Causes and consequences of oncolytic virus infection of non-tumoral cells in cancer immunotherapy

癌症免疫治疗中非肿瘤细胞溶瘤病毒感染的原因和后果

• 批准号: 10066392
• 负责人: Kristin DePeaux
• 金额: $ 4.55万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10066392
• 关键词: Address; Aftercare; Antiviral Response; Apoptosis; Apoptotic; Autoimmune Process; BCL-2 Protein; CD4 Positive T Lymphocytes; CD8-Positive T-Lymphocytes; CTLA4 gene; Cancer Model; Cell Compartmentation; Cell Culture Techniques; Cells; Cessation of life; Clinic; Clinical Trials; Cytolysis; Cytosol; DNA; Data; Disease remission; Dose; Engineering; Environment; Exposure to; FOXP3 gene; Genetic Engineering; Genetic Transcription; Genome; Growth Factor; Herpesviridae; Homeostasis; Hypoxia; Hypoxia Inducible Factor; Immune; Immune response; Immunologics; Immunotherapeutic agent; Immunotherapy; In Vitro; Infection; Internal Ribosome Entry Site; Label; Lead; Malignant Neoplasms; Mediating; Modeling; Mus; Oncolytic; Oncolytic viruses; Oxygen; Patients; Phenotype; Physiologic pulse; Population; Predisposition; Production; Reagent; Regulatory T-Lymphocyte; Reporter; Role; Stains; T-Lymphocyte; Testing; Therapeutic Effect; Thymidine Kinase; TimeLine; Tissues; Treatment Efficacy; Tumor Immunity; Tumor-infiltrating immune cells; Vaccinated; Vaccinia; Vaccinia virus; Viral; Viral Proteins; Viral Tumor Antigens; Virus; Virus Diseases; Virus Replication; anti-tumor immune response; cancer immunotherapy; cell type; cytokine; design; ds-DNA; experience; experimental study; immune checkpoint blockade; improved; in vivo; melanoma; mouse model; neoplastic cell; novel; oncolytic vaccinia virus; patient population; prevent; programmed cell death protein 1; programs; receptor; response; transcription factor; treatment duration; treatment effect; treatment response; tumor; tumor hypoxia; tumor microenvironment; tumor progression

PROJECT SUMMARY Immunotherapy has changed the way we think about and treat cancer. While some patients experience durable remissions, the majority however, will not respond. Some known barriers to response are a lack of immune infiltrate or infiltrate that is suppressed by other cell types in the tumor microenvironment. These patients may find immunotherapies that induce a de novo immune response, such as oncolytic viruses, more successful than one that stimulates the existing immune populations. An oncolytic virus selectively replicates in and lyses tumor cells, stimulating an immune response against viral and tumor antigen, while leaving healthy tissue unharmed. Currently there is one oncolytic approved for use in the clinic. Despite this recent approval and the rapid expansion of clinical trials evaluating oncolytics, little is known about the effects of these treatments on tumor resident immune cells. Many of these trials are currently evaluating oncolytic vaccinia virus as it is an ideal candidate for immunotherapy. Vaccinia replicates entirely in the cytosol preventing incorporation into host DNA, has a dsDNA genome that is easily engineered, and stimulates robust immune responses. Using a genetically engineered strain of oncolytic vaccinia virus (vvDD) with deletions of both viral growth factor and thymidine kinase to increase its tumor selectivity, we have shown that a single dose of this therapy can dramatically remodel the tumor infiltrate. Major increases in CD8+ T cell infiltration are observed as expected, however we also observed surprising phenotypic changes. Seven days post-treatment a loss of regulatory CD4+ T cells (Treg) was seen. Using a GFP expressing strain of the virus (vvDD-GFP) we found that surprisingly, one day post-treatment Tregs were selectively infected. As these cells are experiencing hypoxia in the tumor, we hypothesize that hypoxia leads to infection of these subsets which culminates in their death. The resulting microenvironment, now depleted of immune regulatory cells, is more supportive of immune infiltration and anti-tumor activity. We will test this hypothesis by (1) determining if oncolytic viral infection leads to the death of Treg and determine the contribution of Treg loss to therapeutic efficacy and (2) dissecting the contribution of HIF1α to the ability of vvDD to infect Tregs. The conclusions from these studies will provide us with a better understanding of the mechanism of oncolytic vaccinia. With this information it will be possible to design more efficacious oncolytic viruses as well as determine the patient populations most likely to respond to therapy.

项目摘要 免疫疗法改变了我们对癌症的看法和治疗方式。虽然有些患者经历了耐用 然而，大多数人将没有回应。一些已知的反应障碍是缺乏免疫力 肿瘤微环境中其他细胞类型抑制的浸润或浸润。这些患者可以 找到可诱导从头免疫响应的免疫疗法，例如溶瘤病毒，比 刺激现有免疫种群的一种。溶瘤病毒在肿瘤中有选择地复制并裂解肿瘤 细胞，刺激针对病毒和肿瘤抗原的免疫反应，同时使健康组织不受伤害。 目前，有一项在诊所使用的溶瘤批准。尽管最近获得了批准和快速 评估肿瘤剂的临床试验的扩展，这些治疗对肿瘤的影响知之甚少 居民免疫菌株。这些试验中有许多目前正在评估溶瘤疫苗病毒，因为它是理想的 免疫疗法的候选人。疫苗完全在胞质溶胶中复制，以防止保险进入宿主DNA， 具有易于设计的DSDNA基因组，并刺激可靠的免疫反应。使用一般 具有病毒生长因子和胸苷激酶的缺失的溶瘤疫苗病毒（VVDD）的工程菌株 为了提高其肿瘤的选择性，我们已经表明，这种疗法的单剂量可以显着重塑 肿瘤浸润。如预期的那样，观察到CD8+ T细胞浸润的重大增加，但是我们也观察到 令人惊讶的表型变化。治疗后7天观察了调节性CD4+ T细胞（TREG）的损失。 使用GFP表达病毒（VVDD-GFP）的GFP，我们发现令人惊讶的是在治疗后的Tregs 被选择性感染。由于这些细胞在肿瘤中患缺氧，我们假设缺氧 导致这些子集的感染，这些子集最终导致其死亡。由此产生的微环境，现在 免疫调节细胞耗尽，更支持免疫灌注和抗肿瘤活性。我们将测试 通过（1）确定肿瘤病毒感染是否导致Treg死亡并确定该假设 Treg损失对治疗效率的贡献，以及（2）剖析HIF1α对VVDD能力的贡献 感染的treg。这些研究的结论将使我们对机制有更好的了解 溶瘤疫苗。有了这些信息，也可以设计更有效的溶瘤病毒 根据确定的患者人群最有可能对治疗做出反应。