transforming-growth-factor-beta and Periapical-Diseases

The chronic inflammatory immune response triggered by the infection of the tooth root canal system results in the local upregulation of RANKL, resulting in periapical bone loss. While RANKL has a well-characterized role in the control of bone homeostasis/pathology, it can play important roles in the regulation of the immune system, although its possible immunoregulatory role in infectious inflammatory osteolytic conditions remains largely unknown. Here, we used a mouse model of infectious inflammatory periapical lesions subjected to continuous or transitory anti-RANKL inhibition, followed by the analysis of lesion outcome and multiple host response parameters. Anti-RANKL administration resulted in arrest of bone loss but interfered in the natural immunoregulation of the lesions observed in the untreated group. RANKL inhibition resulted in an unremitting proinflammatory response, persistent high proinflammatory and effector CD4 response, decreased regulatory T-cell (Treg) migration, and lower levels of Treg-related cytokines IL-10 and TGFb. Anti-RANKL blockade impaired the immunoregulatory process only in early disease stages, while the late administration of anti-RANKL did not interfere with the stablished immunoregulation. The impaired immunoregulation due to RANKL inhibition is characterized by increased delayed-type hypersensitivity in vivo and T-cell proliferation in vitro to the infecting bacteria, which mimic the effects of Treg inhibition, reinforcing a possible influence of RANKL on Treg-mediated suppressive response. The adoptive transfer of CD4+FOXp3+ Tregs to mice receiving anti-RANKL therapy restored the immunoregulatory capacity, attenuating the inflammatory response in the lesions, reestablishing normal T-cell response in vivo and in vitro, and preventing lesion relapse upon anti-RANKL therapy cessation. Therefore, while RANKL inhibition efficiently limited the periapical bone loss, it promoted an unremitting host inflammatory response by interfering with Treg activity, suggesting that this classic osteoclastogenic mediator plays a role in immunoregulation.

Topics: Adoptive Transfer; Alveolar Bone Loss; Animals; Antibodies, Monoclonal; Cell Proliferation; Cell Survival; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Flow Cytometry; Gene Expression; Immunity, Mucosal; Inflammation; Infliximab; Interleukin-10; Lymphocyte Activation; Male; Mice; Mice, Inbred C57BL; Osteolysis; Periapical Diseases; RANK Ligand; Real-Time Polymerase Chain Reaction; T-Lymphocytes, Regulatory; Transforming Growth Factor beta

To examine cytokine expression profiles during periapical lesion development in response to synergetic human pathogens in a gnotobiotic mouse model.. Human strains of Fusobacterium nucleatum and Peptostreptococcus prevotii were inoculated into the root canals of germ-free mice in either mono- or bi-association. Animals were killed 7 and 14 days after infection, and periapical tissues were collected. mRNA expression of the cytokines IFN-γ, TNF-α, Receptor activator of nuclear factor kappa-B ligand (RANKL), IL-10, IL-4 and transforming growth factor β (TGF-β) was assessed using real-time PCR. Levene's test was used to assess the equality of variance of the data, whereas a t-test for independent samples was used to evaluate the significance of the differences between groups (P < 0.05).. The mRNA expression of IFN-γ and TNF-α was up-regulated by F. nucleatum during the acute (day 7) and chronic phase (day 14) of periapical lesion development. However, in bi-infection the expression of IFN-γ and TNF-α were effectively absent at both time-points. RANKL mRNA expression was down-regulated during dual infection at the chronic phase. As IL-4 expression was similar at both time-points, IL-4 does not appear to be involved in the periapical response to these bacterial strains. IL-10 was up-regulated during the chronic phase by mono-infection with either F. nucleatum or P. prevotii. Dual infection increased TGF-β mRNA expression on day 7, which paralleled the decrease in IFN-γ and TNF-α mRNA levels at the same time-point. F. nucleatum increased TGF-β mRNA expression during the chronic phase.. Cytokine profiles depend on the nature of the bacterial challenge. Both TGF-β and IL-10 appeared to be regulating the proinflammatory cytokine responses at both time-points of the periapical immune response.

Topics: Animals; Coinfection; Cytokines; Dental Pulp Diseases; Fusobacterium Infections; Fusobacterium nucleatum; Germ-Free Life; Gram-Positive Bacterial Infections; Humans; Inflammation Mediators; Interferon-gamma; Interleukin-10; Interleukin-4; Mice; Peptostreptococcus; Periapical Diseases; RANK Ligand; Real-Time Polymerase Chain Reaction; RNA, Messenger; Time Factors; Transforming Growth Factor beta; Up-Regulation

CD4(+)CD25(hi)Foxp3(+) regulatory T-cells (Tregs) are of crucial importance in regulating the immune response, including the control of any defense against infection. Their presence in periapical lesions has not been demonstrated, as yet. We hypothesized that Tregs infiltrate periapical lesions, where they inhibit T-cell proliferation. The aim of this study was to characterize Tregs in periapical lesions by confocal microscopy, flow cytometry, and functional assays. We showed that CD4(+)CD25(hi)Foxp3(+) cells in periapical lesions expressed IL-10 and TGF-beta. Their frequency was significantly higher than in peripheral blood and correlated with the levels of TGF-beta and IL-10 in culture supernatants of periapical lesion mononuclear cells. Tregs inhibited the proliferation of responder T-cells in vitro, at least in part, by stimulating the production of IL-10. These findings suggest that CD4(+)CD25(hi)Foxp3(+) cells in periapical lesions may play regulatory roles in controlling local immune/inflammatory processes.

Topics: Adolescent; Adult; CD4 Antigens; CD4 Lymphocyte Count; Cell Proliferation; Cells, Cultured; Coculture Techniques; Flow Cytometry; Forkhead Transcription Factors; Glucocorticoid-Induced TNFR-Related Protein; Humans; Interleukin-10; Interleukin-2 Receptor alpha Subunit; Leukocytes, Mononuclear; Lymphocyte Activation; Microscopy, Confocal; Middle Aged; Periapical Diseases; Receptors, Nerve Growth Factor; Receptors, Tumor Necrosis Factor; T-Lymphocytes, Regulatory; Transforming Growth Factor beta; Young Adult

To investigate the effect of the treatment of periapical diseases with recombinant human netic protein (rhBMP-2) composite in dog models so as to provide basis for its clinical application.. The endotoxin-bacteria mixed fluid was injected into each root canal of the experimental teeth of dogs and the animal periapical were built. The rhBMP-2 composite was mixed by rhBMP-2, TCP, collagen and metronidazole and used in the treatment cal diseases in dog models as root apex screen. The imageology and pathology research were went on.. The effective rate of the experimental group was remarkably higher than that of the carrier group and the control group with remarkable ference (P < 0.05). The quality of the repair of tissue was obviously better than the two other groups.. The rhBMP-2 composite is a promising biological root-canal filling material.

Topics: Animals; Bone Morphogenetic Protein 2; Bone Morphogenetic Proteins; Collagen; Dogs; Humans; Periapical Diseases; Recombinant Proteins; Root Canal Filling Materials; Transforming Growth Factor beta