A Combinatory Antibody-Antigen Microarray Assay for High-Content Screening of Single-Chain Fragment Variable Clones from Recombinant Libraries

PLoS One. 2016 Dec 21;11(12):e0168761. doi: 10.1371/journal.pone.0168761. eCollection 2016.

Abstract

We have developed a combinatory antibody-antigen microarray for direct screening of multiple single-chain fragment variable (scFv) clones with no need for pre-purification or enrichment before screening. The straightforward workflow allows for early selection of binders to predefined peptide and glycopeptide targets. A capture antibody is contact printed on microarray slides, side by side with the antigens of interest. A large number of scFv clones, in supernatants, are printed on top of the capture antibody and the antigen in a "spot-on-spot" print. The printed scFv clones, which bind to the capture antibody, are detected using biotinylated antigen, while the binding of scFv clones to the printed antigen is detected through a mouse anti-tag antibody. Two different analyses are thus performed on the same slide, generating two kinds of information: one on the ability of an individual scFv clone to bind to the soluble form of the antigen, which may favour selection for higher affinity rather than avidity, while the other allows the identification of large numbers of clones, simultaneously, due to the binding of scFv clones to densely presented antigens, thus providing an overall increased hit rate. The functionality of the new screening approach was illustrated through the generation of antibodies against peptides from the chaperone complex Ku70/Ku80 and the GalNAcα-serine/threonine epitope on the IgA1 alpha chain hinge region. In total, 659 scFv clones were screened with a hit rate of approximately 20%. This approach allowed the identification of functional antibodies in both cases, illustrating the usefulness and capacity of this combinatory microarray screening technique for efficient analysis and validation of antibodies at an early stage of antibody generation.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antigen-Antibody Reactions
  • Enzyme-Linked Immunosorbent Assay
  • Mice
  • Mice, Inbred BALB C
  • Microscopy, Fluorescence
  • Molecular Sequence Data
  • Peptide Library*
  • Peptides / chemical synthesis
  • Peptides / chemistry
  • Peptides / immunology
  • Protein Array Analysis*
  • Single-Chain Antibodies / analysis*
  • Single-Chain Antibodies / immunology
  • Single-Chain Antibodies / isolation & purification

Substances

  • Peptide Library
  • Peptides
  • Single-Chain Antibodies

Grants and funding

This work was supported by European Union, Seventh Framework Programme, GastricGlycoExplorer (GGE) initial training network: grant number 316929, OB; The Danish Research Council: DFF-4005-00285, OB, BJ, LD, CW; Innovationsfonden in the framework of the EU-ERASynBio project SynGlycTis, OB; and Mrs. Berta Kamprad’s Foundation, CW and BJ.