Infectious delivery of a 135-kb LDLR genomic locus leads to regulated complementation of low-density lipoprotein receptor deficiency in human cells.
The ability to deliver efficiently a complete genomic DNA locus to human and rodent cells will likely find widespread application in functional genomic studies and novel gene therapy protocols. In contrast to a cDNA expression cassette, the use of a complete genomic DNA locus delivers a transgene intact with its native promoter, the exons, all the intervening introns, and the regulatory regions. The presence of flanking, noncoding genomic DNA sequences could prove critical for prolonged and appropriate gene expression. We have recently developed a technology for the rapid conversion of bacterial artificial chromosome (BAC) clones into high-capacity herpes simplex virus-based amplicon vectors. Here, we express the human low-density lipoprotein receptor (LDLR), mutated in familial hypercholesterolemia (FH), from a 135-kb BAC insert. The infectious LDLR genomic locus vectors were shown to express at physiologically appropriate levels in three contexts. First, the LDLR locus was expressed appropriately in the ldl(-/-)a7 Chinese hamster ovary (CHO) cell line immediately following infectious delivery; second, the locus was maintained within a replicating episomal vector and expressed at broadly physiological levels in CHO cells for 3 months following infectious delivery; and third, the locus was efficiently expressed in human fibroblasts derived from FH patients. Finally, we show that the infectious LDLR locus retains classical expression regulation by sterol levels in human cells. This long-term expression and physiological regulation of LDLR prepares the way for in vivo functional studies of infectious delivery of BAC inserts.
Wade-Martins
Richard
R
Molecular Neuro-Oncology Laboratories, Neurosurgery Service, Massachusetts General Hospital-East and Harvard Medical School, Building 149, 13th Street, Charlestown 02129, USA.
Saeki
Yoshinaga
Y
Chiocca
E Antonio
EA
D000818:Animals; D016466:CHO Cells; D022202:Chromosomes, Artificial, Bacterial; D006224:Cricetinae; D020031:Epstein-Barr Virus Infections / Q000235:genetics; D005347:Fibroblasts / Q000378:metabolism / Q000821:virology; D018014:Gene Transfer Techniques; D005816:Genetic Complementation Test; D015316:Genetic Therapy; D005822:Genetic Vectors; D016678:Genome; D049452:Green Fluorescent Proteins; D004854:Herpesvirus 4, Human / Q000235:genetics* / Q000472:pathogenicity; D006801:Humans; D006938:Hyperlipoproteinemia Type II / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D017404:In Situ Hybridization, Fluorescence; D008164:Luminescent Proteins / Q000378:metabolism; D008970:Molecular Weight; D010957:Plasmids / Q000235:genetics; D011973:Receptors, LDL / Q000235:genetics* / Q000378:metabolism; D013261:Sterols / Q000378:metabolism; D014162:Transfection; D014170:Transformation, Genetic; D019076:Transgenes
D008164:Luminescent Proteins; D011973:Receptors, LDL; D013261:Sterols; D049452:Green Fluorescent Proteins