title: A rapid bioassay for recombinant interleukin-22.
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.
authors.affiliation: Department of Biochemistry and Molecular Biology, West China School of Preclinical & Forensic Medicine, Sichuan University, Chengdu, P R China.
authors.forename: Fei
authors.initials: F
authors.lastname: Xu
authors.forename: Xiao-Ying
authors.initials: XY
authors.lastname: Li
authors.forename: Jun-Yao
authors.initials: JY
authors.lastname: Zhang
authors.forename: Rui-Qing
authors.initials: RQ
authors.lastname: Xing
authors.forename: Jun-Hong
authors.initials: JH
authors.lastname: Li
authors.forename: Qiang
authors.initials: Q
authors.lastname: Fu
mesh_terms: D001681:Biological Assay / Q000379:methods*; D002460:Cell Line; D006801:Humans; D007378:Interleukins / Q000032:analysis*; D008156:Luciferases / Q000235:genetics; D010957:Plasmids; D011994:Recombinant Proteins / Q000032:analysis; D000097043:Interleukin-22
chemical_list: D007378:Interleukins; D008156:Luciferases; D011994:Recombinant Proteins; D000097043:Interleukin-22