In vivo tumor targeting and imaging with engineered trivalent antibody fragments containing collagen-derived sequences

PLoS One. 2009;4(4):e5381. doi: 10.1371/journal.pone.0005381. Epub 2009 Apr 29.


There is an urgent need to develop new and effective agents for cancer targeting. In this work, a multivalent antibody is characterized in vivo in living animals. The antibody, termed "trimerbody", comprises a single-chain antibody (scFv) fragment connected to the N-terminal trimerization subdomain of collagen XVIII NC1 by a flexible linker. As indicated by computer graphic modeling, the trimerbody has a tripod-shaped structure with three highly flexible scFv heads radially outward oriented. Trimerbodies are trimeric in solution and exhibited multivalent binding, which provides them with at least a 100-fold increase in functional affinity than the monovalent scFv. Our results also demonstrate the feasibility of producing functional bispecific trimerbodies, which concurrently bind two different ligands. A trimerbody specific for the carcinoembryonic antigen (CEA), a classic tumor-associated antigen, showed efficient tumor targeting after systemic administration in mice bearing CEA-positive tumors. Importantly, a trimerbody that recognizes an angiogenesis-associated laminin epitope, showed excellent tumor localization in several cancer types, including fibrosarcomas and carcinomas. These results illustrate the potential of this new antibody format for imaging and therapeutic applications, and suggest that some laminin epitopes might be universal targets for cancer targeting.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Neoplasm* / chemistry
  • Antibodies, Neoplasm* / genetics
  • Carcinoembryonic Antigen / immunology
  • Cell Line
  • Cell Line, Tumor
  • Collagen Type XVIII / chemistry
  • Collagen Type XVIII / genetics
  • Computer Simulation
  • Epitopes
  • Female
  • Fluorescent Dyes
  • HeLa Cells
  • Humans
  • Immunoglobulin Fragments / chemistry
  • Immunoglobulin Fragments / genetics
  • Laminin / immunology
  • Mice
  • Mice, Nude
  • Models, Molecular
  • Neoplasm Transplantation
  • Neoplasms, Experimental / diagnosis*
  • Neoplasms, Experimental / immunology*
  • Peptide Fragments / chemistry
  • Peptide Fragments / genetics
  • Protein Engineering
  • Protein Structure, Quaternary
  • Transplantation, Heterologous


  • Antibodies, Neoplasm
  • Carcinoembryonic Antigen
  • Collagen Type XVIII
  • Epitopes
  • Fluorescent Dyes
  • Immunoglobulin Fragments
  • Laminin
  • Peptide Fragments