Correction of the sickle cell disease mutation in human hematopoietic stem/progenitor cells.

Sickle cell disease (SCD) is characterized by a single point mutation in the seventh codon of the β-globin gene. Site-specific correction of the sickle mutation in hematopoietic stem cells would allow for permanent production of normal red blood cells. Using zinc-finger nucleases (ZFNs) designed to flank the sickle mutation, we demonstrate efficient targeted cleavage at the β-globin locus with minimal off-target modification.

Enhancing zinc-finger-nuclease activity with improved obligate heterodimeric architectures.

Zinc-finger nucleases (ZFNs) drive efficient genome editing by introducing a double-strand break into the targeted gene. Cleavage is induced when two custom-designed ZFNs heterodimerize upon binding DNA to form a catalytically active nuclease complex. The importance of this dimerization event for subsequent cleavage activity has stimulated efforts to engineer the nuclease interface to prevent undesired homodimerization.

Isogenic human cell lines for drug discovery: regulation of target gene expression by engineered zinc-finger protein transcription factors.

Isogenic cell lines differing only in the expression of the protein of interest provide the ideal platform for cell-based screening. However, related natural lines differentially expressing the therapeutic target of choice are rare. Here the authors report a strategy for drug screening employing isogenic human cell lines in which the expression of the target protein is regulated by a gene-specific engineered zinc-finger protein (ZFP) transcription factor (TF).

Cell lines for drug discovery: elevating target-protein levels using engineered transcription factors.

Drug discovery requires high-quality, high-throughput bioassays for lead identification and optimization. These assays are usually based on immortalized cell lines, which express the selected drug target either naturally or as a consequence of transfection with the cDNA encoding the target. Natural untransfected cell lines often fail to achieve the levels of expression required to provide assays of sufficient quality with a high enough signal-to-noise ratio.