Human stem cell-derived retinal epithelial cells activate complement via collectin 11 in response to stress

Sci Rep. 2017 Nov 7;7(1):14625. doi: 10.1038/s41598-017-15212-z.

Abstract

Age-related macular degeneration (AMD) is a major cause of blindness and is associated with complement dysregulation. The disease is a potential target for stem cell therapy but success is likely to be limited by the inflammatory response. We investigated the innate immune properties of human induced-pluripotent stem cell (iPSC)-derived RPE cells, particularly with regard to the complement pathway. We focused on collectin-11 (CL-11), a pattern recognition molecule that can trigger complement activation in renal epithelial tissue. We found evidence of constitutive and hypoxia-induced expression of CL-11 in iPS-RPE cells, and in the extracellular fluid. Complement activation on the cell surface occurred in conjunction with CL-11 binding. CL-11 has been shown to activate inflammatory responses through recognition of L-fucose, which we confirmed by showing that fucosidase-treated cells, largely, failed to activate complement. The presence of CL-11 in healthy murine and human retinal tissues confirmed the biological relevance of CL-11. Our data describe a new trigger mechanism of complement activation that could be important in disease pathogenesis and therapeutic interventions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cells, Cultured
  • Collectins / metabolism*
  • Complement Activation / immunology*
  • Complement C3 / immunology
  • Complement C3 / metabolism*
  • Eye / cytology
  • Eye / physiopathology
  • Fucose / metabolism
  • Humans
  • Hypoxia / physiopathology*
  • Induced Pluripotent Stem Cells / cytology
  • Induced Pluripotent Stem Cells / physiology*
  • Mice
  • Oxidative Stress
  • Retinal Pigment Epithelium / cytology
  • Retinal Pigment Epithelium / physiopathology*

Substances

  • Colec11 protein, human
  • Colec11 protein, mouse
  • Collectins
  • Complement C3
  • Fucose