Identification of Novel Ah Receptor Agonists Using a High-Throughput Green Fluorescent Protein-Based Recombinant Cell Bioassay†

Biochemistry ◽  
2002 ◽  
Vol 41 (3) ◽  
pp. 861-868 ◽  
Author(s):  
Scott R. Nagy ◽  
Gang Liu ◽  
Kit S. Lam ◽  
Michael S. Denison
2004 ◽  
Vol 11 (2) ◽  
pp. 406-410 ◽  
Author(s):  
Antonio Cosma ◽  
Silja Bühler ◽  
Rashmi Nagaraj ◽  
Caroline Staib ◽  
Anna-Lena Hammarin ◽  
...  

ABSTRACT Vaccination against smallpox is again considered in order to face a possible bioterrorist threat, but the nature and the level of the immune response needed to protect a person from smallpox after vaccination are not totally understood. Therefore, simple, rapid, and accurate assays to evaluate the immune response to vaccinia virus need to be developed. Neutralization assays are usually considered good predictors of vaccine efficacy and more informative with regard to protection than binding assays. Currently, the presence of neutralizing antibodies to vaccinia virus is measured using a plaque reduction neutralization test, but this method is time-consuming and labor-intensive and has a subjective readout. Here, we describe an innovative neutralization assay based on a modified vaccinia virus Ankara (MVA) vector expressing the green fluorescent protein (MVA-gfp). This MVA-gfp neutralization assay is rapid and sensitive and has a high-throughput potential. Thus, it is suitable to monitor the immune response and eventually the efficacy of a large campaign of vaccination against smallpox and to study the vector-specific immune response in clinical trials that use genetically engineered vaccinia viruses. Most importantly, application of the highly attenuated MVA eliminates the safety concern in using the replication-competent vaccinia virus in the standard clinical laboratory.


Viruses ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 655 ◽  
Author(s):  
Yíngyún Caì ◽  
Masaharu Iwasaki ◽  
Brett Beitzel ◽  
Shuīqìng Yú ◽  
Elena Postnikova ◽  
...  

Lassa virus (LASV), a mammarenavirus, infects an estimated 100,000–300,000 individuals yearly in western Africa and frequently causes lethal disease. Currently, no LASV-specific antivirals or vaccines are commercially available for prevention or treatment of Lassa fever, the disease caused by LASV. The development of medical countermeasure screening platforms is a crucial step to yield licensable products. Using reverse genetics, we generated a recombinant wild-type LASV (rLASV-WT) and a modified version thereof encoding a cleavable green fluorescent protein (GFP) as a reporter for rapid and quantitative detection of infection (rLASV-GFP). Both rLASV-WT and wild-type LASV exhibited similar growth kinetics in cultured cells, whereas growth of rLASV-GFP was slightly impaired. GFP reporter expression by rLASV-GFP remained stable over several serial passages in Vero cells. Using two well-characterized broad-spectrum antivirals known to inhibit LASV infection, favipiravir and ribavirin, we demonstrate that rLASV-GFP is a suitable screening tool for the identification of LASV infection inhibitors. Building on these findings, we established a rLASV-GFP-based high-throughput drug discovery screen and an rLASV-GFP-based antibody neutralization assay. Both platforms, now available as a standard tool at the IRF-Frederick (an international resource), will accelerate anti-LASV medical countermeasure discovery and reduce costs of antiviral screens in maximum containment laboratories.


2001 ◽  
Vol 6 (6) ◽  
pp. 421-428
Author(s):  
C. Renee Albano ◽  
Canghai Lu ◽  
William E. Bentley ◽  
Govind Rao

Green fluorescent protein fusions were constructed with several oxidative stress promoters from Escherichia coli. These promoters were chosen for their induction by reactive oxygen species (ROS) such as superoxide, hydrogen peroxide, and hydroxyl radicals. When exposed to various free radical insults, the cells fluoresced with great specificity based on the corresponding ROS. In this work, we propose a way in which these constructs could be used to study the mode of action of a variety of antitumor drugs. This approach offers the possibility of complementing gene chip technology by the creation of living chips for high throughput screening as well as studying differential gene expression.


2002 ◽  
Vol 7 (4) ◽  
pp. 325-332 ◽  
Author(s):  
Arno Pol ◽  
Fred Van Ruissen ◽  
Joost Schalkwijk

Inflamed epidermis (psoriasis, wound healing, ultraviolet-irradiated skin) harbors keratinocytes that are hyperproliferative and display an abnormal differentiation program. A distinct feature of this so-called regenerative maturation pathway is the expression of proteins such as the cytokeratins CK6, CK16, and CK17 and the antiinflammatory protein SKALP/elafin. These proteins are absent in normal skin but highly induced in lesional psoriatic skin. Expression of these genes can be used as a surrogate marker for psoriasis in drug-screening procedures of large compound libraries. The aim of this study was to develop a keratinocyte cell line that contained a reporter gene under the control of a psoriasis-associated endogenous promoter and demonstrate its use in an assay suitable for screening. We generated a stably transfected keratinocyte cell line that expresses enhanced green fluorescent protein (EGFP), under the control of a 0.8-kb fragment derived from the promoter of the SKALP/elafin gene, which confers high levels of tissue-specific expression at the mRNA level. Induction of the SKALP promoter by tumor necrosis factor-ca resulted in increased expression levels of the secreted SKALP-EGFP fusion protein as assessed by direct readout of fluorescence and fluorescence polarization in 96-well cell culture plates. The fold stimulation of the reporter gene was comparable to that of the endogenous SKALP gene as assessed by enzyme-linked immunosorbent assay. Although the dynamic range of the screening system is limited, the small standard deviation yields a Z factor of 0.49. This indicates that the assay is suitable as a high-throughput screen, and provides proof of the concept that a secreted EGFP fusion protein under the control of a physiologically relevant endogenous promoter can be used as a fluorescence-based high-throughput screen for differentiation-modifying or antiinflammatory compounds that act via the keratinocyte.


2016 ◽  
Vol 8 (2) ◽  
pp. 418-424 ◽  
Author(s):  
Samuel P. Askin ◽  
Thomas E. H. Bond ◽  
Patrick M. Schaeffer

Rapid functional characterization of GFP-tagged biotin protein ligase (BirA-GFP) with a high-throughput DSF-GTP assay.


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