The Expression of B7-H3 Molecule in Periodontal Disease.

STATEMENT OF THE PROBLEM: T cells have been shown to play a role in the etiopathogenesis of periodontal disease. B7-H3, a costimulatory molecule, is found to be associated with regulation of T cell function in some tumoral tissues, as well as autoimmune and inflammatory diseases. PURPOSE: The aim of this study was to investigate the expression of B7-H3 molecule in healthy and diseased gingival tissue samples. MATERIALS AND METHOD: Gingival samples were taken from 2 groups (A and B) representing periodontal health and periodontal disease, respectively. These were paraffinized and processed to carry out immunostaining to identify B7-H3 expression. The slides were then examined under light microscope to assess the positive staining in epithelium and connective tissue. The intensity of positive staining in epithelium and the number of positive cells in the connective tissue were evaluated. Statistical analysis was done using kappa analysis and independent t-test. RESULTS: Kappa analysis revealed good inter-examiner agreement for both the groups (group A: 0.718; group B: 0.797). Intensity of staining in the epithelium ranged from intense to moderate for both the groups. In the connective tissue, there was a statistically insignificant decrease (p value= 0.415) in the number of positive cells from group A (mean labeling index: 50.28±26.09) to group B (mean labeling index= 41.37±25.29). CONCLUSION: B7-H3 molecule has been found to be expressed in gingival tissue samples; however, it showed a statistically insignificant decrease in periodontal disease group compared to healthy group.

Plasticity of T helper cell subsets: Implications in periodontal disease.

T helper (Th) cells have an important role in host defence as well in the pathogenesis of periodontal disease. Th cells differentiate from naive cells into various subsets, each of which is associated with a set of inducing and effector cytokines. Previously, it was thought that this differentiation was an irreversible event. Recent evidence suggest that even differentiated Th cells, retain the flexibility to transform from one lineage to another, a phenomenon referred to as plasticity. This plasticity is thought to be brought about by epigenetic modifications that are regulated by external and internal signals in the micro-environment of these cells. The factors and mechanisms which affect the plasticity of these cells and their potential role in the etio-pathogenesis of periodontal disease has been described in this article.