GENETIC MODIFICATION OF HUMAN DENDRITIC CELLS FOR CANCER IMMUNITY

描述（由申请人提供）：我们对人类树突状细胞的理解取得了进展，解决了许多关于先天和适应性免疫发病的重要未知问题，以及树突状细胞如何控制这些对抗癌症的反应。肿瘤抗原本身是较差的免疫原，因为它们要么是自体抗原，要么是异自体抗原。因此，克服对癌症自身抗原的耐受性的门槛虽然可以实现，但相当高。树突状细胞可以通过将肿瘤抗原与所有其他引起免疫反应的必要分子结合来绕过许多这些障碍。然而，涉及吲哚胺2,3-双加氧酶（IDO）并由调节性淋巴细胞介导的反补贴抑制机制也必须得到解决。遗传策略在将肿瘤抗原偶联到树突状细胞方面具有优势。多个表位可以表达，以适应各种MHC等位基因。抗原呈递可以持续一段时间，细胞因子和其他共刺激分子可以被操纵，免疫抑制机制可以被改变。我们将利用人类朗格汉斯型树突状细胞，通过逆转录病毒或质粒载体进行基因修饰，表达黑色素瘤抗原和其他感兴趣的蛋白质，在一系列可测试的假设中解决这些问题。我们将通过郎格汉斯细胞的遗传改变引入IL-12p70来刺激和利用自然杀伤（NK）细胞的佐剂特性。还将测试新的方法，通过转导活化fc - γ Rll， CD32a的表达来持续激活朗格汉斯细胞和改善活化肿瘤抗原的交叉呈递。这将与基于基因的IL-12p70-Fc融合构建体结合进行测试，以评估细胞因子佐剂性的增加。遗传方法干扰抑制机制涉及IDO和调节淋巴细胞将被研究。这些研究的结果将导致通过单一的、基因优化的树突状细胞来改善、协调地刺激先天免疫和适应性免疫来对抗癌症。(与公共卫生相关/Lay摘要：将以黑色素瘤为模型，测试和改进专门的朗格汉斯型树突状细胞的遗传改变，以提高对癌症的免疫力。这些方法应该在治疗初级治疗后的微小残留疾病方面得到最大的应用。

DESCRIPTION (provided by applicant): Advances in our understanding of human dendritic cells have resolved many important unknowns about the onset of innate and adaptive immunity and how dendritic cells could control these responses against cancer. Tumor antigens are poor immunogens by themselves, because they are either self or altered-self antigens. Hence the bar to overcoming tolerance toward cancer-self antigens, while attainable, is quite high. Dendritic cells can circumvent many of these barriers by presenting tumor antigens in association with all the other requisite molecules that elicit immune reactivity. Countervailing suppressor mechanisms involving indoleamine 2,3-dioxygenase (IDO) and mediated by regulatory lymphocytes must also be addressed, however. Genetic strategies offer advantages in coupling tumor antigens to dendritic cells. Multiple epitopes can be expressed, tailored to a variety of MHC alleles. Antigen-presentation is sustained over time, cytokines and other costimulatory molecules can be manipulated, and immune suppressor mechanisms can be altered. We will address these areas in a series of testable hypotheses using human Langerhans-type dendritic cells, genetically modified by retroviral or plasmid vectors to express melanoma antigens and other proteins of interest. We will introduce IL-12p70 by genetic alteration of Langerhans cells to stimulate and harness the adjuvant properties of natural killer (NK) cells. Novel approaches will also be tested for the sustained activation of Langerhans cells and improved cross-presentation of opsonized tumor antigen through transduced expression of the activating Fc-gamma Rll, CD32a. This will be tested in combination with gene-based IL-12p70-Fc fusion constructs to assess increased cytokine adjuvanticity. Genetic methods that interfere with suppressor mechanisms involving IDO and mediated by regulatory lymphocytes will be studied. The results of these studies should lead to improved, coordinate stimulation of innate and adaptive immunity against cancer by a single, genetically optimized dendritic cell. (Relevance to public health/Lay summary: Genetic alterations of specialized Langerhans-type dendritic cells will be tested and improved to increase immunity against cancer, using melanoma as the model. These approaches should find their greatest application in treating minimal residual disease after primary therapy.)