Imler J L, Bout A, Dreyer D, Dieterlé A, Schultz H, Valerio D, Mehtali M, Pavirani A
Transgène S.A. Strasbourg, France.
Hum Gene Ther. 1995 Jun;6(6):711-21. doi: 10.1089/hum.1995.6.6-711.
Treatment of cystic fibrosis by gene therapy will require the development of vectors capable of efficient and safe transfer of a functional cystic fibrosis transmembrane conductance regulator (CFTR) cDNA to airway epithelia. To achieve this goal, replication-deficient (E1-) adenoviruses (Ad) are promising vectors. We have previously demonstrated efficient CFTR gene delivery to the airways of cotton rats and rhesus monkeys using a replication-deficient adenovirus, Ad-CFTR. Here, we have investigated an important safety issue, the interaction between the vector and wild-type virus which can provide the missing E1 function in trans. We show that Ad5 can mobilize the defective Ad-CFTR genome in vitro and in cotton rats. However, the extent of the complementation in vivo by wild-type virus is limited because no additional spreading or shedding of Ad-CFTR to trachea, lungs, and stools is elicited. To attenuate Ad-CFTR further, a mutation was introduced in the cis-acting regulatory sequences that control the encapsidation of the viral genome. We demonstrate that when cells are coinfected with wild-type virus and the new attenuated vector, the viral DNA containing the natural encapsidation sequences is preferentially packaged, leading to a rapid dilution of the recombinant virus.
通过基因疗法治疗囊性纤维化将需要开发能够将功能性囊性纤维化跨膜传导调节因子（CFTR）cDNA高效且安全地转移至气道上皮细胞的载体。为实现这一目标，复制缺陷型（E1-）腺病毒（Ad）是很有前景的载体。我们之前已证明使用复制缺陷型腺病毒Ad-CFTR可将CFTR基因有效递送至棉鼠和恒河猴的气道。在此，我们研究了一个重要的安全问题，即载体与可在反式中提供缺失的E1功能的野生型病毒之间的相互作用。我们表明Ad5可在体外和棉鼠体内调动有缺陷的Ad-CFTR基因组。然而，野生型病毒在体内的互补程度有限，因为未引发Ad-CFTR向气管、肺和粪便的额外扩散或排出。为进一步减弱Ad-CFTR，在控制病毒基因组包装的顺式作用调控序列中引入了一个突变。我们证明，当细胞被野生型病毒和新的减毒载体共感染时，含有天然包装序列的病毒DNA会被优先包装，从而导致重组病毒的快速稀释。
