Expression, purification, and functional characterization of recombinant human interleukin-7

Area of Science:

• Biotechnology
• Immunology
• Protein Expression

Background:

• Human interleukin-7 (IL-7) is crucial for immune cell development and has therapeutic potential.
• Previous prokaryotic expression systems for IL-7 faced limitations due to low recovery rates from refolding steps.
• A need exists for efficient and scalable production methods for bioactive recombinant human IL-7 (rhIL-7).

Purpose of the Study:

• To develop a eukaryotic expression system for producing high-yield, bioactive rhIL-7.
• To establish a simplified purification strategy for rhIL-7.
• To assess the feasibility of yeast-based production for clinical and research applications.

Main Methods:

• Cloning of human IL-7 cDNA and expression in the Pichia pastoris yeast system.
• Development of a straightforward purification protocol from fermentation supernatant.
• Purification using SP Sepharose FF cation-exchange chromatography.
• Functional assessment via pre-B cell proliferation assay (MTT).

Main Results:

• Successful expression of active rhIL-7 in Pichia pastoris.
• Achieved a yield of 35 mg/L with 95% purity using cation-exchange chromatography.
• Purified rhIL-7 exhibited specific activity comparable to commercial standards.
• Demonstrated the efficacy of the yeast expression and purification strategy.

Conclusions:

• Yeast expression in Pichia pastoris is an effective strategy for producing bioactive rhIL-7.
• The developed purification method is simple and yields high-purity protein.
• This approach supports large-scale rhIL-7 production for clinical applications and fundamental research.