title: Phenotypic analysis of immunocompetent cells in healthy human dental pulp.
abstract: BACKGROUND
  Like other tissues in the body, the human dental pulp is equipped with a network of immune cells that can be mobilized against pathogens when they invade the tooth. Very little data, mostly obtained with classic histologic methods, have reported their quantities and relative percentages. The objective of this study was to characterize and precisely quantify immunocompetent cells in healthy human dental pulp by using fluorescence-activated cell sorting, together with identifying specific cell subsets in the leukocyte (CD45(+)) cells.
  
  
  METHODS
  Healthy human third molars were collected from 42 young patients. Dental pulps were separated from the hard tissues and prepared for flow cytometry or immunostaining analyses.
  
  
  RESULTS
  CD45(+) cells represented 0.94% ± 0.65% of cells obtained from the enzymatic digestion of whole dental pulps (n = 34). CD16(+)CD14(+) granulocytes/neutrophils (50.01% ± 9.08%, n = 7) were found to represent the major subpopulation in CD45(+) cells followed by CD3(+) T lymphocytes (32.58% ± 11%, n = 17), CD14(+) monocytes (8.93% ± 5.8%, n = 7), and HLA-DR(high) Lin1(-) dendritic cells (4.51% ± 1.12%, n = 7). Minor subpopulations included CD3(-)CD56(+) natural killer cells (2.63% ± 1.15%, n = 7) and CD19(+) B lymphocytes (1.65% ± 0.89%, n = 17). We further identified cells harboring a phenotype compatible with Foxp3/CD25-expressing regulatory T lymphocytes (CD45(+)CD3(+)CD4(+)CD127(low)). Fluorescence-activated cell sorting analysis and confocal microscopy also revealed expression of HO-1 in HLA-DR(+) cells.
  
  
  CONCLUSIONS
  For the first time, this study identifies and precisely quantifies the relative proportion of immunocompetent cells potentially involved in tissue homeostasis of healthy human dental pulp.
authors.affiliation: Faculty of Odontology, University of Nantes, Nantes, France; INSERM, Institut de Transplantation et de Recherche en Transplantation, Nantes, France. Electronic address: alexis.gaudin1@univ-nantes.fr.
authors.forename: Alexis
authors.initials: A
authors.lastname: Gaudin
authors.affiliation: INSERM, Institut de Transplantation et de Recherche en Transplantation, Nantes, France.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Renard
authors.affiliation: INSERM, Institut de Transplantation et de Recherche en Transplantation, Nantes, France.
authors.forename: Marcello
authors.initials: M
authors.lastname: Hill
authors.affiliation: INSERM, Institut de Transplantation et de Recherche en Transplantation, Nantes, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Bouchet-Delbos
authors.affiliation: Faculty of Odontology, University of Nantes, Nantes, France.
authors.forename: Géraldine
authors.initials: G
authors.lastname: Bienvenu-Louvet
authors.affiliation: Laboratory of Tissue Biology and Therapeutic Engineering, University of Lyon, Lyon, France.
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Farges
authors.affiliation: INSERM, Institut de Transplantation et de Recherche en Transplantation, Nantes, France.
authors.forename: Maria-Cristina
authors.initials: MC
authors.lastname: Cuturi
authors.affiliation: Faculty of Odontology, University of Nantes, Nantes, France; INSERM, Institut de Transplantation et de Recherche en Transplantation, Nantes, France.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Alliot-Licht
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003782:Dental Pulp / Q000276:immunology*; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D016130:Immunophenotyping; D017493:Leukocyte Common Antigens; D007962:Leukocytes / Q000276:immunology*; D055815:Young Adult
chemical_list: D017493:Leukocyte Common Antigens
keywords: Fluorescence-activated cell sorting; healthy dental pulp; immune cells; immunosurveillance