G-CSF Reporter HEK 293 Cells

HEK-Blue™ G-CSF cells signaling pathway

Granulocyte Colony-Stimulating Factor Reporter Cells

HEK-Blue™ G-CSF cells were engineered from the human embryonic kidney HEK 293 cell line to detect bioactive granulocyte colony-stimulating factor (G-CSF) by monitoring the activation of the JAK/STAT3 pathway. G-CSF is a secreted cytokine and hematopoietic growth factor. It regulates the differentiation, proliferation, and function of neutrophils [1].

 More details

Cell line description

HEK-Blue™ G-CSF cells were generated by stable overexpression of the genes encoding for the human CSF receptor (CSFR, aka CD114), human STAT3c, and a STAT3-inducible secreted embryonic alkaline phosphatase (SEAP) reporter. STAT3-dependent SEAP activity is readily assessable in the supernatant using QUANTI-Blue™ Solution, a detection reagent. HEK-Blue™ G-CSF cells detect human and murine G-CSF (see figures). Of note, these cells also respond, to a weaker extent, to two other human STAT3-signaling cytokines, IL-6 and IL-27, as they endogenously express the gp130 co-receptor shared by these cytokine receptors. However, they do not respond to human type I IFNs (IFN-α/IFN-β) (see figures).

Features of HEK-Blue™ G-CSF cells

• Fully functional G-CSF signaling pathway
• Readily assessable STAT3-inducible SEAP reporter activity

Applications of HEK-Blue™ G-CSF cells

• Detection of human and murine G-CSF (300 pg/ml - 100 ng/ml)
• Screening of anti-G-CSF and anti-GCSFR antibodies

Reference:

1. Martin KR, et al., 2021. G-CSF — A double-edged sword in neutrophil-mediated immunity. Sem. Immunol. 54:101516.

Figures

Validation of the expression of human GCSFR by HEK-Blue™ G-CSF cells. 5 x 10⁵ cells were incubated with either a PE-conjugated isotype control (blue) or a PE-conjugated Anti-GCSFR mAb (red) for 30 minutes. The binding affinity was then measured using flow cytometry.

Dose-response of HEK-Blue™ G-CSF cells to recombinant G-CSF. Cells were stimulated with increasing concentrations of recombinant human G-CSF (hG-CSF) and murine G-CSF (mG-CSF). After overnight incubation, the STAT3 response was determined using QUANTI‑Blue™ Solution, a SEAP detection reagent. The optical density (OD) at 630 nm is shown as mean ± SEM.

Dose-dependent inhibition of HEK‑Blue™ G-CSF cellular response using a neutralizing antibody against human G-CSF. An increasing concentration of a neutralizing anti-hG-CSF antibody was incubated with recombinant human G-CSF (0.1 ng/ml) for 2 hours before the addition of HEK-Blue™ G-CSF cells. After overnight incubation, SEAP activity in the cell culture supernatant was assessed using QUANTI-Blue™. Data are shown as a percentage (%) of activity.

Response of HEK-Blue™G-CSF cells to a panel of cytokines. Cells were stimulated with various human and murine recombinant cytokines: 10 ng/ml of hG-CSF, mG-CSF, hGM-CSF, mGM-CSF, hIL-6, hIL-27, hIFN-γ, and 1000 U/ml hIFN-α. After overnight incubation, SEAP activity was assessed using QUANTI‑Blue™. The OD at 630 nm is shown as mean ± SEM.

Specifications

Antibiotic resistance: Blasticidin, Hygromycin, and  Zeocin®

Growth medium: DMEM, 4.5 g/l glucose, 2-4 mM L-glutamine, 10% (v/v) fetal bovine serum, 100 U/ml penicillin, 100 μg/ml streptomycin, 100 μg/ml Normocin™

Specificity: human and murine G-CSF

Detection range: 300 pg/ml - 100 ng/ml

Quality Control:

• STAT3-dependent SEAP reporter activity in response to human and murine G-CSF is validated.
• The expression of human GCSFR is confirmed by flow cytometry.
• The stability for 20 passages, following thawing, is 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 HEK-Blue™ G-CSF cells
• 1 ml Normocin™ (50 mg/ml)
• 2 x 1 ml of HEK-Blue Selection (250X)
• 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)

Details

The granulocyte colony-stimulating factor (G-CSF) is a secreted cytokine and hematopoietic growth factor that belongs to the Type I/II cytokine receptor family. G-CSF regulates the differentiation, proliferation, and function of neutrophils [1]. It exerts its biological functions through the formation of a tetramer consisting of two G-CSF molecules and the homodimeric G-CSF receptor (GCSFR, aka CD114). The binding of G-CSF to its receptor triggers activation of the JAK/STAT signaling pathway [1,2]. STAT1, STAT3, and STAT5 are involved in this activation step and the induction of cellular proliferation [1,2]. Studies in humans and mice indicate that while G-CSF contributes to host defense against pathogens, it can also have detrimental effects by promoting inflammatory diseases and cancer [1,2].

​References:

1. Martin KR., et al., 2021. G-CSF — A double-edged sword in neutrophil-mediated immunity. Sem Immunol. 54:101516.
2. Park, DS., et al., 2022. A review of granulocyte colony-stimulating factor receptor signaling and regulation with implications for cancer. Front Oncol. DOI: 10.3389/fonc.2022.932608.