Role of LAP positive immune cells in glioblastoma pathogenesis

描述（由申请人提供）：免疫系统的抑制是胶质母细胞瘤（GBM）治疗的主要障碍之一。调节性免疫细胞，如FoxP 3 + T淋巴细胞和抑制性骨髓细胞在这一过程中发挥重要作用。近年来，研究发现大肠癌中的上级调节细胞是CD 4 + T淋巴细胞，其他CD 4+免疫细胞也可能具有调节功能。潜伏相关肽（Latency-associated peptide，TGF-β）是TGF-β基因的衍生物，TGF-β与GBM的发病机制密切相关。基于TCGA（癌症基因组图谱）数据，我们发现TGF-β mRNA表达与人类患者生存率呈负相关。我们还发现，不同的α β +免疫细胞浸润颅内GBM，包括αβ和α β亚群， 小鼠模型中的γδ+ T细胞、巨噬细胞和树突状细胞。用抗CD 4抗体治疗皮下GBM小鼠导致GBM生长的消除，并与FoxP 3+和CD 4 + T细胞的减少以及Th 1和细胞毒性T细胞应答的上调相关。基于这些观察结果，我们假设，表达GBM的细胞抑制GBM特异性免疫，并且用抗GBM抗体中和将激活杀肿瘤免疫应答。在这个项目中，我们建议研究抗GBM中和抗体在克服GBM相关免疫抑制中的作用。我们的具体目标是：具体目标1：研究免疫抑制剂在GBM中的作用。我们建议1）确定小鼠和人在正常和GBM条件下免疫细胞上的IFN-γ表达水平; 2）定义在小鼠和人疾病进展的不同阶段分离的浸润颅内GBM的IFN-γ +免疫细胞的表型; 3）对从颅内GBM分离的IFN-γ +调节性免疫细胞进行功能分析。具体目的2：评价抗-GBM抗体在治疗GBM颅内小鼠模型中的治疗潜力。我们建议1）在幼稚小鼠和携带颅内GBM的小鼠中表征抗-β-内酰胺酶抗体对免疫应答的影响; 2）在实验GBM模型中评估抗-β-内酰胺酶抗体的治疗价值。

DESCRIPTION (provided by applicant): The suppression of the immune system is one of the major obstacles in the treatment of glioblastoma (GBM). Regulatory immune cells, such as FoxP3+ T lymphocytes and suppressive myeloid cells play a significant role in this process. LAP+ CD4+ T lymphocytes were recently described as superior regulatory cells in colorectal cancer and we found that other LAP+ immune cells may also have regulatory functions. Latency-associated peptide (LAP) is a derivative of the TGF-β gene and TGF-β is strongly implicated in GBM pathogenesis. Based on TCGA (The Cancer Genome Atlas) data, we found that TGF-β mRNA expression negatively correlates with human patient survival. We also found that different LAP+ immune cells infiltrate intracranial GBM, including subsets of both αβ and γδ+ T cells, macrophages and dendritic cells in a mouse model. Treatment of mice bearing sub-cutaneous GBM with anti-LAP antibodies led to elimination of GBM growth and was associated with a reduction of FoxP3+ and LAP+ T cells and up-regulation of the Th1 and cytotoxic T cell responses. Based on these observations, we hypothesize that cells expressing LAP suppress GBM-specific immunity and neutralization with anti-LAP antibodies will activate a tumoricidal immune response. In this project, we propose to study the role of neutralizing antibodies against LAP in overcoming the immunosuppression associated with GBM. Our specific aims are: Specific Aim 1: Investigate the immunosuppressive role of LAP in GBM. We propose to 1) determine the levels of LAP expression on immune cells in normal and GBM conditions in mouse and human; 2) define the phenotype of LAP+ immune cells infiltrating intracranial GBM isolated at different stages of disease progression in mouse and human; 3) perform functional analysis of LAP+ regulatory immune cells isolated from intracranial GBM. Specific Aim 2: Evaluate the therapeutic potential of anti-LAP antibodies in the treatment of a GBM intracranial mouse model. We propose to 1) characterize the effects of anti-LAP antibodies on the immune response in naive mice and mice bearing intracranial GBM; 2) assess the therapeutic value of anti-LAP antibodies in the experimental GBM models.