TLR2 KO Dual Reporter THP1 Cells

TLR2 knockout dual reporter monocytes

NF-κB and IRF signaling pathways in THP1-Dual™ KO-TLR2 cells

THP1-Dual™ KO-TLR2 cells were generated from the THP1-Dual™ cell line, which is derived from the human THP-1 monocytes, through the stable knockout of the TLR2 gene. THP1-Dual™ KO-TLR2 and THP1-Dual™ cells feature two reporter genes allowing the simultaneous study of the IRF pathway, by monitoring the activity of an inducible secreted Lucia luciferase, and the NF-κB pathway by monitoring the activity of an inducible SEAP (secreted embryonic alkaline phosphatase). Lucia luciferase and SEAP activities are readily assessable in the supernatant using QUANTI-Luc™ and QUANTI-Blue™ Solution detection reagents, respectively.

Toll-like receptor 2 (TLR2) plays an essential role in detecting a diverse range of microbial pathogen-associated molecular patterns (PAMPs) from bacteria, fungi, and parasites, including lipoproteins, lipoteichoic acid, lipoarabinomannan, and chitin [1]. Interestingly, a number of viruses have also been shown to interact directly with TLR2 including HIV and herpes simplex virus [1, 2]. TLR2 forms a heterodimer on the cell surface with either of its co-receptors, TLR1 or TLR6, which is crucial for signaling and ligand specificity. The TLR2/TLR1 and TLR2/TLR6 heterodimers specifically bind lipoproteins depending on whether they are tri- or diacylated, respectively [1]. Ultimately, the activation of TLR2 heterodimers leads to MyD88 and MAL/TIRAP-dependent activation of pro-inflammatory transcription factors such as NF-κB and AP-1 [3].  However, the downstream TLR2 signaling cascade can vary and is highly dependent upon which heterodimer is activated, allowing considerable plasticity in TLR2-dependent signaling outcomes.

Features of THP1-Dual™ KO-TLR2 cells:

• Verified knockout of the TLR2 gene (PCR, DNA sequencing, and functional assays)
• Functionally validated with a selection of PRR ligands and cytokines
• Readily assessable Lucia luciferase and SEAP reporter activities
• The stability for 20 passages, following thawing, has been verified
• Guaranteed mycoplasma-free

Applications for THP1-Dual™ KO-TLR2 cells:

• Defining the role of TLR2 in PRR-induced signaling, or related cell signaling pathways 
• Exclusion of contaminating TLR2 agonist-dependent (e.g. bacterial lipoproteins) signaling
• Highlighting possible overlap between TLR2 and other signaling pathways

References:

1. Oliveira-Nascimento, L. et al. 2012. The Role of TLR2 in Infection and Immunity. Front Immunol 3, 79.
2. Henrick, B.M. et al. 2015. HIV-1 Structural Proteins Serve as PAMPs for TLR2 Heterodimers Significantly Increasing Infection and Innate Immune Activation. Front Immunol 6, 426.
3. Li, J. et al. 2013. Evolving Bacterial Envelopes and Plasticity of TLR2-Dependent Responses: Basic Research and Translational Opportunities. Front Immunol 4, 347.

Figures

Validation of TLR2 KO: (A)The targeted TLR2 region in THP1-Dual™ (WT; blue arrow) parental cells and THP1-Dual™ KO-TLR2 (KO; red arrow) cells was amplified by PCR. THP1-Dual™ KO-TLR2 cells feature a frameshift deletion, causing an early stop codon and inactivation of TLR2. (B) Lysates from THP1-Dual™ (WT) and THP1-Dual™ KO-TLR2 (KO) cells were analyzed using an anti-human TLR2 antibody (green arrow), followed by an HRP‑conjugated anti‑rabbit secondary antibody. As expected a band was detected at ~90 kDa in the WT cells only.

NF-κB responses in THP1-Dual™-derived cells: THP1-Dual™ and THP1-Dual™ KO-TLR2 cells were incubated with 0.3 ng/ml human (h)TNF-α (NF-κB-SEAP positive control), 1 x 104 U/ml hIFN-β (IRF-Lucia positive control), 1 μg/ml VACV70/LyoVec™ (CDS ligand), 300 ng/ml 3p-hpRNA/LyoVec™ (RIG-I agonist), 1 μg/ml LPS-EK Ultrapure (UP; TLR4), 1 ng/ml Pam3CSK4 (TLR2/1 agonist), 0.3 ng/ml FSL-1 (TLR2/6 agonist), 107 c/ml HKLM (TLR2 agonist), and 3 μg/ml 2’3’-cGAMP (STING agonist). After overnight incubation, the activation of NF-κB was assessed by measuring the activity of SEAP in the supernatant using QUANTI-Blue™ Solution. Data are shown as optical density (OD) at 630 nm (mean ± SEM).

IRF responses in THP1-Dual™-derived cells: THP1-Dual™ and THP1-Dual™ KO-TLR2 cells were incubated with 0.3 ng/ml human (h)TNF-α (NF-κB-SEAP positive control), 1 x 104 U/ml hIFN-β (IRF-Lucia positive control), 1 μg/ml VACV70/LyoVec™ (CDS ligand), 300 ng/ml 3php‑RNA/LyoVec™ (RIG-I agonist), 1 μg/ml LPS-EK Ultrapure (UP; TLR4), 1 ng/ml Pam3CSK4 (TLR2/1 agonist), 0.3 ng/ml FSL-1 (TLR2/6 agonist), 107 c/ml HKLM (TLR2 agonist), and 3 μg/ml 2’3’-cGAMP (STING agonist). After overnight incubation, the IRF response was assessed by measuring the activity of Lucia luciferase in the supernatant using QUANTI-Luc™. Data are shown as a fold increase over non-induced cells (Lucia luciferase readout).

 

Specifications

Antibiotic resistance: Blasticidin and Zeocin™

Growth medium: RPMI 1640, 2 mM L-glutamine, 25 mM HEPES, 10% (v/v) fetal bovine serum (FBS), 100 U/ml penicillin, 100 µg/ml streptomycin, 100 µg/ml Normocin™

Quality Control:

• Biallelic TLR2 knockout has been verified by PCR, DNA sequencing, and functional assays.
• The stability for 20 passages, following thawing, has been verified. 
• These cells are guaranteed mycoplasma-free. 

This product is covered by a Limited Use License (See Terms and Conditions).

Contents

• 3-7 x 10⁶ THP1-Dual™ KO-TLR2 cells in a cryovial or shipping flask
• 1 ml of Normocin™ (50 mg/ml). Normocin™ is a formulation of three antibiotics active against mycoplasmas, bacteria, and fungi.
• 1 ml of Zeocin™ (100 mg/ml)
• 1 ml of Blasticidin (10 mg/ml)
• 1 pouch of QUANTI-Luc™
• 1 ml of QB reagent and 1 ml of QB buffer (sufficient to prepare 100 ml of QUANTI-Blue™ Solution, a SEAP detection reagent)

 Shipped on dry ice (Europe, USA & Canada)

FAQ

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