Immunomodulation in melanoma therapy

描述（由申请人提供）：本提案的长期目标是深入了解toll样受体（TLR）增强抗肿瘤免疫治疗的机制，并将这些发现转化为转移性肿瘤患者的实用免疫疗法。黑色素瘤是一种常见的癌症，也是导致生育能力丧失的主要原因。许多正在进行的转移性黑色素瘤试验使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增生李斯特菌（rLM）免疫的有效佐剂。咪喹莫特与rLM疫苗的辅助使用可以对黑色素瘤和局部白癜风的发展产生深刻的保护作用。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性CD8+ t细胞的呈递增强，并可能增强决定因素扩散。本提案的目的1使用小鼠黑色素瘤模型来确定TLR7/8增强基于李斯特菌的抗黑色素瘤疫苗在预防和治疗方式中的分子机制。目的2将在体外确定TLR7/8对小鼠和人dc的影响，并优化使用dc和rLM疫苗进行黑色素瘤免疫治疗的组合方法。Aim 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。在这个目的中，我们将确定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是免疫系统产生宿主防御病原体能力的关键部分。这一建议旨在了解宿主免疫和自身耐受之间的关系，因为它涉及到肿瘤免疫治疗。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、神经外科和皮肤病学的共同研究人员。其中一些研究人员已经参与了人类黑色素瘤免疫疗法的临床试验。这些研究将使我们更好地了解破坏自我耐受性的机制，并将加强对黑色素瘤和其他免疫原性较低的癌症的未来免疫疗法的设计。该提案旨在为我们初步数据的自然转化提供机制基础-用于人体临床试验的GMP级疫苗的开发。GMP疫苗的开发不在本提案的范围之内，将在另一个拨款机制下进行。

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.