Rational design of an EGF-IL18 fusion protein: Implication for developing tumor therapeutics

• Published in: Biochemical and biophysical research communications 2005-08, Vol.334 (1), p.157-161
• Main Authors: Lu, Jian-Xin, Peng, Ying, Meng, Zhe-Feng, Jin, Li-Qin, Lu, Yong-Sui, Guan, Min-Xin
• Format: Article
• Language: English
• Subjects: Animals; Anti-tumor; Baculovirus expression system; Carcinoma, Squamous Cell - genetics; Carcinoma, Squamous Cell - metabolism; Carcinoma, Squamous Cell - therapy; Cell Line; Cytokine; Drug Delivery Systems - methods; Drug Design; EGF-IL18 fusion protein; EGFR binding domain; Epidermal Growth Factor - genetics; Epidermal Growth Factor - metabolism; Epidermal Growth Factor - therapeutic use; Expression; Fusion proteins; Gene Targeting - methods; Humans; IL-18; Interleukin-18 - genetics; Interleukin-18 - metabolism; Interleukin-18 - therapeutic use; Protein Engineering - methods; Receptor, Epidermal Growth Factor - metabolism; Recombinant Fusion Proteins - metabolism; Spodoptera - genetics; Spodoptera - metabolism; Targeting; Targeting tumor cells; Transfection - methods; Tumor therapeutics
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2005.06.076

Interleukin-18 (IL-18) is a proinflammatory cytokine. This protein has a role in regulating immune responses and exhibits significant anti-tumor activities. Epidermal growth factor (EGF) is an important growth factor that plays a central role in the regulation of cell cycle and differentiation. It was proposed that a targeted delivery of IL-18 by generation of IL-18-EGF fusion protein might decrease adverse effects and result in enhancing cytotoxic and antitumor activities. In the present study, a fusion protein, consisting of EGFR binding domain fused to human IL-18 mature peptide via a linker peptide of (Gly 4Ser) 3, was constructed and expressed in the insect cell line Sf9 using Bac-to-Bac baculovirus expression system. We showed that the purified recombinant fusion protein induced similar levels of IFN-γ to that of native IL-18 protein in human PBMC in the presence of ConA. Furthermore, EGF receptor competitive test in human epithelial cancer A431 cell line showed that EGF-IL18 fusion protein can specifically bind with EGFR by competing with native EGF protein. These suggest that this rationally designed protein can be further developed as novel tumor therapeutics.