title: Allostimulatory Effects of Dendritic Cells with Characteristic Features of a Regulatory Phenotype.
abstract: BACKGROUND
  Tolerogenic dendritic cells (DCs) have the potential to prolong graft survival after transplantation. Tolerogenic DCs are in general characterized by a low expression of co-stimulatory molecule and a high IL-10:IL-12 production ratio. Based on promising results with earlier used alternatively activated DCs, we aimed to generate in culture potentially tolerogenic DC by simultaneously blocking GSK3 by lithium chloride (LiCl) and stimulating TLR2 by PAM3CysSerLys4.
  
  
  METHODS
  Bone marrow-derived LiClPAM3 DCs were generated by the addition of LiCl 24 hours before harvesting, and one hour later PAM3CysSerLys4. The phenotype of the DCs was assessed by determining the expression of co-stimulatory molecules in flow cytometry and cytokine production in ELISA, whereas their functional properties were tested in a mixed lymphocyte reaction. A fully MHC mismatched heterotopic heart transplant preceded by infusion of donor-derived LiClPAM3 DC was performed to assess the tolerogenic potential of LiClPAM3 DCs in vivo.
  
  
  RESULTS
  LiClPAM3 DCs displayed a tolerogenic phenotype accompanied with a low expression of co-stimulatory molecules and a high IL-10:IL-12 production ratio. However, in mixed lymphocyte reaction, LiClPAM3 DCs appeared superior in T cell stimulation, and induced Th1 and Th17 differentiation. Moreover, mice pretreated with LiClPAM3 DC displayed a reduced graft survival. Analysis of LiClPAM3 DC culture supernatant revealed high levels of CXCL-1, which was also found in supernatants of co-cultures of LiClPAM3 DC and T cells. Nevertheless, we could not show a role for CXCL-1 in T cell proliferation or activation in vitro.
  
  
  CONCLUSIONS
  LiClPAM3 DCs display in vitro a tolerogenic phenotype with a high IL-10:IL-12 ratio, but appeared to be highly immunogenic, since allograft rejection was accelerated. As yet unidentified LiClPAM3 DC-derived factors, may explain the immunogenic character of LiClPAM3 DCs in vivo.
authors.affiliation: Department of Nephrology, Radboud university medical center, Nijmegen, the Netherlands.
authors.forename: M
authors.identifier: http://orcid.org/0000-0003-1992-920X
authors.initials: M
authors.lastname: Kouwenberg
authors.affiliation: Department of Nephrology, Radboud university medical center, Nijmegen, the Netherlands.
authors.forename: C W M
authors.initials: CW
authors.lastname: Jacobs
authors.affiliation: Department of Nephrology, Radboud university medical center, Nijmegen, the Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: van der Vlag
authors.affiliation: Department of Nephrology, Radboud university medical center, Nijmegen, the Netherlands.
authors.forename: L B
authors.initials: LB
authors.lastname: Hilbrands
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D054360:Chemokine CXCL1 / Q000378:metabolism; D003713:Dendritic Cells / Q000166:cytology* / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors; D006084:Graft Rejection / Q000276:immunology; D016027:Heart Transplantation / Q000009:adverse effects; D018021:Lithium Chloride / Q000494:pharmacology; D008297:Male; D051379:Mice; D009930:Organic Chemicals / Q000494:pharmacology; D010641:Phenotype; D018417:Th1 Cells / Q000166:cytology / Q000187:drug effects; D058504:Th17 Cells / Q000166:cytology / Q000187:drug effects; D051195:Toll-Like Receptor 2 / Q000378:metabolism
chemical_list: D054360:Chemokine CXCL1; D004791:Enzyme Inhibitors; D009930:Organic Chemicals; C493486:Tlr2 protein, mouse; C029248:Tolerogen; D051195:Toll-Like Receptor 2; D038362:Glycogen Synthase Kinase 3; D018021:Lithium Chloride