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.MethodsThe 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. ResultsThe 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). ConclusionThere 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.

TBX21-1993T/C (rs4794067) polymorphism is associated with increased risk of chronic periodontitis and increased T-bet expression in periodontal lesions, but does not significantly impact the IFN-g transcriptional level or the pattern of periodontophatic bacterial infection

“…In a recent study that investigated various Th expression markers, we demonstrated that multiple cytokine clusters are accountable for the activity of osteolytic lesions, including Th1-, Th17-and Thf-biased clusters. 14 While the immune response pattern associated with a clear disease outcome seems to vary significantly, the common point among progressive lesions (in both periodontitis and periapical lesions) seems to be the presence of recognized pathogens. [40][41][42][43] Therefore, the data presented herein demonstrates a disproportionate large effect of the presence/absence of red complex bacteria with the disease status and the periodontitis subrogate variable PD.…”

“…[11][12][13] While recent evidence points to the participation of other T helper subsets (such as Th17 and Thf) in the pathogenesis of osteolytic inflammatory lesions, numerous studies demonstrate that the Th1 subset can be independently responsible for the establishment and progression of periodontitis. 14 Th1 lineage commitment and differentiation involves the activation of the key transcription factor T-bet (a member of the T-box family of transcription factors) 15 and the secretion of the hallmark cytokine IFN-g, involved in the activation of macrophage´s microbicide functions. 16 Indeed, in addition of modulating the periodontitis' outcome from a tissue destruction perspective, it is also important to mention that Th1 responses have a fundamental role in the control of experimental periodontal infection.…”

Treg and Th17 cells in inflammatory periapical disease: a systematic review

“…In phase 2, the full-text of 18 studies were retrieved and evaluated. Of those, only eight 14,15,16,17,18,19,20,21 met the eligibility criteria. No additional study was identified in the reference lists of the included articles and in the grey literature.…”

“…14,15,18,21 All studies involved human periapical lesion fragments. Samples of six articles 14,15,18,19,20,21 were obtained directly through surgery and samples of the other two studies were obtained through institutional archives collected from previous surgical procedures.…”

“…14,15,18,21 All studies involved human periapical lesion fragments. Samples of six articles 14,15,18,19,20,21 were obtained directly through surgery and samples of the other two studies were obtained through institutional archives collected from previous surgical procedures. 16,17 Fou r a r t icles repor ted t he mea n age of participants 18,19,20,21 and five studies defined the range between 17 and 64 years.…”