Recombinant human IL-13 protein - Bioactive cytokine

Human IL-13 protein - Mammalian cell-expressed, tag-free, carrier-free

Recombinant human IL-13 is a high-quality and biologically active cytokine, validated using proprietary IL-4/IL-13 reporter cells. This member of the IL-2/γc superfamily is produced in CHO cells to ensure protein glycosylation and bona fide 3D structure.

Recombinant human IL-13 can be used together with HEK-Blue™ IL-4/IL-13 cells for the screening of inhibitory molecules, such as Dupilumab, a therapeutic monoclonal antibody targeting the IL-4Rα subunit of the IL-13 receptor (see figures).

IL-13 signaling and biological functions

Key features

• Each lot is validated using HEK-Blue™ IL-4/IL-13 cells
• Endotoxin ≤ 0.1 EU/µg
• 0.2 µm sterile-filtered

Applications

• Standard for IL-13 detection and quantification
• Screening and release assays for antibodies blocking IL-13 signaling
• Screening and release assays for engineered IL-13

Interleukin 13 (IL-13) shares a common receptor subunit, IL-4Rα, with IL-4. These two cytokines play an important role in anti-parasitic immune responses. Dysregulated IL-4 /IL-13 expression contributes to Th2-mediated diseases, including asthma and atopic dermatitis.

 More details

All InvivoGen products are for internal research use only and not for human or veterinary use.

Figures

SDS-PAGE analysis of the recombinant human (h)IL-13. 1.5 μg of hIL-13 was loaded on a 12% Mini-PROTEAN® TGX Stain-Free™ Precast Gel (Bio-Rad). Detection was performed as per the manufacturer’s instructions. A band was detected at ~13 kDa.

Dose-response of HEK-Blue™ IL-4/IL-13 cells to recombinant human IL-13. HEK-Blue™ IL-4/IL-13 cells were stimulated with increasing concentrations of recombinant human IL-13. After overnight incubation, the STAT6-induced SEAP activity was determined using QUANTI-Blue™, a SEAP detection reagent. Data are shown as optical density (OD) at 650 nm (mean ± SEM).

Dose-dependent inhibition of IL-13 signaling using Dupilumab biosimilar. HEK-Blue™ IL-4/IL13 cells were incubated with increasing concentrations of Anti-hIL-4R-hIgG4 (S228P) (0.1 ng/ml - 10 µg/ml) for 1 h before the addition of recombinant human IL-13 (1 ng/ml). After overnight incubation, SEAP activity in the cell culture supernatant was assessed using QUANTI-Blue™ Solution. Data are shown in percentage of activity (%) (mean ± SEM).

Specifications

Source: Chinese hamster ovary (CHO) cells

Species: Human

Carrier: Carrier-free

Tag: Tag-free

Accession number: P35225 (with mutation Q144R)

Protein size (predicted): 112 a.a. (G35-N146)

Molecular weight: ~ 13 kDa (SDS-PAGE)

Solubility: 100 μg/ml in water

Formulation: Phosphate buffer saline (pH 7.4), 5% saccharose

Sterility: 0.2 µm filtration

Form:  Lyophilized

Reconstitution buffer:  Endotoxin-free water (provided)

Purity:  ≥98% (SDS-PAGE)

Endotoxin: The absence of bacterial contamination (e.g. lipoproteins and endotoxins) has been confirmed using HEK-Blue™ TLR2 and HEK‑Blue™ TLR4 cells.

Tested applications:  Cellular assays

Quality control: Each lot is functionally tested and validated.

Contents

Recombinant human IL-13 is provided lyophilized and is available in two quantities:

• rcyc-hil13: 10 µg
• rcyc-hil13-5: 5 x 10 µg
• 1.5 ml endotoxin-free water for rcyc-hil13 and rcyc-hil13-5

 Recombinant hIL-13 is shipped at room temperature.

 Upon receipt, the product should be stored at -20°C.

 Avoid repeated freeze-thaw cycles.

Details

IL-13 background

IL-13 is a cytokine that belongs to the IL-2/γc superfamily. IL-13 is produced as a secreted monomeric molecule by activated CD4+ T cells, Natural Killer T cells (NKT cells), group 2 innate lymphoid cells (ILC2s), macrophages, mast cells, basophils, or eosinophils [1].

IL-13 binds a heterodimeric receptor composed of the IL-4Rα and IL-13Rα1 chains. This receptor is shared with IL-4, which can bind two different receptors: Type I (IL-4Rα and common γ chain) and Type II (IL-4Rα and IL-13Rα1). The binding of IL-13 to its receptor triggers a signaling cascade leading to the activation of STAT6. Subsequent gene expression drives M2 macrophage polarization, B-cell proliferation, IgE immunoglobulin class switching, and eosinophil activation and survival [1]. In non-hematopoietic cells, IL-13 is essential for mucus production, goblet cell hyperplasia, and worm expulsion [1]. Altogether, the downstream IL-13 effector functions participate in parasitic infection clearance and allergic reactions [1].

Relevance for therapeutics development

IL-13  is a key cytokine for controlling infections by extracellular parasites. However, along with IL-4, it also contributes to harmful allergic responses [1, 2]. As the prevalence of chronic allergic diseases such as asthma and atopic dermatitis is increasing worldwide, there has been a keen interest in the therapeutic blocking of IL-4 and IL-13 signaling.

Dupilumab is a fully human monoclonal antibody (mAb) that targets the IL-4Rα subunit [3]. It acts like a receptor antagonist and inhibits the signaling of both IL-4 and IL-13 [3]. Dupilimab was FDA-approved in 2017 for treating asthma, atopic dermatitis, and chronic sinusitis [3, 4]. Due to its favorable safety profile and established clinical use, Dupilumab holds significant promise for amending treatment options for many dermatologic conditions [5].

Tralokinumab and Lebrikizumab are fully human mAbs that target IL-13, inhibiting its receptor binding ability. Tralokinumab and Lebrikizumab were FDA-approved in 2021 and 2024, respectively, for treating moderate-to-severe atopic dermatitis [6, 7]

References:

1. Bernstein, Z.J., et al., 2023. Engineering the IL-4/IL-13 axis for targeted immune modulation. Immunol Rev. 320(1):29-57. 
2. Ogulur, I., et al., 2025. Type 2 immunity in allergic diseases. Cell & Mol Immunol, 22(3):211-242.
3. Harb, H. & Chatila, T.A., 2020. Mechanisms of Dupilumab. Clin Exp Allergy. 50(1):5-14.
4. https://www.accessdata.fda.gov/drugsatfda_docs/label/2022/761055s040lbl.pdf
5. Olbrich, H., et al., 2023. Dupilumab in Inflammatory Skin Diseases: A Systematic Review. Biomolecules.13(4):634.
6. https://www.accessdata.fda.gov/drugsatfda_docs/nda/2022/761180Orig1s000lbl.pdf
7. https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/761306Orig1s000correctedlbl.pdf