Fibrotic remodeling of the extracellular matrix through a novel (engineered, dual-function) antibody reactive to a cryptic epitope on the N-terminal 30 kDa fragment of fibronectin

PLoS One. 2013 Jul 23;8(7):e69343. doi: 10.1371/journal.pone.0069343. Print 2013.

Abstract

Fibrosis is characterized by excessive accumulation of scar tissue as a result of exaggerated deposition of extracellular matrix (ECM), leading to tissue contraction and impaired function of the organ. Fibronectin (Fn) is an essential component of the ECM, and plays an important role in fibrosis. One such fibrotic pathology is that of proliferative vitreoretinopathy (PVR), a sight-threatening complication which develops as a consequence of failure of surgical repair of retinal detachment. Such patients often require repeated surgeries for retinal re-attachment; therefore, a preventive measure for PVR is of utmost importance. The contractile membranes formed in PVR, are composed of various cell types including the retinal pigment epithelial cells (RPE); fibronectin is an important constituent of the ECM surrounding these cells. Together with the vitreous, fibronectin creates microenvironments in which RPE cells proliferate. We have successfully developed a dual-action, fully human, fibronectin-specific single chain variable fragment antibody (scFv) termed Fn52RGDS, which acts in two ways: i) binds to cryptic sites in fibronectin, and thereby prevents its self polymerization/fibrillogenesis, and ii) interacts with the cell surface receptors, ie., integrins (through an attached "RGD" sequence tag), and thereby blocks the downstream cell signaling events. We demonstrate the ability of this antibody to effectively reduce some of the hallmark features of fibrosis--migration, adhesion, fibronectin polymerization, matrix metalloprotease (MMP) expression, as well as reduction of collagen gel contraction (a model of fibrotic tissue remodeling). The data suggests that the antibody can be used as a rational, novel anti-fibrotic candidate.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Antibodies / chemistry
  • Antibodies / immunology*
  • Cell Adhesion
  • Cell Movement
  • Cell Proliferation
  • Cell Survival
  • Collagen
  • Epitopes / immunology*
  • Extracellular Matrix / metabolism
  • Extracellular Matrix / pathology*
  • Fibronectins / chemistry*
  • Fibronectins / immunology*
  • Fibrosis / pathology
  • Humans
  • Integrins / metabolism
  • Matrix Metalloproteinases / metabolism
  • Molecular Sequence Data
  • Molecular Weight
  • Pigment Epithelium of Eye / cytology
  • Pigment Epithelium of Eye / enzymology
  • Polymerization
  • Protein Binding
  • Protein Engineering*
  • Single-Chain Antibodies / immunology

Substances

  • Antibodies
  • Epitopes
  • Fibronectins
  • Integrins
  • Single-Chain Antibodies
  • Collagen
  • Matrix Metalloproteinases

Grant support

The study was funded by the Department of Science and Technology (DST), Government of India. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.