Augmenting immune responses to DC-tumor fusions using local 3rd signals

描述(由申请人提供)： 尽管在手术、化疗和放射治疗方面取得了进展，但晚期头颈癌患者的局部复发和远处转移的风险仍然很高。这些癌症是毁灭性的，因为它们会影响多个器官系统和生活质量。需要新的方法来改善对这些患者的护理。解决这些问题的一种策略是树突状细胞(DC)-肿瘤融合混合免疫治疗。单次DC-肿瘤融合疫苗已被证明可以介导小鼠已建立的肿瘤的消退。然而，成功的DC-肿瘤融合免疫治疗需要全身联合应用IL-12。遗憾的是，IL-12的临床应用受到毒性的限制。此外，调节性T细胞(Treg)等免疫调节机制可能会限制DC-肿瘤融合免疫治疗的完全有效性。这种免疫调节机制可以用抗CTLA-4的单抗(MAb)来克服，但这种mAb的系统给药成本高且毒性大，限制了这种方法的临床适用性。提出了一种利用DC-肿瘤融合局部携带IL-12和抗CTLA-4单抗到DC-肿瘤融合/T细胞相互作用部位进行头颈部肿瘤免疫治疗的新方法。这一应用的总体目标是优化DC-肿瘤融合杂交物诱导抗肿瘤反应的能力。中心假设是，局部分泌IL-12的DC-肿瘤融合杂交体将刺激CD4+和CD8+T细胞介导的抗肿瘤反应。此外，我们推测，通过DC-肿瘤融合局部分泌抗CTLA-4单抗，这些融合杂交体刺激抗肿瘤免疫的能力将会增强。这一中心假设将通过追求三个具体目标来验证：1)通过局部分泌IL-12的DC-肿瘤融合杂交瘤疫苗诱导抗肿瘤CD4+和CD8+效应T细胞。小鼠模型将被用来验证DC-肿瘤融合局部分泌IL-12将通过CD4+和CD8+T细胞诱导肿瘤消退的假设；2)通过取消局部Treg介导的免疫抑制，进一步增强DC-肿瘤融合杂交体刺激抗肿瘤免疫的能力。小鼠模型将被用来验证这样的假设，即通过DC融合局部递送抗CTLA-4单抗来消除Treg免疫抑制将导致增强抗肿瘤免疫；3)在人类体外模型中，使用局部分泌IL-12和抗CTLA-4单抗的DC-Tumor杂交体诱导抗肿瘤CD4+和CD8+效应T细胞。人类体外模型将检验这样一种假设，即同时分泌IL-12和抗CTLA-4单抗的人DC-肿瘤融合杂交物与单独使用其中任何一种相比，将增强CD4+和CD8+T细胞的抗肿瘤反应。沃尔特·李(Pi)博士非常熟悉目前治疗头颈部癌症的局限性和挑战。他表现出致力于寻求免疫治疗方法来治疗这些癌症，并将工作重点放在树突状细胞(DC)-肿瘤融合杂交上。他召集了合格的导师和顾问，以促进他作为专注于DC-肿瘤融合免疫疗法的外科科学家的发展。李博士的职业发展计划包括教学课程和研讨会，这些课程和研讨会被整合到他的实验室学习目标中。他还将在涉及DC-肿瘤融合杂交和其他免疫治疗方法的临床试验的设计、执行和数据分析方面得到指导。通过退伍军人管理局职业发展奖-2(VA-CDA-2)，李博士将阐明影响DC-肿瘤融合成功的机制，并获得将实验室结果转化为临床试验所需的技能。此外，这一VA-CDA-2将使Lee博士能够建立以VA为基础的职业生涯，并使他能够成熟为一名独立资助的外科科学家。 公共卫生相关性： 据估计，每年有3.5万名退伍军人被诊断患有癌症。这导致癌症成为退伍军人的第二大死因。在这些癌症中，由于其对呼吸、吞咽和说话的影响，晚期头颈部癌症尤其令人虚弱。此外，退伍军人由于以前或继续使用烟草和酒精而患上头颈部癌症的风险很高，这是公认的危险因素。尽管手术、化疗和放射治疗方法有所改善，但晚期头颈癌患者局部复发和远处转移的风险仍然很高。此外，现有治疗方案的副作用影响退伍军人及其家人的生活质量。迫切需要新的和改进的治疗策略，不仅要提高头颈癌患者的长期存活率，而且要提高他们的生活质量。这项提议将研究树突状细胞-肿瘤融合免疫疗法，作为一种无副作用地引导免疫细胞攻击肿瘤的手段。

DESCRIPTION (provided by applicant): Despite advances in surgery, chemotherapy, and radiation modalities, patients with advanced head and neck cancer continue to be at high risk for loco-regional recurrences and distant metastasis. These cancers are devastating due to their impact on multiple organ systems and quality of life. New approaches are needed to improve the care of these patients. One strategy to address these issues is dendritic cell (DC)-tumor fusion hybrid immunotherapy. A single DC-tumor fusion vaccination has been shown to mediate the regression of established tumors in mice. However, successful DC-tumor fusion immunotherapy has required the systemic co-administration of IL-12. Unfortunately, the clinical use of IL-12 is limited by toxicity. Furthermore, immune regulatory mechanisms such as regulatory T cells (Treg) may limit the full effectiveness of DC-tumor fusion-based immunotherapy. Such immune regulatory mechanisms can be overcome using anti-CTLA-4 monoclonal antibody (mAb), but systemic administration of this mAb is costly and associated with toxicity, limiting the clinical applicability of such an approach. A novel approach is proposed for the immunotherapy of head and neck cancer using DC-tumor fusions that locally deliver IL-12, as well anti-CTLA-4 mAb, to the site of DC-tumor fusion/T cell interactions. The overall objective of this application is to optimize the ability of DC-tumor fusion hybrids to induce anti-tumor responses. The central hypothesis is that DC-tumor fusion hybrids that locally secrete IL-12 will stimulate a CD4+ and CD8+ T cell mediated anti-tumor response. Furthermore, we hypothesize that the ability of these fusion hybrids to stimulate anti-tumor immunity will be enhanced by local secretion of anti-CTLA-4 mAb by the DC-tumor fusion. This central hypothesis will be tested by pursuing three specific objectives: 1) Induce anti-tumor CD4+ and CD8+ effector T cells through vaccination with DC-tumor fusion hybrids locally secreting IL-12. Murine models will be used to test the hypothesis that local secretion of IL-12 by the DC-tumor fusion will induce tumor regression via both CD4+ and CD8+ T cells; 2) Further enhance the ability of DC-tumor fusion hybrids to stimulate anti-tumor immunity by abrogating Treg-mediated immunosuppression locally. Murine models will be used to test the hypothesis that abrogating Treg immunosuppression through local delivery of anti-CTLA-4 mAb by the DC-fusion will result in enhanced anti- tumor immunity; 3) In a human in vitro model, induce anti-tumor CD4+ and CD8+ effector T cells using DC-tumor hybrids locally secreting IL-12 and anti-CTLA-4 mAb. Human in vitro models will test the hypothesis that human DC-tumor fusion hybrids secreting both IL-12 and anti-CTLA-4 mAb will potentiate the CD4+ and CD8+ T cell anti-tumor response compared with using either one alone. Dr. Walter Lee (PI) is intimately familiar with the limitations and challenges of current therapies for head and neck cancers. He has demonstrated a commitment to pursuing immunotherapy approaches to treating these cancers and has focused his work on dendritic cell (DC) - tumor fusion hybrids. He has assembled well qualified mentors and consultants to further his development as a surgeon-scientist focused on DC-tumor fusion immunotherapy. Dr. Lee's career development plan includes didactic courses and seminars that are integrated into his laboratory learning objectives. He will also be mentored in the design, execution, and data analysis of clinical trials that involve DC-tumor fusion hybrids and other immunotherapy approaches. Through this VA Career Development Award-2 (VA-CDA-2), Dr. Lee will elucidate mechanisms that influence successful DC-tumor fusion as well as obtain the skills needed to move laboratory findings to clinical trials. Furthermore, this VA-CDA-2 will allow Dr. Lee to establish a VA-based career and enable him to mature into an independently funded surgeon scientist. PUBLIC HEALTH RELEVANCE: There are an estimated 35,000 veterans a year diagnosed with cancer. This contributes to making cancer the second leading cause of death among veterans. Of these cancers, advanced head and neck cancer is especially debilitating due to its impact on breathing, swallowing, and speaking. Furthermore, veterans are at high risk for developing head and neck cancers due to prior or continued use of tobacco and alcohol, which are well established risk factors. Despite improvements in surgery, chemotherapy, and radiation modalities, patients with advanced head and neck cancer remain at high risk for loco-regional recurrence and distant metastasis. Furthermore, the side effects from available treatment options impact the quality of life of veterans and their families. New and improved treatment strategies are urgently needed to not only increase long term survival but also quality of life for patients with head and neck cancer. This proposal will investigate dendritic- cell - tumor fusion immunotherapy as a means to direct immune cells to attack tumor without side effects.