scholarly journals Use of Leishmania donovani Field Isolates Expressing the Luciferase Reporter Gene in In Vitro Drug Screening

2005 ◽  
Vol 49 (9) ◽  
pp. 3776-3783 ◽  
Author(s):  
Ashutosh ◽  
Suman Gupta ◽  
Ramesh ◽  
Shyam Sundar ◽  
Neena Goyal

ABSTRACT Currently available primary screens for the selection of candidate antileishmanial compounds are not ideal. These techniques are time-consuming, laborious, and difficult to scale and require macrophages, which limit their use for high-throughput screening. We have developed Leishmania donovani field isolates that constitutively express the firefly luciferase reporter gene (luc) as a part of an episomal vector. An excellent correlation between parasite number and luciferase activity was observed. luc expression was stable, even in the absence of drug selection, for 4 weeks. The transfectants were infective to macrophages, and intracellular amastigotes exhibited luciferase activity. The suitability of these recombinant field isolates for in vitro screening of antileishmanial drugs was established. The luciferase-expressing sodium stibogluconate-resistant cell lines offer a model for the screening of compounds for resistance. The system is in routine use at the Central Drug Research Institute, Lucknow, India, for high-throughput screening of newly synthesized compounds.

2007 ◽  
Vol 73 (20) ◽  
pp. 6436-6443 ◽  
Author(s):  
Andreas Urban ◽  
Stefan Eckermann ◽  
Beate Fast ◽  
Susanne Metzger ◽  
Matthias Gehling ◽  
...  

ABSTRACT Cells containing reporters which are specifically induced via selected promoters are used in pharmaceutical drug discovery and in environmental biology. They are used in screening for novel drug candidates and in the detection of bioactive compounds in environmental samples. In this study, we generated and validated a set of five Bacillus subtilis promoters fused to the firefly luciferase reporter gene suitable for cell-based screening, enabling the as yet most-comprehensive high-throughput diagnosis of antibiotic interference in the major biosynthetic pathways of bacteria: the biosynthesis of DNA by the yorB promoter, of RNA by the yvgS promoter, of proteins by the yheI promoter, of the cell wall by the ypuA promoter, and of fatty acids by the fabHB promoter. The reporter cells mainly represent novel antibiotic biosensors compatible with high-throughput screening. We validated the strains by developing screens with a set of 14,000 pure natural products, representing a source of highly diverse chemical entities, many of them with antibiotic activity (6% with anti-Bacillus subtilis activity of ≤25 μg/ml]). Our screening approach is exemplified by the discovery of classical and novel DNA synthesis and translation inhibitors. For instance, we show that the mechanistically underexplored antibiotic ferrimycin A1 selectively inhibits protein biosynthesis.


1996 ◽  
Vol 1 (2) ◽  
pp. 85-88 ◽  
Author(s):  
Alfred J. Kolb ◽  
Kenneth Neumann

Luminescence assays are becoming more popular in high throughput screening (HTS) laboratories with the luciferase reporter gene being the most common. As with other assays that are adapted to HTS, improvements have been made to the luciferase assay to make it better suited to the requirements of HTS. For the luciferase reporter gene, these improvements included stabilization of the enzyme, increasing the half-life of the luminescence signal to 5 h, and eliminating separation steps (centrifugation and aliquot transfer) after cell lysis. The improved assay, LucLite, is homogeneous and is measured directly in the cell culture media. In addition to reagent improvements, a temperature-controlled, multidetector microplate counter, TopCount, can quickly and accurately measure luminescence signals.


2012 ◽  
Vol 18 (4) ◽  
pp. 453-461 ◽  
Author(s):  
Ellen Siebring-van Olst ◽  
Christie Vermeulen ◽  
Renee X. de Menezes ◽  
Michael Howell ◽  
Egbert F. Smit ◽  
...  

The firefly luciferase gene is commonly used in cell-based reporter assays. Convenient luciferase assay reagents for use in high-throughput screening (HTS) are commercially available. However, the high cost of these reagents is not within the means of some academic laboratories. Therefore, we set out to develop an affordable luciferase assay reagent applicable in an HTS format using simple liquid-handling steps. The reagent was homemade from individual chemical components and optimized for luminescence intensity and stability. We determined the minimal concentrations of the most expensive components, dithiothreitol (DTT) and D-luciferin, resulting in a total assay reagent cost of less than 1 cent per sample. Signal stability was maximized by omission of coenzyme A and reduction of DTT concentration. The assay was validated in a high-throughput setting using two cancer cell lines carrying a p53-dependent luciferase reporter construct and siRNAs modulating p53 transcriptional activity. Induction of p53 activity by silencing PPM1D or SYVN1 and reduction of p53 activity by silencing p53 remained constant over a 2-h measurement period, with good assay quality (Z′ factors mostly above 0.5). Hence, the luciferase assay described herein can be used for affordable reporter readout in cell-based HTS.


2001 ◽  
Vol 45 (12) ◽  
pp. 3456-3461 ◽  
Author(s):  
Mervi Tenhami ◽  
Kaisa Hakkila ◽  
Matti Karp

ABSTRACT The spread of antibiotic resistance among pathogenic bacteria is a serious threat to humans and animals. Therefore, unnecessary use should be minimized, and new antimicrobial agents with novel mechanisms of action are needed. We have developed an efficient method for measuring the action of antibiotics which is applied to a gram-positive strain,Staphylococcus aureus RN4220. The method utilizes the firefly luciferase reporter gene coupled to the metal-induciblecadA promoter in a plasmid, pTOO24. Correctly timed induction by micromolar concentrations of antimonite rapidly triggers the luciferase gene transcription and translation. This sensitizes the detection system to the action of antibiotics, and especially for transcriptional and translational inhibitors. We show the results for 11 model antibiotics with the present approach and compare them to an analytical setup with a strain where luciferase expression is under the regulation of a constitutive promoter giving only a report of metabolic inhibition. The measurement of light emission from intact living cells is shown to correlate extremely well (r = 0.99) with the conventional overnight growth inhibition measurement. Four of the antibiotics were within a 20% concentration range and four were within a 60% concentration range of the drugs tested. This approach shortens the assay time needed, and it can be performed in 1 to 4 h, depending on the sensitivity needed. Furthermore, the assay can be automatized for high-throughput screening by the pharmaceutical industry.


1998 ◽  
Vol 274 (3) ◽  
pp. C681-C687 ◽  
Author(s):  
Steven J. Swoap

The myosin heavy chain (MHC) IIB gene is preferentially expressed in fast-twitch muscles of the hindlimb, such as the tibialis anterior (TA). The molecular mechanism(s) for this preferential expression are unknown. The goals of the current study were 1) to determine whether the cloned region of the MHC IIB promoter contains the necessary cis-acting element(s) to drive fiber-type-specific expression of this gene in vivo, 2) to determine which region within the promoter is responsible for fiber-type-specific expression, and 3) to determine whether transcription off of the cloned region of the MHC IIB promoter accurately mimics endogenous gene expression in a muscle undergoing a fiber-type transition. To accomplish these goals, a 2.6-kilobase fragment of the promoter-enhancer region of the MHC IIB gene was cloned upstream of the firefly luciferase reporter gene and coinjected with pRL-cytomegalovirus (CMV) (CMV promoter driving the renilla luciferase reporter) into the TA and the slow soleus muscle. Firefly luciferase activity relative to renilla luciferase activity within the TA was 35-fold greater than within the soleus. Deletional analysis demonstrated that only the proximal 295 base pairs (pGL3IIB0.3) were required to maintain this muscle-fiber-type specificity. Reporter gene expression of pGL3IIB0.3 construct was significantly upregulated twofold in unweighted soleus muscles compared with normal soleus muscles. Thus the region within the proximal 295 base pairs of the MHC IIB gene contains at least one element that can drive fiber-type-specific expression of a reporter gene.


2014 ◽  
Vol 2014 ◽  
pp. 1-11
Author(s):  
Ya-Ju Hsieh ◽  
Luen Hwu ◽  
Chien-Chih Ke ◽  
Skye Hsin-Hsien Yeh ◽  
Chien-Feng Lin ◽  
...  

Multimodality imaging using noncytotoxic triple fusion (TF) reporter genes is an important application for cell-based tracking, drug screening, and therapy. The firefly luciferase(fl), monomeric red fluorescence protein(mrfp), and truncated herpes simplex virus type 1 thymidine kinase SR39 mutant(ttksr39)were fused together to create TF reporter gene constructs with different order. The enzymatic activities of TF protein in vitro andin vivowere determined by luciferase reporter assay,H-FEAU cellular uptake experiment, bioluminescence imaging, and micropositron emission tomography (microPET). The TF construct expressed in H1299 cells possesses luciferase activity and red fluorescence. The tTKSR39 activity is preserved in TF protein and mediates high levels ofH-FEAU accumulation and significant cell death from ganciclovir (GCV) prodrug activation. In living animals, the luciferase and tTKSR39 activities of TF protein have also been successfully validated by multimodality imaging systems. The red fluorescence signal is relatively weak forin vivoimaging but may expedite FACS-based selection of TF reporter expressing cells. We have developed an optimized triple fusion reporter constructDsRedm-fl-ttksr39for more effective and sensitivein vivoanimal imaging using fluorescence, bioluminescence, and PET imaging modalities, which may facilitate different fields of biomedical research and applications.


2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Tana A. Omokoko ◽  
Uli Luxemburger ◽  
Shaheer Bardissi ◽  
Petra Simon ◽  
Magdalena Utsch ◽  
...  

Immunotherapy is rapidly evolving as an effective treatment option for many cancers. With the emerging fields of cancer vaccines and adoptive cell transfer therapies, there is an increasing demand for high-throughputin vitrocytotoxicity assays that efficiently analyze immune effector functions. The gold standard51Cr-release assay is very accurate but has the major disadvantage of being radioactive. We reveal the development of a versatile and nonradioactive firefly luciferasein vitrotranscribed (IVT) RNA-based assay. Demonstrating high efficiency, consistency, and excellent target cell viability, our optimized luciferase IVT RNA is used to transfect dividing and nondividing primary antigen presenting cells. Together with the long-lasting expression and minimal background, the direct measurement of intracellular luciferase activity of living cells allows for the monitoring of killing kinetics and displays paramount sensitivity. The ability to cotransfect the IVT RNA of the luciferase reporter and the antigen of interest into the antigen presenting cells and its simple read-out procedure render the assay high-throughput in nature. Results generated were comparable to the51Cr release and further confirmed the assay’s ability to measure antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity. The assay’s combined simplicity, practicality, and efficiency tailor it for the analysis of antigen-specific cellular and humoral effector functions during the development of novel immunotherapies.


2003 ◽  
Vol 8 (6) ◽  
pp. 676-684 ◽  
Author(s):  
Bart W. Nieuwenhuijsen ◽  
Youping Huang ◽  
Yuren Wang ◽  
Fernando Ramirez ◽  
Gary Kalgaonkar ◽  
...  

To study the biology of regulators of G-protein signaling (RGS) proteins and to facilitate the identification of small molecule modulators of RGS proteins, the authors recently developed an advanced yeast 2-hybrid (YTH) assay format for GαZand RGS-Z1. Moreover, they describe the development of a multiplexed luciferase-based assay that has been successfully adapted to screen large numbers of small molecule modulators of protein-protein interactions. They generated and evaluated 2 different luciferase reporter gene systems for YTH interactions, a Gal4 responsive firefly luciferase reporter gene and a Gal4 responsive Renilla luciferase reporter gene. Both the firefly and Renilla luciferase reporter genes demonstrated a 40-to 50-fold increase in luminescence in strains expressing interacting YTH fusion proteins versus negative control strains. Because the firefly and Renilla luciferase proteins have different substrate specificity, the assays were multiplexed. The multiplexed luciferase-based YTH platform adds speed, sensitivity, simplicity, quantification, and efficiency to YTH high-throughput applications and therefore greatly facilitates the identification of small molecule modulators of protein-protein interactions as tools or potential leads for drug discovery efforts.


2003 ◽  
Vol 372 (2) ◽  
pp. 529-534 ◽  
Author(s):  
Zufan ARAYA ◽  
Wanjin TANG ◽  
Kjell WIKVALL

The mitochondrial sterol 27-hydroxylase (CYP27A1) is a multifunctional cytochrome P450 enzyme that catalyses important hydroxylations in the biosynthesis of bile acids and bioactivation of vitamin D3. Previous results [Babiker, Andersson, Lund, Xiu, Deeb, Reshef, Leitersdorf, Diczfalusy and Björkhem (1997) J. Biol. Chem. 272, 26253–26261] suggest that CYP27A1 plays an important role in cholesterol homoeostasis and affects atherogenesis. In the present study, the regulation of the human CYP27A1 gene by growth hormone (GH), insulin-like growth factor-1 (IGF-1), dexamethasone, thyroid hormones and PMA was studied. HepG2 cells were transfected transiently with luciferase reporter gene constructs containing DNA fragments flanking the 5′-region of the human CYP27A1 gene. GH, IGF-1 and dexamethasone increased the promoter activity by 2–3-fold, whereas thyroxine (T4) and PMA repressed the activity significantly when measured with luciferase activity expressed in the cells. The endogenous CYP27A1 enzyme activity in the cells was stimulated by GH, IGF-1 and dexamethasone, whereas T4 and PMA inhibited the activity. Experiments with progressive deletion/luciferase reporter gene constructs indicated that the response elements for GH may be localized in a region upstream to position −1094 bp. The putative response elements for dexamethasone were mapped to positions between −792 and −1095 bp. The −451 bp fragment of the human CYP27A1 gene was found to confer the activation by IGF-1, and the inhibition by T4 and PMA. Results of the present study suggest that CYP27A1 is regulated in human cells by hormones and signal-transduction pathways.


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