Treg-Th17 Axis Modulation and Induction of Tumor Immunity with Cryosurgery

描述(申请人提供)：癌症是一种很难治疗的疾病，因为它具有破坏性。在老龄化的人口中尤其如此，患者无法忍受更激进的治疗，如侵入性手术和化疗方案。或者，冷冻手术，即使用冰冻温度来破坏病变组织，越来越被认为是治疗实体肿瘤的一种有效的、微创的方法。与手术切除相比，冷冻手术对周围结构的破坏较小，对身体的压力较小，改善了患者的舒适度，更实惠，并提供了更好的美容效果。更重要的是，冷冻手术有可能诱导对肿瘤相关抗原的免疫反应，这些抗原是从切除的肿瘤中释放出来的。这种免疫反应不仅能够防止患者肿瘤复发，而且还能够消除远处转移灶。然而，冷冻消融诱导抗肿瘤免疫的机制尚不清楚。这个项目的目标是通过研究免疫调节系统和冷冻消融之间的相互作用来解决这些机制。该项目将重点研究免疫系统中存在的免疫抑制(T调节细胞)和促炎(Th17细胞)轴。这个轴可以从一个光谱转移到另一个光谱，创造各种免疫抑制或刺激环境。我们的初步数据显示，冷冻消融增加了T调节(Treg)和Th17群体，表明Treg-Th17轴在冷冻手术后具有重要作用。我们假设，这一轴向促炎症谱(Th17细胞)的转变将允许免疫效应器克服自身耐受并诱导长期的抗肿瘤免疫。为了验证这一假设，我们提出了以下目标：1)表征冷冻手术后小鼠T细胞激活的动力学和细胞因子谱，以确定Treg-Th17轴的变化；2)改变小鼠的免疫环境，使其有利于Th17与冷冻手术的协同反应；以及3)评估DNA疫苗和冷冻手术联合使用时的抗肿瘤活性。 公共卫生相关性：目标是通过冷冻手术消除实体肿瘤块，并释放所有与肿瘤相关的抗原，以增强抗肿瘤免疫反应。冷冻手术是一种侵入性较小的手术，对于不能忍受苛刻治疗选择的老年患者可能是有利的。为了促进冷冻治疗后效应器的激活，而不是抑制T细胞，我将测试一种假设，即在冷冻手术前通过IL-6的表达来诱导调节性T细胞向产生IL-17的T细胞转变将有利于抗肿瘤免疫反应。此外，还将测试DNA疫苗的系统免疫，以补充冷冻手术。这项研究的结果可以显著促进癌症的治疗，特别是在老年患者中。

DESCRIPTION (provided by applicant): Cancer is a difficult disease to treat due to its destructive nature. This is especially true in the aging population, where patients cannot tolerate more aggressive therapies, such as invasive surgery and chemotherapy regimens. Alternatively, cryosurgery, the use of freezing temperatures to destroy diseased tissue, is increasingly recognized as an efficient, minimally invasive method of treating solid tumors. Compared to surgical resection, cryosurgery is less damaging to surrounding structures, places less stress on the body, has improved patient comfort, is more affordable, and provides a better cosmetic result. More importantly, cryosurgery has the potential to induce an immunologic response to tumor-associated antigens, which are released from the ablated tumor. Not only is this immune response able to prevent tumor recurrence in patients but it is also capable of eliminating distant metastatic foci. However the mechanisms by which cryoablation induces anti-tumor immunity have yet to be elucidated. The goal of this project is to resolve these mechanisms by studying the interaction between the immune regulatory system and cryoablation. This project will focus on the immune inhibitory (T regulatory cells) and pro-inflammatory (Th17 cells) axis that exists within the immune system. This axis can be shifted from one spectrum to the other creating a variety of immune inhibitory or stimulatory environments. Our preliminary data have shown that cryoablation increases both T regulatory (Treg) and Th17 populations, indicating that the Treg-Th17 axis has a significant role after cryosurgery. We hypothesize that a shift in this axis towards the pro-inflammatory spectrum (Th17 cells) will allow immune effectors to overcome self tolerance and induce long term anti-tumor immunity. To test this hypothesis we propose the following aims: 1) Characterize the kinetics of T-cell activation and cytokine profiles in mice after cryosurgery to determine the shifts in the Treg-Th17 axis, 2) Alter the mouse immune environment to favor Th17 response in coordination with cryosurgery, and 3) Evaluate anti-tumor activity when DNA vaccination and cryosurgery are combined. PUBLIC HEALTH RELEVANCE: The goal is to eliminate the solid tumor mass by cryosurgery and release all tumor-associated antigens to boost anti-tumor immune response. A less invasive procedure, cryosurgery may be advantageous for senior patients who are not able to endure harsh treatment options. To facilitate the activation of effectors, rather than suppressive T cells following cryotherapy, I will test the hypothesis that inducing a shift from the regulatory T cells toward IL-17 producing T cells before cryosurgery by intratumoral expression of IL-6 will favor anti-tumor immune response. Furthermore, systemic immunization with DNA vaccine will be tested to compliment cryosurgery. Results from this study could significantly advance cancer treatment, especially in senior patients.