An Assay for TLR-Dependent NF-кB/AP-1 Transcription Factor Signaling in Macrophages
Published: January 31, 2024
Abstract
Source: McKiel, L. A., et al. A Macrophage Reporter Cell Assay to Examine Toll-Like Receptor-Mediated NF-kB/AP-1 Signaling on Adsorbed Protein Layers on Polymeric Surfaces. J. Vis. Exp. (2020).
This video demonstrates an assay to examine the toll-like receptor(TLR)-dependent activity of the transcription factors nuclear factor-kappa-B (NF-κB) and activator protein-1 (AP-1) in macrophages. The TLRs trigger a pro-inflammatory signaling cascade upon recognizing damage-associated molecular patterns (DAMPs), activating NF-κB and AP-1. The engineered reporter macrophages produce secreted embryonic alkaline phosphatase (SEAP) enzyme upon NF-κB and AP-1 activation, which is detected via a chromogenic reaction.
Protocol
1. Media and Reagent Preparation Prepare fibroblast media. Combine 450 mL of Dulbecco's modified Eagle medium (DMEM), 50 mL of fetal bovine serum (FBS), and 5 mL of penicillin/streptomycin. Store at 4 °C for up to 3 months. Prepare reporter macrophage growth media in 50 mL aliquots. Combine 45 mL of DMEM, 5 mL of FBS, 5 μg/mL mycoplasma elimination reagent (Table of Materials), and 200 μg/mL phleomycin D1 (Table of Materials). Sto…
Representative Results
Figure 1: Methods and results for the alkaline phosphatase assay of NF-кB/AP-1 reporter macrophages on TCPS, PMMA, PDMS, and fPTFE. (A) Diagram of the workflow for the reporter macrophage alkaline phosphatase assay. (B) Western blot of lysate confirming the presence of DAMP species HMGB1 and HSP60, with β-actin as the loading control. (C</stron…
Disclosures
The authors have nothing to disclose.
Materials
| Cell culture reagents | |||
| anti-mouse/human CD282 (TLR2) | Biolegend | 121802 | |
| CLI-095 (TLR4 inhibitor) | Invivogen | TLRL-CLI95 | |
| C57 complement plasma K2 EDTA 10ml, innovative grade US origin | InnovativeResearch | IGMSC57-K2 EDTA-Compl-10ml | Mouse plasma |
| Dulbecco's modified eagle medium (DMEM) | Sigma Aldrich | D6429-500ML | |
| Dulbecco's phosphate buffered saline (DPBS) | Fisher Scientific | 14190250 | No calcium, no magnesium |
| Fetal bovine serum (FBS), research grade | Wisent | 98150 | |
| LPS-EK | Invivogen | TLRL-EKLPS | Lipopolysaccharide from Escherichia coli K12 |
| NIH/3T3 fibroblasts | ATCC | CRL-1658 | |
| Pam3CSK4 | Invivogen | tlrl-pms | Synthetic triacylated lipopeptide – TLR1/2 ligand |
| Penicillin/streptomycin | Sigma Aldrich | P4333-100ML | |
| Plasmocin | Invivogen | ANT-MPP | Mycoplasma elimination reagent |
| RAW-Blue cells | Invivogen | raw-sp | NF-κB/AP-1 reporter macrophage cell line |
| Trypan blue solution, 0.4% | Fisher Scientific | 15250061 | |
| TrypLE express enzyme (1X) | Fisher Scientific | 12604021 | animal origin-free recombinant cell dissociation enzyme |
| Zeocin | Invivogen | ANT-ZN-1 | |
| Kits and assays | |||
| ELISA precoated plates, mouse IL-6 | Biolegend | B213022 | |
| ELISA precoated plates, mouse TNF-α | Biolegend | B220233 | |
| Endotoxin (Escherichia coli) – Control standard endotoxin (CSE) | Associates of Cape Cope Inc. | E0005-5 | Endotoxin for standard curve in chromogenic endotoxin assay |
| LAL water, 100 mL | Associates of Cape Cope Inc. | WP1001 | Used with chromogenic endotoxin assay |
| Micro BCA protein assay | Fisher Scientific | PI23235 | |
| Limulus amebocyte lysate (LAL) Pyrochrome endotoxin test kit | Associates of Cape Cope Inc. | C1500-5 | Chromogenic endotoxin assay reagent |
| QUANTI-Blue alkaline phosphatase detection medium | Invivogen | rep-qb2 | Alkaline phosphatase assay to indirectly measure NF-κB/AP-1 activity |
| Polymeric coating reagents | |||
| Chloroform, anhydrous | Sigma Aldrich | 288306-1L | |
| Ethyl alcohol anhydrous | Commercial Alcohols | P006EAAN | Sigma: Reagent alcohol, anhydrous, 676829-1L |
| Straight tapered fine tip forceps | Fisher Scientific | 16-100-113 | |
| Fluorinert FC-40 solvent | Sigma Aldrich | F9755-100ML | Fluorinated solvent for fPTFE |
| Cell culture grade water (endotoxin-free) | Fisher Scientific | SH30529LS | |
| Poly(methyl methacrylate) (PMMA) | Sigma Aldrich | 182230-25G | |
| Sylgard 184 elastomer kit | Fisher Scientific | 50822180 | |
| Teflon-AF (fPTFE) | Sigma Aldrich | 469610-1G | Poly[4,5-difluoro-2,2-bis(trifluoromethyl)-1,3-dioxole-co-tetrafluoroethylene] |
| Consumables | |||
| Adhesive plate seals | Fisher Scientific | AB-0580 | |
| Axygen microtubes, 1.5 mL | Fisher Scientific | 14-222-155 | |
| Borosilicate glass scintillation vials, with white polypropylene caps | Fisher Scientific | 03-337-4 | |
| Clear PS 48-well plate | Fisher Scientific | 08-772-52 | |
| Clear TCPS 96-well plate | Fisher Scientific | 08-772-2C | |
| Clear TCPS 48-well plate | Fisher Scientific | 08-772-1C | |
| Cover glasses, circles | Fisher Scientific | 12-545-81 | |
| Falcon tissue culture treated flasks, T25 | Fisher Scientific | 10-126-10 | |
| sticky-Slide 8 Well | Ibidi | 80828 | |
| Superfrost microscope slides | Fisher Scientific | 12-550-15 | |
| Tissue culture treated flasks, T150 | Fisher Scientific | 08-772-48 |
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Cite This Article
An Assay for TLR-Dependent NF-кB/AP-1 Transcription Factor Signaling in Macrophages. J. Vis. Exp. (Pending Publication), e21916, doi: (2024).