Adenovirus gene therapy for hypercholesterolemia, thrombosis and restenosis

Abstract

Time for primary review 28 days. Human adenoviruses are non-enveloped, icosahedral viruses, approximately 130 nm in diameter. The linear, double-stranded DNA viral genome containing covalently attached terminal protein derived from a unique replication process is almost 36 Kb in length. Although forty nine serotypes of human adenovirus in six serological subgroups have been identified, only serotypes 2 and 5 of subgroup C have been extensively employed as gene transfer vectors. Recombinant helper-independent adenovirus vectors are easily constructed, analyzed and propagated using standard recombinant DNA and virological techniques (reviewed in [1, 2]). Foreign genes can be inserted into the adenovirus genome in a variety of locations to generate recombinant vectors, although substitution of early region 1 (E1) has been most widely used. Replacement of E1, since it is required for the efficient expression of the remainder of the viral genome, generates a vector which can only be propagated in a complementing cell line which supply the missing E1A functions in trans from an integrated copy of the appropriate fragment of the viral genome. Such E1 replacement vectors are typically propagated in the 293 [3]or 911 [4]cell lines. Recombinant viruses produced in this manner can be stably propagated to a titer of 108–109 plaque forming units per ml and are readily purified free of contaminating viral proteins and empty capsids using CsCl density gradient centrifugation for in vivo use [2]. Recombinant adenoviruses are highly efficient vectors for the transfer of foreign genes into cells both in vitro and in vivo. Because adenovirus vectors can infect a broad range of mammalian cell types, they have become the preferred vector for a wide variety of in vivo applications [5]and are currently approved for use in a limited number of human gene therapy trials. The high efficiency of … * Corresponding author. Tel.: +32 16 346182; Fax: +32 16 345990.