title: Involvement of T-lymphocytes in periodontal disease and in direct and indirect induction of bone resorption.
abstract: Periodontal disease is a peripheral infection involving species of gram-negative organisms. T-lymphocytes can be found in the dense inflammatory infiltrate in this disease. CD4+ and CD8+ T-cells are present in periodontal lesions, as are memory/activated T-lymphocytes. In addition, Th1- and Th2-type T-lymphocytes and their associated cytokines with a subtle polarization to Th1 may be present. Th1-type T-cells up-regulate the production of pro-inflammatory cytokines IL-1 and TNF-alpha, which can induce bone resorption indirectly by promoting differentiation of osteoclast precursors and subsequently by activating osteoclasts. Such osteoclast differentiation is dependent on stimulation of osteoprotegerin ligand (OPG-L) production by osteoblastic cells. By contrast, activated T-cells, by virtue of direct production and expression of OPG-L, can directly promote osteoclast differentiation. OPG-L appears to be predominantly expressed on Th1-type cells. The direct and indirect T-cell involvement in periodontal bone resorption appears to be dependent on the degree of Th1-type T-cell recruitment into inflamed gingival tissues. This T-cell recruitment is regulated by adhesion molecules and chemokines/chemokine receptors. The adhesion molecules involved include alpha4 and alpha6 integrins, LFA-1, and ICAM-1. The Th1-type T-cells preferentially express CCR5 and CXCR3, which are found prominently in diseased gingivae. By contrast, little CCR4, expressed by Th2-type T-cells, can be detected. Also, the chemokine ligands RANTES, MIP1-alpha (both CCR5), and IP-10 (CXCR3 ligand) were elevated in inflamed periodontal tissues. The T-cell features in diseased periodontal tissues can be compared with those in rheumatoid arthritis, wherein bone resorption often attributed to Th1-type T-cell involvement has also been demonstrated.
authors.affiliation: Department of Immunology, The Forsyth Institute, Boston, MA 02115-3799, USA. mtaubman@forsyth.org
authors.forename: M A
authors.initials: MA
authors.lastname: Taubman
authors.forename: T
authors.initials: T
authors.lastname: Kawai
mesh_terms: D016301:Alveolar Bone Loss / Q000276:immunology*; D000818:Animals; D002352:Carrier Proteins / Q000096:biosynthesis; D015815:Cell Adhesion Molecules / Q000096:biosynthesis; D002454:Cell Differentiation; D018925:Chemokines / Q000096:biosynthesis; D006801:Humans; D007375:Interleukin-1 / Q000096:biosynthesis; D008562:Membrane Glycoproteins / Q000096:biosynthesis; D010010:Osteoclasts / Q000502:physiology; D010518:Periodontitis / Q000276:immunology*; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; D019707:Receptors, Chemokine / Q000096:biosynthesis; D016176:T-Lymphocyte Subsets / Q000378:metabolism*; D018417:Th1 Cells / Q000378:metabolism*; D018418:Th2 Cells / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis; D015854:Up-Regulation
chemical_list: D002352:Carrier Proteins; D015815:Cell Adhesion Molecules; D018925:Chemokines; D007375:Interleukin-1; D008562:Membrane Glycoproteins; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; D019707:Receptors, Chemokine; C505686:TNFRSF11A protein, human; C505688:TNFSF11 protein, human; D014409:Tumor Necrosis Factor-alpha