IFN-λ Reporter HEK 293 Cells

Human HEK293 cells - Type III IFNs Reporter Cells

HEK-Blue™ IFN-λ Cells signaling pathway

HEK-Blue™ IFN-λ cells are designed to monitor the activation of the JAK/STAT/ISGF3 pathway induced by interferons lambda (IFN-λ), also known as type III IFNs. These cells do not respond to type I and type II IFNs due to IFNAR2 and IFNGR1 gene knockouts. 

The IFN-λ family is essential to the anti-viral response at epithelial barriers [1,2]. In humans, this family comprises four distinct proteins; IFN-λ1 (interleukin-29, IL-29), IFN-λ2 (IL-28A), IFN-λ3 (IL-28B), and IFN-λ4. IFN-λs bind to a heterodimeric receptor, consisting of IFNLR1 and IL10Rβ associated with TyK2 and JAK1, respectively. The binding of IFN-λs to this receptor leads to the activation of the JAK-STAT-IRF pathway and the formation of the IFN-stimulated gene factor 3 (ISGF3) complex. ISGF3 binds to IFN-stimulated response elements (ISRE) in the promoters of IFN-stimulated genes (ISG) to regulate their expression.

 More details

Cell line description:

HEK-Blue™ IFN-λ cells were generated by stable transfection of the human embryonic kidney (HEK)-293 cells with the human IFNLR and IL10R receptor genes. These were also transfected with the human signal transducers and activators of transcription 2 (STAT2) and  IFN regulatory factor 9 (IRF9) genes to obtain a fully active IFN-λ signaling pathway.
To detect pathway activation, these cells harbor the secreted embryonic alkaline phosphatase (SEAP) under the control of the ISG54 promoter that is activated by IFN-λ. Therefore, stimulation with human or murine IFN-λ triggers the JAK/STAT/ISGF3 pathway and induces SEAP production that can be monitored by a simple colorimetric assay with QUANTI-Blue™ Solution, a medium that turns purple/blue in the presence of SEAP.

HEK-Blue™ IFN-λ cells are resistant to Blasticidin, Hygromycin, G418, Puromycin, and Zeocin®.

Features of HEK-Blue™ IFN-λ cells:

• Fully functional IFN-λ signaling pathway
• Do not respond to human IFN-α/β (type I IFN) nor to human IFN-γ (type II IFN)
• Readily assessable SEAP reporter activity
• Functionally tested and guaranteed mycoplasma-free

Applications of HEK-Blue™ IFN-λ cells:

• Detection of human and murine IFN-λs
• Screening of anti-IFN-λ antibodies

References:

1. Lazear HM. et al., 2015. Interferon-λ: Immune Functions at Barrier Surfaces and Beyond. Immunity. 43(1):15-28.
2. Lee S. & Baldridge MT., 2017. Interferon- Lambda: A Potent Regulator of Intestinal Viral Infections. Front Immunol. 8:749. 

Figures

Response of HEK-Blue™ IFN-λ cells to type I, II and III IFNs: HEK-Blue™ IFN-λ cells were incubated with increasing concentrations of recombinant human or mouse IFN-λ (ng/ml) or human IFN-α, IFN-β or IFN-γ (IU/ml). After 24h incubation, ISG activation was assessed by measuring SEAP levels in the supernatant using Quanti-Blue™. EC50 is indicated for each  cytokine (N/A: non applicable).

Specifications

Antibiotic resistance: Blasticidin, Hygromycin, G418, Puromycin, and Zeocin®.

Growth medium: DMEM medium, 4.5 g/l glucose, 2mM L-glutamine, 10% FBS, 50 U/ml penicillin, 50 μg/ml streptomycin, 100 µg/ml Normocin™, 30 µg/ml blasticidin and 100 µg/ml Zeocin®.

Quality control:
- HEK-Blue™ IFN-λ cells were stimulated by various cytokines. As expected, human and murine IL-28A and IL-28B and human IL-29 induced the production of SEAP. These cells do not respond to type I and type II IFNs (see validation data sheet).
- Biallelic IFNAR2 and IFNGR1 gene knockouts were verified by functional assays, PCR and DNA sequencing.
- 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

• 1 vial containing 3-7 x 10⁶ cells
• 1 ml blasticidin (10 mg/ml)
• 1 ml puromycin (10 mg/ml)
• 1 ml Zeocin® (100 mg/ml)
• 1 ml Normocin™ (50 mg/ml)
• 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 and some areas in Asia)

Details

The IFN-λ family is essential to the antiviral response at epithelial barriers [1,2]. In humans, this family comprises four distinct proteins called IFN-λ1 (interleukin-29, IL-29), IFN-λ2 (IL-28A), IFN-λ3 (IL-28B), and the poorly secreted IFN-λ4. In mice, two functional orthologs (IL-28A and IL-28B) have been described. IFN-λs are produced when a viral infection is sensed by pattern recognition receptors. IFN-λs bind to a heterodimeric receptor formed by the assembly of IFNLR1 and IL10Rβ. This leads to the recruitment of the Janus kinases, JAK1 and TyK2, and phosphorylation of STAT1 and STAT2, which then dimerize and interact with IFN regulatory factor 9 (IRF9), forming the ISGF3 complex. ISGF3 binds to IFN-stimulated response elements (ISRE) in the promoters of IFN-stimulated genes (ISG) to regulate their expression.

1. Lazear HM. et al., 2015. Interferon-λ: Immune Functions at Barrier Surfaces and Beyond. Immunity. 43(1):15-28.
2. Lee S. & Baldridge MT., 2017. Interferon- Lambda: A Potent Regulator of Intestinal Viral Infections. Front Immunol. 8:749. 

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