Dendritic Cell-Brain Tumor Stem Cell Fusion Vaccines

描述（由申请人提供）：本研究项目的长期目标是开发和测试由树突状细胞（DC）和脑肿瘤干细胞（BTSC）电融合形成的脑肿瘤疫苗。BTSC包含体细胞获得的克隆细胞遗传学变化，这些变化保存在构成肿瘤主体的分化程度更高的后代中。BTSC是高度优先的治疗靶点，因为它们有能力；肿瘤的迁移、退出和重新进入循环、自我更新和重建。T细胞免疫疗法是一种很有前途的辅助治疗恶性脑肿瘤，因为免疫反应对靶向抗原非常特异性，并且高度集中于解剖结构。建立的颅内肿瘤可以通过体外激活的、肿瘤致敏的T细胞的系统性过继转移或通过DC-肿瘤融合细胞和佐剂的脾内疫苗接种来治愈。在初步实验中，电融合异嵌合体已从几种人胶质母细胞瘤干细胞系和人DC中产生。我们建议对DC-BTSC融合细胞的生物学和免疫学特性进行临床前表征，以确定其在后续临床试验中的适用性。将在培养中建立脑肿瘤样本，并研究和优化选择性允许肿瘤干细胞生长的条件。将证实BTSC细胞系与原始肿瘤之间的遗传异常保存，以及祖细胞标记物的表达。制备人DC和BTSC的电融合异嵌合体，优化控制融合的细胞成分和物理参数。由小鼠dc -人BTSC嵌合体组成的半异种融合疫苗的病理和治疗反应将在患有进行性颅内人BTSC肿瘤的小鼠中进行研究。这些研究将探讨抗肿瘤免疫反应是否与正常脑祖细胞交叉反应，以及BTSC是否有效靶向。将DC-BTSC融合细胞在体外致敏正常人或GBM患者的T细胞，并分析其对神经干细胞、各种BTSC系和自身肿瘤的反应性。将确定免疫交叉反应的模式，以探索共同抗原是否可以被有限数量的特征良好的BTSC系靶向，目的是开发标准化的胶质瘤疫苗。

DESCRIPTION (provided by applicant): The long-term goal of this research program is to develop and test brain tumor vaccines formed by electrofusion of dendritic cells (DC) and brain tumor stem cells (BTSC). BTSC contain somatically acquired clonal cytogenetic changes that are preserved in the more differentiated progeny that constitutes the bulk of the tumor. BTSC are high priority therapeutic targets because they have the capacity for; migration, exit and re-entry into cycle, self-renewal, and reconstitution of tumors. T cell immunotherapy is a promising adjuvant therapy for malignant brain tumors because the immune response is exquisitely specific for targeted antigens and is highly anatomically focused. Established intracranial tumors can be cured through systemic adoptive transfer of in vitro activated, tumor-sensitized T cells or through intrasplenic vaccination with DC- tumor fusion cells and adjuvant. In preliminary experiments electrofusion heterochimeras have been generated from several human glioblastoma stem cell lines and human DC. We propose to perform preclinical characterization of the biologic and immunologic properties of DC-BTSC fusion cells in order to establish their suitability for subsequent clinical testing. Brain tumor samples will be established in culture and conditions that selectively permit tumor stem cell growth will be investigated and optimized. Preservation of genetic abnormalities between the BTSC lines and the original tumor will be confirmed, as will expression of progenitor cell markers. Generation of electrofusion heterochimeras between human DC and BTSC will be performed and the cellular components and physical parameters that control fusion will be optimized. The pathologic and therapeutic responses to semi-xenogeneic fusion vaccines consisting of murine DC-human BTSC chimeras will be investigated using mice bearing progressive intracranial human BTSC tumors. These studies will explore whether the anti-tumor immune response is cross-reactive with normal brain progenitor cells and whether BTSC are effectively targeted. T cells from normal humans or GBM patients will be sensitized in vitro with DC-BTSC fusion cells and their reactivity against neural stem cells, various BTSC lines and autologous tumor will be analyzed. Patterns of immunologic cross-reactivity will be determined to explore whether common antigens can be targeted with a limited number of well-characterized BTSC lines with the goal of developing a standardized glioma vaccine.