IBT/014 Phage display - An advanced technique for antibody library production

Phage display is the linkage of phenotype to genotype. It involves use of filamentous phages like M13, f1, ft, fd and allows the presentation of large peptide and protein libraries on the surface of filamentous phage. It leads to the selection of peptides and proteins, including antibodies, with high affinity and specificity to almost any target. For production of proteins the protein encoding genes are fused with phage coat protein encoding genes. Most commonly used coat protein genes are 3 and 8. According to coat protein genes, phage display systems are classified as – 3, 33, 3+3, 8, 88, 8+8. Major steps in phage display include; splicing an exogenous gene of interest, transduction, selection (Biopanning) and peptide sequencing. Phage display can be effectively used for production of Abs and other therapeutic agents. It has already been used to derive an antibody-based prophylactic measure for preventing HIV-l infections. The concept is further narrowed for single domain antibody i.e. Nanobody production which involves use of phage display by cloning VHH region of Abs in phage coat protein encoding genes. Nanobodies are being researched for multiple pharmaceutical applications and have potential for use in cancer and Alzheimer's disease treatments