Cellular Transduction with Replication-Competent Retrovirus Vectors

多形性胶质母细胞瘤(GBM)是成人最常见的原发性脑肿瘤，与一种令人沮丧的 尽管进行了积极的手术、放疗和化疗，但预后仅为12-15个月。缺乏 有效的治疗选择使这种疾病成为基因治疗等新策略的目标。然而， 基因治疗的唯一重大第三阶段临床试验，涉及使用传统的复制缺陷 GBM患者中的逆转录病毒载体导致令人失望的低转导和治疗不足 水平仅为0.02%。标准复制缺陷逆转录病毒载体无法实现 因此，肿瘤在体内的有效转导是胶质瘤基因治疗的主要障碍。对.的使用 基因转移的复制能力载体将会更有效，因为每个成功转移的肿瘤细胞 被转导的细胞本身将成为一个产生病毒的细胞，即使在最初的 行政管理。我们先前已经证明，直接瘤内注射小鼠白血病病毒 基于MLV的复制能力逆转录病毒(RCR)载体制剂可以实现非常高效的 胶质瘤中的自杀基因转移，其转导严格限制在活跃分裂的肿瘤细胞中 没有明显扩散到肿瘤外部位的证据，并导致显著延长生存时间 在给药前，没有可检测到的全身副作用。在此，我们建议进一步完善 将同种异体反应性细胞毒性T淋巴细胞(AllCTL)工程化为RCR的效率 载体产生细胞，然后可以作为移动的细胞输送平台，可以渗透到 并促进复制载体的多焦点扩散。同种异体反应性CTL表现出特征 这为这一目的提供了独特的优势：异体CTL可以在组织中移动，自己能否杀死肿瘤 接触后，可产生细胞因子，诱导细胞凋亡或启动内源性免疫 回应。在CMS胶质瘤中，免疫特权部位内的免疫抑制环境， 他们自身的免疫系统的破坏可能会被避开足够长的时间，使他们有一个有益的 但在泄漏到一般循环中时，应迅速将其销毁。我们将测试他们的 作为细胞递送载体的可行性、生物分布、安全性和实用性，以增强RCR载体的传播和 治疗效果，比较体内免疫缺陷和免疫活性胶质瘤模型。

Glioblastoma multiforme (GBM), the most common primary brain tumor in adults, is associated with a dismal prognosis of only 12-15 months despite aggressive surgery, radiation, and chemotherapy. The lack of effective treatment options has made this disease a target for new strategies such as gene therapy. However, the only major Phase III clinical trial of gene therapy, involving the use of conventional replication-defective retrovirus vectors in GBM patients, resulted in disappointingly low and therapeutically inadequate transduction levels on the order of only 0.02%. The inability of standard replication-defective retroviral vectors to achieve effective transduction of tumors in vivo is therefore a major obstacle to gene therapy for gliomas. The use of replication-competent vectors for gene transfer would be more efficient, as each tumor cell that is successfully transduced would itself become a virus-producing cell, sustaining further transduction events even after initial administration. We have previously demonstrated that direct intratumoral injection of murine leukemia virus (MLV)-based replication-competent retrovirus (RCR) vector preparations can achieve tremendously efficient suicide gene transfer in gliomas, with transduction stringently restricted to the actively dividing tumor cells without evidence of significant spread to extratumoral sites, and resulting in significantly prolonged survival upon prodrug administration, without detectable systemic side effects. Here we propose to further improve the efficiency of this approach by engineering alloreactive cytotoxic T lymphocytes (alloCTLs) to become RCR vector producer cells, which can then serve as motile cellular delivery platforms that can penetrate into the tumor mass and facilitate multifocal spread of the replicating vectors. Alloreactive CTL exhibit characteristics that provide unique advantages for this purpose: alloCTLs can move through tissue, can themselves kill tumor upon contact, and can produce cytokines that induce apoptosis or can initiate an endogenous immune response. Within CMS gliomas, an immunosuppressive environment within an immunologically privileged site, their own destruction by the immune system may be circumvented long enough for them to have a beneficial effect, but alloCTLs should be rapidly destroyed upon leakage into the general circulation. We will test their viability, biodistribution, safety, and utility as cellular delivery vehicles to enhance RCR vector spread and therapeutic efficacy, comparing immunodeficient and immunocompetent glioma models in vivo.