Abstract
The recent advances in vector development and gene delivery systems are significant. The knowledge acquired from the wealth of experiments performed over the past decade was instrumental in guiding the directions in which modifications were targeted. In case of adenoviral (Ad) vectors, which have been found to be especially useful as gene delivery vectors, the main draw back was vector-mediated immunogenicity. Recent modifications of the Ad backbone led to the development of helper-dependent Ad vectors (HD), which are completely devoid of all viral protein coding sequences. These modifications have significantly contributed to the safety and reduced immunogenicity of the new HD vector system. In this manuscript, the efficiency of Ad-mediated gene delivery compared to other therapeutic approaches, in the context of a leptin-deficient mouse model, will be presented. Furthermore, we will review our results from comparative studies which support the significant safety enhancement achieved by the use of HD vectors over that observed with Ist generation Ad vectors.