Construction of a Bacteriophage-Derived Vector with Potential applications in Targeted Drug Delivery and Cell Imaging

Abstract

Abstract There is a strong relation between dysregulation of epidermal growth factor receptor (EGFR) and the development of epithelial-derived cancers. Therefore, EGFR has usually been considered the desired target for gene therapy. Here, we propose an approach for targeting EGFR expressing cells by phage particles capable of displaying EGF and GFP as the tumor-targeting and reporting elements, respectively. For this, the superfolder GFP-EGF (sfGFP-EGF) coding sequence was inserted at the N-terminus of the pIII gene in pIT2 phagemid. The capability of constructed phage to recognize EGFR overexpressing cells was monitored by fluorescence microscopy, fluorescence-activated cell sorting (FACS), and cell-based ELISA experiments. The FACS analysis showed a significant shift in the mean fluorescence intensity (MFI) of the cells treated with phage displaying sfGFP-EGF compared to phage displaying only sfGFP. The binding of phage displaying sfGFP-EGF to A-431 cells, monitored by fluorescence microscopy, indicated formation of sfGFP-EGF-EGFR complex on the surface of the treated cells. Cell-based ELISA experiments showed that the phages displaying either EGF or sfGFP-EGF can specifically bind EGFR expressing cells. The vector constructed in the current study has the potential to be engineered for gene delivery purposes as well as cell-based imaging for tumor detection.