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Updated: Jun 13, 2026
Visualization of IL-22-expressing Lymphocytes Using Reporter Mice
Published on: January 25, 2017
A rapid bioassay for recombinant interleukin-22
Fei Xu1, Xiao-Ying Li, Jun-Yao Zhang
1Department of Biochemistry and Molecular Biology, West China School of Preclinical & Forensic Medicine, Sichuan University, Chengdu, P R China.
Insights
Researchers developed a new bioassay to measure the activity of Interleukin-22 (IL-22), a cytokine involved in immune responses. This rapid assay uses a modified human liver cell line to quantify IL-22 bioactivity efficiently.
Area of Science:
- Immunology
- Cell Biology
- Biotechnology
Background:
- Interleukin-22 (IL-22) is a cytokine primarily produced by activated T cells.
- The in vivo biological functions of IL-22 remain largely uncharacterized.
- Understanding IL-22's role requires reliable methods to assess its bioactivity.
Purpose of the Study:
- To develop a rapid, simple, and reproducible in vitro cell-based bioassay for measuring recombinant Interleukin-22 (IL-22) bioactivity.
- To facilitate the study of IL-22's primary biological functions.
- To establish a quantitative method for IL-22 assessment.
Main Methods:
- Development of a stable human hepatocyte (HepG2) cell line transfected with a STAT3-responsive luciferase reporter plasmid (pSTAT3-Luc).
- Stimulation of the engineered cell line with recombinant human IL-22 (rhIL-22) to measure dose-dependent luciferase activity.
- Validation of the assay using anti-IL-22 monoclonal antibodies (mAbs) to confirm specificity.
Main Results:
- A stable HepG2-derived clone demonstrated a strong, dose-dependent response to rhIL-22 stimulation.
- The assay yielded an ED50 value of 17.0 +/- 1.4 ng/mL for rhIL-22.
- Neutralization with anti-IL-22 mAb completely abolished the observed bioactivity, confirming assay specificity.
- The entire assay procedure can be completed within a single day.
Conclusions:
- A novel, rapid, and reproducible in vitro bioassay for quantifying IL-22 bioactivity has been established.
- This assay provides a valuable tool for studying IL-22's biological functions and for quality control of recombinant IL-22 preparations.
- The developed method enables efficient assessment of IL-22's biological activity in vitro.
Abstract:
Interleukin-22 is a novel cytokine produced mainly in activated T cells. The elaborate biological functions of IL-22 in vivo are still widely unknown. In this report, we describe a rapid, simple, and reproducible in vitro cell-based bioassay for measuring the bioactivity of recombinant interleukin-22 (IL-22) to study the primary function of IL-22 in vivo. Human hepatocyte cell line (HepG2) was transfected with pSTAT3-Luc, a plasmid carrying the luciferase gene under the control of STAT3. After screening and selection, one stable clone was established which generates a strong response to recombinant human IL-22 (rhIL-22) stimulation in a dose-dependent manner. The cell showed ED50 of 17.0 +/- 1.4 ng/mL (n = 15) to recombinant human IL-22. Pre-incubation of anti-IL-22 mAb with IL-22 recombinant proteins completely blocked the bioactivities. The assay can be completed within one day. The current assay provides a rapid analytical method to measure the biological activity of IL-22 in vitro.
