Abstract
ABSTRACT
Delivering heterologous gene expression in specific tissues for correcting genetic defects or vaccination is an extensively studied strategy. Prerequisite for this approach is the use of efficient nucleic acid transport systems that allow release and constitutive expression of specific genes in target cells (trasduction). Because of restricted targeting, due to the interaction between cell and viral receptors, viruses can only enter specific cells and express their genes., When appropriately engineered viruses can therefore be succesfully used as transduction vectors.
Among viral vectors, those derived from lentiviruses perform better because they integrate into cell genome,important for obtaining heterologous gene long-term expression and are capable of infecting non dividing cells. On this premises, lentivirus derived vectors are extensively used for heterologous gene delivery.
High trasduction efficiency vectors have been derived from human immunodeficency virus (HIV) the etiologic agent of AIDS in humans. Ethical remarks and potential residual infectivity have so far prevented their in vivo application.
From safety issue, feline immunodeficiency virus (FIV), a lentivirus similiar to HIV which does not infect humans, is considered an alternative option. The aim of this work is the development of a self-inactivating FIV vector. This vector is considere safe as it contain almost no viral genes and two promoter regions within LTR.
Removal of non essential genes allowed the insertion of a transcriptional promoter which drives the expressione of a reporter gene downstream and that has been used for testing vector transduction efficiency.
To optimize the system, a second construct containing the FIV central polypurine tract (cPPT) was also developed and compared to the first one Transduction efficiency was characterized on Crandell feline Kidney cells (CrFK) and human kideny cells (293T). Results showed that both constructs
Abstract
are capable of transducing heterologous cells even if at suboptimal levels compared to feline cells.
Unexpectedly and contrarywise to what reported by a few Authors, insertion of cPPT did not improve the vector performance.
