Designing Lymph Nodes for Cancer Immunotherapy

描述(由申请人提供)：我们已经证明，小鼠肿瘤负载的树突状细胞(TL-DC)在体外和体内都可以诱导肿瘤特异性T细胞反应。这种观察已经在各种不同组织学特征的小鼠肿瘤中进行，包括肉瘤、癌和黑色素瘤。我们进一步证明，通过TL-DC免疫，同基因宿主可以有效地在体内免疫，以排斥侵袭性、弱免疫原性肉瘤、乳腺癌和免疫原性较差的B16黑色素瘤亚系，TL-DC依赖于宿主来源的CD8+和CD4+T细胞。TL-DC治疗在某些情况下也可以导致已建立的皮下肿瘤结节和肺转移的消退。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类临床试验。最近，我们首次证明了将TL-DC基因修饰为产生趋化因子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和抑制肿瘤生长。本申请中概述的新的实验研究旨在扩展我们的工作，从48种已知趋化因子的小组中确定更多的候选者，以通过在注射部位创建“设计的淋巴结样”结构来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免疫部位的伴随表达将导致功能性、异位“淋巴结节”的形成，并通过提高宿主免疫细胞在这些结构内的招募和激活水平，显著增加肿瘤的反应性。我们提出以下具体目标：1.体外筛选重组趋化因子对免疫细胞亚型的特异、阳性生物活性；2.评价S基因修饰的TL-DC对荷瘤小鼠体内抗肿瘤治疗作用的能力；3.探讨S基因修饰的TL-DC治疗小鼠肿瘤反应的机制。治疗趋化因子策略的范围将在最小和最严重疾病状态的环境中进行测试和比较。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癌症的治疗。 公共卫生相关性：免疫疗法作为癌症治疗的第四种方式显示出很大的前景。癌症疫苗是免疫疗法的重要组成部分。拟议的调查应该为治疗性癌症疫苗的作用机制和效力的提高提供重要的见解。

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. PUBLIC HEALTH RELEVANCE: Immunotherapy is showing much promise as a fourth modality for the treatment of cancer. Cancer vaccines are a significant part of the immunotherapy armamentarium. The proposed investigations should provide important insights into the mechanisms of action of and improvements in the potency of therapeutic cancer vaccines.