Expression Of Tim-3 And Galectin-9 On Macrophages In Gingival Tissue Of Human Chronic Periodontitis

Background and objectiveChronic periodontitis is a kind of chronic infectious disease caused by oral mixed bacteria.Macrophages(M?)are an important part of the innate immune system of human body.They are not only capable of recognizing pathogens,phagocytizing bacteria and foreign bodies,but also play the role of antigen presentation and immune regulation in the acquired immune response.T cell immunoglobulin-containing protein-3(Tim-3)is a negative regulator of T cell function,belonging to the Tim family,which is mainly expressed in T cells,M?and dendritic cells.Tim-3 is the main receptor of galectin-9.Galectin-9binds to Tim-3 specifically,Galectin-9 can activate galectin-9-Tim-3 signaling pathway,inhibit CD4~+T cells and CD8~+T cells,produce inhibition signals and lead to Th1 cell apoptosis.Galectin-9 can also induce intracellular Ca2~+outflow,activate caspase-1 signaling pathway or apoptosis signaling pathway,further promote Tim3~+-Th1 cell apoptosis and inhibit Th1 mediated immune response.At present,there is no report on the role of macrophages Tim-3 and galectin 9 in chronic periodontitis.At present study,the expression of Tim-3 and galectin-9 on macrophages in gingival tissue with periodontitis was observed to explore the role and mechanism of Tim-3 and galectin-9 on macrophages in periodontitis.The results will provide a scientific theoretical basis for the follow-up immunoprophylaxis and treatment of chronic periodontitis with macrophages Tim-3 and galectin-9 as targets.MethodsAccording to the severity of periodontitis,80 gingival tissue samples were divided into four groups:20 healthy control group,20 slight chronic periodontitis group,20 moderate chronic periodontitis group and 20 severe chronic periodontitis group.The tissue samples were fixed with 10%formalin,embedded,sectioned and stained with HE.The histological changes of each group were observed under the light microscope and the inflammation scores were made.The expression of CD68-Tim-3 double positive M?and CD68-Gal-9 double positive M?in gingival tissue was observed by double immunofluorescence staining(DIF).Results1.Histological observation results1)The infiltration of inflammatory cells in gingival tissue of each periodontitis group was significantly higher than that of healthy group,and the inflammatory degree score of chronic periodontitis group was significantly higher than that of healthy group(P<0.01);2)The score of inflammation degree in moderate chronic periodontitis group was significantly higher than that of slight chronic periodontitis group(P<0.01);3)The score of inflammation degree in severe chronic periodontitis group was higher than that of slight and moderate chronic periodontitis group significantly(P<0.01).2.Double-immunofluorescence staining resultsCompared with the healthy control group,the cell density of CD68-Tim-3double positive M?and CD68-Gal-9 double positive M?in the three groups increased significantly(P<0.01);the cell density of CD68-Tim3 double positive M?and CD68-Gal-9 double positive M?in the severe periodontitis group was significantly higher than that of the moderate periodontitis group(P<0.01);the cell density of CD68-Tim-3 double positive M?and CD68-Gal-9double positive M?in the moderate periodontitis group was higher than that of the slight periodontitis group significantly(P<0.01).Conclusions1.In chronic periodontitis,with the aggravation of the pathological changes of periodontitis,the score of inflammation degree increased significantly.2.The cell density of CD68-Tim-3 double positive M?and CD68-Gal-9 double positive M?increased with the aggravation of chronic periodontitis,suggesting that the CD68-TIM-3 and CD68-Gal-9 double positive M?may play important roles in the initiation,development and pathogenesis of the human chronic periodontitis.