Project 2: Analyses of the human GBM microenvironment form clinical trial specimens treated with the oncolytic HSV, rQNestin34v.2

项目概要-项目2 胶质母细胞瘤（GBM），可以说是所有癌症中最致命的一种，仍然无法接受治疗，包括 免疫疗法在其他癌症中取得了成功。深刻的免疫抑制 GBM中的微环境阻碍免疫激活刺激，如免疫检查点阻断， 限制活化的T细胞肿瘤浸润。事实上，GBM被描述为免疫沙漠。作为其中的一部分 计划项目，我们计划分析从人GBM注射的临床标本中的免疫浸润 用新型溶瘤病毒（NCT 03152318，clinicaltrial.gov）。溶瘤病毒（OV）是一种 临床上正在研究用一种溶瘤性单纯疱疹病毒对多种癌症进行免疫治疗 在美国批准用于抗黑色素瘤的oHSV和在日本批准用于抗GBM的不同oHSV。在 在上一个资助期，我们开始并完成了新型oHSV rQNestin34.5v.2的1期临床试验， 收集了50名患有复发性高级别神经胶质瘤的人类受试者。原位移植后肿瘤的初步数据 这种oHSV的施用显示增加的TIL。此外，我们还发现，T细胞和/或B细胞受体的升高， (TCR/BCR）转录物与改善的受试者存活相关。受试者MRI的体积分析 还表明生长速率的变化与治疗患者的反应增加相关。这些出版物和 因此，初步数据提供了一个概念框架，证明原位施用OV以恢复 GBM的免疫抑制微环境转变为细胞和分子成分成为 免疫激活。基于上述，我们假设原位oHSV给药深刻地影响了 将人类GBM微环境改变为更有利于免疫治疗的微环境。我们计划 利用从当前临床试验中获得的临床GBM标本，通过 遵循具体目标：目标1。研究人类GBM中的免疫激活变化 微环境受oHSV原位施用干扰;目的2.研究受试者的血浆 蛋白质组、血清细胞因子/趋化因子和MRI体积测量作为oHSV应答的潜在生物标志物 并与TCR/BCR转录本丰度相关;以及Aim 3.利用人GBM患者来源的细胞 和从当前临床试验患者获得的异种移植物来表征HLA-免疫肽段， oHSV感染。这些目标，如果成功的话，将支持oHSV诱导的肿瘤抗原的开发， 增强对oHSV感染的免疫应答，从而改善患者的预后。此外，我们将努力 与项目4一起开发将新型oHSV带入未来临床试验所需的研究， 将我们发现的oHSV-肿瘤抗原添加到具有武装的oHSV的临床前治疗模型中。与项目 3、我们将测量活检标本中的免疫抑制代谢物。

PROJECT SUMMARY – PROJECT 2 Glioblastoma (GBM), arguably the deadliest of all cancers, has remained impervious to treatments, including immunotherapies that have seen evidence of success in other cancers. The profound immunosuppressive microenvironment in GBM thwarts immune activating stimuli like immune checkpoint blockade and significantly limits activated T cell tumor infiltration. In fact, GBM has been described as an immune-desert. As part of this Program Project, we plan to analyze the immune infiltration in clinical specimens from human GBMs injected with a novel oncolytic virus (NCT03152318, clinicaltrial.gov). Oncolytic viruses (OV) are a form of immunotherapy being investigated clinically against multiple cancers with one oncolytic Herpes Simplex Virus (oHSV) approved in the USA against melanoma and a different oHSV approved against GBM in Japan. In the previous funding period, we started and finished a phase 1 clinical trial of the novel oHSV, rQNestin34.5v.2, that accrued 50 human subjects with recurrent high-grade gliomas. Preliminary data from tumors after in situ administration of this oHSV shows increased TILs. In addition, we show that elevated T cell and/or B cell receptor (TCR/BCR) transcripts are associated with improved subject survival. Volumetric analyses of MRIs from subjects also show that growth rate changes correlate with increased response in treated patients. These published and preliminary data thus provide a conceptual framework justifying in situ administration of OVs to revert the immunosuppressive microenvironment of GBM into one whose cellular and molecular components become immuno-activating. Based on the above, we hypothesize that in situ oHSV administration profoundly changes the human GBM microenvironment into one that is more favorable for immunotherapy. We plan to utilize clinical GBM specimens obtained from the current clinical trial to validate the hypothesis, via the following Specific Aims: Aim 1. Validate the immune-activating changes in the human GBM microenvironment perturbed by oHSV in situ administration; Aim 2. Investigate subjects’ plasma proteome, serum cytokine/chemokine and MRI volumetrics as potential biomarkers of oHSV response and correlate with TCR/BCR transcript abundance; and Aim 3. Utilize human GBM patient derived cells and xenografts obtained from current clinical trial patients to characterize HLA-immunopeptidomes after oHSV infection. These aims, if successful, will support the development of oHSV-elicited tumor antigens to boost the immune response to oHSV infection and thereby improve patient outcomes. In addition, we will work with Project 4 to develop the studies needed to bring the novel oHSVs to future clinical trials and with Project 1 to add our discovered oHSV-tumor antigens to the preclinical therapeutic models with armed oHSV. With Project 3, we will measure immunosuppressive metabolites in biopsy specimens.