Expanded-capacity adenoviral vectors - the helper-dependent vectors

Significant advances have recently been made in the development of vectors and gene-delivery systems for gene therapy. Experiments performed over the past decade have revealed how vectors will have to be modified to make them a clinically viable treatment option. In the case of adenovirus (Ad) vecto rs, which have been particularly useful as gene delivery vehicles, the main drawback associated with their use is vector-mediated immunogenicity, Rece nt modifications of the Ad backbone have led to the development of helper-d ependent (HD) Ad vectors, which are completely devoid of all viral protein- coding sequences. These modifications have significantly reduced the immuno genicity of Ad vectors and have enhanced their safety It is expected that H D vectors will become important tools for future clinical gene therapy.