"Stealth" adenoviruses blunt cell-mediated and humoral immune responses against the virus and allow for significant gene expression upon readministration in the lung
"Stealth" adenoviruses blunt cell-mediated and humoral immune responses against the virus and allow for significant gene expression upon readministration in the lung
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DOI：
10.1128/jvi.75.10.4792-4801.2001
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发表时间：
2001-05-01
影响因子：
5.4
通讯作者：
Wilson, JM
中科院分区：
文献类型：
--
作者：
Croyle, MA;Chirmule, N;Wilson, JM
大多数囊性纤维化的早期基因治疗试验都是使用腺病毒载体。删除了 E1a 和 E1b 的第一代病毒受到转基因瞬时表达和大量炎症反应的限制。在注射第二剂病毒后，基因转移也显着减少。为了减少腺病毒相关炎症，第一代载体的衣壳用各种活化的单甲氧基聚乙二醇进行修饰。单次气管内施用修饰载体后，C57BL/6 小鼠中细胞毒性 T 淋巴细胞的产生显着减少，基因表达时间从 4 天延长至 42 天。与接受天然病毒的动物相比，暴露于缀合载体的小鼠的 T 细胞亚群显示 Th1 反应显着降低，而 Th2 反应略有增强。单剂量修饰病毒后，动物血清和支气管肺泡灌洗液中针对腺病毒衣壳蛋白的中和抗体（NAB）减少，从而在用天然腺病毒再次攻击时基因表达水平显着提高。聚乙二醇（PEG）修饰还允许新载体在先前用未修饰病毒免疫的动物中大量表达基因。然而，在使用两剂相同的 PEG 缀合载体后，基因表达显着降低。在剂量之间交替 PEG 的激活组确实在重新给药后产生了显着的基因表达。该技术与第二代或辅助依赖性腺病毒相结合，可以产生剂量策略，促进载体在临床试验中成功重新给药，并在具有显着抗腺病毒NAB水平的患者中显着表达，并减少针对基因治疗病毒载体的免疫反应的可能性。
Most of the early gene therapy trials for cystic fibrosis have been with adenovirus vectors. First-generation viruses with E1a and E1b deleted are limited by transient expression of the transgene and substantial inflammatory responses. Gene transfer is also significantly curtailed following a second dose of virus. In an effort to reduce adenovirus-associated inflammation, capsids of first-generation vectors were modified with various activated monomethoxypolyethylene glycols. Cytotoxic T-lymphocyte production was significantly reduced in C57BL/6 mice after a single intratracheal administration of modified vectors, and length of gene expression was extended from 4 to 42 days. T-cell subsets from mice exposed to the conjugated vectors demonstrated a marked decrease in Th1 responses and slight enhancement of Th2 responses compared to animals dosed with native virus. Neutralizing antibodies (NAB) against adenovirus capsid proteins were reduced in serum and bronchoalveolar lavage fluid of animals after a single dose of modified virus, allowing significant levels of gene expression upon rechallenge with native adenovirus. Modification with polyethylene glycol (PEG) also allowed substantial gene expression from the new vectors in animals previously immunized with unmodified virus. However, gene expression was significantly reduced after two doses of the same PEG-conjugated vector. Alternating the activation group of PEG between doses did produce significant gene expression upon readministration. This technology in combination with second-generation or helper-dependent adenovirus could produce dosing strategies which promote successful readministration of vector in clinical trials and marked expression in patients with significant anti-adenovirus NAB levels and reduce the possibility of immune reactions against viral vectors for gene therapy.