Chemerin in Tumor Immunity and Surveillance

描述(由申请人提供)：肿瘤发生由免疫监视机制控制。自然杀伤细胞是天然抗肿瘤免疫的重要介体，免疫刺激树突状细胞和细胞毒性T细胞也参与肿瘤抑制。然而，免疫监视效应细胞募集的生理机制仍然知之甚少。这一提议的基本假设是趋化蛋白是一种最近被描述的自然杀伤(NK)细胞和树突状细胞亚群的趋化物质，是免疫监视和肿瘤免疫的关键生理介质。这一假说是通过观察到趋化蛋白在动物模型和许多人类实体组织肿瘤(包括黑色素瘤和前列腺癌)发生过程中在基因水平上下调而提出的。我们的目标如下：1：确定趋化蛋白在肿瘤中的表达或瘤内是否抑制移植瘤的建立或生长，并明确趋化蛋白受体CMKLR1在趋化蛋白介导的肿瘤抑制中的作用。将使用成熟的可移植肿瘤的小鼠模型。通过比较携带趋化蛋白编码或对照载体的肿瘤细胞或瘤内注射趋化蛋白的肿瘤细胞在体内和体外的生长情况来评价肿瘤表达或相关趋化蛋白的效果。CMKLR1缺陷小鼠将被用来定义观察到的肿瘤抑制中的CMKRL1。对侧给予野生型肿瘤或静脉“转移”模型将评估局部肿瘤趋化蛋白表达诱导全身抗肿瘤免疫反应的能力。2：确定趋化蛋白招募到肿瘤中的细胞类型，以及它们在趋化蛋白抑制肿瘤生长中的作用。趋化蛋白对肿瘤浸润性白细胞(TIL)亚群(包括NK细胞、树突状细胞(DC)和淋巴细胞)募集的影响 通过比较从表达趋化蛋白的肿瘤中分离出的TIL与对照肿瘤的TIL进行研究。为了确定它们参与趋化蛋白介导的肿瘤生长抑制，招募的白细胞亚群将使用抗体和遗传方法来耗尽。CMKLR1在TIL亚群募集中的作用将使用CMKLR1-/-小鼠进行评估。3.验证内源性趋化蛋白在自发肿瘤发生过程中介导转化细胞的生理免疫监视和抑制的假说。内源性CMKLR1和趋化蛋白在肿瘤抑制中的作用将在癌基因驱动的腺癌和黑色素瘤发展和转移模型中进行评估。肿瘤的发展、进展和分化将在野生型、CMKLR1-/-和趋化蛋白缺陷小鼠中进行比较，并在具有免疫细胞特异性CMKRL1缺陷的工程小鼠中进行比较。拟议的研究将确定趋化蛋白在肿瘤发生的生理控制中的作用，并将阐明相关的关键机制。这一结果可能会导致为癌症治疗引入宿主免疫防御的新方法。

DESCRIPTION (provided by applicant): Tumorigenesis is controlled by mechanisms of immune surveillance. Natural killer cells are important mediators of innate anti-tumor immunity, and immunostimulatory dendritic cells and cytotoxic T cells participate in tumor suppression as well. However, physiologic mechanisms of effector cell recruitment for immune surveillance remain poorly understood. The underlying hypothesis of this proposal is that chemerin, a recently described chemoattractant for natural killer (NK) cells and subsets of dendritic cells, isa key physiological mediator of immune surveillance and of tumor immunity. This hypothesis is suggested by the observation that chemerin is downregulated at the gene level during tumorigenesis in animal models and in many human solid tissue neoplasms, including melanoma and prostate cancer. Our Aims are as follows: 1: Determine whether tumor-expressed or intratumoral chemerin inhibits the establishment or growth of transplanted tumors, and define the role of the chemerin receptor CMKLR1 in chemerin-mediated tumor suppression. Well-established mouse models of transplantable tumors will be used. The effects of tumor- expressed or associated chemerin will be evaluated by comparing the in vivo and in vitro growth of tumor cells transfected with chemerin-encoding or control vectors, or of tumors injected with chemerin intratumorally. CMKLR1-deficient mice will be used to define the CMKRL1 in observed tumor suppression. Contralateral administration of wild type tumors or intravenous "metastasis" models will assess the ability of local tumor chemerin expression to induce systemic anti-tumor immune responses. 2: Define cell types recruited to tumors by chemerin, and their involvement in chemerin suppression of tumor growth. The effects of chemerin on recruitment of tumor infiltrating leukocyte (TIL) subsets including NK cells, dendritic cells (DC), and lymphocytes will be studied by comparing TIL isolated from chemerin-expressing vs control tumors. To define their involvement in chemerin-mediated tumor growth inhibition, recruited leukocyte subsets will be depleted using antibody and genetic approaches. The role of CMKLR1 in recruitment of TIL subsets will be evaluated using CMKLR1-/- mice. 3. Test the hypothesis that endogenous chemerin mediates physiologic immune surveillance and inhibition of transformed cells during spontaneous tumorigenesis. The role of endogenous CMKLR1 and chemerin in tumor suppression will be evaluated in oncogene driven models of adenocarcinoma and melanoma development and metastasis. Tumor development, progression and differentiation will be compared in wild type, CMKLR1-/- and chemerin-deficient mice, and in mice engineered to have immune-cell specific CMKRL1 deficiency. The proposed studies will define the role of chemerin in the physiologic control of tumorigenesis, and will elucidate key mechanisms involved. The results may lead to novel approaches to engage host immune defenses for cancer therapy.