Oncolytic Adenovirus Group, German Cancer Research Center (DKFZ), Heidelberg, Germany.
Molecular OncoSurgery, German Cancer Research Center (DKFZ) and Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Heidelberg, Germany.
Int J Cancer. 2015 Aug 15;137(4):978-90. doi: 10.1002/ijc.29442. Epub 2015 Feb 20.
Oncolytic viruses have demonstrated in pre-clinical and clinical studies safety and a unique pleiotropic activity profile of tumor destruction. Yet, their delivery suffers from virus inactivation by blood components and sequestration to healthy tissues. Therefore, mesenchymal stromal cells (MSCs) have been applied as carrier cells for shielded virus delivery to tumors after ex vivo infection with oncolytic viruses. However, infection and particle production by MSCs have remained unsatisfying. Here, we report engineered oncolytic adenoviruses (OAds) for improved virus production and delivery by MSCs. OAds are uniquely amenable to molecular engineering, which has facilitated improved tumor cell destruction. But for MSC-mediated regimens, OAd engineering needs to achieve efficient infection and replication in both MSCs and tumor cells. We show that an Ad5/3 chimeric OAd capsid, containing the adenovirus serotype 3 cell-binding domain, strongly increases the entry into human bone marrow-derived MSCs and into established and primary pancreatic cancer cells. Further, we reveal that OAd with engineered post-entry functions-by deletion of the anti-apoptotic viral gene E1B19K or expression of the death ligand TRAIL--markedly increased virus titers released from MSCs, while MSC migration was not hampered. Finally, these virus modifications, or viral expression of FCU1 for local 5-FC prodrug activation, improved tumor cell killing implementing complementary cytotoxicity profiles in a panel of pancreatic cancer cell cultures. Together, our study establishes post-entry modification of OAd replication for improving virus delivery by carrier cells and suggests a panel of optimized OAds for future clinical development in personalized treatment of pancreatic cancer.
溶瘤病毒在临床前和临床研究中已被证实具有安全性，并且具有独特的肿瘤破坏的多效性活性谱。然而，它们的传递受到血液成分的病毒失活和对健康组织的隔离的影响。因此，间充质基质细胞（MSCs）已被用作载体细胞，用于在体外感染溶瘤病毒后将屏蔽的病毒递送到肿瘤中。然而，MSCs 的感染和颗粒生产仍然不尽如人意。在这里，我们报告了经过工程改造的溶瘤腺病毒（OAd），用于改善 MSCs 中的病毒生产和传递。OAd 非常适合分子工程改造，这促进了对肿瘤细胞的破坏。但是对于 MSC 介导的方案，OAd 工程需要在 MSCs 和肿瘤细胞中实现有效的感染和复制。我们表明，含有腺病毒血清型 3 细胞结合结构域的 Ad5/3 嵌合 OAd 衣壳强烈增加了对人骨髓来源的 MSCs 以及已建立和原发性胰腺癌的进入。此外，我们揭示了通过删除抗凋亡病毒基因 E1B19K 或表达死亡配体 TRAIL 对进入后功能进行工程改造的 OAd，可显着提高从 MSCs 释放的病毒滴度，而 MSC 迁移不受阻碍。最后，这些病毒修饰或病毒表达 FCU1 用于局部 5-FC 前药激活，改善了肿瘤细胞杀伤作用，在一系列胰腺癌细胞培养物中实施了互补的细胞毒性谱。总之，我们的研究建立了 OAd 复制的进入后修饰，以改善载体细胞的病毒传递，并为未来个性化治疗胰腺癌的临床开发提出了一系列优化的 OAd。
