Isolation of monoclonal antibodies with predetermined conformational epitope specificity

PLoS One. 2012;7(6):e38943. doi: 10.1371/journal.pone.0038943. Epub 2012 Jun 21.

Abstract

Existing technologies allow isolating antigen-specific monoclonal antibodies (mAbs) from B cells. We devised a direct approach to isolate mAbs with predetermined conformational epitope specificity, using epitope mimetics (mimotopes) that reflect the three-dimensional structure of given antigen subdomains. We performed differential biopanning using bacteriophages encoding random peptide libraries and polyclonal antibodies (Abs) that had been affinity-purified with either native or denatured antigen. This strategy yielded conformational mimotopes. We then generated mimotope-fluorescent protein fusions, which were used as baits to isolate single memory B cells from rhesus monkeys (RMs). To amplify RM immunoglobulin variable regions, we developed RM-specific PCR primers and generated chimeric simian-human mAbs with predicted epitope specificity. We established proof-of-concept of our strategy by isolating mAbs targeting the conformational V3 loop crown of HIV Env; the new mAbs cross-neutralized viruses of different clades. The novel technology allows isolating mAbs from RMs or other hosts given experimental immunogens or infectious agents.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Antibodies, Monoclonal / chemistry
  • Antibodies, Monoclonal / isolation & purification*
  • Autoantigens / chemistry
  • B-Lymphocytes / immunology
  • Bacteriophages / metabolism
  • Cell Line, Tumor
  • Cell Separation
  • Epitope Mapping / methods
  • Epitopes / chemistry*
  • Flow Cytometry
  • HIV / metabolism
  • Humans
  • Immunologic Techniques / methods
  • Leukocytes, Mononuclear / virology
  • Peptide Library
  • Peptides / chemistry
  • Polymerase Chain Reaction / methods
  • Simian Acquired Immunodeficiency Syndrome / virology
  • Simian Immunodeficiency Virus / genetics
  • env Gene Products, Human Immunodeficiency Virus / chemistry

Substances

  • Antibodies, Monoclonal
  • Autoantigens
  • Epitopes
  • Peptide Library
  • Peptides
  • env Gene Products, Human Immunodeficiency Virus