Restoration of membrane TNF-like activity by cell surface targeting and matrix metalloproteinase-mediated processing of a TNF prodrug

Cell Death Differ. 2006 Feb;13(2):273-84. doi: 10.1038/sj.cdd.4401735.

Abstract

Tumor necrosis factor (TNF) prodrugs are fusion proteins comprised of an N-terminal single-chain antibody variable fragment (scFv) targeting a TNF effector and a C-terminal TNF receptor (TNFR)1-derived inhibitor module. Introduction of matrix metalloproteinase (MMP)-2 recognition motifs between TNF and the TNFR1 fragment allowed activation by recombinant MMP-2 and MMP-expressing HT1080 cells. Processing by endogeneous MMPs required specific membrane binding of the TNF prodrug via the targeting scFv, ensuring strictly antigen-dependent activation. Interestingly, TNF bioactivity of the processed prodrug was approximately 1000-fold higher upon scFv-mediated targeting, and signaled juxtatropic cell death also to antigen-negative cells. Microscopical analyses of TNFR2 clustering and TNF receptor-associated factor 2 recruitment at contact sites to adjacent cells revealed the formation of stable TNFR complexes by target-bound, processed prodrug, resembling the increased signal capacity of natural, membrane-expressed TNF. MMP-2-sensitive TNF prodrugs represent novel cytokine-based reagents for targeted cancer therapy, which should be exploitable for MMP-overexpressing tumors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomarkers, Tumor / analysis
  • Blotting, Western
  • Cell Death*
  • Cell Line, Tumor
  • Cell Membrane / chemistry
  • Cell Membrane / drug effects*
  • Flow Cytometry
  • Humans
  • Matrix Metalloproteinase 2 / genetics
  • Matrix Metalloproteinase 2 / metabolism*
  • Peptide Hydrolases / metabolism
  • Prodrugs / chemistry
  • Prodrugs / metabolism
  • Prodrugs / pharmacology*
  • Protein Binding
  • Receptors, Tumor Necrosis Factor / chemistry
  • Receptors, Tumor Necrosis Factor / metabolism
  • Recombinant Fusion Proteins / immunology
  • Recombinant Fusion Proteins / metabolism
  • Recombinant Fusion Proteins / pharmacology
  • Tumor Necrosis Factor-alpha / analysis
  • Tumor Necrosis Factor-alpha / genetics
  • Tumor Necrosis Factor-alpha / metabolism
  • Tumor Necrosis Factor-alpha / pharmacology*

Substances

  • Biomarkers, Tumor
  • Prodrugs
  • Receptors, Tumor Necrosis Factor
  • Recombinant Fusion Proteins
  • Tumor Necrosis Factor-alpha
  • Peptide Hydrolases
  • Matrix Metalloproteinase 2