Expression of CD163, interleukin‐10, and interferon‐gamma in oral squamous cell carcinoma: mutual relationships and prognostic implications

Tumor‐associated macrophages (TAMs) and their associated inflammatory cytokines represent the major inflammatory component of the stroma of many tumors and can affect prognosis in the case of neoplasms. The objective of this study was to determine the prognostic significance of CD163⁺ cells, interleukin‐10 (IL‐10), and interferon‐gamma (IFN‐γ) in oral lesions associated with oral squamous cell carcinoma (OSCC). The levels of CD163, IFN‐γ, and IL‐10 in the tissue samples of 240 patients with OSCC and 58 patients with other oral lesions were assessed by immunohistochemistry. Individuals with low IFN‐γ levels, high IL‐10 levels, and low CD163 levels were of special concern with respect to OSCC progression. We found that high levels of CD163, or a combination of low IFN‐γ levels, high IL‐10 levels, and low CD163 levels, were associated with poorer overall survival (OS). CD163⁺ cells provide better predictive power for OS in comparison with traditional markers, such as clinical stage and lymph node metastasis. Therefore, CD163⁺ cells may be effective prognostic predictors of OSCC. IL‐10 may also indicate poor outcomes when IFN‐γ secretion is low and the cells are CD163^?.     

Distinct roles for interleukin‐12p40 and tumour necrosis factor in resistance to oral candidiasis defined by gene‐targeting

Cell‐mediated immunity is important for anti‐Candida host defence in mucosal tissues. In this study we used cytokine‐specific gene knockout mice to investigate the requirement for T helper type 1 (Th1) and Th2 cytokines in recovery from oral candidiasis. Knockout mice used in this study included interleukin‐4 (IL‐4), IL‐10, IL‐12p40, interferon‐γ (IFN‐γ), and tumour necrosis factor (TNF). The mice were challenged either orally or systemically with Candida albicans yeasts, and levels of colonization were determined. IL‐12p40 knockout mice developed chronic oropharyngeal candidiasis, but were not more susceptible to systemic challenge. On the other hand, TNF knockout mice displayed increased susceptibility to both oral and systemic challenge, but only in the acute stages of infection. TNF apparently has a protective effect in the acute stages of both oral and systemic candidiasis, whereas IL‐12p40 is essential for recovery from oral but not systemic candidiasis. The role of IL‐12p40, and its relation to T‐cell‐mediated responses remain to be determined.     

Effects of Resolvin D1 on Cell Survival and Cytokine Expression of Human Gingival Fibroblasts

Background: Tissue breakdown in periodontitis is initiated by bacteria, such as Porphyromonas gingivalis, and is caused largely by host responses. Resolvins protect the host against acute inflammation by blocking the migration of polymorphonuclear neutrophils to initiate resolution. The effects of resolvins on human gingival fibroblasts (HGFs) are unknown. This study examines the effects of resolvin D1 on HGF survival and cytokine expression when treated with or without P. gingivalis supernatant. Methods: Cytotoxicity of resolvin D1 on HGFs with or without a toxic level of P. gingivalis supernatant was measured with lactate dehydrogenase assays. Cytokine arrays were performed on HGF‐conditioned media treated with or without resolvin D1 and with or without P. gingivalis supernatant. Results: Resolvin D1 had no cytotoxic effects on HGFs at concentrations between 1 and 1,000 nM (all P > 0.05). Resolvin D1 (1,000 nM) significantly inhibited the toxic effects of 13.5% (v/v) P. gingivalis supernatant on HGFs (P = 0.002). Resolvin D1 significantly reduced the expression of interleukin (IL)‐6 (P = 0.010) and monocyte chemoattractant protein (MCP)‐1 (P = 0.04) in untreated fibroblasts. P. gingivalis (10%) supernatant significantly increased the expression levels of granulocyte‐macrophage colony‐stimulating factor (CSF), granulocyte CSF, growth‐regulated oncogene (GRO), IL‐5, IL‐6, IL‐7, IL‐8, IL‐10, MCP‐1, MCP‐2, MCP‐3, and monokine induced by γ‐interferon. Resolvin D1 significantly reduced the expression of GRO (P = 0.04), marginally reduced the levels of MCP‐1 (P = 0.10), and marginally increased the levels of transforming growth factor (TGF)‐β1 (P = 0.07) from HGFs treated with P. gingivalis supernatant. Conclusions: Resolvin D1 altered the cytotoxicity of P. gingivalis supernatant on HGFs. Resolvin D1 significantly reduced GRO, marginally reduced MCP‐1, and marginally increased TGF‐β1 from P. gingivalis–treated HGFs, which could alter the ability of P. gingivalis to induce inflammation.     

A composite index for determining the impact of oral ulcer activity in Behcet's disease and recurrent aphthous stomatitis

Background:  Although number, frequency and healing time of oral ulcers and pain are generally used for clinical practice and studies in Behcet's disease (BD) and recurrent aphthous stomatitis (RAS), no standardized activity index is currently present to monitor clinical manifestations associated with oral ulcers. The aim of this study was to develop a standardized composite index (CI) to assess oral ulcer activity in BD and RAS.
Methods:  In this cross-sectional study, 121 patients with BD and 45 patients with RAS were included. Sixty-five percentage of BD and 68.9% of RAS patients were in active stage during the previous 3 months. The developed CI included the presence of oral ulcers, ulcer-related pain and functional status and was evaluated in patients with both active and inactive disease for content validity.
Results:  Composite index score was observed to be higher in active patients with RAS (6.94 ± 2.19) compared with active BD patients (6.01 ± 2.04) ( P  = 0.04). The number of oral ulcers and healing time of oral ulcers were significantly higher in RAS compared with BD ( P  = 0.018, P  = 0.001 respectively). CI score correlated with the number of oral ulcers in both BD and RAS ( P  = 0.000, P  = 0.002 respectively). CI score was '0' for inactive patients without oral ulcer in BD and RAS.
Conclusions:  The presented CI as an oral ulcer activity index seems to be a reliable and suitable tool for evaluating the clinical impact and disease-specific problems in BD and RAS.     

Cytokines in healthy temporomandibular joint synovial fluid

Analysis of temporomandibular joint (TMJ) synovial fluid may elucidate the aetiology of temporomandibular disorders and arthritic conditions, as well as the inflammatory mechanisms involved. Knowledge about healthy synovial fluid is necessary to understand TMJ pathologies. We aimed to quantify the proinflammatory cytokines interleukin (IL)‐1β, IL‐2, IL‐6 and tumour necrosis factor (TNF), and the anti‐inflammatory cytokines IL‐10 and interferon (IFN)‐γ in healthy TMJ synovial fluid to serve as reference values for future studies on TMJ pathologies. Twenty healthy, young adult volunteers without temporomandibular dysfunction were included. Bilateral synovial fluid samples were obtained using the push‐pull technique with hydroxocobalamin described by Alstergren in 1999. Cytokines were quantified with Luminex multiplex assays and compared using nonparametric statistical analysis. No serious adverse effects were reported. Of 40 possible samples, 14 fulfilled the strict sampling criteria and were included in the analysis. Cytokine values (reported as medians with interquartile ranges) were as follows: TNF, 23 (13–37) pg mL^?1; IL‐2, 1·8 (0–22) pg mL^?1; and INF‐γ, 10 (0–47) pg mL^?1. IL‐1β, IL‐6 and IL‐10 were almost undetectable. In addition, TNF and INF‐γ cytokine levels correlated. We demonstrated that TNF was consistently detected and IFN‐γ and IL‐2 sporadically detected in the TMJ synovial fluid of healthy individuals using the hydroxocobalamin method and a multiplex assay. The cytokines IL‐10, IL‐1β and IL‐6 were barely detectable in this sample of healthy TMJs.     

Effect of Curcumin on Systemic T Helper 17 Cell Response; Gingival Expressions of Interleukin‐17 and Retinoic Acid Receptor‐Related Orphan Receptor γt; and Alveolar Bone Loss in Experimental Periodontitis

Background: Curcumin has anti‐inflammatory and antioxidant effects and is reported to have many biologic activities. The current study examines effect of curcumin on: 1) systemic T helper 17 (Th17) cell response; 2) gingival expressions of interleukin (IL)‐17 and retinoic acid receptor‐related orphan receptor (ROR) γt; and 3) alveolar bone loss (ABL) in experimental periodontitis. Methods: Thirty‐eight male albino Wistar rats were divided into four groups: 1) group 1 = periodontitis; 2) group 2 = periodontitis with curcumin treatment; 3) group 3 = periodontally healthy with curcumin treatment; and 4) group 4 = periodontally healthy. Curcumin was administered via oral gavage (30 mg/kg/d) for 15 days. After sacrifice via exsanguination, the following serum levels were determined using enzyme‐linked immunosorbent assay: 1) IL‐1β; 2) IL‐6; 3) IL‐17A; 4) IL‐23; and 5) transforming growth factor‐ β. Morphometric evaluation of ABL was conducted and expression levels of IL‐17 and RORγt in gingival tissues were evaluated immunohistochemically. Results: Group 2 had significantly lower ABL than group 1 (P <0.0125). Highest expression levels of IL‐17 and RORγt were observed in group 1 and were significantly higher than those in all other groups (P <0.0125). The only serum biochemical parameter significantly different among groups was level of IL‐23 (P <0.05). Serum IL‐23 levels were higher in groups 1 and 2 than groups 3 and 4 (P <0.0125); however, they were not significantly different for groups 1 and 2 (P >0.0125). Conclusion: Curcumin seems to be a promising host modulatory agent in periodontal disease pathogenesis regarding IL‐17/IL‐23 axis, with a decreasing effect on ABL and gingival expressions of IL‐17 and RORγt.     

Comparison of Azithromycin and Amoxicillin Before Dental Implant Placement: An Exploratory Study of Bioavailability and Resolution of Postoperative Inflammation

Background: Studies suggest that a single prophylactic dose of amoxicillin reduces early implant complications, but it is unclear whether other antibiotics are also effective. This study compared the local antimicrobial and anti‐inflammatory effects resulting from a single dose of azithromycin or amoxicillin before surgical placement of one‐stage dental implants. Methods: Healthy adult patients requiring one‐stage dental implant placement were allocated randomly to receive either 2 g amoxicillin (n = 7) or 500 mg azithromycin (n = 6) before surgery. Peri‐implant crevicular fluid (PICF) samples from the new implant and gingival crevicular fluid (GCF) from adjacent teeth were sampled on postoperative days 6, 13, and 20. Inflammatory mediators in the samples were analyzed by immunoassay, and antibiotic levels were measured by bioassay. Results: On day 6, azithromycin concentrations in GCF and PICF were 3.39 ± 0.73 and 2.77 ± 0.90 μg/mL, respectively, whereas amoxicillin was below the limit of detection. During early healing, patents in the azithromycin group exhibited a significantly greater decrease in GCF volume (P = 0.03, analysis of variance). At specific times during healing, the azithromycin group exhibited significantly lower levels of interleukin (IL)‐6 and IL‐8 in GCF than the amoxicillin group and exhibited significantly lower levels of granulocyte colony stimulating factor, IL‐8, macrophage inflammatory protein‐1β, and interferon‐gamma‐inducible protein‐10 in PICF. Conclusions: Azithromycin was available at the surgical site for a longer period of time than amoxicillin, and patients taking azithromycin exhibited lower levels of specific proinflammatory cytokines and chemokines in GCF and PICF. Thus, preoperative azithromycin may enhance resolution of postoperative inflammation to a greater extent than amoxicillin.     

Oral health related quality of life is affected by disease activity in Behçet's disease

Objectives: This study aimed to investigate oral and general health related quality of life (QoL) in patients with Behçet's Disease (BD) and to assess the performance of Turkish versions of oral health related quality questionnaires. Subjects and methods: Ninety‐four BD patients, 24 patients with recurrent aphthous stomatitis (RAS), 113 healthy controls (HC) and 44 dental patients were investigated. QoL was assessed by oral health impact profile‐14 (OHIP‐14), oral health related quality of life (OHQoL) and short form‐36 (SF‐36) questionnaires. Results: OHQoL, OHIP‐14 and SF‐36 subscale scores were significantly worse in patients with BD compared with those in HC (P < 0.05). Both OHIP‐14 and OHQoL scores were significantly worse in active patients compared with inactives in BD and RAS (P < 0.05). Scores of SF‐36 Role physical, Role emotional and Vitality were also lower in active patients than in inactives in BD (P < 0.05). Scores of OHIP‐14 and OHQoL were significantly worse in patients treated with colchicine compared with those treated with immunosuppressives (P < 0.05). Conclusions: Both oral and general QoL was impaired in BD and associated with disease activity and treatment modalities. Translated Turkish versions of OHIP‐14 and OHQoL were also observed to be valid and reliable questionnaires for further studies.     

Distinct Th1, Th2 and Treg cytokines balance in chronic periapical granulomas and radicular cysts

J Oral Pathol Med (2010) 39 : 250–256 Background: Periapical lesions are a host response that involves immune reaction to prevent dissemination of bacteria from an infected root canal. The purpose of this study was to evaluate the levels of nitric oxide (NO), IL‐4, TGF‐β, tumor necrosis factor‐α (TNF‐α), and interferon‐γ (IFN‐γ) in chronic periapical lesions and to determine their possible association with clinical and radiographic parameters. Methods: Seventeen human radicular cysts and 30 periapical granulomas were used in this study. Cytokines and NO were assessed by enzyme‐linked immunosorbent assay and by the Griess reaction respectively confirmed by immunohistochemical. Results: TNF‐α and IFN‐γ were detected in 10% of granulomas and in 41.2% and 70% of radicular cysts. IL‐4 was reactive in 24% of cysts, and TGF‐β was positive in all samples. Patients with tenderness showed significantly higher levels of IFN‐γ and IL‐4 (P < 0.05). Swelling was associated with high levels of TNF‐α, IFN‐γ, and IL‐4 (P < 0.05). Lesions presenting bone resorption were associated with high levels of NO (P < 0.05). Conclusions: Periapical granulomas display a regulatory environment characterized by high TGF‐β and low inflammatory cytokine levels, while radicular cysts has mist Th1 and Th2 inflammatory reaction with the presence of IFN‐γ, TNF‐α, and IL‐4.     

HLA-DR and DQ antigens in Chinese patients with Behçet's disease

The frequencies of HLA-DR and DQ antigens in 24 Chinese patients with Behçet's disease (BD) were calculated and compared with those in 130 healthy control Chinese and those in 80 Chinese patients with recurrent oral ulcers (ROU). Although an increased trend of DRw6 and DRw8 antigens in patients with BD was noted, there was no significant difference in frequencies of HLA-DR and DQ antigens between patients with BD and healthy control subjects or patients with ROU after correction of P values (Pc>0.05). Further analysis of our data of the phenotype frequencies of DRw6 and DRw8 antigens according to the subtypes of BD also showed the increased frequencies of DRw6 and DRw8 antigens in patients with mucocutaneous type of BD as compared with those in healthy control subjects. However, only the phenotype frequency of DRw8 antigen in patients with mucocutaneous type of BD was significantly higher than that in patients with ROU (P< 0.005, PC < 0.05, relative risk= 17.7, and etiologic fraction =0.30). This significant increase of the phenotype frequency suggests that the gene coding for HLA-DRw8 antigen in patients with ROU was only partially (30%) responsible for susceptibility to the mucocutaneous type of BD.     

Cytokines and bone-related factors in systemically healthy patients with chronic periodontitis and patients with type 2 diabetes and chronic periodontitis

Background: This study compares the levels of cytokines and bone‐related factors in the gingival crevicular fluid (GCF) of systemically healthy patients with chronic periodontitis (CP); and better‐controlled, and poorly controlled patients with type 2 diabetes and CP. Methods: Thirty‐seven patients with type 2 diabetes and CP and 20 systemically healthy patients with CP were enrolled in this study. The patients with diabetes mellitus were categorized as better‐controlled (n = 17; HbA_1c levels ≤8%) or poorly controlled (n = 20; glycated hemoglobin values >8%). Levels of tumor necrosis factor‐α, interleukin (IL)‐4, interferon (IFN)‐γ, IL‐23, IL‐17, soluble receptor activator of nuclear factor‐kappa B ligand (sRANKL), and osteoprotegerin (OPG) in GCF of diseased sites were analyzed by enzyme‐linked immunosorbent assay. Results: Type 2 diabetes mellitus, as a whole, upregulates the levels of OPG, sRANKL, IFN‐γ, IL‐17, and IL‐23 and downregulates the production of IL‐4 in sites with CP (P <0.05). Better‐controlled individuals exhibited the highest levels of IFN‐γ, whereas poorly controlled patients presented the highest levels of IL‐17 (P <0.05). There were no differences in the levels of tumor necrosis factor‐α, OPG, and IL‐23 among systemically healthy, better‐controlled, and poorly controlled patients with diabetes (P >0.05). Conclusions: Increased levels of proinflammatory cytokines and RANKL were observed in the GCF of patients with type 2 diabetes with CP, compared to patients without diabetes. In addition, poor or good glycemic status seems to modulate osteo‐immunoinflammatory mediators in a different manner.     

Levamisole and Chinese medicinal herbs can modulate the serum interleukin-6 level in patients with recurrent aphthous ulcerations

Background: Recurrent aphthous ulcerations (RAU) are common oral inflammatory lesions. Interleukin‐6 (IL‐6) is a pro‐inflammatory cytokine that has effects on cellular and humoral immunities. Previous studies have shown that the high serum IL‐6 levels in some RAU patients can be reduced by drug treatment. This finding suggests that IL‐6 may be a useful marker in evaluating therapeutic effects of RAU. Methods: In this study, we used a solid phase, two‐site sequential chemiluminescent immunometric assay to determine the baseline serum levels of IL‐6 in a group of 228 patients with RAU, erythema multiforme (EM), traumatic ulcers (TU), oral submucous fibrosis (OSF), pemphigus vulgaris (PV), or Sjögren's syndrome (SS), and in 77 normal control subjects. Some RAU patients were treated with levamisole plus Chinese medicinal herbs or levamisole only for 0.5–5 months and their serum IL‐6 levels were measured after treatment. Results: We found that about 99% of the normal control subjects and the patients with EM, TU, or OSF had a serum IL‐6 level within the normal limit of 5.0 pg/ml. However, 24% (48/197) RAU patients, 14% (1/7) EM patients, 43% (3/7) PV patients, and 100% (6/6) SS patients had a serum level of IL‐6 greater than 5.0 pg/ml. The mean serum level of IL‐6 in patients with RAU (3.6 ± 3.5 pg/ml, P < 0.001), minor type RAU (2.7 ± 2.0 pg/ml, P < 0.05), major type RAU (5.2 ± 4.6 pg/ml, P < 0.001), or herpetiform type RAU (4.1 ± 3.8 pg/ml, P < 0.01) was higher than that in normal control subjects. The mean serum level of IL‐6 in major type (P < 0.001) or in herpetiform type RAU patients (P < 0.05) was higher than that in minor type RAU patients. The mean reduction of serum IL‐6 level (10.0 ± 7.1 pg/ml) in RAU patients after treatment with levamisole plus Chinese medicinal herbs was significantly higher than that (5.1 ± 3.7 pg/ml) in RAU patients after treatment with levamisole only (P < 0.005), suggesting that the combination therapy is superior to the single therapy of levamisole only. Conclusion: We conclude that levamisole and levamisole plus Chinese medicinal herbs can modulate the serum IL‐6 level in RAU patients. Although the therapeutic effect of RAU can be assessed by a decrease in the frequency, duration and number of the oral ulcerations, it can also be monitored by a reduction of serum IL‐6 level in RAU patients.     

Oral bacterial DNA differ in their ability to induce inflammatory responses in human monocytic cell lines

Background: Deoxyribonucleic acids (DNA) of periodontal pathogens, Porphyromonas gingivalis (Pg) and Tannerella forsythia, stimulate cytokine production in human monocytic cells (THP‐1) through Toll‐like receptor 9 (TLR‐9) and nuclear factor‐κB signaling. Fusobacterium nucleatum (Fn) is one of the most frequently isolated bacteria in periodontally diseased tissues and is reported to synergize with Pg, enhancing the pathogenicity. We investigate inflammatory mediator production in THP‐1 cells challenged with Fn and Streptococcus sanguinis (Ss) DNA, a non‐pathogenic oral bacteria, and further assess whether cytokines triggered by whole pathogens or Pg lipopolysaccharide (LPS) are affected by TLR‐9 signaling inhibitors (chloroquine). Methods: THP‐1 cells were stimulated with Pg‐DNA (100 ng/μL), Fn‐DNA (100 ng/μL), Ss‐DNA (100 ng/μL), Pg‐LPS (10 ng/μL), and heat‐killed whole bacteria (multiplicity of infection, 1:100) for 16 hours with or without chloroquine pretreatment (10 μg/mL). Interleukin (IL)‐1β, IL‐6, IL‐8, and tumor necrosis factor‐α levels were determined using enzyme‐linked immunosorbent assay. Statistical analyses included analysis of variance with multiple comparisons using Dunnett or Tukey methods and paired t test. A value of P <0.05 was significant. Results: Inflammatory mediator levels were increased in response to all the stimuli with the exception of Ss‐DNA (P <0.05). Chloroquine pretreatment significantly decreased cytokine production from THP‐1 cells with the exception of IL‐6 production triggered by whole Fn and Ss (P <0.05). Conclusions: Differences exist among oral bacterial DNA in inducing immune responses. By altering the conditions in cytosolic compartments, we can interfere with cellular responses triggered by extracellular receptor activation. Thus, alternative treatment approaches targeted to intracellular receptors might be of benefit in controlling periodontal inflammation.     

Serum interleukin-6 level is a useful marker in evaluating therapeutic effects of levamisole and Chinese medicinal herbs on patients with oral lichen planus

Background: Oral lichen planus (OLP) is a T cell‐mediated inflammatory disease. Interleukin‐6 (IL‐6) is a pro‐inflammatory cytokine that has effects on cellular and humoral immunities. Previous studies have shown that keratinocytes and tissue‐infiltrating mononuclear cells from OLP lesions can secrete IL‐6. In some OLP patients, the high serum IL‐6 levels are reduced after treatment, suggesting that IL‐6 may be a useful marker in evaluating therapeutic effects and in monitoring the disease status of OLP. Methods: In this study, we used a solid phase, two‐site sequential chemiluminescent immunometric assay to determine the baseline serum levels of IL‐6 in a group of 180 patients with erosive OLP (EOLP), nonerosive OLP (NEOLP), erythema multiforme (EM), traumatic ulcers (TU), oral submucous fibrosis (OSF), pemphigus vulgaris (PV), or Sjögren's syndrome (SS), and in 77 normal control subjects. Some OLP patients were treated with levamisole plus Chinese medicinal herbs or levamisole only for 0.5–5.5 months and their serum IL‐6 levels were measured after treatment. Results: We found that approximately 99% of the normal control subjects and the patients with EM, TU, or OSF had a normal serum IL‐6 level less than 5.0 pg/ml. However, 15% (22/149) OLP patients, 15% (20/136) EOLP patients, 20% (5/25) major type EOLP patients, 14% (15/111) minor type EOLP patients, 15% (2/13) NEOLP patients, 14% (1/7) EM patients, 43% (3/7) PV patients, and 100% (6/6) SS patients had a serum IL‐6 level greater than 5.0 pg/ml. The mean serum IL‐6 level in patients with OLP (3.4 ± 3.1 pg/ml, P < 0.001), EOLP (3.4 ± 3.2 pg/ml, P < 0.001), major type EOLP (4.9 ± 3.5 pg/ml, P < 0.001), minor type EOLP (3.0 ± 3.0 pg/ml, P < 0.01), or NEOLP (4.2 ± 1.5 pg/ml, P < 0.001) was significantly higher than that in normal control subjects (2.0 ± 1.5 pg/ml). A significant difference in the mean serum IL‐6 level was also found between major type and minor type EOLP patients (P < 0.01). The mean reduction of serum IL‐6 level in OLP patients treated with levamisole plus Chinese medicinal herbs was significantly higher (7.4 ± 4.7 pg/ml) than that in OLP patients treated with levamisole only (3.8 ± 2.3 pg/ml, P < 0.05), suggesting that the combination therapy was superior to levamisole only. Conclusion: We conclude that levamisole and levamisole plus Chinese medicinal herbs can modulate the serum IL‐6 level in OLP patients. IL‐6 may be a useful marker in evaluating therapeutic effects and in monitoring the disease status of OLP.     

Regulation of IL‐24 in human oral keratinocytes stimulated with Tannerella forsythia

Interleukin‐24 is a pleiotropic immunoregulatory cytokine and a member of the IL‐20R subfamily of the IL‐10 family. The aim of this study was to investigate the regulation of IL‐24 in the human oral keratinocyte cell line HOK‐16B following infection with Tannerella forsythia, a major periodontal pathogen. T. forsythia induced the expression of IL‐24 mRNA and the secretion of glycosylated IL‐24 in HOK‐16B cells. Glycosylation of IL‐24 is linked to its solubility and bioavailability. T. forsythia‐stimulated reactive oxygen species (ROS) induced the expression of IL‐24, which was regulated by IL‐6. The ROS inhibitor N‐acetylcysteine and MAPK inhibitors significantly reduced the expression of IL‐6 and IL‐24 induced by T. forsythia. Recombinant human IL‐24 significantly enhanced the expression of IL‐1α, IL‐8, CXCL10, and MCP‐1 in HOK‐16B cells. Together, these results indicate that ROS, MAPKs, and IL‐6 comprise the axis of IL‐24 expression in HOK‐16B cells stimulated with T. forsythia. Thus, IL‐24 may be involved in inflammation in oral keratinocytes.     

Azithromycin may inhibit interleukin-8 through suppression of Rac1 and a nuclear factor-kappa B pathway in KB cells stimulated with lipopolysaccharide

Background: Recent studies have shown that the 15‐member macrolide antibiotic azithromycin (AZM) not only has antibacterial activity, but also results in the role of immunomodulator. Interleukin (IL)‐8 is an important inflammatory mediator in periodontal disease. However, there have been no reports on the effects of AZM on IL‐8 production from human oral epithelium. Therefore, we investigated the effects of AZM on IL‐8 production in an oral epithelial cell line. Methods: KB cells were stimulated by Escherichia coli or Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans) lipopolysaccharide (LPS) with or without AZM. IL‐8 mRNA and protein expression and production in response to LPS were analyzed by quantitative polymerase chain reaction, flow cytometry, and enzyme‐linked immunosorbent assay. The activation of nuclear factor‐kappa B (NF‐κB) and Rac1, which is important for IL‐8 expression, was analyzed by enzyme‐linked immunosorbent assay and Western blotting, respectively. Results: IL‐8 mRNA expression, IL‐8 production, and NF‐κB activation in LPS‐stimulated KB cells were inhibited by the addition of AZM. LPS‐induced Rac1 activation was also suppressed by AZM. Conclusions: This study suggests that AZM inhibits LPS‐induced IL‐8 production in an oral epithelial cell line, in part caused by the suppression of Rac1 and NF‐κB activation. The use of AZM might provide possible benefits in periodontal therapy, with respect to both its antibacterial action and apparent anti‐inflammatory effect.     

The high expression level of programmed death‐1 ligand 2 in oral lichen planus and the possible costimulatory effect on human T cells

J Oral Pathol Med (2011) 40 : 525–532 Background: Oral lichen planus (OLP) is a T‐cell‐mediated chronic autoimmune disease whose precise etiology is unknown. The recently identified costimulatory programmed death‐1 (PD‐1) molecule and its ligands, PD‐L1 and PD‐L2, have been identified as CD28‐B7 family molecules and constitute a regulatory pathway of potential therapeutic use in immune‐mediated diseases. Methods: We examined the expression of two ligands of PD‐1 at both the protein and gene level in the focal mucosa and peripheral blood of OLP patients using immunohistochemistry and real‐time PCR. Next, we used the PD‐L2.Ig fusion protein and observed its effects on T cells, which were co‐cultured with IFN‐γ‐treated keratinocytes (KCs) in the presence of PHA. Results: We found that the expression of PD‐L2 at both the gene and protein level was statistically different in peripheral blood and local lesion tissue of patients with OLP compared to the normal controls. The proliferation ability of T cells and the expression level of IFN‐γ in the supernatant of the above co‐culture model were significantly augmented (P < 0.05). PD‐L2.Ig fusion protein significantly aggravated the apoptosis of T cells, inhibited the proliferation of T cells and decreased the release levels of IL‐2 and IFN‐γ in the model (P < 0.05). Conclusion: These data show that the increased expression of PD‐L2, as a costimulatory molecule, may have an important modulatory function on the local immune responses of OLP in vivo.