Lysosomal enzyme delivery by ICAM-1-targeted nanocarriers bypassing glycosylation- and clathrin-dependent endocytosis

Mol Ther. 2006 Jan;13(1):135-41. doi: 10.1016/j.ymthe.2005.07.687. Epub 2005 Sep 8.

Abstract

Enzyme replacement therapy, a state-of-the-art treatment for many lysosomal storage disorders, relies on carbohydrate-mediated binding of recombinant enzymes to receptors that mediate lysosomal delivery via clathrin-dependent endocytosis. Suboptimal glycosylation of recombinant enzymes and deficiency of clathrin-mediated endocytosis in some lysosomal enzyme-deficient cells limit delivery and efficacy of enzyme replacement therapy for lysosomal disorders. We explored a novel delivery strategy utilizing nanocarriers targeted to a glycosylation- and clathrin-independent receptor, intercellular adhesion molecule (ICAM)-1, a glycoprotein expressed on diverse cell types, up-regulated and functionally involved in inflammation, a hallmark of many lysosomal disorders. We targeted recombinant human acid sphingomyelinase (ASM), deficient in types A and B Niemann-Pick disease, to ICAM-1 by loading this enzyme to nanocarriers coated with anti-ICAM. Anti-ICAM/ASM nanocarriers, but not control ASM or ASM nanocarriers, bound to ICAM-1-positive cells (activated endothelial cells and Niemann-Pick disease patient fibroblasts) via ICAM-1, in a glycosylation-independent manner. Anti-ICAM/ASM nanocarriers entered cells via CAM-mediated endocytosis, bypassing the clathrin-dependent pathway, and trafficked to lysosomes, where delivered ASM displayed stable activity and alleviated lysosomal lipid accumulation. Therefore, lysosomal enzyme targeting using nanocarriers targeted to ICAM-1 bypasses defunct pathways and may improve the efficacy of enzyme replacement therapy for lysosomal disorders, such as Niemann-Pick disease.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Antibodies, Monoclonal / chemistry
  • Cells, Cultured
  • Clathrin / physiology*
  • Drug Delivery Systems
  • Endocytosis*
  • Endothelial Cells / enzymology
  • Fibroblasts / enzymology
  • Glycosylation
  • Humans
  • Intercellular Adhesion Molecule-1 / immunology
  • Intercellular Adhesion Molecule-1 / metabolism*
  • Lysosomes / enzymology*
  • Nanostructures
  • Niemann-Pick Diseases / enzymology
  • Recombinant Proteins / administration & dosage
  • Recombinant Proteins / metabolism
  • Sphingomyelin Phosphodiesterase / administration & dosage
  • Sphingomyelin Phosphodiesterase / metabolism*

Substances

  • Antibodies, Monoclonal
  • Clathrin
  • Recombinant Proteins
  • Intercellular Adhesion Molecule-1
  • Sphingomyelin Phosphodiesterase