A membrane antibody receptor for noninvasive imaging of gene expression

Development of nonimmunogenic and specific reporter genes to monitor gene expression in vivo is important for the optimization of gene therapy protocols. We developed a membrane-anchored form of mouse b-glucuronidase (mbG) as a reporter gene to hydrolyze a nonfluorescent glucuronide probe (fluorescein di-b-D-glucuronide, (FDGlcU) to a highly fluorescent reporter to assess the location and persistence of gene expression. A functional b-glucuronidase (bG) was stably expressed on the surface of murine CT26 colon adenocarcinoma cells where it selectively hydrolyzed the cell-impermeable FDGlcU probe. FDGlcU was also preferentially converted to fluorescent probe by (bG) on CT26 tumors. The fluorescent intensity in bG-expressing CT26 tumors was 240 times greater than the intensity in control tumors. Selective imaging of gene expression was also observed after intratumoral injection of adenoviral bG vector into carcinoma xenografts. Importantly, mbG did not induce an antibody response after hydrodynamic plasmid immunization of Balb/c mice, indicating that the reporter gene product displayed low immunogenicity. A membraneanchored form of human bG also allowed in vivo imaging, demonstrating that human bG can be employed for imaging. This imaging system therefore, displays good selectivity with low immunogenicity and may help assess the location, magnitude and duration of gene expression in living animals and humans.

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“…40 The plasmids were i.v. injected in 2 ml PBS within 8 s for hydrodynamicbased gene transfer on days 1 and 8.…”

Section: Mbg Immunogenicitymentioning

confidence: 99%

Gene expression imaging by enzymatic catalysis of a fluorescent probe via membrane-anchored β-glucuronidase

Chuang

Wang

et al. 2007

Gene Ther

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“…We previously showed that DNS receptors can specifically trap a bivalent (DNS) 2 -dithylenetriaminepentaacetate-111 Indium ((DNS) 2 -DTPA-111 In) probe in mice, as assessed by gamma camera imaging. 11 These results suggest that multimodality imaging (MR, optical and gamma camera imaging) can be employed to monitor DNS receptors in vivo by choosing the proper DNS probe.…”

Section: Discussionmentioning

confidence: 99%

“…We previously reported a novel gene/probe imaging system based on the expression of anti-DNS (5-dimethylamino-1-naphthalene sulfonic acid) single-chain antibody receptors (DNS receptor) on cells to trap DNS-derivatized imaging probes to assess the location, extent and persistence of gene expression in live animals. 11 We showed that a bivalent (DNS) 2 -diethylenetriaminepentaacetate-111 Indium ((DNS) 2 -DTPA- 111 In) probe could specifically localize to DNS receptors on B16/F1 tumors in mice as assessed by gamma camera imaging. 11 However, an analogous gadolinium probe ((DNS) 2 -DTPA-Gd (III)) could not be detected by MR imaging due to poor sensitivity (unpublished results).…”

Section: Introductionmentioning

confidence: 99%

“…11 We showed that a bivalent (DNS) 2 -diethylenetriaminepentaacetate-111 Indium ((DNS) 2 -DTPA- 111 In) probe could specifically localize to DNS receptors on B16/F1 tumors in mice as assessed by gamma camera imaging. 11 However, an analogous gadolinium probe ((DNS) 2 -DTPA-Gd (III)) could not be detected by MR imaging due to poor sensitivity (unpublished results). Recently, non-toxic cross-linked iron oxide (CLIO) superparamagnetic nanoparticles have been developed as an excellent MR signal enhancer to resolve a major weakness of current MR imaging techniques for gene expression 12,13 and cell tracking 14,15 in vivo.…”

Section: Introductionmentioning

confidence: 99%

“…In 11 and DNS-derivatized b-glucuronidase 21 could localize to DNS receptors on cells in vitro and in vivo. Similar results were also shown in this study for DNS-derivatized CLIO and qdots.…”

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confidence: 99%

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Hapten-derivatized nanoparticle targeting and imaging of gene expression by multimodality imaging systems

et al. 2008

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Non-invasive gene monitoring is important for most gene therapy applications to ensure selective gene transfer to specific cells or tissues. We developed a non-invasive imaging system to assess the location and persistence of gene expression by anchoring an anti-dansyl (DNS) single-chain antibody (DNS receptor) on the cell surface to trap DNS-derivatized imaging probes. DNS hapten was covalently attached to cross-linked iron oxide (CLIO) to form a 39±0.5 nm DNS-CLIO nanoparticle imaging probe. DNS-CLIO specifically bound to DNS receptors but not to a control single-chain antibody receptor. DNS-CLIO (100 mM Fe) was non-toxic to both B16/DNS (DNS receptor positive) and B16/phOx (control receptor positive) cells. Magnetic resonance (MR) imaging could detect as few as 10% B16/DNS cells in a mixture in vitro. Importantly, DNS-CLIO specifically bound to a B16/DNS tumor, which markedly reduced signal intensity. Similar results were also shown with DNS quantum dots, which specifically targeted CT26/DNS cells but not control CT26/phOx cells both in vitro and in vivo. These results demonstrate that DNS nanoparticles can systemically monitor the expression of DNS receptor in vivo by feasible imaging systems. This targeting strategy may provide a valuable tool to estimate the efficacy and specificity of different gene delivery systems and optimize gene therapy protocols in the clinic.

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Membrane‐tethered proteins for basic research, imaging, and therapy

Cheng

Roffler

2008

Medicinal Research Reviews

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Secreted and intracellular proteins including antibodies, cytokines, major histocompatibility complex molecules, antigens, and enzymes can be redirected to and anchored on the surface of mammalian cells to reveal novel functions and properties such as reducing systemic toxicity, altering the in vivo distribution of drugs and extending the range of useful drugs, creating novel, specific signaling receptors and reshaping protein immunogenicity. The present review highlights progress in designing vectors to target and retain chimeric proteins on the surface of mammalian cells. Comparison of chimeric proteins indicates that selection of the proper cytoplasmic domain and introduction of oligiosaccharides near the cell surface can dramatically enhance surface expression, especially for single-chain antibodies. We also describe progress and limitations of employing surface-tethered proteins for preferential activation of prodrugs at cancer cells, imaging gene expression in living animals, performing high-throughput screening, selectively activating immune cells in tumors, producing new adhesion molecules, creating local immune privileged sites, limiting the distribution of soluble factors such as cytokines, and enhancing polypeptide immunogenicity. Surface-anchored chimeric proteins represent a rich source for developing new techniques and creating novel therapeutics.

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A membrane antibody receptor for noninvasive imaging of gene expression

Cited by 23 publications

References 36 publications

Gene expression imaging by enzymatic catalysis of a fluorescent probe via membrane-anchored β-glucuronidase

Gene expression imaging by enzymatic catalysis of a fluorescent probe via membrane-anchored β-glucuronidase

Hapten-derivatized nanoparticle targeting and imaging of gene expression by multimodality imaging systems

Membrane‐tethered proteins for basic research, imaging, and therapy

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