title: Simultaneous analysis of T helper subsets (Th1, Th2, Th9, Th17, Th22, Tfh, Tr1 and Tregs) markers expression in periapical lesions reveals multiple cytokine clusters accountable for lesions activity and inactivity status.
abstract: Previous studies demonstrate that the balance between pro- and anti-inflammatory mediators determines the stable or progressive nature of periapical granulomas by modulating the balance of the osteoclastogenic factor RANKL and its antagonist OPG. However, the cytokine networks operating in the development of periapical lesions are quite more complex than what the simple pro- versus anti-inflammatory mediators' paradigm suggests. Here we simultaneously investigated the patterns of Th1, Th2, Th9, Th17, Th22, Thf, Tr1 and Tregs cytokines/markers expression in human periapical granulomas.
  
  
  METHODS
  The expression of TNF-α, IFN-γ, IL-17A, IL23, IL21, IL-33, IL-10, IL-4, IL-9, IL-22, FOXp3 markers (via RealTimePCR array) was accessed in active/progressive (N=40) versus inactive/stable (N=70) periapical granulomas (as determined by RANKL/OPG expression ratio), and also to compare these samples with a panel of control specimens (N=26). A cluster analysis of 13 cytokine levels was performed to examine possible clustering between the cytokines in a total of 110 granulomas.
  
  
  RESULTS
  The expression of all target cytokines was higher in the granulomas than in control samples. TNF-α, IFN-γ, IL-17A and IL-21 mRNA levels were significantly higher in active granulomas, while in inactive lesions the expression levels of IL-4, IL-9, IL-10, IL-22 and FOXp3 were higher than in active granulomas. Five clusters were identified in inactive lesion groups, being the variance in the expression levels of IL-17, IL-10, FOXp3, IFN-γ, IL-9, IL-33 and IL-4 statistically significant (KW p<0.05). Three clusters were identified in active lesions, being the variance in the expression levels of IL-22, IL-10, IFN-γ, IL-17, IL-33, FOXp3, IL-21 and RANKL statistically significant (KW p<0.05).
  
  
  CONCLUSIONS
  There is a clear dichotomy in the profile of cytokine expression in inactive and active periapical lesions. While the widespread cytokine expression seems to be a feature of chronic lesions, hierarchical cluster analysis demonstrates the association of TNF-α, IL-21, IL-17 and IFN-γ with lesions activity, and the association of FOXP3, IL-10, IL-9, IL-4 and IL-22 with lesions inactivity.
authors.affiliation: Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil.
authors.forename: Ana Claudia
authors.initials: AC
authors.lastname: Araujo-Pires
authors.affiliation: Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil.
authors.forename: Carolina Favaro
authors.initials: CF
authors.lastname: Francisconi
authors.affiliation: Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil.
authors.forename: Claudia Cristina
authors.initials: CC
authors.lastname: Biguetti
authors.affiliation: Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil.
authors.forename: Franco
authors.initials: F
authors.lastname: Cavalla
authors.affiliation: Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil.
authors.forename: Andreza Maria Fabio
authors.initials: AM
authors.lastname: Aranha
authors.affiliation: Department of Endodontics, School of Dentistry, University of Texas Health Science Center at Houston, Houston, USA.
authors.forename: Ariadne
authors.initials: A
authors.lastname: Letra
authors.affiliation: Department of Biological and Allied Health Sciences, Sacred Heart University, Bauru, SP, Brazil.
authors.forename: Ana Paula Favaro
authors.initials: AP
authors.lastname: Trombone
authors.affiliation: Department of Periodontology, Dental Research Division, Guarulhos University, Guarulhos, SP, Brazil.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Faveri
authors.affiliation: Department of Endodontics, School of Dentistry, University of Texas Health Science Center at Houston, Houston, USA.
authors.forename: Renato Menezes
authors.initials: RM
authors.lastname: Silva
authors.affiliation: Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil.
authors.forename: Gustavo Pompermaier
authors.initials: GP
authors.lastname: Garlet
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D015415:Biomarkers / Q000032:analysis; D002908:Chronic Disease; D016207:Cytokines / Q000032:analysis* / Q000276:immunology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010484:Periapical Granuloma / Q000276:immunology / Q000473:pathology*; D060888:Real-Time Polymerase Chain Reaction; D012016:Reference Values; D018709:Statistics, Nonparametric; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology / Q000378:metabolism*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D016207:Cytokines