Expressão imuno-histoquímica de IL-17, TGF-β1 e FOXP3 em ganulomas periapicais, cistos radiculares e cistos radiculares residuais

Periapical lesions are chronic inflammatory conditions of periradicular tissues considered direct consequences of infectious diseases resulting from pulp necrosis and subsequent progression to periapical region. The participation of the immune response and bone resorption in the formation of these lesions has been investigated, so that different cell types and cytokines have been identified as contributors to this process. In this perspective, this study aimed to evaluate the immunohistochemical expression of IL-17, TGF-β1 and FoxP3 in periapical granulomas (PGs), radicular cysts (RCs) and residual radicular cysts (RRCs), seeking a better understanding of the etiopathogenesis these periapicopatias. To this end, we selected 20 cases of GPs, 20 CRs and 10 RRCs to undergo morphological analysis and immunohistochemistry for biomarkers above, the latter being performed quantitatively using scores and average percentages of immunostaining for the analysis of IL-17 and TGF- β1, while for the FoxP3 were counted only the positive lymphocytes. The results showed statistically significant differences between TGF-β1 and FoxP3 imunoexpressions, in relation to the periapical lesions studied (p = 0.002, p <0.001, respectively) but not between IL-17 and these (p = 0.355). Furthermore, the analysis of lymphocytes FoxP3-positive revealed significant statistical differences in that refers to the intensity of inflammatory infiltrate (p = 0.003) and also regarding thickness of the epithelial lining (p = 0.009). Finally, it was observed in the case of PGs, strong positive correlation between the amount of FoxP3- positive lymphocytes and the immunohistochemical expression of TGF-β1 (r = 0.755, p<0.001), as well as moderate positive correlation between IL-17 and TGF-β1 imunoexpressions (r = 0.503, p = 0.024). Thus, we can conclude that interactions between Th17 and Treg cells seem to be established at the site of injury, suggesting the involvement of both pro-inflammatory and immunoregulatory cytokines in the pathogenesis of periapical lesions

Imunoexpressão da IL-17 e RORγt em carcinomas de células escamosas de lábio e língua

Th17 cells have been strongly associated to the pathogenesis of inflammatory and autoimmune diseases, although their influence on the carcinogenesis is still little known, there are reports of anti-tumor and protumoral actions. The objective of this study is to research the presence of Th17 lineage in lip and tongue SCC, using the analysis of the immunoexpression of IL-17 and RORγt, relating this immunoexpression with clinical and morphological findings in the attempt to better comprehend the role of these cells on the tumoral immunity of OSCCs. The results were submitted to non-parametric statistical tests with significance level of 5%. On the histomorphological analysis, it was observed the predominance of low level lesions on lip and high level lesions on tongue (p=0,024). It was not observed statistical significance between clinical stage and histological gradation of malignancy (p=0,644). For the immunohistochemical study, 5 random fields with greater immunoreactivity of the peritumoral inflammatory infiltrate were photomicrographed on the 400x magnification. It was done the count of lymphocytes which showed cytoplasmic and pericytoplasmic staining for the IL-17 cytokine as well as nuclear and cytoplasmic staining for RORγt. It was observed statistical significance difference on the quantity of immunopositive lymphocytes to IL-17 between the groups of SCC of lip and tongue (p=0,028). For the RORγt it was not observed statistical significance difference between the groups of SCC of lip and tongue (p=0,915). It was not observed statistical difference between the immunostaining of IL-17 and RORγt with histological gradation of malignancy and clinical staging. The findings of this research suggest a possible anti-tumor role of IL-17 for cases of lip. The results of the analysis of the RORγt are possibly due to the wide duality of the anti-tumor and protumoral role of the Th17 cells and their plasticity which, in the presence of different cytokines expressed on the tumor microenvironment, can alter its phenotype.

Análise da imuno expressão das proteínas IL-17, IL-23 E RORγt na patogenia da doença periodontal

Periodontal disease is a chronic inflammatory condition primarily caused by bacteria in dental biofilm, which interact with the host, thus determining the nature of the resulting disease. Despite the wide knowledge about the pathogenesis of these diseases, the exact composition of the T cell profile during the active phase of the disease (Th1, Th2 or Th17) remains unknown. This study aimed to evaluate by immunohistochemical expression, the presence of the markers (IL-17, IL-23 and RORγt), involved in Th17 response in clinically healthy gingiva cases (n = 32), biofilm-induced gingivitis (n = 30), chronic periodontitis (n = 32) and aggressive periodontitis (n = 25), in order to analyze if the expression and/or distribution of these molecules in lymphocytes and macrophages, present in the inflammatory infiltrate of periodontal tissue, influences the tissue destruction observed in these diseases. The morphological analysis of cases was performed which assessed the intensity of the inflammatory infiltrate in mild, moderate and intense. For each case, in the area with the most representative immunostaining, 5 fields were chosen and analyzed, both for the intensity of the inflammatory infiltrate as for the quantity of immunostained cells, based on predetermined scores: score 0 (absence of inflammatory infiltrate/immunostaining), score 1 (the infiltrate/immunostaining covered less than 25% of the field area), score 2 (the infiltrate/immunostaining occupied between 25 and 50%) and score 3 (infiltrate/immunostaining present in over 50% of the field area). From this, a median was generated representing each case. The intensity of the inflammatory infiltrate correlated with the disease progression, in other words, it was crescent from clinically healthy gingiva to aggressive periodontitis (P <0.001). It was detected the presence of IL-17, IL-23 and RORγt in most of the evaluated cases and the number of immunostained cells correlated with the intensity of the inflammatory infiltrate (P <0.001) and with the clinical parameters analyzed (P <0.001), showing a positive correlation, mainly moderate. Aggressive periodontitis showed a higher percentage of immunostaining for all markers in relation to other clinical conditions assessed, suggesting a possible association of these markers with the progression of this disease, in which the higher the loss of periodontal support, the greater the amount of inflammatory infiltrate and larger the number of immunostained cells.