Creation of an In vivo cytosensor using engineered mesangial cells. Automatic sensing of glomerular inflammation controls transgene activity

J Clin Invest. 1997 Sep 15;100(6):1394-9. doi: 10.1172/JCI119659.

Abstract

Automatic control over exogenous gene expression in response to the activity of disease is a crucial hurdle for gene transfer-based therapies. Towards achieving this goal, we created a "cytosensor" that perceives local inflammatory states and subsequently regulates foreign gene expression. alpha-Smooth muscle actin is known to be expressed in glomerular mesangial cells exclusively in pathologic situations. CArG box element, the crucial regulatory sequence of the alpha-smooth muscle actin promoter, was used as a sensor for glomerular inflammation. Rat mesangial cells were stably transfected with an expression plasmid that introduces a beta-galactosidase gene under the control of CArG box elements. In vitro, the established cells expressed beta-galactosidase exclusively after stimulation with serum. To examine whether the cells are able to automatically control transgene activity in vivo, serum-stimulated or unstimulated cells were transferred into normal rat glomeruli or glomeruli subjected to anti-Thy 1 glomerulonephritis. When stimulated cells were transferred into the normal glomeruli, beta-galactosidase expression was switched off in vivo within 3 d. In contrast, when unstimulated cells were transferred into the nephritic glomeruli, transgene expression was substantially induced. These data indicate the feasibility of using the CArG box element as a molecular sensor for glomerular injury. In the context of advanced forms of gene therapy, this approach provides a novel concept for automatic regulation of local transgene expression where the transgene is required to be activated during inflammation and deactivated when the inflammation has subsided.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / genetics
  • Animals
  • Biosensing Techniques*
  • Cells, Cultured
  • Culture Media, Conditioned / pharmacology
  • Dose-Response Relationship, Drug
  • Gene Expression Regulation*
  • Glomerular Mesangium / enzymology*
  • Glomerulonephritis / chemically induced
  • Glomerulonephritis / metabolism
  • Rats
  • Regulatory Sequences, Nucleic Acid / genetics
  • Time Factors
  • Transgenes / physiology*
  • beta-Galactosidase / genetics
  • beta-Galactosidase / metabolism

Substances

  • Actins
  • Culture Media, Conditioned
  • beta-Galactosidase