CD4+ Memory T-Cells in Human Lung Tumor Micorenvironment

描述(申请人提供)：CD4+记忆性T细胞存在于大多数人类非小细胞肺肿瘤的微环境中，并表现为静止和对肿瘤无反应。我们在这里质疑这些细胞是如何在肿瘤内维持较长时间的，以及它们如何被原位激活以杀死肿瘤。将未中断的人肺肿瘤活检组织植入SCID小鼠皮下，建立了具有结构和功能完整的肿瘤微环境的异种移植。通过监测组织学、基因表达模式、细胞耗竭分析和功能阻断抗体的使用，已证实外源性IL-12通过依赖于干扰素-γ的间接机制动员效应记忆CD4+T细胞(TEM)原位杀伤肿瘤细胞。利用这一人-鼠嵌合模型，我们将首先测试这一假设，即在人类肿瘤微环境中CD4+TEM细胞的持续存在依赖于肿瘤相关的间质成纤维细胞和浆细胞样树突状细胞，它们释放I型干扰素并抑制激活的T细胞的凋亡。在目标2中，趋化因子及其受体影响来自肿瘤微环境的CD+T细胞结合和根除经IL-12治疗的异种肿瘤的能力将与来自患者肿瘤引流淋巴结的中央记忆T细胞(CD_4+TM)进行比较。在最后的目标中，涉及到关于IL-12功能激活记忆T细胞的两个具体问题。目的3将在肿瘤微环境中确定由树突状细胞、间质细胞或肿瘤细胞表达的一个或多个B7家族共刺激(或负调控)分子是否调节由IL-12激活的TEM细胞协调的抗肿瘤反应。在最终目标中，将确定肿瘤相关记忆T细胞对T细胞受体刺激的反应性、与这种刺激相关的细胞内事件以及IL-12改变反应的能力，并将其与中央记忆T细胞和原始T细胞进行比较。预计在此产生的关于肿瘤相关记忆T细胞的生存、迁移和激活潜力的知识将导致改进的免疫治疗方法的设计，该方法可以利用记忆T细胞的抗肿瘤活性，并通过靶向和调节肿瘤微环境中的其他炎性白细胞和基质细胞来增强其活性。

DESCRIPTION (provided by applicant): CD4+ memory T-cells are present within the microenvironment of most human non-small cell lung tumors and appear quiescent and non-responsive to the tumor. We question here how these cells are maintained within the tumor for prolonged periods, and how they may be activated in situ to kill tumors. The implantation of non-disrupted human lung tumor biopsy tissues into the subcutis of SCID mice, results in the establishment of xenografts with structurally and functionally intact tumor microenvironments. By monitoring changes in the histology, gene expression patterns, cell depletion analysis and the use of function blocking antibodies, it has been established that exogenous IL-12 mobilizes effector memory CD4+ T cells (TEM) to kill tumor cells in situ by indirect mechanisms that are dependent upon IFN-y. Using this human mouse chimeric model, we will first test the hypothesis that the sustained presence of the CD4+ TEM cells within human tumor microenvironments is dependent upon tumor-associated stromal fibroblasts and plasmacytoid dendritic cells that release Type I interferons and inhibit apoptosis of activated T cells. In Aim 2, the ability of chemokines and their receptors to influence CD4+ TEM cells derived from the tumor microenvironment to home to and eradicate IL-12 treated tumor xenografts will be compared to central memory T cells (CD4+ TCM) derived from patients' tumor draining lymph nodes. In the final Aims, two specific issues regarding the IL-12 functional activation of memory T cells are addressed. Aim 3 will establish in the tumor microenvironment whether one or more B7 family co-stimulatory (or negative regulatory) molecules expressed by dendritic cells, stromal cells or tumor cells regulate the anti-tumor response that is orchestrated by IL-12 activated TEM cells. In the final Aim, tumor-associated memory T cell responsiveness to T cell receptor stimuli, the intracellular events associated with this stimulation, and the ability of IL-12 to alter the responsiveness will be determined and compared to central memory and nave T cells. It is expected that the knowledge generated here with respect to the survival, migration and activation potential of tumor-associated memory T cells will lead to the design of improved immunotherapeutic approaches that can harness the anti-tumor activity of the memory T cells and enhance their activity by targeting and modulating other inflammatory leukocytes and stromal cells in the tumor microenvironment.