Journal Article

SUMO-fusion and autoinduction-based combinatorial approach for enhanced production of bioactive human interleukin-24 in Escherichia coli

2020

Overview

High-level production of recombinant human interleukin-24 (IL-24), a multifunctional immunomodulatory cytokine, has been challenging due primarily to its aggregation as inclusion bodies in the bacterial host while persistent poor-expression in the insect/mammalian expression systems. The present study presents a robust, vector-host combination (pE-SUMO-IL24), auto-inducible medium (YNG/M9NG), and a simple purification scheme for soluble, bioactive, and cost-effective production of native-like IL-24 (nIL-24) in Escherichia coli. The final protein yield, following a three-step purification scheme (IMAC, SEC, dialysis), was 98 mg/L in shake-flask culture (with scale-up potential), which was several folds higher than reported earlier. In vitro cytotoxicity assays with HeLa and HCT116 cancer cell lines (performed using different concentrations of nIL-24) and the fluorescence activated cell sorting analysis (FACS) revealed a dose- and concentration-dependent increase in the population of pro-apoptotic cells with concomitant, statistically significant drop in the number of cells existent at Go/G1-, S-, and G2/M-phases (P < 0.002). The bioactive nIL-24, developed through this study, holds promise for use in further functional characterizations/applications.Key points• Yeast SUMO fusion partner at N-terminus for improved solubility of an otherwise insoluble IL-24 in E. coli.• Enhanced cell densities with concomitant several-fold increase in protein yield by lactose-inducible media.• Improved inhibition of cervical and colorectal carcinomas by native-like nIL-24 compared with Met-containing IL.• Heterologous nIL-24 may enable better understanding of the functional intricacies linked up with its unique cancer-specific features.

• Publisher: Springer Nature B.V
• Subject: Apoptosis / Biocompatibility / Biological activity / Cancer / Cell culture / Cervical carcinoma / Cervix / Colorectal cancer / Colorectal carcinoma / Combinatorial analysis / Cytokines / Cytotoxicity / Dialysis / E coli / Escherichia coli / Flow cytometry / Fluorescence / Immunomodulation / Immunomodulators / Inclusion bodies / Insects / Interleukin 24 / Lactose / N-Terminus / Protein folding / Protein purification / Proteins / Purification / Statistical analysis / Toxicity / Tumor cell lines / Yeast