Structural guided scaffold phage display libraries as a source of bio-therapeutics.
We have developed a structurally-guided scaffold phage display strategy for identification of ligand mimetic bio-therapeutics. As a proof of concept we used the ligand of integrin αvβ6, a tumour cell surface receptor and a major new target for imaging and therapy of many types of solid cancer. NMR structure analysis showed that RGD-helix structures are optimal for αvβ6 ligand-interaction, so we designed novel algorithms to generate human single chain fragment variable (scFv) libraries with synthetic VH-CDR3 encoding RGD-helix hairpins with helices of differing pitch, length and amino acid composition. Study of the lead scFv clones D25scFv and D34scFv and their corresponding VH-CDR3 derived peptides, D25p and D34p, demonstrated: specific binding to recombinant and cellular αvβ6; inhibition of αvβ6-dependent cell and ligand adhesion, αvβ6-dependent cell internalisation; and selective retention by αvβ6-expressing, but not αvβ6-negative, human xenografts. NMR analysis established that both the D25p and D34p retained RGD-helix structures confirming the success of the algorithm. In conclusion, scFv libraries can be engineered based on ligand structural motifs to increase the likelihood of developing powerful bio-therapeutics.
Centre for Tumour Biology, Barts Cancer Institute, Queen Mary's University of London, London, United Kingdom.
Y K Stella
YK
Man
Danielle
D
DiCara
Nicole
N
Chan
Sandrine
S
Vessillier
Stephen J
SJ
Mather
Michelle L
ML
Rowe
Mark J
MJ
Howard
John F
JF
Marshall
Ahuva
A
Nissim
D000465:Algorithms; D000595:Amino Acid Sequence; D000818:Animals; D000951:Antigens, Neoplasm / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites; D005260:Female; D006801:Humans; D016023:Integrins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D008819:Mice, Nude; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D019151:Peptide Library; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D057127:Single-Chain Antibodies / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D040681:Structural Homology, Protein; D047368:Tumor Burden / Q000187:drug effects; D023041:Xenograft Model Antitumor Assays
D000951:Antigens, Neoplasm; D016023:Integrins; D008024:Ligands; D009842:Oligopeptides; D019151:Peptide Library; D057127:Single-Chain Antibodies; C073878:integrin alphavbeta6; C047981:arginyl-glycyl-aspartic acid