Dendritic Cell-Brain Tumor Stem Cell Fusion Vaccines

描述(申请人提供)：该研究计划的长期目标是开发和测试由树突状细胞(DC)和脑瘤干细胞(BTSC)电融合形成的脑瘤疫苗。BTSC含有体细胞获得性克隆性细胞遗传学改变，这些改变被保存在构成肿瘤主体的分化程度较高的后代中。BTSC是高度优先的治疗靶点，因为它们具有肿瘤的迁移、退出和重新进入周期、自我更新和重建的能力。T细胞免疫治疗是一种很有前途的辅助治疗恶性脑肿瘤的方法，因为免疫反应对靶抗原具有极高的特异性，并且在解剖学上是高度集中的。已建立的颅内肿瘤可以通过全身过继转移体外激活的、肿瘤致敏的T细胞或通过脾内接种DC-肿瘤融合细胞和佐剂来治愈。在初步实验中，已经从几个人胶质母细胞瘤干细胞系和人DC中产生了电融合异染色体。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鉴定，以确定它们是否适合随后的临床测试。脑瘤样本将在培养中建立，选择性允许肿瘤干细胞生长的条件将被调查和优化。BTSC系和原始肿瘤之间的遗传异常的保存将得到确认，祖细胞标记的表达也将得到确认。将在人DC和BTSC之间进行电融合异染色体的产生，并将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携带进展性人BTSC肿瘤的小鼠身上进行研究。这些研究将探索抗肿瘤免疫反应是否与正常脑祖细胞发生交叉反应，以及BTSC是否有效靶向。用DC-BTSC融合细胞体外致敏正常人或GBM患者的T细胞，并分析其对神经干细胞、不同BTSC系和自体肿瘤的反应性。将确定免疫交叉反应的模式，以探索共同抗原是否可以与有限数量特征良好的BTSC株靶向，目标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.