A humanized system for pharmacologic control of gene expression.
Gene therapy was originally conceived as a medical intervention to replace or correct defective genes in patients with inherited disorders. However, it may have much broader potential as an alternative delivery platform for protein therapeutics, such as cytokines, hormones, antibodies and novel engineered proteins. One key technical barrier to the widespread implementation of this form of therapy is the need for precise control over the level of protein production. A suitable system for pharmacologic control of therapeutic gene expression would permit precise titration of gene product dosage, intermittent or pulsatile treatment, and ready termination of therapy by withdrawal of the activating drug. We set out to design such a system with the following properties: (1) low baseline expression and high induction ratio; (2) positive control by an orally bioavailable small-molecule drug; (3) reduced potential for immune recognition through the exclusive use of human proteins; and (4) modularity to allow the independent optimization of each component using the tools of protein engineering. We report here the properties of this system and demonstrate its use to control circulating levels of human growth hormone in mice implanted with engineered human cells.
Rivera
V M
VM
ARIAD Gene Therapeutics, Cambridge, Massachusetts 02139, USA.
Clackson
T
T
Natesan
S
S
Pollock
R
R
Amara
J F
JF
Keenan
T
T
Magari
S R
SR
Phillips
T
T
Courage
N L
NL
Cerasoli
F
F
Holt
D A
DA
Gilman
M
M
D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D017690:Cell Transplantation; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects*; D015316:Genetic Therapy; D013006:Growth Hormone / Q000235:genetics*; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D020104:Immunophilins; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D051379:Mice; D008819:Mice, Nude; D017853:Phosphotransferases (Alcohol Group Acceptor); D011090:Polyenes / Q000494:pharmacology*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D020123:Sirolimus; D058570:TOR Serine-Threonine Kinases; D022021:Tacrolimus Binding Proteins; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014407:Tumor Cells, Cultured
D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D006360:Heat-Shock Proteins; D007166:Immunosuppressive Agents; D011090:Polyenes; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; C091215:ZFHD1 protein, recombinant; D013006:Growth Hormone; D017853:Phosphotransferases (Alcohol Group Acceptor); C546842:MTOR protein, human; C546843:mTOR protein, mouse; D058570:TOR Serine-Threonine Kinases; D022021:Tacrolimus Binding Proteins; D020104:Immunophilins; D020123:Sirolimus