Th1 and Th2 cytokines such as interferon-γ (IFN-γ ) , tumor necrosis factor- α (TNF-α ), and IL-4 are expressed in T-cell-mediated inflammation in the oral cavity. We tested the hypothesis that those cytokines may act on CXCR3-agonistic chemokines, T-cell recruiting factors, and on neighboring cells, including oral keratinocytes and fibroblasts. Human immortalized oral keratinocytes (RT7) and fibroblasts (GT1) after 24-hour stimulation with IFN-γ showed increased mRNA levels of CXCL9 (600- and 700-fold), CXCL10 (10,000- and 150-fold), and CXCL11 (5000- and 300-fold), respectively. In contrast, TNF-α caused an increase in CXCL9 (300-fold), CXCL10 (2000-fold), and CXCL11 (2000-fold) mRNA levels in GT1, but not RT7 cells, at 24 hrs. IL-4 reinforced the promotion of CXCL9, CXCL10, and CXCL11 expression by IFN-γ in RT7 cells, whereas IL-4 inhibited the increased levels by IFN-γ and TNF-α in GT1 cells. Thus, IFN-γ , TNF-α , and IL-4 appear cooperatively to regulate CXCR3-agonistic chemokines in oral keratinocytes and fibroblasts in T-cell-mediated oral inflammation sites.

Oral keratinocytes and fibroblasts may be the first line of host defense against oral microorganisms. Here, the contention that oral keratinocytes and fibroblasts recognize microbial components via Toll-like receptors (TLRs) and participate in development of oral inflammation was examined. It was found that immortalized oral keratinocytes (RT7), fibroblasts (GT1) and primary cells express mRNA of TLRs 1–10. Interleukin-8 (IL-8) production by RT7 cells was induced by treatment with TLRs 1–9 with the exception of TLR7 agonist, whereas GT1 cells were induced to produce IL-8 by all TLR agonists tested except for TLR7 and TLR9. GT1 cells showed increased CXCL10 production following treatment with agonists for TLR1/2, TLR3, TLR4, and TLR5, whereas only those for TLR3 and TLR5 increased CXCL10 production in RT7 cells. Moreover, TLR agonists differentially regulated tumor necrosis factor-alpha-induced IL-8 and CXCL10 production by the tested cell types. These findings suggest that recognition of pathogenic microorganisms in oral keratinocytes and fibroblasts by TLRs may have important roles in orchestrating host immune responses via production of various chemokines.

Lugol's iodine staining (Lugol-staining) has been widely used to detect malignant changes in the cervix uteri and esophagus. However, pathological and histochemical changes in the border between Lugol-stained and -unstained areas in oral epithelial dysplastia and malignant lesions are not well understood. We examined the histological appearance of 20 cases of epithelial dysplasia surrounding squamous cell carcinoma using HE and PAS staining in the borders between Lugol-stained and -unstained areas. Subsequently, differences in the expression of cytokeratin 13 (CK13), an epithelium differentiation marker, and Ki-67, a cell proliferative marker, in those areas were investigated by immunohistochemistry. Lugol-stained areas of all cases showed mild dysplasia or normal epithelium appearance, while Lugol-unstained areas in most cases were diagnosed as moderate/severe dysplasia and carcinoma in situ. PAS reactions were limited or not found in the Lugol-unstained areas as compared to intense positivity in Lugol-stained areas. CK13 and Ki-67 protein expression was significantly different between Lugol-stained and -unstained areas. It was confirmed that epithelia showing precancerous or cancerous features were detected as Lugol-unstained boundary areas. A reduction in glycogen production caused by alterations of cell differentiation and proliferation associated with malignant changes may result in a lack of Lugol-staining.

Summary: Stroke can be a cause of death, while in non-fatal cases it is a common cause of various disabilities resulting from associated brain damage. However, whether a specific periodontal pathogen is associated with increased risk of unfavorable outcome after stroke remains unknown. We examined risk factors for unfavorable outcome following stroke occurrence, including serum antibody titers to periodontal pathogens. The enrolled cohort included 534 patients who had experienced an acute stroke, who were divided into favorable (n = 337) and unfavorable (n = 197) outcome groups according to modified ranking scale (mRS) score determined at 3 months after onset (favorable = score 0 or 1; unfavorable = score 2–6). The associations of risk factors with unfavorable outcome, including serum titers of IgG antibodies to 16 periodontal pathogens, were examined. Logistic regression analysis showed that the initial National Institutes of Health stroke scale score [odds ratio (OR) = 1·24, 95% confidence interval (CI) = 1·18–1·31, P < 0·001] and C-reactive protein (OR = 1·29, 95% CI = 1·10–1·51, P = 0·002) were independently associated with unfavorable outcome after stroke. Following adjustment with those, detection of the antibody for Fusobacterium nucleatum ATCC 10953 in serum remained an independent predictor of unfavorable outcome (OR = 3·12, 95% CI = 1·55–6·29, P = 0·002). Determination of the antibody titer to F. nucleatum ATCC 10953 in serum may be useful as a predictor of unfavorable outcome after stroke.