Abstract: Objective To obtain the short peptides from phage-displayed random peptide library through screening the epitope of monoclonal antibody against tumor necrosis factor(TNF-α). Methods Anti-TNF-α was used to immunoscreen a phage random peptide library of 12 amino-acidresidues displayed as a fusion to protein Ⅲ of filamentous phage M13. The positive clones were obtained by three rounds of biopanning, and the reactivity of each clone binding to anti-TNF-α was examined by double-antibody sandwich ELISA and Dot-ELISA. Mixed positive phage clones were used to detect the serum from SLE patients and healthy persons by Dot-ELISA. Results The eluted phages were enriched nearly 100 fold through three rounds of biopanning, 7 phage clones from the third round biopanning were randomly selected and 5 clones of them could bind to the anti-TNF-α. The binding rate of mixed clones with SLE patients was significantly higher than that of healthy persons. Conclusion The phage display technique can be applied to study the anti-TNF-α antigenic peptides, and these epitopes provide the potential for developing immunodiagnostic reagents of vaccines.

Key words: Tumor necrosis factor, Peptide library, Bacteriophage M13