The changes in T lymphocyte subsets following periodontal treatment in patients with chronic periodontitis

Evaluation of morphological, histological, and immune-related cellular changes in ligature-induced experimental periodontitis in mice

Background/purpose

The ligature-induced periodontitis model is an effective approach to induce inflammation and bone loss similar to that of human periodontitis. Previous clinical and in vitro studies have shown the involvement of lymphocytes in periodontitis, while, the local and systemic profile of immune cells associated with periodontitis in the ligature-induced periodontitis model in mice remains unclear.

Materials and methods

Experimental periodontitis was constructed in mice by ligating around the maxillary second molars for 14 and 28 days, respectively. Alveolar bone loss was assessed by micro-computed tomography (micro-CT). Hematoxylin and eosin (H&E) and tartrate-resistant acid phosphatase (TRAP) staining were used to evaluate the histological changes in the periodontal tissues. B and T cells in the cervical lymph nodes, spleen, and peripheral blood were analyzed by flow cytometry.

Results

The 14-day ligation effectively induced significant periodontal inflammation and alveolar bone loss in C57BL/6J mice, which were progressive and maintained for a relatively long-term period until day 28. In addition, CD3+ T cells and CD19+ B cells were the dominant population in both health and disease, and the B cell population within the cervical lymph nodes (LN) increased significantly under periodontitis condition, while, no significant differences of the T and B cell population among the spleen and peripheral blood were observed.

Conclusion

The ligature-induced periodontitis mice model was established to perform a longitudinal assessment of changes in periodontal tissues morphologically and histologically, meanwhile, explore the local and systemic changes of the predominant immune-associated cells.

Changes of Oral Flora, Inflammatory Factors, and Immune Function Indicators in Patients with Chronic Periodontitis and Their Clinical Significance

This research focuses on investigating the changes of oral flora, inflammatory factors, and immune function indicators in patients with chronic periodontitis (CP) and their clinical significances. Clinical indices such as gingival index (GI) and sulcus bleeding index (SBI) of the study subjects were recorded. The levels of oral flora, inflammatory factors and T lymphocyte subsets in gingival crevicular fluid (GCF) of the study subjects were measured. To analyze the correlation between GI and gingival SBI and oral flora, inflammatory factors, and immune function indicators, Pearson correlation analysis was performed. Porphyromonas gingivalis, Streptococcus digestiveis, Prevotella intermedia, Veronococcus, tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), IL-8, CD3+, CD4+, and CD4+/CD8+ had a positive correlation with GI and SBI, while IL-10 and CD8+ were negatively correlated with GI and SBI. Oral flora, inflammatory factors and immune function indicators levels are largely elevated in patients with CP and they are correlated with CP clinical indicators.

Differences between inflammatory and catabolic mediators of peri-implantitis and periodontitis lesions following initial mechanical therapy: An exploratory study

BACKGROUND AND OBJECTIVE

The aim of this study was to analyze the differences in inflammatory and catabolic mediators expressed in peri-implantitis compared to periodontitis lesions after non-surgical therapy. Peri-implantitis is associated with a faster rate of bone loss when compared with periodontitis, and peri-implant non-surgical therapy is ineffective to cure peri-implantitis. This may be due to persistent inflammation in peri-implantitis tissues after initial mechanical treatment.

MATERIAL AND METHODS

Eleven patients with peri-implantitis and 10 with severe chronic periodontitis received non-surgical therapy. They were included at re-evaluation (8 weeks) if they presented pocket depth ≥6 mm with bleeding on probing, and the indication for open flap debridement surgery. Connective tissues were harvested during surgery from diseased sites. Healthy gingiva were harvested during third molar extraction in a third group of healthy patients (n=10). Explants were incubated for 24 hours in media culture and the release of cytokines, chemokines, growth factors, osteoprotegerin, receptor activator of nuclear factor kappa-B ligand (RANKL), matrix metalloproteinase and tissue inhibitors of matrix metalloproteinase (TIMP) in the conditioned media was analyzed by an exploratory multiplex immunoassay. When difference was found in the conditioned media, an immunohistochemistry was performed to compare expression in the tissues.

RESULTS

Connective tissues from non-stabilized peri-implantitis exhibited a distinct cytokine profile compared to periodontitis lesions that did not respond to initial therapy. Indeed, TIMP-2 was significantly increased in media from peri-implantitis (P≤.05). In addition, the in situ expression of TIMP-2, interleukin-10 and RANKL was also significantly increased in peri-implantitis tissues (P≤.05). However, the ratio of RANKL/osteoprotegerin-positive cells did not vary (P≥.05).

CONCLUSION

This study suggests that peri-implantitis and periodontitis connective tissues exhibit differences in response to non-surgical treatment, which may contribute to a different pattern of disease evolution.

Chlamydia felis: Lack of association between clinical signs and the presence of the cryptic plasmid

Chlamydia felis is an obligate intracellular bacterial pathogen that infects cats, causing severe conjunctivitis associated with upper respiratory tract disease (URTD). In the present study, 186 cats from three non-commercial catteries in São Paulo, SP, Brazil were evaluated. The detection of Chlamydia felis was performed by PCR. The clinical severity was scored from 1 to 4, with a score of 4 as the most severe manifestation. The total occurrence of C. felis was of 18.82% (35/186) of cats overall, but notably, 58.06% (18/31) of infected cats originated from a single cattery. All animals harboring C. felis had URTD clinical signs and higher scores (3 and 4). In addition, C. felis occurrence was associated with the presence of cryptic plasmid. However, the virulence and clinical severity were not correlated.

Response of subgingival bacteria to smoking cessation

It has been demonstrated that smoking cessation alters the subgingival microbial profile; however, the response of individual bacteria within this ecosystem has not been well studied. The aim of this investigation, therefore, was to longitudinally examine the effect of smoking cessation on the prevalence and levels of selected subgingival bacteria using molecular approaches for bacterial identification and enumeration. Subgingival plaque was collected from 22 smokers at the baseline and 12 months following periodontal nonsurgical management and smoking cessation counseling. The prevalence and abundance of selected organisms were examined using nested PCR and multiplexed bead-based flow cytometry. Eleven subjects successfully quit smoking over 12 months (quitters), while 11 continued to smoke throughout (smokers). Smoking cessation led to a decrease in the prevalence of Porphyromonas endodontalis and Dialister pneumosintes at 12 months and in the levels of Parvimonas micra, Filifactor alocis, and Treponema denticola. Smoking cessation also led to an increase in the levels of Veillonella parvula. Following nonsurgical periodontal therapy and smoking cessation, the subgingival microbiome is recolonized by a greater number of health-associated species and there are a significantly lower prevalence and abundance of putative periodontal pathogens. The results indicate a critical role for smoking cessation counseling in periodontal therapy for smokers in order to effectively alter the subgingival microbiome.

Acute inflammation at a mandibular solitary horizontal incompletely impacted molar

Acute inflammation is frequently seen in the elderly around incompletely impacted molars located apart from molars or premolars. To identify the factors causing acute inflammation in the solitary molars without second molars or without second and first molars, ages of patients and rates of acute inflammation in 75 horizontal incompletely impacted mandibular molars in contact or not in contact with molars in subjects 41 years old or older were studied using orthopantomographs. Acute inflammation was seen in nine third molars out of 48 third molars in contact with second molars (18.8%), whereas acute inflammation was seen in 11 molars out of 19 solitary molars without second molars or without first and second molars (57.9%) (p < 0.01). The mean age of 48 subjects with third molars in contact with the second molar was 50.42 +/- 7.62 years, and the mean age of 19 subjects with isolated molars was 65.16 +/- 10.41 years (p < 0.0001). These indicate that a solitary horizontal incompletely impacted molar leads more frequently to acute inflammation along with aging due to possible bone resorption resulting from teeth loss.

The changes in the T-lymphocyte subsets in a population of Turkish children with puberty gingivitis

OBJECTIVE

The aim of the study was to investigate the number of CD4 and CD8 T lymphocytes, analyse subjects with gingivitis and those without, and determine the role of T lymphocytes in the pathobiology of puberty gingivitis.

MATERIAL AND METHODS

Fifty individuals with and without puberty gingivitis were recruited for this study. The CD4(+) and CD8(+) T-lymphocyte counts were determined using flow cytometry on the biopsy samples, and the CD4(+)/CD8(+) ratio was calculated. At the same time, periodontal index scores were recorded to assess the periodontal status. Acquired data were analysed statistically using a paired t-test to compare laboratory values obtained before and after the treatment in individuals with puberty gingivitis and disease-free individuals. In addition, Pearson's correlation analysis was performed to investigate the relation between laboratory values and clinical measurements.

RESULTS

The CD4(+)/CD8 ratio in gingival tissues obtained from test group was significantly higher (P < 0.05) than that found in the gingival tissue obtained from control group. We found that the CD4(+) and CD8(+) lymphocyte counts continued to increase significantly (P < 0.001) and the CD4(+)/CD8(+) ratio continued to drop significantly (P < 0.05) after treatment in test group.

CONCLUSIONS

T lymphocytes could play a significant role in the pathobiology of puberty gingivitis.

Gene expression in periodontal tissues following treatment

BACKGROUND

In periodontitis, treatment aimed at controlling the periodontal biofilm infection results in a resolution of the clinical and histological signs of inflammation. Although the cell types found in periodontal tissues following treatment have been well described, information on gene expression is limited to few candidate genes. Therefore, the aim of the study was to determine the expression profiles of immune and inflammatory genes in periodontal tissues from sites with severe chronic periodontitis following periodontal therapy in order to identify genes involved in tissue homeostasis.Gingival biopsies from 12 patients with severe chronic periodontitis were taken six to eight weeks following non-surgical periodontal therapy, and from 11 healthy controls. As internal standard, RNA of an immortalized human keratinocyte line (HaCaT) was used. Total RNA was subjected to gene expression profiling using a commercially available microarray system focusing on inflammation-related genes. Post-hoc confirmation of selected genes was done by Realtime-PCR.

RESULTS

Out of the 136 genes analyzed, the 5% most strongly expressed genes compared to healthy controls were Interleukin-12A (IL-12A), Versican (CSPG-2), Matrixmetalloproteinase-1 (MMP-1), Down syndrome critical region protein-1 (DSCR-1), Macrophage inflammatory protein-2beta (Cxcl-3), Inhibitor of apoptosis protein-1 (BIRC-1), Cluster of differentiation antigen 38 (CD38), Regulator of G-protein signalling-1 (RGS-1), and Finkel-Biskis-Jinkins murine osteosarcoma virus oncogene (C-FOS); the 5% least strongly expressed genes were Receptor-interacting Serine/Threonine Kinase-2 (RIP-2), Complement component 3 (C3), Prostaglandin-endoperoxide synthase-2 (COX-2), Interleukin-8 (IL-8), Endothelin-1 (EDN-1), Plasminogen activator inhibitor type-2 (PAI-2), Matrix-metalloproteinase-14 (MMP-14), and Interferon regulating factor-7 (IRF-7).

CONCLUSION

Gene expression profiles found in periodontal tissues following therapy indicate activation of pathways that regulate tissue damage and repair.

CD137L- and RANKL-mediated reverse signals inhibit osteoclastogenesis and T lymphocyte proliferation

Members of the tumor necrosis factor-related family of ligands and receptors appear to be critical regulators of osteoclastogenesis and various cellular responses in T cells. In the present study, we have investigated CD137L and RANKL (receptor activator of nuclear factor (NF)-kappaB ligand)-induced biological responses in osteoclasts and T cells, respectively. Osteoclast-like cells were generated from murine bone marrow in the presence of RANKL and monocyte-macrophage colony-stimulating factor (M-CSF). RAW264.7 cells (murine monocytic cell line) constitutively express CD137L. Ligation of CD137L with anti-CD137L mAb (TKS-1) inhibits RANKL-induced osteoclast formation in a dose-dependent manner. Bone marrow cells expressed CD137L only when induced by treatment with M-CSF. In bone marrow cells, cross-linking of CD137L with anti-CD137L mAb (TKS-1) inhibits M-CSF/RANKL-evoked formation of multi-nucleated osteoclasts. Further we examined RANKL-mediated regulation of T cell proliferation. Both mouse CD4(+) and CD8(+) T cells expressed RANKL following their activation by anti-CD3 Ab and anti-CD137 Ab. Ligation of RANKL with OPG-Fc, the decoy receptor for RANKL, inhibited both mouse CD4(+) and CD8(+) T cell proliferation. From the above results, we suggest that the cellular responses in cell-to-cell interactions between T cells and osteoclasts are regulated through reciprocal regulations of CD137/CD137L and RANK/RANKL interactions.

The effects of age and gender on gingival tissue and peripheral blood T-lymphocyte subsets: a study in mice

The aim of this study is to investigate the effects of age and gender on relative number of CD4+ and CD8+ T lymphocyte and CD4+/CD8+ ratios in gingival tissue and peripheral blood of periodontally healthy BALB/c mice with flow cytometric analysis. The study was carried out on periodontally healthy 60 BALB/c mice. They were separated into five groups according to the life expectancy: Group I (newborn, 1-10 days old), Group II (age at weaning, 21-28 days old), Group III (age of sexual maturity, puberty, 7-8 weeks old), Group IV (adult, 8 months old), and Group V (the aged, 14 and over). Males and females were equally represented in each group. CD4+ and CD8+ T lymphocytes and CD4+/CD8+ ratio values in gingival tissue and peripheral blood were determined using flow cytometry in the biopsy samples. The relative number of CD8+ T lymphocyte in gingival tissue was higher in puberty (p < 0.05) and the aged (p < 0.05), with more significantly difference in males (p < 0.05). The CD4+/CD8+ ratios in gingival tissue were lower in puberty group and the-aged groups compared to the other groups (p < 0.05). The peripheral blood CD4+/CD8+ ratio increased in puberty and the aged groups. These differences were more significant in females than in males (p < 0.05). There were considerable negative correlations between CD4+/CD8+ T lymphocyte ratio in gingival tissue and CD4+/CD8+ T lymphocyte ratio in peripheral blood in puberty (r = 0.647, p < 0.01) and the aged ( r = 0.599, p < 0.05). In conclusion, our data suggest that CD4+/CD8+ T lymphocyte ratios in peripheral blood increase periodontally healthy mice in puberty and the old groups, while CD4+/CD8+ T lymphocyte ratios in gingival tissue decrease in the same groups. The relative number of CD8+ T lymphocytes increases in gingival tissue in puberty and the old groups when it decreases in peripheral blood. Results from this study indicated that periodontally healthy BALB/c mice may represent important information to determine the character of an immune response in the course of a lifetime.