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S C Williams

Bio: S C Williams is an academic researcher. The author has contributed to research in topics: Phage display & Synthetic antibody. The author has an hindex of 1, co-authored 1 publications receiving 1277 citations.

Papers
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Journal ArticleDOI
TL;DR: This work created highly diverse repertoires of heavy and light chains entirely in vitro from a bank of human V gene segments and generated a large synthetic repertoire of Fab fragments displayed on filamentous phage to help dissect the contributions of biological mechanisms and structural features governing V gene usage in vivo.
Abstract: Antibody fragments of moderate affinity (approximately microM) can be isolated from repertoires of approximately 10(8) immunoglobulin genes by phage display and rounds of selection with antigen, and the affinities improved by further rounds of mutation and selection. Here, as an alternative strategy, we attempted to isolate high affinity human antibodies directly from large repertoires. We first created highly diverse repertoires of heavy and light chains entirely in vitro from a bank of human V gene segments and then, by recombination of the repertoires in bacteria, generated a large (close to 6.5 x 10(10)) synthetic repertoire of Fab fragments displayed on filamentous phage. From this repertoire we isolated Fab fragments which bound to a range of different antigens and haptens, and with affinities comparable with those of antibodies from a secondary immune response in mice (up to 4 nM). Although the VH-26 (DP-47) segment was the most commonly used segment in both artificial and natural repertoires, there were also major differences in the pattern of segment usage. Such comparisons may help dissect the contributions of biological mechanisms and structural features governing V gene usage in vivo.

1,286 citations


Cited by
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Patent
29 Apr 1996
TL;DR: In this paper, a transgenic animal has been modified to produce antibodies in response to antigenic challenge, but whose endogenous loci have been disabled, and various subsequent manipulations can be performed to obtain either antibodies per se or analogs thereof.
Abstract: Fully human antibodies against a specific antigen can be prepared by administering the antigen to a transgenic animal which has been modified to produce such antibodies in response to antigenic challenge, but whose endogenous loci have been disabled. Various subsequent manipulations can be performed to obtain either antibodies per se or analogs thereof.

2,667 citations

Journal ArticleDOI
TL;DR: C-terminal fusion to the Aga2p mating adhesion receptor of Saccharomyces cerevisiae has been used for the selection of scFv antibody fragments with threefold decreased antigen dissociation rate from a randomly mutated library.
Abstract: Display on the yeast cell wall is well suited for engineering mammalian cell-surface and secreted proteins (e.g., antibodies, receptors, cytokines) that require endoplasmic reticulum-specific post-translational processing for efficient folding and activity. C-terminal fusion to the Aga2p mating adhesion receptor of Saccharomyces cerevisiae has been used for the selection of scFv antibody fragments with threefold decreased antigen dissociation rate from a randomly mutated library. A eukaryotic host should alleviate expression biases present in bacterially propagated combinatorial libraries. Quantitative flow cytometric analysis enables fine discrimination of kinetic parameters for protein binding to soluble ligands.

1,880 citations

Journal ArticleDOI
TL;DR: This work shows that conventional hybridoma technology may be superseded by large phage libraries that are proving to be a stable and reliable source of specific, high affinity human monoclonal antibodies.
Abstract: To generate a stable resource from which high affinity human antibodies to any given antigen can be rapidly isolated, functional V-gene segments from 43 non-immunized human donors were used to construct a repertoire of 1.4 x 10(10) single-chain Fv (scFv) fragments displayed on the surface of phage. Fragments were cloned in a phagemid vector, enabling both phage displayed and soluble scFv to be produced without subcloning. A hexahistidine tag has been incorporated to allow rapid purification of scFv by nickel chelate chromatography. This library format reduces the time needed to isolate monoclonal antibody fragments to under two weeks. All of the measured binding affinities show a Kd < 10 nM and off-rates of 10(-3) to 10(-4) s-1, properties usually associated with antibodies from a secondary immune response. The best of these scFvs, an anti-fluorescein antibody (0.3 nM) and an antibody directed against the hapten DTPA (0.8 nM), are the first antibodies with subnanomolar binding affinities to be isolated from a naive library. Antibodies to doxorubicin, which is both immunosuppressive and toxic, as well as a high affinity and high specificity antibody to the steroid hormone oestradiol have been isolated. This work shows that conventional hybridoma technology may be superseded by large phage libraries that are proving to be a stable and reliable source of specific, high affinity human monoclonal antibodies.

1,409 citations

Journal ArticleDOI
TL;DR: The small number of 49 master genes will allow future improvements to be incorporated quickly, and the separation of the frameworks may help in analyzing why nature has evolved these distinct subfamilies of antibody germline genes.

1,122 citations

Journal ArticleDOI
TL;DR: Domain Antibels (dAbs) as discussed by the authors are the smallest known antigen-binding fragments of antibodies, ranging from 11 kDa to 15 kDa, and they are the robust variable regions of the heavy and light chains of immunoglobulins (VH and VL respectively).

1,078 citations