The adverse effect of fibrin-clot inhibiting drugs on intravesical bacillus Calmette-Guérin efficacy for superficial bladder cancer

Bacillus Calmette-Guérin (BCG) is currently thought to act as a biological immune modifier in effecting antitumour activity. Recent evidence suggests that BCG binding to fibronectin (FN), a tissue glycoprotein, may be a prerequisite step in initiating this response. Drugs inhibiting the availability of exposed FN in the bladder after urothelial disruption may adversely affect the efficacy of BCG. Data are presented of 45 patients with tumour limited to mucosa (pTa) or carcinoma in situ (CIS) given intravesical BCG therapy, with (group 1) or without (group 2) fibrin clot-inhibiting drugs concurrently during treatment. The success rate of 11.1% for group 1 (1/9) patients was significantly less than that of 69.4% for group 2 (25/36), (chi 2 = 7.79, P < 0.01 Fisher's exact test) supporting the suggestion that the concurrent administration of fibrin-clot inhibiting drugs may adversely affect the outcome of BCG therapy.

Microbiological Studies of the Intestinal Microflora of the Koala, Phascolarctos-Cinereus .1. Colonization of the Cecal Wall by Tannin-Protein-Complex-Degrading Enterobacteria

The tannin-protein-complex-degrading enterobacterium (T-PCDE), which specifically colonises the caecal wall of the koala, was investigated immunohistologically. Polyclonal antisera were raised against three strains of T-PCDE. Tissue from six koalas was subjected to immunogold staining using a pooled, absorbed antiserum. Numerous T-PCDE cells were observed in the bacterial layer attached to the caecal wall of five of the animals. The distribution pattern of T-PCDE varied: cells were either scattered throughout the bacterial layer or congregated in areas that apparently contained debris of digesta. The sixth animal, which had been treated with oxytetracycline and showed severe loss of body weight, did not have any bacterial layer attached to the caecal wall and did not stain positive for T-PCDE. The evidence suggests a symbiotic association between T-PCDE and the koala; the caecal wall and the wall of the proximal colon were 'strategically' colonised by the bacterium, which may facilitate access, although it is likely to be indirect, for the host animal to the nitrogen moiety liberated from breakdown of tannin-protein complexes.

Different responses in B cells induced by Porphyromonas gingivalis and Fusobacterium nucleatum

A phenotypic study had shown that gingival B cells respond differently to two periodontopathic bacteria, Porphyromonas gingivalis and Fusobacterium nucleatum. Further investigation now shows a reduction in the percentage of Ki-67 + T cells in cultures of gingival and peripheral blood mononuclear cells stimulated with P. gingivalis for 3 and 6 days, respectively, but no suppression of Ki-67 expression in B cells in response to either P. gingivalis or F. nucleatum. Depletion studies of cultures of peripheral blood mononuclear cells showed that in the absence of CD4 cells, the percentage of CD19+ and CD20+ B cells stimulated with P. gingivalis increased after 6 days whereas depletion of CD8 cells resulted in a rise in the percentage of F. nucleatum- and P. gingivalis-stimulated B cells, although this was not significant in the case of P. gingivalis. Specific antibody to P. gingivalis and F. nucleatum was found in culture supernatants of gingival but not of peripheral blood mononuclear cells, indicating a possible higher frequency of antigen-specific B cells in periodontal lesions. IgG was the predominant isotype in both gingival and control peripheral blood cultures, followed closely by IgA in gingival cultures. F. nucleatum stimulated higher levels of Ig in cultures of peripheral blood mononuclear cells than P. gingivalis or cells cultured in medium only, whereas in gingival cell cultures, stimulation by P. gingivalis appeared to result in higher levels of IgG. Also Ig was present at day 3 in gingival cultures, whereas in the blood cell cultures, Ig was only detected at day 6, further suggesting a degree of activation of of gingival B cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Patient attendance compliance in periodontal therapy

Attendance compliance of patients presenting for periodontal therapy during one calendar year at two practice locations (Perth, Western Australia and Darwin, Northern Territory) was observed over a period of three to four years, depending on whether the patients were seen in the earlier or latter part of the initial year. Both venues (full-time practice and visiting practice every quarter) gave very similar results, of around 10 per cent of patients who dropped out after initial consultation, without commencing treatment. As well, both venues showed a similar trend of subsequent patient 'attrition' after the initial phase of treatment, with the retention of approximately 40 per cent of the original group of patients after three to four years. Of these, a very high proportion (90 per cent) were totally compliant with maintenance recall appointments.

Suppressor cell function in oral lichen planus

Oral lichen planus (OLP) is a common inflammatory condition of the oral mucous membranes which affects between one and two percent of the general population. In accordance with the protracted clinical course of OLP and its association with known auto-immune diseases, the level of self-tolerance is questionable and possibly diminished in patients with this disorder. Normal suppressor T lymphocyte function is reputedly an essential element in the maintenance of self-tolerance, and deficient cell-mediated suppressor activity is implicated in the pathogenesis of auto-immune diseases. For assessment of in vitro cell-mediated suppressor activity in OLP, peripheral blood mononuclear cells (PBMC) from ten patients with OLP and from 11 control subjects were activated with the plant mitogen concanavalin A (Con A), followed by co-culture with autologous responder cells. The ability of irradiated Con A-activated cells to suppress the proliferation of Con A-stimulated responder cells was determined. Con A-induced suppressor activity of PBMC in the OLP patients was significantly less than that in control subjects (p = 0.001). Results of the present investigation complement previous in vitro findings which provided indirect evidence of deficient cell-mediated suppressor activity in OLP, particularly a decreased proportion of circulating CD4+CD45RA+ lymphocytes and reduced Con A-stimulated PBMC proliferation. The depressed Con A-induced suppressor activity of PBMC in the OLP patients provides direct evidence of deficient in vitro cell-mediated suppressor function in OLP, and suggests that defective cell-mediated suppressor circuits and reduced self-tolerance may be involved in the pathogenesis of this disorder.

Phenotypic and functional analysis of peripheral blood lymphocytes in oral lichen planus

To assess cellular immunity in oral lichen planus (OLP), peripheral blood mononuclear cells (PBMC) were obtained from 19 OLP patients and 30 control subjects. The proportions of circulating CD45RA+ and CD29+ lymphocyte subsets were determined. The proliferative activity of PBMC to the non-specific plant mitogens phytohemagglutinin (PHA) and concanavalin A (Con A) was examined together with the spontaneous proliferative response and the response in the autologous mixed lymphocyte reaction (AMLR). In the OLP group, the proportion of CD4+ CD45RA+ T lymphocytes was significantly less than control subjects and the proportion of CD4+ CD29+ T lymphocytes was increased significantly. The proliferative response to PHA was similar in OLP and controls subjects. Con A-stimulated PBMC proliferation was decreased significantly in the OLP group. Spontaneous PBMC proliferation in patients with non-reticular lesions was significantly less than control subjects. Despite a mildly depressed response in the AMLR in OLP patients, this result was not statistically significant. Results of the phenotypic analysis of peripheral blood lymphocytes indicate a decreased proportion of naive T cells and an increased proportion of primed memory T cells, although the antigen specificity of these memory cells remains to be determined. Results of the functional assays would seem to reflect this phenotypic shift, and as T cells responding to Con A stimulation and in the AMLR possess suppressor-inducer activity, these results may also suggest an association between OLP and defective innate T cell-mediated suppressor circuits.

Direct and indirect effects of Porphyromonas gingivalis lipopolysaccharide on interleukin-6 production by human gingival fibroblasts

We examined the production of interleukin-6 (IL-6) by human gingival fibroblasts (ATCC CRL 1292) stimulated with lipopolysaccharide (LPS) from Porphyromonas gingivalis and Escherichia coli, or supernatant of human peripheral blood adherent cell culture medium incubated in the presence of IL-1 and the same two LPS. Confluent monolayers of gingival fibroblasts were incubated with stimulants for 6 h at 37 degrees C in 5% CO2 and air. After removal of stimulants, the cell cultures were incubated for an additional 2 or 24 h in the same environment. At the end of the culture period, supernatants were collected and assayed for IL-6 activity by stimulatory IgG production with the human B-lymphoblastoid cell line CESS. The direct effect of LPS on IL-6 production by gingival fibroblasts was much weaker than the indirect one via IL-1 production by adherent cells. The stimulating effect of culture supernatants of adherent cells stimulated with LPS on IL-6 production by gingival fibroblasts was as effective as that of recombinant IL-1, when this latter was added at a concentration equivalent to that contained in the culture supernatant of adherent cells. These results suggest that, although gingival fibroblasts may be involved in the pathogenesis of chronic periodontal disease by the production of cytokines, such a role may not result from a direct stimulation by periodontopathic bacteria. The phenomenon is more likely to be mediated indirectly by IL-1 produced by infiltrating inflammatory cells.

The establishment of human T cell lines reactive with specific periodontal bacteria

Human T cell lines (TCLs) were obtained by stimulation of peripheral blood mononuclear cells (PBMCs) with the 2 periodontopathic bacteria, Porphyromonas gingivalis FDC-381 and Fusobacterium nucleatum FDC-263. After the first round of stimulation and rest, the cells responded specifically to the bacteria originally used to establish each line. Throughout the culture period, the responsiveness of each of the TCLs to their specific bacteria increased. Phenotypic analysis of the TCLs revealed heterogeneity of cell types. In both TCLs approximately 80% of the cells were T cells, all of which bore the alpha beta T cell receptor. The P. gingivalis-reactive TCL (PG-TCL) showed approximately equal proportions of CD4+ and CD8+ cells, whereas the F. nucleatum-reactive TCL (FN-TCL) was predominantly CD4+. The expression of CD25, HLA-DR, CD45RA and CD29 on these CD4+ cells varied throughout the culture period of 45 days. These results demonstrate that it is possible to establish long-term T cell lines reacting to specific periodontopathic bacteria.

The effect of cyclosporin and lipopolysaccharide on fibroblasts: implications for cyclosporin-induced gingival overgrowth

Drug-induced gingival overgrowth is an adverse side effect associated principally with 3 different types of drugs; specifically the antiepileptic phenytoin, the calcium channel antagonist nifedipine, and the immunosuppressant cyclosporin. The present study has analyzed the effect of cyclosporin and lipopolysaccharide on fibroblasts from 3 different sources: 1) normal healthy human gingiva (NHGF); 2) overgrown gingiva from 2 patients taking cyclosporin (CHGF); and 3) human fetal lung (WI-38). Fibroblasts isolated from cyclosporin-associated gingival overgrowth were significantly less responsive to cyclosporin in terms of DNA, total protein, and proteoglycan synthesis. This finding supports the in vivo response where few fibroblasts are seen but marked overgrowth of fibrous tissue occurs. Lipopolysaccharide derived from Fusobacterium nucleatum and Escherichia coli was capable of inhibiting DNA synthesis significantly in all 3 fibroblast types. Total protein synthesis by CHGF cells was inhibited differentially by Fusobacterium nucleatum LPS and addition of cyclosporin to this system resulted in reversal of the inhibition. A synergistic effect was noted when the proteoglycan output of NHGF cells was assessed in response to co-incubation with cyclosporin and Escherichia coli LPS. The study shows that bacterial LPS may be an important co-factor in the pathogenesis of cyclosporin-induced gingival overgrowth.

CD45RA and CD45RO positive CD4 cells in human peripheral blood and periodontal disease tissue before and after stimulation with periodontopathic bacteria

Flow cytometric analysis was used to examine naive and primed or memory CD4 cells extracted from periodontal lesions compared with cells from peripheral blood of healthy subjects before and after stimulation with the periodontopathic bacteria, Porphyromonas gingivalis and Fusobacterium nucleatum. In peripheral blood, approximately 60% and 40% of CD4 cells were CD45RO+ and CD45RA+ respectively at day 0. Phytohaemagglutinin (PHA) induced CD45RO expression on almost 100% of CD4 cells. However, P. gingivalis and F. nucleatum stimulation did not cause any significant change in percentage of CD45RO+ CD4 cells except for a loss of antigen at day 6 together with re-expression at day 7, which also occurred on cells cultured in medium only. CD45RA expression on PHA and bacterial-stimulated peripheral blood CD4 cells remained fairly stable for the 10-d culture period. Greater than 90% CD4 cells extracted from healthy or marginal gingivitis (H/MG) and adult periodontitis (AP) lesions were CD45RO+ and this was maintained on AP cells throughout the 6-d culture period, except for a small decrease in the percentage of positive cells induced by P. gingivalis at day 3. Approximately 9% CD4 cells from H/MG tissue were CD45RA+, but about 22% AP cells expressed this antigen, and this increased again in P. gingivalis- and F. nucleatum-stimulated cultures after 3 d. Therefore, in peripheral blood P. gingivalis and F. nucleatum do not act as nonspecific T-cell mitogens and, in AP cells, these bacteria induce changes in phenotype, supporting previous data that although they may be polyclonal B-cell activators, they activate antigen specific T-cells.

An immunohistological demonstration of c-erbB-2 oncoprotein expression in primary urothelial bladder cancer

Sections of formalin-fixed, paraffin-blocked tissue from 116 primary transitional cell carcinomas were stained immunohistochemically using a polyclonal antibody against the c-erbB-2 oncoprotein. Positive staining of cell membranes, known to correlate with gene amplification, was seen in 22 (19%) of the 116, with variable staining from tumour to tumour and within tumours themselves. Consistent with its mooted value as a prognosticator in bladder cancer, the c-erbB-2 oncoprotein was detected in 13 (of 40) grade III and 9 of the 26 muscle-invasive tumours examined compared to 1 (of 25) grade I and 6 (of 66) mucosa only (pTa) lesions. These results support further examination of c-erbB-2 expression in bladder cancer.

Phenotypic analysis of B-cells extracted from human periodontal disease tissue

B-cells extracted from periodontal disease tissue were analyzed for the presence of activation markers using a range of monoclonal antibodies. In adult periodontitis (AP), 6% of B-cells expressed the IL-2 receptor (CD25) compared with 1-2% in peripheral blood and healthy or marginal gingivitis (H/MG) gingival B-cells. There was also an increase in the mean percentage of IgD-positive B-cells and a decrease in CD21 and CD22 expression. In both AP and H/MG lesions, 20-22% of the B-cells expressed CD23 compared with less than 5% in peripheral blood. As B-cells are activated by day 3 in culture and start differentiating into immunoglobulin-secreting cells by day 6, B-cell phenotypes were assayed at these times in this study. Following stimulation with the periodontopathic bacterium Porphyromonas gingivalis, the expression of CD23, CD21 and CD22 on B-cells extracted from AP lesions remained relatively constant over the 6-d culture period. However, with Fusobacterium nucleatum stimulation, there was a significant decrease in CD23, CD21 and CD22 expression after 3 d in culture, which corresponds to the activation time for B-cells. These results show that B-cells extracted from periodontal disease tissue display a range of activation markers and on stimulation, demonstrate differing responses to individual periodontopathic bacteria.

Effect of initial treatment of chronic inflammatory periodontal disease on the frequency of peripheral blood T-lymphocytes specific to periodontopathic bacteria

Limit dilution analysis (LDA) was used to determine the effect of initial treatment of chronic inflammatory periodontal disease on the frequency of periodontopathic bacteria-specific T-cells in peripheral blood. Eleven marginal gingivitis (MG) and 8 adult periodontitis (AP) subjects took part in the study. The proliferative T-lymphocyte precursor (PTL-P) frequencies to Porphyromonas gingivalis and Actinomyces viscosus were determined using LDA and Poisson statistics both before and after treatment. Tetanus toxoid was used as a control antigen. Treatment resulted in a significant reduction in clinical disease parameters in both groups. The median peak PTL-P frequency for P. gingivalis was significantly higher in the AP group compared with the MG group before treatment. This was not the case after treatment nor with A. viscosus. In the MG group the median peak PTL-P frequency with both P. gingivalis and A. viscosus declined as a result of treatment. Although this decline was not statistically significant it may indicate an antigen-specific response in this group. In the AP group the median peak PTL-P frequency with P. gingivalis before treatment was 83.76 x 10(-6) (approximately 1 in 12,000) and after treatment it was 36.17 x 10(-6) (approximately 1 in 28,000). Dose-response relationships showed at each concentration of organisms/well this trend for a decline in PTL-P frequency after treatment, suggesting that any increased responsiveness to this organism in this group may be largely antigen-specific. However, there was no difference in this group in the median peak PTL-P frequency with A. viscosus before and after treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Renal insufficiency and secondary hyperparathyroidism in elderly patients

Glomerular filtration rate (GFR) is frequently reduced in elderly people. However, the effect of this on mineral metabolism in this population has received little attention. GFR, serum intact parathyroid hormone (PTH) and vitamin D metabolites were measured in 37 patients admitted to hospital for various reasons. In 20 patients with GFR greater than 50 mL/min, an elevated serum intact PTH concentration (greater than 5.4 pmol/L) was found in two, while in 17 patients with GFR less than 50 mL/min PTH was elevated in 13. One of this group was hypercalcaemic and presumed to have primary hyperparathyrodism. Adjusted calcium was normal in all other patients. Two patients had a low serum 25-hydroxyvitamin D concentration (less than 9 nmol/L) suggesting vitamin D insufficiency while a further five had a reduced 1,25-dihydroxyvitamin D concentration, four of these having a GFR less than 50 mL/min. We conclude that hyperparathyrodism is common in hospitalized elderly patients, particularly in those with mild to moderate renal insufficiency. This may contribute to bone mineral loss in such patients.

Importance of the host response in the periodontium

Immunological mechanisms have been implicated in the pathogenesis of periodontal disease for over 25 years. Studies throughout the 1970s established that advanced forms of the disease were dominated by B-cells/plasma cells while early and putative stable forms of the disease were dominated by T-cells/lymphocytes. Based on these observations, a model of disease was put forward which highlighted a possible T-cell/macrophage immunoregulatory imbalance being involved in disease pathogenesis. Studies throughout the 1980s have supported such a concept although the precise nature of this imbalance remains elusive. At the same time, clinical studies have established that patient susceptibility may be of overriding importance in determining disease outcome. In this context therefore, factors which influence this susceptibility should be fundamental in determining periodontal disease activity. These factors may include genetic variation between individuals in the way in which they respond to periodontopathic bacteria upon which environmental factors would be superimposed. These environmental factors would include anything that altered the balance between the host and the parasite and may be as diverse as recent viral infections resulting in T-cell anergy or physical and mental stress. Recent studies have shown that in elite atheletes, physical stress during training and competition leads to a suppression of mucosal immunity as evidenced by a reduction in salivary IgA. The subsequent effect of these environmental factors at the level of the periodontium, however, remains to be determined.

A scoring system for the quantitative evaluation of oral mucositis during bone marrow transplantation

A system for assessing the severity of mucositis in patients undergoing bone marrow transplantation (BMT) is presented. Ten criteria were graded to give component scores together with a total score. The overall severity score ranged from 0 through 21. Scores were assigned three times daily by nursing staff members and verified daily by the attending dental and medical practitioners. Total scores were highly reproducible and were related to the severity of neutropenia. Variation between sequential total scores was not related to interexaminer variation but rather to changes in the severity of oral mucositis. Component scores provided a useful means for transmitting oral health information between health care personnel. Total scores were used to regulate the nature and frequency of oral hygiene procedures for patients undergoing BMT as well as other hematology/oncology patients. Application of this oral assessment system to other institutional settings may be beneficial.

Immunopathogenesis of oral lichen planus

Oral lichen planus (LP) is a common mucosal disorder in which cell mediated immunity is thought to play a major role. In this paper, a unifying hypothesis which attempts to integrate cellular and molecular signals in the local immune response in oral LP is presented. In this model, modified keratinocyte surface antigens are the target for the cytotoxic cell response which characterizes oral LP, whereas mast cells and antigen presenting Langerhans cells are key cellular elements in the evolving lesion. It has been established that mast cell degranulation induces adhesion molecule expression on endothelium which facilitates lymphocyte homing to the tissues. These adhesive interactions between lymphocytes and keratinocytes are postulated to be important determinants in the effector phase of the lesion. Cytokines produced by both lymphocytes and keratinocytes which influence the local immune response could promote chronicity. Accordingly, modulation of immunologic events is a potential therapeutic approach for oral LP.

Modulation of Langerhans cell surface antigen expression by recombinant cytokines

This study examined the influence of cytokines on surface antigen expression by gingival Langerhans cells (LC) in organ culture, interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-alpha) upregulated the expression of CD1a, HLA-DR and HLA-DP antigens on LC. TNF-alpha, interleukin-4 (IL-4), and transforming growth factor beta (TGF-beta) suppressed CD29 expression, while other cytokines, including interleukin-3 and granulocyte-macrophage colony stimulating factor, were without effect. No cytokines induced CD3, CD4, CD23, CD25 or CD45 RA antigen expression in organ culture. Since TNF-alpha and IL-6 can be secreted by keratinocytes, these molecules, together with interleukin-1, are likely to play a role in the local control of LC number and function within the epithelial milleu. Thus, alterations in cytokine secretion by keratinocytes may at least in part be responsible for variations in LC number and antigen expression which occur in oral mucosal disorders.

Human gingival Langerhans cells stimulate allogeneic lymphocytes: requirement for MHC class II antigens

Langerhans cells (LC) are antigen-presenting cells which express high levels of Class II MHC antigens on their plasma membranes. While the expression of these antigens on gingival LC has been documented, their functional significance is unclear. In this study, the mixed epithelial cell-lymphocyte culture reaction (MECLR) between stimulator cells (LC) and allogenic lymphocytes was used as an in vitro model for investigating the role of the MHC Class II antigens HLA-DR, -DQ, and -DP in alloantigen presentation by gingival LC. In epithelial cell suspensions prepared from human gingiva, MHC Class II antigen expression (HLA-DR, -DP, -DQ) was confined to CD1a-positive LC. Depletion of Class II antigen-bearing LC from epithelial cells using monoclonal antibodies (L243, B7/21, and SK10) and complement inhibited the ability of epithelial cells to stimulate proliferation in the MECLR. Pre-treatment of epithelial cell suspensions with the same monoclonal antibodies suppressed proliferation in the MECLR, as did direct addition of these antibodies to co-cultures of epithelial cells and lymphocytes. These results indicate that HLA-DQ and -DP, together with DR antigens on gingival LC, are involved in LC-lymphocyte interactions. Since LC are potent antigen presenting cells, alterations in the expression of MHC Class II antigens on the surface of these cells will influence their ability to stimulate lymphocytes during the initiation of the cellular immune response to the accumulation of dental plaque.

The bistratenes: new cytotoxic marine macrolides which induce some properties indicative of differentiation in HL-60 cells

The biological effects of cytotoxic macrolide polyethers, the bistratenes, isolated from the ascidian Lissoclinum bistratum, have been examined. Bistratene A was toxic to HL-60 human promyelocytic leukemia cells with an IC50 value of 424 nM. At lower concentrations (10-100 nM), bistratene A induced the incomplete differentiation of these cells along the monocyte/macrophage pathway. These effects were not due to inhibition of DNA synthesis. Bistratene B had similar effects to bistratene A. At micromolar concentrations these compounds enhance the phospholipid-dependent activity of type II protein kinase C from bovine spleen. The bistratenes provide new probes for studying the molecular mechanisms governing cell growth and differentiation.

RAS oncogene product expression in normal and malignant oral mucosa

Proto-oncogenes are important in both normal cellular differentiation and in carcinogenesis. The majority of transforming genes belong to the ras family and the ras gene product has been shown to be elevated in some oral carcinomas. RAP-5 monoclonal antibody was used to determine the expression of the p21ras protein in normal and neoplastic oral mucosa in an immunohistological study. The expression of p21ras protein was generally restricted to acanthous cells with strong staining in normal oral mucosa and well-differentiated carcinomas. In contrast, the p21ras protein was not detected in significant amounts in severely dysplastic lesions and poorly differentiated carcinomas. These results suggest that expression of p21ras is a normal feature of more fully differentiated tissues, both normal and neoplastic, and is not useful as an indicator of cell proliferation or 'malignant potential'.

Transferrin receptor expression in primary superficial human bladder tumours identifies patients who develop recurrences

A group of 65 patients with superficial bladder carcinoma was followed for 2 years and tumour recurrence rate was correlated both with transferrin receptor status of the initial primary tumour and with the results of voided urine cytology. Nine of 24 patients with transferrin receptor negative tumours had recurrences compared with 30 of 41 patients with transferrin receptor positive tumours. This difference was highly significant. Urine cytology at presentation was also predictive of further tumour formation: of 30 patients who were transferrin receptor positive and had positive urine cytology, 25 developed recurrences.

Immunohistologic analysis of epithelial cell populations in oral lichen planus

Previous studies have demonstrated heterogeneity within lesional lymphocytes in drug-related oral lichen planus (D-LP) and idiopathic lichen planus (I-LP). This study examined the phenotype of Langerhans cells (LC) and keratinocytes in non-erosive D-LP and I-LP. In I-LP, keratinocytes expressed HLA-DR antigens whilst LC co-expressed CDIa, MHC Class II and CD4 antigens. The high levels of expression of MHC Class II antigens by LC were maintained during short term organ culture. In I-LP, the epithelium contained occasional CD25+ dendritic cells (putative activated LC). These cell phenotypes are suggestive of cell activation and likely result from local production of gamma interferon. In D-LP, expression of MHC Class II antigens on LC was reduced and no CD25+ cells were detected. The epithelium contained an increased number of CD45RA+ dendritic cells. While no differences between the production of interleukin-1 and interleukin-1 inhibitors by tissue samples could be detected, it is likely that the variations in epithelial cell phenotypes in I-LP and D-LP reflect altered cytokine production.

Effects of periodontopathic bacteria on IL-1 and IL-1 inhibitor production by human polymorphonuclear neutrophils

The effect of heat-killed periodontopathic bacteria on the production of interleukin-1 (IL-1) and an IL-1 inhibitor by human polymorphonuclear neutrophils (PMN's) was examined. Peripheral blood was obtained from 18 healthy volunteers and the PMN's were separated using dextran sedimentation and Ficoll-Paque density gradient centrifugation. The PMN's (5 x 10(5) cells/well) were cultured in serum-free media with or without heat-killed periodontopathic bacteria. Four gram-negative periodontopathic bacteria were used; Bacteroides gingivalis FDC 381, Bacteroides forsythus FDC 338, Actinobacillus actinomycetemcomitans Y4 and Fusobacterium nucleatum FDC 263. The non-oral Fusobacterium mortiferum ATCC 25557 was used as a control organism. IL-1 activity was assayed using thymocyte proliferation. The non-oral organism F. mortiferum stimulated IL-1 production by PMN's, in contrast none of the periodontopathic bacteria stimulated IL-1 release although the bacteria themselves had an IL-1 enhancing effect. Following fractionation of the periodontopathic bacteria stimulated PMN supernatants, an IL-1 inhibitory fraction was identified. These results may illustrate a further mechanism by which periodontopathic bacteria may evade the protective effect of PMN's and may also suggest a regulatory role for PMN's in chronic inflammatory periodontal disease.