Immunolocalization Of IL-17F In Human Apical Periodontitis Lesions

Objective T lymphocytes and it’s cytokines have been found in variable quantities in human and experiment models of periapical lesions. Interleukin (IL)-17F is a novel cytokine and is derived from a recently discovered Th17cells. IL-17F is known to induce several cytokines and chemokines. However, its involvement in periapical lesions has not been well understood. To this end, this research adopt immunohistoehemistry method to deteet the expression and distribution of IL-17F during the development of periapical lesions, and measure the integrated optical density average value(A)with image analysis instruments of the IL-17F positive sites in both apical periapical cyst and apical periapical granuloma.Methods Human apical periodontitis lesions were collected in Department of pathology after periapical surgery in Oral and Maxillofacial Surgery of Anhui Medical University Affiliated Stomatological Hospital from November1,2009to August1,2011.33periapical cysts and18periapica granulomas were selected for immunohistochemical analysis for IL-17F. Five alveolar bone samples were obtained from agroup of impacted third molars recommended for extraction.These tissues did not show any inflammation and were used as normal control samples. Differences in IL-17F expression between tissue with periapical cyst and periapica granuloma were subsequently analyzed by rank-sum test.Results1.Epithelial cells, lymphocytes and endothelial cells presented IL-17F positive immunostaining in both types of lesions.Howere, IL-17F expression was not de-tected in the healthy alveolar bone samples.2.The expression of IL-17F in apical cyst and apical granuloma was significant differences. In apical periapical cyst samples, IL-17F signal was mainly expressed in epithelial cells(100%),lymphocytes(100%)followed by endothelial cells (36.4%) and fibroblasts(15.2%).But,in apical periapical granuloma samples, IL-17F was mainly expressed in lymphocytes(100%) followed by endothelial cells(88.9%) and fibroblasts(65.0%).The integrated optical density average value(A) of IL-17F positive sites in the apical periapical cyst tissue is0.8852±0.0576,while the integrated optical density average value(A) value of IL-17F positive sites in the apical periapical granuloma tissue is0.2365±0.0708.The rank-sum test was applied for the statistical analysis of the results.A P-value of<0.05was considered to be statistically significant.Conclusions1.These findings first showed that IL-17F could be observed and might possibly be involved in the inflammatory response and bone resorption of periapical tissues as well asassociated with periapical lesion pathogenesis.2.The expression of IL-17F in apical periapical cyst and apical periapical granuloma was significant differences. The mechanisms of granuloma can be converted to inflammatory cysts may be the differential expresion of IL-17F in periapical lesions.