Designing Lymph Nodes for Cancer Immunotherapy

描述（由申请人提供）：我们已经证明，小鼠肿瘤负载树突状细胞（TL-DC）可以在体外和体内引发肿瘤特异性T细胞反应。在多种组织学上不同的小鼠肿瘤（包括肉瘤、癌和黑色素瘤）中都观察到了这一现象。我们进一步证明，同源宿主可以通过免疫TL-DC在体内有效地排斥侵袭性、弱免疫原性的肉瘤、乳腺癌和B16黑色素瘤的低免疫原性亚群，TL-DC依赖于宿主来源的CD8+和CD4+ T细胞。在某些情况下，TL-DC治疗也可导致已建立的皮下肿瘤结节消退和肺转移。我们已经将这些实验研究转化为一系列针对癌症患者的人体临床试验。最近，我们首次发现对TL-DC进行基因修饰以产生趋化因子CCL-21，可以通过在结外启动肿瘤反应性T细胞来增强疫苗效力并抑制肿瘤生长。本申请中概述的新实验研究旨在扩展我们的工作，通过在注射部位创建“设计淋巴结样”结构，从48个已知趋化因子中确定额外的候选因子，以进一步提高肿瘤疫苗的效力。我们的假设是，某些趋化因子在TL-DC免疫部位的同时表达将导致功能性异位“淋巴结”的形成，并通过这些结构内宿主免疫细胞募集和激活水平的提高而显著增加肿瘤反应性。我们提出以下具体目标：体外筛选重组趋化因子对免疫细胞亚型具有特异性、阳性的生物活性；2. 评估选定的趋化因子基因修饰的TL-DC对荷瘤小鼠的治疗能力，以介导体内增强的治疗性抗肿瘤反应；和3。探讨趋化因子基因修饰的TL-DC对小鼠肿瘤反应的作用机制。治疗性趋化因子策略的范围将在最小和晚期疾病状态的设置中进行测试和比较。我们研究工作的总体目标将是开发和优化一种新的策略，将趋化因子与基于dc的疫苗方法相结合，用于治疗癌症。

DESCRIPTION (provided by applicant): We have shown that murine tumor-loaded dendritic cells (TL-DC) can elicit tumor-specific T cell reactivities in vitro and in vivo. This observation has been made in a variety of histologically-distinct murine tumors, including sarcoma, carcinoma, and melanoma. We have further shown that syngeneic hosts can be effectively immunized in vivo to reject aggressive, weakly-immunogenic sarcomas, a breast carcinoma, and a poorly-immunogenic subline of the B16 melanoma by immunization with TL-DC, which is dependent upon host-derived CD8+ and CD4+ T cells. TL-DC treatments can under certain circumstances also result in regression of both established subcutaneous tumor nodules and lung metastases. We have translated these experimental studies to a series of human clinical trials in cancer patients. Recently, we showed for the first time that gene-modification of TL-DC to produce a chemokine, CCL-21, can enhance vaccine efficacy and inhibit tumor growth by priming tumor-reactive T cells extranodally. The new experimental studies outlined in this application is intended to extend our work to identify additional candidates from a panel of 48 known chemokines to further improve tumor vaccine potency, by creating "designer lymph node-like" structures at injection sites. It is our hypothesis that concomitant expression of certain chemokines at the immunization site of TL-DC will result in the formation of functioning, ectopic "lymph nodes" and in substantial increases in tumor reactivity through elevated levels of host immune cell recruitment and activation within these structures. We propose the following Specific Aims: 1. To screen recombinant chemokines in vitro for specific, positive biologic activities on immune cell subtypes; 2. To evaluate the capacity of treatment of tumor-bearing mice with selected chemokine(s) gene-modified TL-DC to mediate an enhanced therapeutic antitumor response in vivo; and 3. To determine the mechanism of tumor response in mice treated with chemokine(s) gene-modified TL-DC. The range of therapeutic chemokine strategies will be tested and compared in settings of minimal and advanced disease states. The overall goal of our research effort will be to develop and optimize a new strategy that combines chemokines with DC-based vaccine approaches for the treatment of cancer.