PLoS ONE (Jan 2021)

A hybridoma-derived monoclonal antibody with high homology to the aberrant myeloma light chain.

  • Ghasidit Pornnoppadol,
  • Boya Zhang,
  • Alec A Desai,
  • Anthony Berardi,
  • Henriette A Remmer,
  • Peter M Tessier,
  • Colin F Greineder

DOI
https://doi.org/10.1371/journal.pone.0252558
Journal volume & issue
Vol. 16, no. 10
p. e0252558

Abstract

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The identification of antibody variable regions in the heavy (VH) and light (VL) chains from hybridomas is necessary for the production of recombinant, sequence-defined monoclonal antibodies (mAbs) and antibody derivatives. This process has received renewed attention in light of recent reports of hybridomas having unintended specificities due to the production of non-antigen specific heavy and/or light chains for the intended antigen. Here we report a surprising finding and potential pitfall in variable domain sequencing of an anti-human CD63 hybridoma. We amplified multiple VL genes from the hybridoma cDNA, including the well-known aberrant Sp2/0 myeloma VK and a unique, full-length VL. After finding that the unique VL failed to yield a functional antibody, we discovered an additional full-length sequence with surprising similarity (~95% sequence identify) to the non-translated myeloma kappa chain but with a correction of its key frameshift mutation. Expression of the recombinant mAb confirmed that this highly homologous sequence is the antigen-specific light chain. Our results highlight the complexity of PCR-based cloning of antibody genes and strategies useful for identification of correct sequences.