Ultrasensitive immuno-detection using viral nanoparticles with modular assembly using genetically-directed biotinylation

Biotechnol Lett. 2014 Sep;36(9):1863-8. doi: 10.1007/s10529-014-1555-9. Epub 2014 Jun 15.

Abstract

We report a novel, modular approach to immuno-detection based on antibody recognition and PCR read-out that employs antibody-conjugated bacteriophage and easily-manipulated non-pathogenic viruses as affinity agents. Our platform employs phage genetically tagged for in vivo biotinylation during phage maturation that can easily be linked, through avidin, to any biotinylated affinity agent, including full-length antibodies, peptides, lectins or aptamers. The presence of analyte is reported with high sensitivity through real-time PCR. This approach avoids the need to clone antibody-encoding DNA fragments, allows the use of full-length, high affinity antibodies and, by having DNA reporters naturally encapsulated inside the bacteriophage, greatly reduces nonspecific binding of DNA. We validate the efficacy of this new approach through the detection of Vascular Endothelial Growth Factor, a known angiogenic cancer biomarker protein, at attomolar concentrations in bronchoalveolar lavage fluid.

Publication types

  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Antibodies, Viral / metabolism
  • Bacteriophages / genetics*
  • Biotinylation*
  • Humans
  • Immunoassay / methods
  • Lectins / metabolism
  • Nanoparticles*
  • Peptides / metabolism
  • Protein Binding
  • Real-Time Polymerase Chain Reaction / methods*
  • Sensitivity and Specificity
  • Vascular Endothelial Growth Factor A / analysis

Substances

  • Antibodies, Viral
  • Lectins
  • Peptides
  • VEGFA protein, human
  • Vascular Endothelial Growth Factor A