Related Experiment Video
Updated: Jan 4, 2026
In Vitro Methods for Comparing Target Binding and CDC Induction Between Therapeutic Antibodies: Applications in Biosimilarity Analysis
Published on: May 4, 2017
Expression of recombinant human ICOS and in vitro characterization of its bioactivity on B lymphocytes
Zhong-Bin Deng1, Chang-Ming Lu, Wei-Da Huang
1Biotechnology Research Institute, Soochow University, Suzhou 215007, China. smbxuegz@public1.sz.js.cn
Insights
Inducible costimulator (ICOS), a key molecule in immune responses, was cloned and expressed. The recombinant ICOS protein enhanced B cell growth and IgG secretion in the presence of IL-10.
Area of Science:
- Immunology
- Molecular Biology
- Protein Expression
Background:
- Inducible costimulator (ICOS) is a novel costimulatory molecule.
- ICOS is expressed in activated T cells and regulates immune responses.
Purpose of the Study:
- To clone and express the human ICOS cDNA.
- To investigate the function of recombinant human ICOS (rhICOS) in B cell activation and antibody production.
Main Methods:
- Cloning of human ICOS cDNA from activated tonsil cells using RT-PCR.
- Expression of rhICOS in E. coli using the pET28 vector.
- Confirmation of protein expression and molecular weight via SDS-PAGE and Western blot.
- Assessment of rhICOS effects on pokeweed mitogen (PWM)-stimulated B cell growth and IgG secretion in the presence of IL-10.
Main Results:
- Recombinant ICOS protein was successfully expressed in E. coli with a molecular weight of 14 kD.
- Purified rhICOS significantly increased in vitro B cell growth stimulated by PWM.
- rhICOS enhanced IgG secretion from B cells in the presence of IL-10.
Conclusions:
- The study successfully produced functional recombinant human ICOS.
- rhICOS plays a role in augmenting B cell responses, particularly in antibody production, in conjunction with IL-10.
Abstract:
Inducible costimulator (ICOS) is a novel costimulatory molecule expressed in activated T cell and has critical regulation effect on special immune response. In this study, the cDNA encoding human ICOS was cloned from activated tonsil cells via RT-PCR, and was expressed in E. coli on pET28 expression vector. The recombinant ICOS protein expressed from E. coli showed a molecular weight of 14 kD on SDS-polyacrylamide gel electrophoresis and was further confirmed by Western blot. In presence of IL-10, the purified rhICOS significantly increased in vitro B cell growth stimulated by pokeweed mitogen (PWM), and enhanced the secretion of IgG from B cells.
