title: Production of IL-10 and IL-12 by antigen-presenting cells in periapical lesions.
abstract: BACKGROUND
  Interferon-γ (IFN-γ) plays an important role in the pathogenesis of periapical lesions. Its expression is up-regulated by interleukin (IL)-12) and down-regulated by IL-10. The aim of this work was to study the cellular source of these cytokines and their mutual interactions in human periapical lesions.
  
  
  METHODS
  Mononuclear cells, macrophages and dendritic cells were isolated from periapical lesions using plastic adherence and osmotic gradients. Cytokines were measured in culture supernatants by a microbeads fluorescence assay. Phenotypic characteristics of cells were studied by immunocytochemistry, whereas allostimulatory activity of antigen-presenting cells was tested using a mixed leukocyte reaction.
  
  
  RESULTS
  We observed the positive correlations between the levels of IL-12 and IFN-γ as well as IL-12 and IL-10 in cultures of mononuclear cells. As IL-10 and IL-12 are produced by dendritic cells and activated macrophages, we examined their contribution to the production of these cytokines. Macrophages, CD14(+) adherent cells, produced high levels of IL-10 and very low levels of IL-12. In contrast, non-adherent, strongly HLA-DR(+) dendritic cells, potent stimulators of the alloreactive T-cell response, produced low levels of IL-10 and moderate levels of IL-12. Dendritic cells stimulated the production of IFN-γ by allogeneic CD4(+) T cells. In contrast, the level of IFN-γ was significantly decreased and the production of IL-10 was enhanced by addition of macrophages to the culture system.
  
  
  CONCLUSIONS
  Our results suggest that a fine balance between the production of IL-10 and IL-12 by different antigen-presenting cells, through IFN-γ, may control the course of chronic inflammation in periapical lesions.
authors.affiliation: Institute for Medical Research, Military Medical Academy, Belgrade, Serbia. vmaimi@eunet.rs
authors.forename: Miodrag
authors.initials: M
authors.lastname: Colic
authors.forename: Dragan
authors.initials: D
authors.lastname: Gazivoda
authors.forename: Sasa
authors.initials: S
authors.lastname: Vasilijic
authors.forename: Dragana
authors.initials: D
authors.lastname: Vucevic
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Lukic
mesh_terms: D000293:Adolescent; D000328:Adult; D000938:Antigen-Presenting Cells / Q000378:metabolism*; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism; D002478:Cells, Cultured; D018920:Coculture Techniques; D017077:Culture Media, Conditioned; D003713:Dendritic Cells / Q000378:metabolism; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006801:Humans; D016130:Immunophenotyping; D007371:Interferon-gamma / Q000096:biosynthesis*; D016753:Interleukin-10 / Q000096:biosynthesis*; D018664:Interleukin-12 / Q000096:biosynthesis*; D008264:Macrophages / Q000378:metabolism; D008875:Middle Aged; D010485:Periapical Periodontitis / Q000276:immunology* / Q000378:metabolism; D055815:Young Adult
chemical_list: D017077:Culture Media, Conditioned; D016753:Interleukin-10; D018664:Interleukin-12; D007371:Interferon-gamma