A comparative study of impedance versus optical label-free systems relative to labelled assays in a predominantly Gi coupled GPCR (C5aR) signalling

Halai, Reena, Croker, Daniel E., Suen, Jacky Y., Fairlie, David P. and Cooper, Matthew A. (2012) A comparative study of impedance versus optical label-free systems relative to labelled assays in a predominantly Gi coupled GPCR (C5aR) signalling. Biosensors, 2 3: 273-290.


Author Halai, Reena
Croker, Daniel E.
Suen, Jacky Y.
Fairlie, David P.
Cooper, Matthew A.
Title A comparative study of impedance versus optical label-free systems relative to labelled assays in a predominantly Gi coupled GPCR (C5aR) signalling
Journal name Biosensors   Check publisher's open access policy
ISSN 2079-6374
Publication date 2012-07-26
Sub-type Article (original research)
DOI 10.3390/bios2030273
Volume 2
Issue 3
Start page 273
End page 290
Total pages 18
Place of publication Basel Switzerland
Publisher M D P I AG
Collection year 2013
Language eng
Formatted abstract Profiling ligand function on G-protein coupled receptors (GPCRs) typically involves using transfected cells over-expressing a target of interest, a labelled ligand, and intracellular secondary messenger reporters. In contrast, label-free assays are sensitive enough to allow detection in native cells, which may provide a more physiologically relevant readout. Here, we compare four agonists (native agonists, a peptide full agonist and a peptide partial agonist) that stimulate the human inflammatory GPCR C5aR. The receptor was challenged when present in human monocyte-derived macrophages (HMDM) versus stably transfected human C5aR-CHO cells. Receptor activation was compared on label-free optical and impedance biosensors and contrasted with results from two traditional reporter assays. The rank order of potencies observed across label-free and pathway specific assays was similar. However, label-free read outs gave consistently lower potency values in both native and transfected cells. Relative to pathway-specific assays, these technologies measure whole-cell responses that may encompass multiple signalling events, including down-regulatory events, which may explain the potency discrepancies observed. These observations have important implications for screening compound libraries against GPCR targets and for selecting drug candidates for in vivo assays.
Keyword Impedance and optical biosensors
Label-free
Secondary messenger
Signal transduction
Open Access Mandate Compliance Yes - Open Access (Publisher DOI)
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2013 Collection
Institute for Molecular Bioscience - Publications
 
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Created: Fri, 21 Sep 2012, 14:35:47 EST by Susan Allen on behalf of Institute for Molecular Bioscience