This video demonstrates a reporter cell-based assay for screening potential bioactive nanoparticles that inhibit Toll-like receptor (TLR) signaling. The assay involves introducing lipopolysaccharides (LPS) mixed with peptide-gold nanoparticle hybrids to reporter macrophages expressing the reporter proteins — secreted embryonic alkaline phosphatase (SEAP) and luciferase. The reduction of LPS-induced TLR signal mediated by the hybrids is determined by measuring the reporter signals.
Protocol
1. Screening for Potential TLR4 Nano-inhibitors Using the Reporter Cells NOTE: Since TLR4 signaling utilizes both MyD88-dependent land TRIF-dependent pathways, it is selected as the primary target to encompass a wide range of TLR signaling pathways. THP-1-XBlue reporter cells are used to mainly examine the NF-κB/AP-1 activation while THP-1-Dual cells are for IRF activation from the TRIF-dependent signal transduction. Identify the optimal LPS d…
Disclosures
The authors have nothing to disclose.
Materials
THP-1-XBlue reporter cell
InvivoGen
thpx-sp
keep cell culture passage under 20
THP-1-Dual repoter cell
InvivoGen
thpd-nfis
keep cell culture passage under 20
RPMI-1640 (no L-glutamine)
GE Health Care
SH30096.02
Warm up to 37 °C before use; add supplements to make a complete medium R10
Fetal bovine serum (qualified)
Thermo Fisher Scientific
12484028
Heat inactivated; 10% in RPMI-1640
L-glutamine
Thermo Fisher Scientific
SH30034.02
2 mM in the complete medium R10
Sodium pyruvate
Thermo Fisher Scientific
11360-070
1 mM in the complete medium R10
Dulbecco's phosphate buffered saline, 1X, without calcium, magnesium
GE Health Care
SH30028.02
Use for cell washing and reagent preparation
QUANTI-Blue
InvivoGen
rep-qb1
SEAP substrate
QUANTI-Luc
InvivoGen
rep-qlc2
Luciferase substrate
Zeocin
InvivoGen
ant-zn-1
Selection antibiotics for reporter cells
Blasticidin
InvivoGen
anti-bl-1
Selection antibiotics for reporter cells
Dimethyl sulfoxide (DMSO) for molecular biology
Sigmal-Aldrich
D8418-100ML
Use for reagent preparation
Lipopolysaccharide (LPS) from E. coli K12
InvivoGen
tlrl-eklps
TLR4 ligand
Flagellin from S. Typhimurium (FLA-ST), ultrapure
InvivoGen
tlrl-epstfla
TLR5 ligand
SpectraMax Plus 384 microplate reader
Molecular Devices
N/A
Read colorimetric assay
Infinite M200 Pro multimode microplate reader with injectors
Tecan
N/A
Read luminiscience
Costar assay plate, 96-well white with clear flat bottom, tissue culure treated