title: Cell-mediated immune system regulation in periodontal diseases.
abstract: The adaptive immune system consists of humoral and cell-mediated immunity. T-lymphocytes are the key components of cell-mediated immunity. CD4+ helper T-lymphocytes facilitate B-cells to differentiate and produce specific antibodies, whereas CD8+ cytotoxic T-lymphocytes kill virally infected cells. Periodontal diseases have been associated with a variety of imbalances in the regulation of immune responses. Changes in the ratios of peripheral blood CD4+ and CD8+ T-lymphocytes, depressed proliferative responses of peripheral blood lymphocytes, and increased frequency of CD45RO+ memory T-lymphocytes in diseased tissues have been reported in individuals with various forms of periodontal disease. While some studies have shown an increased frequency of gamma delta + T-cells in periodontal lesions, the role of gamma delta + T-cells in periodontal disease remains controversial. The ability of putative periodontopathic bacteria selectively to stimulate certain V beta-expressing T-cells is intriguing and could determine whether a CD4+ Th1 or a CD4+ Th2 cell response is elicited. The prominence of a particular subset of helper T-cells within the periodontal lesion could be a reflection of the stage and activity of the disease, or the types of bacteria present. Regardless, longitudinal studies of the involvement of T-cell subsets and cytokines in periodontal disease are clearly needed.
authors.affiliation: Department of Oral Science, School of Dentistry, University of Minnesota, Minneapolis, USA.
authors.forename: A
authors.initials: A
authors.lastname: Mathur
authors.forename: B S
authors.initials: BS
authors.lastname: Michalowicz
mesh_terms: D000942:Antigens, Bacterial / Q000276:immunology; D016516:CD4-CD8 Ratio; D005881:Gingiva / Q000276:immunology; D006801:Humans; D007156:Immunologic Memory; D007694:Killer Cells, Natural / Q000276:immunology; D008213:Lymphocyte Activation; D010518:Periodontitis / Q000276:immunology*; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000276:immunology; D018089:Superantigens / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology*
chemical_list: D000942:Antigens, Bacterial; D016692:Receptors, Antigen, T-Cell, gamma-delta; D018089:Superantigens