title: Thrombin may modulate dendritic cell activation in kidney transplant recipients with delayed graft function.
abstract: BACKGROUND
  Coagulation and complement activation represent key events in ischaemia-reperfusion-induced renal injury leading to delayed graft function (DGF). It is still unclear whether the coagulation cascade may also influence the acquired immunity. The aim of the present study was to investigate the expression of protease-activated receptor 1 (PAR-1), the main thrombin receptor, by graft-infiltrating dendritic cells (DCs), and to evaluate whether thrombin may influence DCs complement production and T-cell response.
  
  
  METHODS
  PAR-1, BDCA1, CD11c, BDCA4, fibrin, C3c and C3d protein expression were evaluated by confocal microscopy. Cultured DCs were obtained incubating monocytes (Ms) with IL-4 and GM-CSF. DC maturation was obtained with IFN-g+sCD40L or with a cytokine cocktail (IL-1b, TNF-a, PGE2, IL-6). PAR1 protein expression on cultured DC was evaluated by flow-cytometry. Complement receptors, C3, IL12/IL17p40 and IL10 gene expression was evaluated by qPCR. T cell phenotype was evaluated by ELISPOT. IFN-g protein presence was evaluated by ELISA.
  
  
  RESULTS
  PAR-1 was expressed by infiltrating myeloid DCs in pre-transplant and in DGF biopsies. In DGF grafts, myeloid DCs localized within fibrin and C3d deposits and expressed C3c. In vitro, PAR-1 protein expression was increased in monocyte-derived immature DCs and in cytokine-induced mature DCs compared to monocytes. PAR-1 activation caused a time-dependent increase in C3 and complement receptors expression. Moreover, thrombin stimulation, while reducing interleukin-10 mRNA abundance, induced interleukin-12/IL-17 p40 gene expression, and promoted C3a ability to increase interleukin-12/IL17 mRNA abundance. These changes in the DCs' cytokine pattern influenced their ability to induce interferon-g production by T cells, suggesting the activation of a T helper-1 bias.
  
  
  CONCLUSIONS
  Our data suggest that PAR-1 is expressed by DCs in DGF grafts and its activation may induce complement production and a Th1 bias. This observation suggests a potential pathogenic link between DGF and acquired allo-response leading to graft damage.
authors.affiliation: Nephrology, Dialysis and Transplantation Unit, Department of Emergency and Organ Transplantation, University of Bari 'Aldo Moro', Bari, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Pontrelli
authors.affiliation: Medical Clinic 'C. Frugoni', Interdisciplinary Department of Medicine, University of Bari, Italy.
authors.forename: Marica
authors.initials: M
authors.lastname: Cariello
authors.affiliation: Nephrology, Dialysis and Transplantation Unit, Department of Medical and Surgical Sciences, University of Foggia, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Rascio
authors.affiliation: Nephrology, Dialysis and Transplantation Unit, Department of Emergency and Organ Transplantation, University of Bari 'Aldo Moro', Bari, Italy.
authors.forename: Margherita
authors.initials: M
authors.lastname: Gigante
authors.affiliation: Nephrology, Dialysis and Transplantation Unit, Department of Emergency and Organ Transplantation, University of Bari 'Aldo Moro', Bari, Italy.
authors.forename: Raffaella
authors.initials: R
authors.lastname: Verrienti
authors.affiliation: Laboratory of Pre-Clinical and Translational Research, IRCCS, Centro di Riferimento Oncologico Della Basilicata, Rionero in Vulture, PZ, Italy.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Tataranni
authors.affiliation: Nephrology, Dialysis and Transplantation Unit, Department of Emergency and Organ Transplantation, University of Bari 'Aldo Moro', Bari, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Castellano
authors.affiliation: Nephrology, Dialysis and Transplantation Unit, Department of Emergency and Organ Transplantation, University of Bari 'Aldo Moro', Bari, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Divella
authors.affiliation: Clinical Pathology Unit, Department of Medical and Surgical Sciences, University of Foggia, Foggia, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Ranieri
authors.affiliation: Nephrology, Dialysis and Transplantation Unit, Department of Medical and Surgical Sciences, University of Foggia, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Stallone
authors.affiliation: Nephrology, Dialysis and Transplantation Unit, Department of Emergency and Organ Transplantation, University of Bari 'Aldo Moro', Bari, Italy.
authors.forename: Loreto
authors.initials: L
authors.lastname: Gesualdo
authors.affiliation: Nephrology, Dialysis and Transplantation Unit, Department of Medical and Surgical Sciences, University of Foggia, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Grandaliano
mesh_terms: D002478:Cells, Cultured; D016207:Cytokines / Q000235:genetics / Q000378:metabolism*; D051799:Delayed Graft Function / Q000188:drug therapy / Q000276:immunology* / Q000473:pathology; D003713:Dendritic Cells / Q000187:drug effects / Q000276:immunology* / Q000473:pathology; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D006490:Hemostatics / Q000494:pharmacology; D006801:Humans; D016030:Kidney Transplantation / Q000009:adverse effects*; D007687:Kidney Tubules, Proximal / Q000187:drug effects / Q000276:immunology* / Q000473:pathology; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology* / Q000473:pathology; D013917:Thrombin / Q000494:pharmacology*
chemical_list: D016207:Cytokines; D006490:Hemostatics; D012333:RNA, Messenger; D013917:Thrombin
keywords: T cells; complement; delayed graft function; dendritic cells; ischaemia–reperfusion; thrombin