Dendritic Cell-Brain Tumor Stem Cell Fusion Vaccines

描述（申请人提供）：本研究项目的长期目标是开发和测试树突状细胞（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，这些变化保留在构成肿瘤主体的更分化的后代中。BTSC是高度优先的治疗靶点，因为它们具有迁移、退出和重新进入周期、自我更新和肿瘤重建的能力。T细胞免疫疗法是恶性脑肿瘤的一种有前途的辅助疗法，因为免疫应答对靶抗原具有高度特异性，并且高度解剖学聚焦。建立的颅内肿瘤可以通过体外活化的肿瘤致敏T细胞的全身过继转移或通过用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，电融合异源嵌合体已经从几种人胶质母细胞瘤干细胞系和人DC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，以确定其对后续临床试验的适用性。将在培养物中建立脑肿瘤样本，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系和原始肿瘤之间遗传异常的保留，以及祖细胞标志物的表达。将进行人DC和BTSC之间的电融合异源嵌合体的产生，并优化控制融合的细胞组分和物理参数。将使用携带进行性颅内人BTSC肿瘤的小鼠研究对由鼠DC-人BTSC嵌合体组成的半异种融合疫苗的病理和治疗应答。这些研究将探索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。来自正常人或GBM患者的T细胞将在体外用DC-BTSC融合细胞致敏，并将分析它们对神经干细胞、各种BTSC系和自体肿瘤的反应性。将确定免疫交叉反应性的模式，以探索是否可以用有限数量的表征良好的BTSC系靶向常见抗原，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.