| Abstract
Purpose: EGFRvIII as the most common mutant variant of the epidermal growth factor
receptor is resulting from deletion of exons 2–7 in the coding sequence and junction of
exons 1 and 8 through a novel glycine residue. EGFRvIII is highly expressed in
glioblastoma, carcinoma of the breast, ovary, and lung but not in normal cells. The aim of
the present study was identification of a novel single chain antibody against EGFRvIII as a
promising target for cancer therapy.
Methods: In this study, a synthetic peptide corresponding to EGFRvIII protein was used for
screening a naive human scFv phage library. A novel five-round selection strategy was used
for enrichment of rare specific clones.
Results: After five rounds of screening, six positive scFv clones against EGFRvIII were
selected using monoclonal phage ELISA, among them, only three clones had expected size
in PCR reaction. The specific interaction of two of the scFv clones with EGFRvIII was
confirmed by indirect ELISA. One phage clone with higher affinity in scFv ELISA was
purified for further analysis. The purity of the produced scFv antibody was confirmed using
SDS-PAGE and Western blotting analyses.
Conclusion: In the present study, a human anti- EGFRvIII scFv with high affinity was first
identified from a scFv phage library. This study can be the groundwork for developing more
effective diagnostic and therapeutic agents against EGFRvIII expressing cancers |