Immunomodulation in melanoma therapy

描述(申请人提供)：这项建议的长期目标是深入了解Toll样受体(TLR)增强抗肿瘤免疫治疗所涉及的机制，并将这些发现转化为转移性肿瘤患者的实用免疫治疗。黑色素瘤是一种常见的癌症，也是导致多产年限丧失的主要原因。许多转移性黑色素瘤的活跃试验利用肿瘤抗原靶向免疫疗法。初步数据表明，TLR7激动剂咪喹莫特是表达黑色素瘤抗原的重组单核细胞增生性李斯特菌免疫的有效佐剂。将咪喹莫特与RLM疫苗配合使用，可显著预防黑色素瘤，并可导致局限性白癜风的发生。我们假设TLR7的刺激导致树突状细胞(DC)的激活、成熟和迁移到肿瘤部位和引流淋巴结。这种DC活性导致疫苗和非疫苗黑色素瘤相关抗原向细胞溶解CD8+T细胞的递呈增强，并潜在地增强决定簇的扩散。这项建议的目的1使用小鼠黑色素瘤模型来确定TLR7/8在预防和治疗两种方式中增强基于李斯特菌的抗黑色素瘤疫苗的分子机制。目的2确定TLR7/8对体外培养的小鼠和人树突状细胞的影响，并优化使用树突状细胞和RLM疫苗进行黑色素瘤免疫治疗的组合方法。目的3将研究TLR7/8激活对高危黑色素瘤患者免疫反应的直接影响，并将作为未来人类联合治疗的垫脚石。为此，我们将检测皮肤和前哨淋巴结中的非特异性细胞免疫反应，以及外周血和前哨淋巴结中的黑色素瘤抗原特异性免疫反应。TLR是免疫系统产生对病原体的宿主防御能力的关键部分。这项建议旨在了解宿主免疫和自身耐受之间的关系，因为它与肿瘤免疫治疗有关。研究团队是多学科的，包括来自微生物学和免疫学、血液肿瘤学、外科肿瘤学、神经外科和皮肤科的联合研究人员。其中几名研究人员已经参与了黑色素瘤免疫疗法在人类的临床试验。这些研究将有助于更好地理解打破自我耐受的机制，并将加强未来黑色素瘤和其他免疫原性较低的癌症的免疫疗法的设计。这项提议旨在为我们的初步数据的自然翻译--开发用于人体临床试验的GMP级疫苗--提供一个机械基础。GMP疫苗的开发不在本提案的范围内，将在另一个赠款机制下进行。 项目说明： 黑色素瘤是一种在美国发病率迅速上升的癌症。本申请中提出的研究将有助于更好地了解癌症免疫疗法涉及的机制，并将加强未来针对黑色素瘤和其他可以逃避免疫系统的癌症的免疫疗法的设计。这项提议旨在为我们的初步数据的自然转换提供一个机械基础--开发安全的疫苗，用于对患有转移性癌症的人类进行现实和实用的临床试验。

DESCRIPTION (provided by applicant): The long term objective of this proposal is to gain insight into the mechanisms involved in Toll-like receptor (TLR) enhancement of anti-tumor immune therapy and to translate these findings towards practical immunotherapies for patients with metastatic tumors. Melanoma is a common cancer and a leading cause of loss of productive years. Many active trials for metastatic melanoma utilize tumor antigen targeted immunotherapies. Preliminary data suggests that the TLR7 agonist, imiquimod, is an effective adjuvant to immunization with recombinant Listeria monocytogenes (rLM) expressing melanoma antigens. Adjuvant use of imiquimod with the rLM vaccine leads to profound protection from melanoma and to development of localized vitiligo. We hypothesize that stimulation of TLR7 leads to activation, maturation, and migration of dendritic cells (DCs) to the tumor site and to the draining lymph nodes. This DC activity leads to enhanced presentation of both vaccine and non-vaccine melanoma associated antigens to cytolytic CD8+ T-cells and potentially enhanced determinant spreading. Aim 1 of this proposal uses a mouse melanoma model to determine the molecular mechanism involved in TLR7/8 enhancement of Listeria based anti-melanoma vaccines in both prophylactic and therapeutic modalities. Aim 2 will determine the effects of TLR7/8 on mouse and human DCs in vitro and optimize a combinatorial approach to melanoma immunotherapy using both DCs and rLM vaccines. Aim 3 will study the direct effects of TLR7/8 activation on the immune response in patients with high risk melanoma and will serve as a stepping stone to futre combinatorial therapies in humans. In this aim, we will determine the non-specific cellular immune response in the skin and sentinel lymph node as well as the melanoma-antigen-specific immune response in the peripheral blood and sentinel lymph node. TLRs are a critical part of the immune system's ability to generate host defense to pathogens. This proposal is aimed at understanding the relationship between host immunity and self tolerance as it relates to tumor immunotherapy. The team of investigators is multidisciplinary and includes co-investigators from Microbiology and Immunology, Hematology-Oncology, Surgical-Oncology, Neurosurgery, and Dermatology. Several of these investigators are already involved in clinical trials of melanoma immunotherapies in humans. These studies will lead to a better understanding of the mechanisms involved in breaking self tolerance and will enhance the design of future immunotherapies for melanoma and other, less immunogenic cancers. This proposal is designed to provide a mechanistic foundation for the natural translation of our preliminary data--the development of GMP grade vaccines for clinical trials in humans. Development of GMP vaccines is outside the scope of this proposal and will be pursued under another grant mechanism. Project Narrative: Melanoma is a cancer that is rapidly increasing in prevalence in the U.S. The studies proposed in this application will lead to a better understanding of the mechanisms involved in cancer immune therapies and will enhance the design of future immunotherapies for melanoma and other cancers that can evade the immune system. This proposal is designed to provide a mechanistic foundation for the natural translation of our preliminary data -- the development of safe vaccines for realistic and practical clinical trials in humans with metastatic cancers.