immune system destroyed by immunosuppressed drugs prior to receiving bone marrow stem cell transplants, these patients often develop systemic infections with different viruses. These infections, which may be due to new infections or to activation of latent viruses, occur because the patient's immune system cannot keep the virus in check. Adenoviruses are one of the types of viruses that cause these infections, and the infections frequently result in the death of the patient. Unfortunately, no anti-adenovirus drugs have been examined in controlled clinical trials, and therefore no drugs are approved to treat these adenovirus infections. One reason that clinical trials for anti-adenovirus drugs have not been conducted is because there is no suitable animal model available to test the effectiveness and toxicity of such drugs. In this grant application, we propose to develop the Syrian hamster as an immunosuppressed animal model to evaluate anti-adenovirus drugs. Success in this project could lead to the eventual approval of drugs to treat adenovirus infections in immunosuppressed patients.

描述（由申请人提供）：人类腺病毒（Ads）是免疫抑制人类的一个重大问题，特别是对于接受同种异体干细胞移植的儿童。这些儿科患者中约 20% 发生播散性 Ad 感染，约一半患者死亡。目前还没有批准用于治疗这些 Ad 感染的抗病毒药物。在某些情况下会使用西多福韦和利巴韦林，但尚不清楚它们是否有效，因为尚未对它们进行系统控制的研究。由于没有复制人类Ads的动物模型，抗Ad药物的开发受到阻碍。这是因为广告具有高度的物种特异性。我们正在开发叙利亚仓鼠作为肿瘤模型，以研究溶瘤 Ad 载体的功效、复制、毒性和生物分布。我们发现，人类 Ad 血清型 5 (Ad5) 和基于 Ad5 的溶瘤载体在瘤内或静脉注射后在仓鼠肿瘤、肝脏、肺和其他器官中复制良好。令人感兴趣的是，使用环磷酰胺（CP）对仓鼠进行免疫抑制会导致病毒复制水平更高。施用病毒后，肿瘤和肝脏中的复制持续高水平至少 42 天（实验结束）。基于这些观察，我们建议使用 CP 免疫抑制的叙利亚仓鼠作为新的动物模型来评估抗 Ad 药物对免疫功能低下患者播散性 Ad 感染的疗效和毒理学。为了获得该模型的初步原理验证，我们将评估十六烷氧基丙基西多福韦 (HDP-CDV) 的抗 Ad 功效和毒理学。在具体目标 1 中，我们将检查 HDP-CDV 对 Ad5（人类 Ad 物种 C 的成员）在受到 CP 免疫抑制的仓鼠肝脏中复制的抑制作用。 Ad5 在肝脏和血液中的复制将通过 qPCR、组织培养感染剂量测定 50（TCID50 测定）和 Ad 病毒体蛋白的免疫组织化学来确定。将根据肝脏的组织病理学和血清化学来评估毒性。在目标 2 中，我们将确定人类 Ad Species A、B、D、E 和 F 的血清型是否在 CP 免疫抑制的仓鼠肝脏中复制。如果它们确实复制，那么我们将确定 HDP-CDV 是否抑制它们在培养细胞中的复制。 当人类的免疫系统严重受到抑制时，例如患有白血病的儿童在接受骨髓干细胞移植之前其免疫系统被免疫抑制药物破坏，这些患者通常会出现不同病毒的全身感染。这些感染可能是由于新的感染或潜伏病毒的激活造成的，发生的原因是患者的免疫系统无法控制病毒。腺病毒是引起这些感染的病毒类型之一，这些感染常常导致患者死亡。不幸的是，尚未在对照临床试验中检查过抗腺病毒药物，因此没有药物被批准用于治疗这些腺病毒感染。抗腺病毒药物尚未进行临床试验的原因之一是没有合适的动物模型来测试此类药物的有效性和毒性。在本次拨款申请中，我们建议开发叙利亚仓鼠作为免疫抑制动物模型来评估抗腺病毒药物。该项目的成功可能导致治疗免疫抑制患者腺病毒感染的药物最终获得批准。