title: Antibody evolution from the centre to the periphery: applied to a human antibody fragment recognising the tumour-associated antigen mucin-1.
abstract: Mucin-1 has proven to be a suitable target for antibody-based diagnosis and therapy of certain tumours, but no appropriate human antibody or antibody fragment displaying slow dissociation rate kinetics against this target is available. Since a rapid dissociation character prevents an antibody fragment from remaining at the site of the antigen, this fact may prevent the successful application of a human mucin-1 specific antibody in diagnosis and therapy. We have now used iterative antibody libraries to evolve a human antibody fragment originally obtained from a naïve antibody library. A strategy was devised whereby molecular variants displaying slow dissociation kinetics against the repetitive mucin-1 tumour-associated antigen can be selected in vitro. The evolved clones, that allowed for a reduced dissociation from the tumour antigen, carried substitutions in the outer parts of the binding site. This demonstrated the ability of this in vitro evolution technique to mimic the process whereby antibodies evolve in vivo. We have thus devised a strategy through which molecular variants displaying slow dissociation from a repetitive target like the mucin-1 tumour-associated antigen can be obtained in vitro. These or related molecules obtained by this approach will serve as a starting point for the development of fully human antibodies for use in mucin-1 specific tumour therapy of diagnosis.
authors.affiliation: The Wallenberg Laboratory, Department of Immunotechnology, Lund University, P.O. Box 7013, 220-07 Lund, Sweden.
authors.forename: Pernilla
authors.initials: P
authors.lastname: Jirholt
authors.forename: Carl A K
authors.initials: CA
authors.lastname: Borrebaeck
authors.forename: Mats
authors.initials: M
authors.lastname: Ohlin
mesh_terms: D000595:Amino Acid Sequence; D000916:Antibody Diversity; D022801:Complementarity Determining Regions; D019143:Evolution, Molecular; D006801:Humans; D007128:Immunoglobulin Fragments / Q000737:chemistry* / Q000235:genetics*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D018396:Mucin-1 / Q000276:immunology*; D009369:Neoplasms / Q000175:diagnosis / Q000276:immunology / Q000628:therapy; D011487:Protein Conformation
chemical_list: D022801:Complementarity Determining Regions; D007128:Immunoglobulin Fragments; D018396:Mucin-1