Investigation of the effect of smoking on regulatory T cell biomarkers in healthy individuals and periodontitis patients

The aim of this study is to determine the effects of smoking which are biomarkers of regulatory T cells (Treg) on Forkhead Box Protein 3 (FOXP3), Cluster of Differentiation 69 (CD69), Interleukin-2 (IL-2), Transforming Growth Factor-Beta 1 (TGF-β1) and Janus Kinase 3 (JAK3) in the gingival tissues of healthy individuals and individuals with periodontitis. This study is a cross-sectional study including a total of 36 patients, 21 males and 15 females. In the study there are a total of 4 groups including, healthy group (7 women and 2 men, group A), healthy group of smokers (4 women and 5 men, group B), periodontitis stage III degree C group (3 women and 6 men, group C) and smoker periodontitis stage III degree C group (9 men, group D). In the gingival tissue samples obtained from these patients; FOXP3, CD69, IL-2, TGF-β1, JAK3 expressions were evaluated by immunohistochemistry method in epithelial tissue (ED) and connective tissue (BD). According to the findings, Group C shows statistically significant higher FOXP3, CD69, IL-2 expression compared to Group A (p < 0.001). JAK3-BD values are also higher in Group C than in Group A (p< 0.001). TGF-β1-ED and JAK3-ED were lower in Group C than in Group A (p< 0.05); JAK3-BD is higher (p< 0.001). Group B shows lower TGF-β1-ED (p< 0.05), higher IL-2-BD, CD69-ED, CD69-BD, FOXP3-ED and JAK-BD values than Group A (p< 0,001). Group D has higher CD69-ED, IL-ED, TGF-β1-BD values and lower FOXP3-BD values than than Group C (p< 0.001). In conclusion; FOXP3, CD69, IL-2 expression increases in periodontitis; TGF-β1 and JAK3 values decrease in the epithelium and increase in the connective tissue. Smoking stimulates CD69 and IL-2 expression. It stimulates FOXP3 and JAK3 expression in healthy individuals and suppresses FOXP3 in individuals with periodontitis. Smoking suppresses TGF-β1 expression through the epithelium in healthy individuals and stimulates it through the connective tissue in diseased individuals. Keywords: Treg, FOXP3, JAK3, periodontitis, smoking