IMMUNOTHERAPY WITH ELECTROFUSED DENDRITIC TUMOR HYBRIDS

描述：(申请者摘要)癌症免疫治疗的疗效 高度依赖于诱导免疫反应的效力和持续时间。至 到目前为止，癌症疫苗使用了完整的肿瘤细胞，幼稚的蛋白质， CTL定义的多肽、核酸、细胞膜和重组病毒 以及转基因肿瘤。尽管一些方法已经达到了 提高肿瘤细胞的抗原提呈能力，在大多数情况下， 宿主抗原提呈细胞(APC)的主导作用已被证明。 在各种APC中，树突状细胞(DC)似乎具有基本的特性 激发T细胞反应所必需的：迁移和归巢，抗原 加工和呈现以及协同刺激。最近，DC已经习惯于 呈现肿瘤抗原。这通常通过向DC施加脉冲来实现 来自肿瘤细胞的多肽、肿瘤裂解物或RNA。它也一直是 证明DC-肿瘤融合细胞免疫可导致 已建立的转移瘤的消退。融合的细胞应该有能力 通过处理和处理来引起MHC I类和II类限制性反应 呈现已知和未定义的肿瘤抗原。然而，在大多数报告的案例中， 融合是通过使用聚乙二醇来完成的，导致效率较低 而且毒性很高。使用这种方法，可能是技术上的，而不是 限制其应用的概念方面。申请人最近 通过外加电场实现树突状细胞与肿瘤细胞的融合 脉冲的效率至少是聚乙二醇法的10倍。有趣的是， 未成熟DC与肿瘤细胞的电融合导致杂交细胞具有 高表达MHC-II、B7.1和MHC-2的成熟DC的特性 B7.2分子。分析它们的生物学和免疫学功能 人工产生的嵌合细胞，当前的应用程序将利用 表征良好的模型肿瘤相关抗原，B-半乳糖苷酶，以解决 根本问题。随后的实验将使用几个弱的和差的 免疫原性肿瘤。目前应用的目标是在小鼠身上开发 利用DC与全盘融合的模式、原则和方法 肿瘤细胞用于癌症的主动和过继免疫治疗。具体目标 它们是：1)优化电融合技术；2)鉴定抗原 FUSED的加工和呈递、MHC限制和贩运模式 3)分析树突状细胞瘤免疫应答的特点。 融合细胞；4)探索嵌合细胞的治疗潜力；以及 5)发展一次体外免疫的方法，以产生 肿瘤特异性T细胞。

DESCRIPTION: (Applicant's Abstract) The efficacy of cancer immunotherapy depends highly on the potency and duration of the induced immune response. To date, cancer vaccinations have utilized intact tumor cells, naive proteins, CTL-defined peptides, nucleic acids, cell membranes and recombinant viruses as well as genetically modified tumors. Although some approaches have been to increase the antigen presenting capacity of tumor cells, in most cases, the dominant role of host antigen-presenting cells (APCs) has been demonstrated. Among various APCs, dendritic cells (DCs) seem to have the essential properties required for eliciting T-cell responses: migration and homing, antigen processing and presentation and co-stimulation. Recently, DCs have been used to present tumor antigens. This is generally achieved by pulsing DCs with peptides, tumor lysates or RNA derived from neoplastic cells. It has also been demonstrated that immunization with DC-tumor fused chimeric cells results in the regression of established metastases. Fused cells should have the ability to elicit both MHC class I and II-restricted responses by processing and presenting known and undefined tumor antigens. In most reported cases, however, fusion has been accomplished with the use of PEG, resulting in low efficiency and high toxicity. With this approach, it may be the technical rather than conceptual aspects that limit its application. The applicant has recently demonstrated that fusion of DCs and tumor cells by applying electric field pulses is at least 10-fold more efficient than that by PEG. Interestingly, electrofusion of immature DCs with tumor cells resulted in hybrid cells having characteristics of mature DCs with high expression of MHC class II, B7.1 and B7.2 molecules. To analyze biological and immunological functions of these artificially generated chimeric cells, the current application will utilize the well-characterized model tumor-associated antigen, B-galactosidase, to address fundamental issues. Subsequent experiments will use several weakly and poorly immunogenic tumors. The goal of the current application is to develop in murine models, the principles and methodologies for utilizing DCs fused with entire tumor cells for active and adoptive immunotherapy of cancer. The specific aims are: 1) To optimize electrofusion techniques; 2) To characterize antigen processing and presentation, MHC restriction and trafficking patterns of fused cells; 3) To analyze characteristics of immune responses elicited by DC-tumor fused cells; 4) To explore the therapeutic potential of the chimeric cells; and 5) To develop methods for primary in vitro immunization for generating tumor-specific T cells.