PLoS ONE (Jan 2013)

Generation and characterization of a diabody targeting the αvβ6 integrin.

  • Heide Kogelberg,
  • Enrique Miranda,
  • Jerome Burnet,
  • David Ellison,
  • Berend Tolner,
  • Julie Foster,
  • Carmen Picón,
  • Gareth J Thomas,
  • Tim Meyer,
  • John F Marshall,
  • Stephen J Mather,
  • Kerry Chester

DOI
https://doi.org/10.1371/journal.pone.0073260
Journal volume & issue
Vol. 8, no. 9
p. e73260

Abstract

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The αvβ6 integrin is up-regulated in cancer and wound healing but it is not generally expressed in healthy adult tissue. There is increasing evidence that it has a role in cancer progression and will be a useful target for antibody-directed cancer therapies. We report a novel recombinant diabody antibody fragment that targets specifically αvβ6 and blocks its function. The diabody was engineered with a C-terminal hexahistidine tag (His tag), expressed in Pichia pastoris and purified by IMAC. Surface plasmon resonance (SPR) analysis of the purified diabody showed affinity in the nanomolar range. Pre-treatment of αvβ6-expressing cells with the diabody resulted in a reduction of cell migration and adhesion to LAP, demonstrating biological function-blocking activity. After radio-labeling, using the His-tag for site-specific attachment of (99m)Tc, the diabody retained affinity and targeted specifically to αvβ6-expressing tumors in mice bearing isogenic αvβ6 +/- xenografts. Furthermore, the diabody was specifically internalized into αvβ6-expressing cells, indicating warhead targeting potential. Our results indicate that the new αvβ6 diabody has a range of potential applications in imaging, function blocking or targeted delivery/internalization of therapeutic agents.