Distribution And Significance Of Th17 Cells And Treg Cells In Periodontitis Of Rats With Experimental Periodontitis

Objective: Periodontitis is a chronic inflammatory disease occurring in the tooth support tissue.The immune response of the host have an important influence on the development of periodontitis and destruction of periodontal tissues.Helper T cell 17(T helper cell 17,Th17)and regulatory T cells(regulation T cells,Treg)and its related cytokines,such as IL-17.TGF-beta,play an important role in the occurrence of periodontitis and alveolar bone resorption.In this study,we established periodontitis model in SD rats,and examined the distribution and expression level of Th17 cell specific transcription factor ROR gamma T and Treg cell specific transcription factor Foxp3 in periodontal tissues of maxillary first molar by immunohistochemical method.To explore the mechanism of Th17 and Treg cells in different stages of periodontitis,and to provide a preliminary theoretical basis for the interpretation of the occurrence and development of periodontitis.Methods: 30 adult female SD rats aged 8 weeks were selected and randomly divided into 3 groups(ABC): normal control group(group A),gingivitis group(B group),periodontitis group(C group),10 rats in each group,A group without any treatment,the remaining 2 groups were treated with orthodontic 0.2mm ligature rats with bilateral maxillary first molar and fed sugar water preparation experimental rat model of gingivitis and periodontitis.The specimens were collected at fourth and eighth weeks after the ligature of the periodontal ligature,and the first molar and its periodontal tissue were taken,and the continuous sections of the periodontium were made.The expression of ROR gamma T and Foxp3 in periodontium was detected by conventional HE staining and the establishment of osteoclast count to determine the periodontitis model.Results:1 The establishment of animal models of gingivitis and periodontitis1.1 Naked eye observation:4 weeks after ligation,intraperitoneal injection of chloral hydrate anesthesia,observe rat maxillary first molar gingiva and gingival papilla is red,gingival swelling,bleeding on probing,but without significant exploration and periodontal pockets,the diagnosis of gingivitis;when the rats were 8 weeks after operation,in addition to swollen gums probe,bleeding,but also of the periodontal pocket,the diagnosis of periodontitis.2 HE staining results of periodontal tissue:In the normal group,the epithelium in the sulcus was intact,and the epithelium was normal.There was no inflammatory cell infiltration in the gingival epithelium.The periodontal ligament fibers arranged orderly and regularly,and the alveolar bone edges were clear and intact.No osteoclasts were found.In gingivitis group,the epithelium in the sulcus was intact,and the location of the epithelium was normal.The connective tissue in the gingival was edema.There were inflammatory cell infiltration,increased capillaries and dilated lumen.The number of spikes in the epithelium increased,elongated,the periodontal ligament was arranged normally,the edge of the alveolar bone was clear and complete,and no osteoclasts were found.Periodontitis group: epithelial reticular degeneration,connective tissue hyperplasia,edema and degeneration of collagen fibers,inflammatory cells,periodontal ligament gap widened,alveolar crest and alveolar bone irregular shape,bone resorption,alveolar damage,there were more osteoclasts in bone resorption.The absorption of alveolar bone near the root tip.3 Immunohistochemical results of periodontiumThe expression level of ROR gamma t in gingivitis group was higher than that in normal group,and there was a significant difference between the three groups(P < 0.05).The expression level of Foxp3 in gingivitis group was higher than that in periodontitis group and normal group.The Foxp3 expression level in periodontitis group was higher than that in normal group,and there was a significant difference between three groups(P < 0.05).Conclusions:1.ROR gamma t for the occurrence and development of specific transcription factor of Th17 cells and related cytokines and periodontal inflammation is closely related,can reflect the severity of periodontal inflammation.2.Foxp3 for the development of specific transcription factor of Treg cells and related cytokines can inhibit the periodontitis group.3.In inflammation group,there was a negative correlation between ROR gamma T and Foxp3 photometric value.Indicating that the imbalance of Th17 and Treg cells appeared with the development of periodontal inflammation.