title: Cellular infiltrates and NFκB subunit c-Rel signaling in kidney allografts of patients with clinical operational tolerance.
abstract: BACKGROUND
  Nuclear factor kappa B (NFκB) plays a potential role in tolerance by orchestrating onset and resolution of inflammation and regulatory T cell differentiation through subunit c-Rel. We characterized cellular infiltrates and expression of NFκB1, c-Rel and its upstream regulators phosphatidylinositol 3-kinase/RAC-alpha serine/threonine kinase, in allograft biopsies from patients with spontaneous clinical operational tolerance (COT).
  
  
  METHODS
  Paraffin-fixed kidney allograft biopsies from 40 patients with COT (n=4), interstitial rejection (IR; n=12), borderline changes (BC; n=12), and long-term allograft function without rejection (NR; n=12) were used in the study. Cellular infiltrates and immunohistochemical expression of key proteins of the NFκB pathway were evaluated in the cortical tubulointerstitium and in cellular infiltrates using digital image analysis software. Results were given as mean±SEM.
  
  
  RESULTS
  Biopsies from patients with COT exhibited a comparable amount of cellular infiltrate to IR, BC, and NR (COT, 191±81; IR, 291±62; BC, 178±45; and NR, 210±42 cells/mm) but a significantly higher proportion of forkhead box P3-positive cells (COT, 11%±1.7%; IR, 3.5%±0.70%; BC, 3.4%±0.57%; and NR, 3.7%±0.78% of infiltrating cells; P=0.02). c-Rel expression in cellular infiltrates was significantly elevated in IR, BC, and NR when analyzing the number of positive cells per mm (P=0.02) and positive cells per infiltrating cells (P=0.04). In contrast, tubular PI3K and c-Rel expression were significantly higher in IR and BC but not in NR compared with COT (P=0.03 and P=0.006, respectively). With RAC-alpha serine-threonine kinase, similar tendencies were observed (P=0.2).
  
  
  CONCLUSIONS
  Allografts from COT patients show significant cellular infiltrates but a distinct expression of proteins involved in the NFκB pathway and a higher proportion of forkhead box P3-positive cells.
authors.affiliation: Division of Nephrology, Department of Medicine, University of Heidelberg, Heidelberg, Germany. luis.becker@med.uni-heidelberg.de
authors.forename: Luis E
authors.initials: LE
authors.lastname: Becker
authors.forename: Fúvia
authors.initials: F
authors.lastname: de Oliveira Biazotto
authors.forename: Heike
authors.initials: H
authors.lastname: Conrad
authors.forename: Matthias
authors.initials: M
authors.lastname: Schaier
authors.forename: Lars P
authors.initials: LP
authors.lastname: Kihm
authors.forename: Marie-Luise
authors.initials: ML
authors.lastname: Gross-Weissmann
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Waldherr
authors.forename: Angelika
authors.initials: A
authors.lastname: Bierhaus
authors.forename: Peter P
authors.initials: PP
authors.lastname: Nawroth
authors.forename: Martin
authors.initials: M
authors.lastname: Zeier
authors.forename: Christian
authors.initials: C
authors.lastname: Morath
mesh_terms: D000328:Adult; D001706:Biopsy; D016009:Chi-Square Distribution; D005260:Female; D051858:Forkhead Transcription Factors / Q000032:analysis; D006084:Graft Rejection / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D006085:Graft Survival; D006684:HLA-DR Antigens / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007668:Kidney / Q000737:chemistry* / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D016030:Kidney Transplantation / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D052002:NF-kappa B p50 Subunit / Q000032:analysis*; D058539:Phosphatidylinositol 3-Kinase / Q000032:analysis; D051057:Proto-Oncogene Proteins c-akt / Q000032:analysis; D020569:Proto-Oncogene Proteins c-rel / Q000032:analysis*; D015398:Signal Transduction / Q000187:drug effects; D013997:Time Factors; D023001:Transplantation Tolerance / Q000187:drug effects
chemical_list: C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D006684:HLA-DR Antigens; D007166:Immunosuppressive Agents; D052002:NF-kappa B p50 Subunit; C489548:NFKB1 protein, human; D020569:Proto-Oncogene Proteins c-rel; D058539:Phosphatidylinositol 3-Kinase; D051057:Proto-Oncogene Proteins c-akt