Hellebrand E, Mautner J, Reisbach G, Nimmerjahn F, Hallek M, Mocikat R, Hammerschmidt W
Department of Gene Vectors, GSF-National Research Center for Environment and Health, Munich, Germany.
Gene Ther. 2006 Jan;13(2):150-62. doi: 10.1038/sj.gt.3302602.
The efficient gene transfer of immunostimulatory cytokines into autologous tumor cells or the transfer of tumor-associated antigens into professional antigen-presenting cells is a prerequisite for many immunotherapeutic approaches. In particular with B cells, the efficiency of gene uptake is one of the limiting factors in cell-based vaccine strategies, since normal and malignant human B cells are commonly refractory to transducing gene vectors. Due to its natural tropism for human B cells, Epstein-Barr virus (EBV), a human herpes virus, might be an option, which we wanted to explore. EBV efficiently infects human B cells and establishes a latent infection, while the viral genome is maintained extrachromosomally. Although these characteristics are attractive, EBV is an oncogenic virus. Here, we present a novel EBV-derived vector, which lacks three EBV genes including two viral oncogenes and an essential lytic gene, and encodes granulocyte-macrophage colony-stimulating factor (GM-CSF) as a cytokine of therapeutic interest. We could show that EBV vectors efficiently transduce different B-cell lines, primary resting B cells, and tumor cells of B-cell lineage. Vector-derived GM-CSF was expressed in sufficient amounts to support the maturation of dendritic cells and their presentation of model antigens to cognate T-cell clones in autologous settings and an allogeneic, HLA-matched assay. We conclude that the EBV vector system might offer an option for ex vivo manipulation of B cells and gene therapy of B-cell lymphomas.
将免疫刺激细胞因子有效基因转移至自体肿瘤细胞，或将肿瘤相关抗原转移至专职抗原呈递细胞，是许多免疫治疗方法的前提条件。特别是对于B细胞，基因摄取效率是基于细胞的疫苗策略中的限制因素之一，因为正常和恶性人B细胞通常对转导基因载体具有抗性。由于人类疱疹病毒爱泼斯坦-巴尔病毒（EBV）对人B细胞具有天然嗜性，它可能是一个可供探索的选择。EBV能有效感染人B细胞并建立潜伏感染，同时病毒基因组以染色体外形式维持。尽管这些特性很有吸引力，但EBV是一种致癌病毒。在此，我们展示了一种新型的源自EBV的载体，它缺少三个EBV基因，包括两个病毒癌基因和一个必需的裂解基因，并编码粒细胞-巨噬细胞集落刺激因子（GM-CSF）作为具有治疗意义的细胞因子。我们能够证明，EBV载体能有效转导不同的B细胞系、原代静息B细胞以及B细胞谱系的肿瘤细胞。载体衍生的GM-CSF能以足够的量表达，以支持树突状细胞的成熟及其在自体环境和同种异体、HLA匹配检测中向同源T细胞克隆呈递模型抗原。我们得出结论，EBV载体系统可能为B细胞的体外操作和B细胞淋巴瘤的基因治疗提供一种选择。
