Llama single-domain antibodies directed against nonconventional epitopes of tumor-associated carcinoembryonic antigen absent from nonspecific cross-reacting antigen

Authors

  • Ghislaine Behar,

    1.  CNRS, Laboratoire d’Ingénierie des Systèmes Macromoléculaires, Marseille, France
    2.  CNRS, Groupement de Recherche Immunociblage des Tumeurs, Marseille, France
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    • Present addresses
      UMR6204, CNRS, Université de Nantes, France

  • Patrick Chames,

    1.  CNRS, Laboratoire d’Ingénierie des Systèmes Macromoléculaires, Marseille, France
    2.  CNRS, Groupement de Recherche Immunociblage des Tumeurs, Marseille, France
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    • INSERM, U624, Stress Cellulaire, Marseille, France

  • Isabelle Teulon,

    1.  CNRS, Groupement de Recherche Immunociblage des Tumeurs, Marseille, France
    2.  INSERM, Centre de Recherche en cancérologie de Montpellier, Université Montpellier, France
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  • Amélie Cornillon,

    1.  CNRS, Laboratoire d’Ingénierie des Systèmes Macromoléculaires, Marseille, France
    2.  CNRS, Groupement de Recherche Immunociblage des Tumeurs, Marseille, France
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  • Faisal Alshoukr,

    1.  CNRS, Groupement de Recherche Immunociblage des Tumeurs, Marseille, France
    2.  INSERM, Centre de Recherche Biomédicale Bichat-Beaujon, Paris, France
    3.  Université Denis Diderot-Paris 7, France
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  • Françoise Roquet,

    1.  CNRS, Groupement de Recherche Immunociblage des Tumeurs, Marseille, France
    2.  CNRS, Université Montpellier 1, France
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  • Martine Pugnière,

    1.  CNRS, Groupement de Recherche Immunociblage des Tumeurs, Marseille, France
    2.  CNRS, Université Montpellier 1, France
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  • Jean-Luc Teillaud,

    1.  CNRS, Groupement de Recherche Immunociblage des Tumeurs, Marseille, France
    2.  INSERM, Centre de Recherche des Cordeliers, Paris, France
    3.  Université Pierre et Marie Curie – Paris 6, France
    4.  Université Paris Descartes, France
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  • Anne Gruaz-Guyon,

    1.  CNRS, Groupement de Recherche Immunociblage des Tumeurs, Marseille, France
    2.  INSERM, Centre de Recherche Biomédicale Bichat-Beaujon, Paris, France
    3.  Université Denis Diderot-Paris 7, France
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  • André Pèlegrin,

    1.  CNRS, Groupement de Recherche Immunociblage des Tumeurs, Marseille, France
    2.  INSERM, Centre de Recherche en cancérologie de Montpellier, Université Montpellier, France
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  • Daniel Baty

    1.  CNRS, Laboratoire d’Ingénierie des Systèmes Macromoléculaires, Marseille, France
    2.  CNRS, Groupement de Recherche Immunociblage des Tumeurs, Marseille, France
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    • INSERM, U624, Stress Cellulaire, Marseille, France


  • Database
    The nucleotide sequences in this study have been submitted to the GenBank database under the accession numbers ABS29543 (C3), ABS29544 (C17), ABS29545 (C25), ABS29546 (C43) and ABS29547 (C44)

D. Baty, INSERM, U624, Stress Cellulaire, Marseille, France
Fax: +33 4 91 82 60 83
Tel: +33 4 91 82 88 33
E-mail: daniel.baty@inserm.fr

Abstract

Single-domain antibodies (sdAbs), which occur naturally in camelids, are endowed with many characteristics that make them attractive candidates as building blocks to create new antibody-related therapeutic molecules. In this study, we isolated from an immunized llama several high-affinity sdAbs directed against human carcinoembryonic antigen (CEA), a heavily glycosylated tumor-associated molecule expressed in a variety of cancers. These llama sdAbs bind a different epitope from those defined by current murine mAbs, as shown by binding competition experiments using immunofluorescence and surface plasmon resonance. Flow cytometry analysis shows that they bind strongly to CEA-positive tumor cells but show no cross-reaction toward nonspecific cross-reacting antigen, a highly CEA-related molecule expressed on human granulocytes. When injected into mice xenografted with a human CEA-positive tumor, up to 2% of the injected dose of one of these sdAbs was found in the tumor, despite rapid clearance of this 15 kDa protein, demonstrating its high potential as a targeting moiety. The single-domain nature of these new anti-CEA IgG fragments should facilitate the design of new molecules for immunotherapy or diagnosis of CEA-positive tumors.

Structured digital abstract

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