Induction of monocyte-to-dendritic cell maturation by extracorporeal photochemotherapy: initiation via direct platelet signaling

Transfus Apher Sci. 2014 Jun;50(3):370-8. doi: 10.1016/j.transci.2013.11.008. Epub 2013 Nov 28.


Extracorporeal Photochemotherapy (ECP) is a widely used therapy for cutaneous T cell lymphoma (CTCL). Although the mechanism of clinical action of ECP is not precisely established, previous studies have shown evidence of induction of dendritic cells (DCs). Here we show that, under flow conditions similar to those in post-capillary venules, ECP promotes platelet immobilization and activation, initiating stepwise receptor-ligand interactions with monocytes, which then differentiate into DC. These findings clarify how ECP directly stimulates DC maturation; suggest a new clinically applicable approach to the obtainment of DC; and identify a novel mechanism that may reflect physiological induction of DC.

Keywords: Dendritic cells; Extracorporeal photochemotherapy; Monocytes; P-selectin; Platelets.

Publication types

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

MeSH terms

  • Adult
  • Blood Platelets / immunology*
  • Cells, Cultured
  • Dendritic Cells / immunology*
  • Female
  • Humans
  • Male
  • Monocytes / immunology*
  • Photopheresis*
  • Platelet Activation* / drug effects
  • Platelet Activation* / radiation effects
  • Signal Transduction* / drug effects
  • Signal Transduction* / radiation effects