Retroviruses are enveloped RNA viruses that possess the ability to integrate into the host cell genome by transcribing DNA from their RNA template via viral reverse transcriptase. The transcribed viral DNA is then integrated into the host cell genome nonspecifically. There is relative specificity for tumors because, except for lentiviruses, retroviral DNA preferentially integrates into the geno...

The chromatin insulator cHS4 can reduce silencing chromosomal position effects and genotoxicity associated with integrating viral vectors. However, the fully active version of this element can also reduce vector titers and is only partially effective. In order to identify alternatives to cHS4, we developed a functional lentiviral vector-based reporter screen for enhancer-blocking insulators. Us...

Inverse RT-PCR was used for detecting doxycycline-induced mRNA expression after viral transduction with a retroviral vector harboring human TDAG51. After the circularization of double-stranded cDNA, induced transcripts originating from integrated vector genomes were selectively amplified, even in the presence of DNA templates. Thus, DNase treatment before amplification was unnecessary.

We have investigated the utility of the green fluorescent protein (GFP) to serve as a marker to assess retroviral gene transfer into hematopoietic cells and as a tool to identify and enrich for cells expressing high levels of the vector-encoded transcript. GFP, by virtue of a naturally occurring chromophore encoded in its primary sequence, displays autonomous fluorescence, thus eliminating the ...

Retroviral transduction efficiency is related to the multiplicity of infection and the physiological state of the target cells. It is generally not known what proportion of a cell population is susceptible to transduction. We used coinfection with two retroviral vectors containing the marker genes for green fluorescent protein and the truncated human nerve growth factor receptor. In the CD34+ c...

Prolonged stability and controlled expression of gene constructs transferred directly to human skin improve the possibility of using this tissue in somatic gene therapy. We aim to develop a simple transfection method resulting in retroviral mediated gene transfer to keratinocyte stem cells in situ. We here show that after DNA-mediated gene transfer into primary human keratinocytes it is possibl...

The generation of retroviral vectors that infect specific cell types through recognition of cell surface antigens is a promising and effective approach to targeted gene therapy of cancer. Carcinoembryonic antigen (CEA), a highly characterized, cell surface glycoprotein overexpressed by various tumor cells, provides a specific tool for tumor tissue-specific targeting by retroviral vectors. The c...

cDNA expression cloning is a powerful method for the rescue and identification of genes that are able to confer a readily identifiable phenotype on specific cell types. Retroviral vectors provide several advantages over DNA-mediated gene transfer for the introduction of expression libraries into eukaryotic cells since they can be used to express genes in a wide range of cell types, including th...