Oral mucosal keratinocytes express RANTES and ICAM-1, but not interleukin-8, in oral lichen planus and oral lichenoid reactions induced by amalgam fillings

MAIT cells modulating the oral lichen planus immune microenvironment: a cellular crosstalk perspective

Mucosal-associated invariant T (MAIT) cells, a type of T lymphocytes with innate-like characteristics, are crucial in bridging innate and adaptive immunity. When activated, MAIT cells release various inflammatory molecules and swiftly respond to antigens. Notably, numerous studies highlight the significant impact of MAIT cells on tumors and various immune disorders by influencing the immune microenvironment. Oral lichen planus (OLP) is an immune-mediated inflammatory condition mainly involving T lymphocytes. Previous research primarily focused on T cells alone, neglecting the broader immune environment. However, there is a current growing recognition of the complex interactions among multiple immune cells and inflammatory factors in patients with OLP. This immune microenvironment comprises T lymphocytes, fibroblasts, keratinocytes, dendritic cells, macrophages, inflammation-related cytokines, and chemokines, orchestrating intricate interactions that contribute to OLP initiation and persistence. Therefore, this review consolidates current research on the interplay between MAIT cells and other immune cells within the OLP microenvironment. We also delve into potential mechanisms through which MAIT cells regulate inflammation in patients with OLP, aiming to further explore the role of MAIT cells in these patients.

A Tissue-Engineered Model of T-Cell-Mediated Oral Mucosal Inflammatory Disease

T-cell-mediated oral mucocutaneous inflammatory conditions, including oral lichen planus, are common, but development of new treatments aimed at relieving symptoms and controlling oral lichen planus progression is hampered by the lack of experimental models. In this study, we developed a tissue-engineered oral mucosal equivalent containing polarized T-cells to replicate oral lichen planus pathogenesis. Peripheral blood CD4+ and CD8+ T-cells were isolated, activated, and polarized into T helper 1 and cytotoxic T cells. Oral mucosal equivalents were constructed by culturing oral keratinocytes on an oral fibroblast-populated hydrogel to produce a stratified squamous epithelium. Oral mucosal equivalent stimulated with IFN-γ and TNF-α or medium from T helper 1 cells caused increased secretion of inflammatory cytokines and chemokines. A model of T-cell-mediated inflammatory disease was developed by combining oral mucosal equivalent on top of a T helper 1 and cytotoxic T-cell-containing hydrogel, followed by epithelial stimulation with IFN-γ and TNF-α. T-cell recruitment toward the epithelium was associated with increased secretion of T-cell chemoattractants CCL5, CXCL9, and CXCL10. Histological assessment showed tissue damage associated with cleaved caspase-3 and altered laminin-5 expression. Treatment with inhibitors directed against Jak, KCa3.1 channels, or clobetasol in solution and through a mucoadhesive patch prevented cytokine and chemokine release and tissue damage. This disease model has potential to probe for mechanisms of pathogenesis or as a test platform for novel therapeutics or treatment modalities.

An exotic pathogenetic mechanism of angiogenesis in oral lichen planus-A systematic review

OBJECTIVE

Angiogenesis plays a vital role at the molecular level in various inflammatory lesions, that lead to their chronicity. Oral lichen planus is an immune-mediated chronic inflammatory disorder. The angiogenetic role and exact mechanisms in oral lichen planus are still unclear due to a dearth of studies. Its clinical significance with angiogenesis also requires further elucidation necessitating a thorough review of the studies that have been conducted so far. The present review was designed to identify the dependence of oral lichen planus progression on angiogenesis which could aid in devising metronomic treatments required to halt the progression of this disease.

MATERIALS AND METHODS

A thorough search was made using MEDLINE by PubMed, Scopus, Google scholar, Cochrane library, and EMBASE databases. Original research articles, that immunohistochemically evaluated angiogenesis in oral lichen planus were included for review. Risk of bias was analysed for each study using Modified Newcastle-Ottawa scale and Review Manager 5.4 was used to output its result.

RESULTS

Twenty-nine published articles were included for data synthesis. The most commonly employed antibody was CD34, however, upregulated VEGF expression was the principal while ICAM-1, VCAM-1, and PECAM-1 were critical angiogenic factors to mediate angiogenesis in oral lichen planus.

CONCLUSION

The current evidence supports that angiogenesis, a fundamental pathogenetic mechanism of oral lichen planus, leads to its persistence and chronicity. However, studies with a larger sample size, standard evaluation criteria, different subtypes, and adequate follow-up are warranted.

ASCT2-mediated glutamine uptake of epithelial cells facilitates CCL5-induced T cell infiltration via ROS-STAT3 pathway in oral lichen planus

BACKGROUND

Oral lichen planus (OLP) is a chronic inflammatory disease characterized by T cell infiltration at lesion sites. T cell migration is greatly facilitated by chemokines produced by epithelial cells. Studies have noted the potential role of glutamine uptake in OLP and other inflammatory diseases. Here, we investigated the effect of altered glutamine uptake of epithelial cells on T cell infiltration and its underlying mechanisms in OLP.

METHODS

Immunohistochemistry was used to identify the expressions of glutamine transporter alanine-serine-cysteine transporter 2 (ASCT2) and C-C motif chemokine ligand 5 (CCL5) in oral tissues of OLP and healthy controls. Human gingival epithelial cells (HGECs) were treated with glutamine deprivation and ASCT2 inhibiter GPNA respectively to detect the expressions of CCL5 and its related signaling molecules. Additionally, we had determined the impact of epithelial cell-derived CCL5 on T-cell migration using a co-culture system in vitro.

RESULTS

ASCT2 and CCL5 expressions in OLP were significantly higher than healthy controls and positively correlated with the density of inflammatory infiltrations. Glutamine supplement significantly increased CCL5 production in HGECs, which was effectively inhibited by GPNA. Besides, glutamine could inhibit reactive oxygen species (ROS) production to activate the signal transducer and activator of transcription 3 (STAT3) causing higher expression level of CCL5 in HGECs. Simultaneously, T cell migration could be blocked by anti-CCL5 neutralizing antibody and STAT3 inhibitor stattic in the co-culture system.

CONCLUSION

The upregulated ASCT2-mediated glutamine uptake in epithelial cells promotes CCL5 production via ROS-STAT3 signaling, which boosts the T-cell infiltration in OLP lesion.

Updates on immunological mechanistic insights and targeting of the oral lichen planus microenvironment

Oral lichen planus (OLP) is a chronic immune inflammatory disease that is an oral potentially malignant disorder (OPMD), occurs in the oral mucosa and affects approximately 0.5% to 4% of the general population. There are usually five types of OLP: reticular/papular, plaque-like, atrophic/erythematous, erosive/ulcerative, and bullous. Furthermore, the chance of causing oral squamous cell carcinoma (OSCC) is 1.4%. Although the etiology of OLP is still unknown, accumulating evidence supports that immune dysregulation may play a vital role in the pathogenesis of OLP, especially the massive production of various inflammatory cells and inflammatory mediators. In this review, we focus on the relationship between OLP and its immune microenvironment. We summarize current developments in the immunology of OLP, summarizing functional cell types and crucial cytokines in the OLP immune microenvironment and the underlying mechanisms of key signaling pathways in the OLP immune microenvironment. We highlight the application potential of targeted immune microenvironment therapy for OLP.

The expression of salivary microRNAs in oral lichen planus: Searching for a prognostic biomarker

Oral lichen planus (OLP) is a premalignant disease with unknown etiology. It has been demonstrated that inflammation and immune activation play a central role in the pathogenesis of OLP. Various cellular and molecular mechanisms are involved in the pathogenesis of OLP. Studies have shown that 2-7% of OLP patients develop oral squamous cell carcinoma (OSCC). As a result, determining the prognosis of the disease will be promising in preventing oral carcinoma. MicroRNAs are involved in the regulation of cytokine expression and cytokines have a central role in the pathogenesis of OLP. As a result, their evaluation in body fluids may be helpful in assessing the disease's status and progression, and facilitating the treatment process. In this regard, much attention has been paid to the saliva of OLP patients as the sampling is cost-effective and non-invasive. Here, we discuss the potential of miRNAs in predicting the disease severity and progression.

Immune mechanisms in oral lichen planus

Oral lichen planus (OLP) is a T-cell-mediated inflammatory disease of the oral mucosa that has been extensively researched over many years but as yet the mechanisms of pathogenesis are still not fully understood. Whilst the specific etiologic factors driving OLP remain ambiguous, evidence points to the development of a chronic, dysregulated immune response to OLP-mediating antigens presented by innate immune cells and oral keratinocytes leading to increased cytokine, chemokine and adhesion molecule expression. These molecules recruit T-cells and mast cells to the diseased site and orchestrate a complex interplay between cells that culminates in keratinocyte cell death, mucosal basement membrane destruction and long-term chronicity of the disease. The main lymphocytes involved are thought to be CD8+ cytotoxic and CD4+ Th1 polarised T-cells although recent evidence indicates the involvement of other Th subsets such as Th9, Th17 and Tregs, suggesting that a more complex immune cell relationship exists during the disease process. This review provides an overview of the immune mechanisms at play in OLP pathogenesis with particular emphasis on the role of the different Th subsets and how these recent discoveries may guide research toward identifying potential therapeutic targets.

PECAM-1 overexpression signifies aggressive biologic behavior of oral lichen planus - A pilot study

Context

The etiopathogenesis of oral lichen planus (OLP) is still debatable. According to literature, many studies have illustrated OLP as a T-cell-mediated chronic autoimmune disease. Currently, there is increased evidence of chronic inflammation in OLP and its association with vascular adhesion molecules (VAMs).

Aim

The aim of this study was to evaluate the expression of VAM (PECAM-1) in OLP.

Setting and Design

Tissue samples involved 20 archival cases of histopathologically confirmed OLP (n = 15) and normal mucosa (n = 5) as controls.

Materials and Methods

The sections were subjected to immunohistochemical analysis using antibody to PECAM-1. Brown staining of the endothelial cells of blood vessels was considered positive. The expression of PECAM-1 in OLP was statistically analyzed using Wilcoxon sign-rank test.

Results

The expression of PECAM-1 in OLP was statistically significant when compared with normal mucosa (P < 0.05). A statistically significant difference was also observed in PECAM-1 expression between the reticular type and erosive type of OLP.

Conclusion

PECAM-1 was found to be overexpressed in OLP; difference in PECAM-1 expression was noted between the reticular and erosive types. The VAMs could be exploited as a possible therapeutic target in OLP to modulate the disease process thereby reducing the dependency on corticosteroids.

Immune receptors CD40 and CD86 in oral keratinocytes and implications for oral lichen planus

Lichen planus (LP) is a chronic T-cell-mediated mucocutaneous inflammatory disease that targets stratified epithelia, including those lining the oral cavity. The intraoral variant of LP (OLP) is associated with interferon (IFN)-γ production by infiltrating T lymphocytes; however, the role of epithelial cells in the etiopathogenesis OLP is not completely understood. There is however a growing body of evidence regarding the involvement of epithelial-derived cytokines, immune receptors, and costimulatory molecules in the pathobiological processes that promote and sustain OLP. In the present study, we used a reverse transcriptase-polymerase chain reaction assay to assess whether CD40-a receptor found mainly on antigen presenting cells-and the costimulatory molecule CD86 were expressed in oral keratinocytes (three strains of primary normal oral keratinocytes and the H357 cell line) in the presence or absence of IFN-γ. To further characterize the involvement of CD40 in OLP, expression and distribution of receptor and ligand (CD40/CD154) in tissues from OLP were evaluated by immunohistochemistry. The present results are the first to show that both CD40 and CD86 are constitutively expressed at low levels in oral keratinocytes and that their expression was enhanced by IFN-γ stimulation. The intensity of CD40 staining in OLP tissues was strong. Taken together, the results strongly suggest that CD40 and CD86 play a role in the pathophysiology of oral inflammatory diseases such as OLP.

The presence of bacteria within tissue provides insights into the pathogenesis of oral lichen planus

Oral lichen planus (OLP) is a chronic T cell-mediated mucocutaneous disease of unknown etiopathogenesis. Although various antigens have been considered, what actually triggers the inflammatory response of T cells is unknown. In the present study, we propose that intracellular bacteria present within tissues trigger T cell infiltration and provide target antigens. Sections of OLP (n = 36) and normal (n = 10) oral mucosal tissues were subjected to in situ hybridization using a universal probe targeting the bacterial 16S rRNA gene and immunohistochemistry with anti-CD3, anti-CD4, anti-CD8, and anti-macrophage-specific antibodies. Bacteria were abundant throughout the epithelium and the lamina propria of OLP tissues, which exhibited positive correlations with the levels of infiltrated CD3(+), CD4(+), and CD8(+) cells. Furthermore, bacteria were detected within the infiltrated T cells. Pyrosequencing analysis of the mucosal microbiota from OLP patients (n = 13) and control subjects (n = 11) revealed a decrease in Streptococcus and increases in gingivitis/periodontitis-associated bacteria in OLP lesions. Using the selected bacterial species, we demonstrated that certain oral bacteria damage the epithelial physical barrier, are internalized into epithelial cells or T cells, and induce production of T cell chemokines CXCL10 and CCL5. Our findings provide insights into the pathogenesis of OLP.

Association of CD24 and the adenomatous polyposis coli gene polymorphisms with oral lichen planus

OBJECTIVE

CD24 and the adenomatous polyposis coli (APC) gene polymorphisms are known to predispose to malignant disease. We aimed to investigate their association with risk and susceptibility of oral lichen planus (OLP) in an Israeli Jewish population.

STUDY DESIGN

The study included 54 patients, of which 41 were females (75.9%) and 13 males (24.1%); of the 533 controls, 224 were females (42.0%) and 309 males (57.9%). Genotyping was performed. Two APC (I1307 K, E1317 Q) and four CD24 variants--C170 T (rs52812045), TG1527 del (rs3838646), A1626 G (rs1058881), and A1056 G (rs1058818)--were assessed. Frequencies were analyzed using the Chi-square test. Two-sided P < .05 values were considered significant. Odds ratios and 95% confidence intervals were obtained by logistic regression analyses.

RESULTS

CD24 A1056 G carriers have a significantly lower risk of OLP compared with individuals with the wild-type variant (P = .001). A significantly lower risk was found for heterozygote (P = .008) and homozygote carriers (P = .002). Homozygote CD24 A1626 G carriers had a significant higher risk for OLP compared with nonhomozygote carriers (P = .040). CD24 C170 T, TG1527 del, and APC polymorphisms did not show significant associations with OLP risk.

CONCLUSIONS

CD24 A1626 G is more frequent in OLP patients, contributes to disease risk, and could play a role in OLP susceptibility. A significant association between CD24 A1056 G and a lower OLP incidence was found, suggesting that it may confer protection against OLP risk and progression.

Oral lichen planus and lichenoid mucositis

Oral lichen planus (OLP) is commonly found in middle-aged women. Although the cause is unknown, research points to several complex immunologic events and cells that are responsible for the inflammatory destruction and chronicity of these lesions. Biopsy for histologic diagnosis is recommended. The mainstay of treatment remains topical corticosteroids; however, newer therapies such as immunomodulating agents are available for recalcitrant lesions. In cases of lichenoid mucositis or reactions, treatment should be directed at identifying and removing the presumed cause. Given the apparent risk of squamous cell carcinoma in these patients, frequent follow-up and repeat biopsy are vital.

Inflammation-related cytokines in oral lichen planus: an overview

Cytokines are powerful mediators which play a central role in both innate and adapted immune responses. Aberrant productions of cytokines may lead to the onset of immune deficiency, allergy or autoimmunity, which are involved in the mechanisms of various immune-mediated inflammatory diseases. Oral lichen planus (OLP) is a chronic inflammation disease affecting the oral mucosa with unknown aetiology. Previous studies have described the abnormal expression patterns of various inflammation-related cytokines, such as IL-1, 2, 4, 5, 6, 8, 10, 12, 17, 18, TGF-β, IFN-γ and TNF-α, in lesions, saliva, serum and peripheral blood mononuclear cells from patients with OLP, which may reflect the immune dysregulation status and emerge as central players in the immunopathogenesis of OLP. Besides, the gene polymorphisms of several cytokines such as IFN-γ, TNF-α, IL-4, IL-10 have been found to be involved in the susceptibility of OLP. In this review, we gave a brief introduction of the characteristics and biological functions of these inflammation-related cytokines and summarized for the first time the current knowledge on the involvement of inflammation-related cytokines in OLP. Further research on the exact roles of these cytokines will aid the understanding of the pathogenesis and the identification of novel therapeutic approaches of OLP.

Cutaneous manifestations of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a multiorgan autoimmune disease of unknown etiology with many clinical manifestations. The skin is one of the target organs most variably affected by the disease. The American College of Rheumatology (ACR) established 11 criteria as a classificatory instrument to operationalise the definition of SLE in clinical trials. They were not intended to be used to diagnose individuals and do not do well in that capacity. Cutaneous lesions account for four of these 11 revised criteria of SLE. Skin lesions in patients with lupus may be specific or nonspecific. This paper covers the SLE-specific cutaneous changes: malar rash, discoid rash, photosensitivity, and oral mucosal lesions as well as SLE nonspecific skin manifestations, their pathophysiology, and management. A deeper thorough understanding of the cutaneous manifestations of SLE is essential for diagnosis, prognosis, and efficient management. Thus, dermatologists should cooperate with other specialties to provide optimal care of SLE patient.

Cutaneous manifestations of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a multiorgan autoimmune disease of unknown etiology with many clinical manifestations. The skin is one of the target organs most variably affected by the disease. The American College of Rheumatology (ACR) established 11 criteria as a classificatory instrument to operationalise the definition of SLE in clinical trials. They were not intended to be used to diagnose individuals and do not do well in that capacity. Cutaneous lesions account for four of these 11 revised criteria of SLE. Skin lesions in patients with lupus may be specific or nonspecific. This paper covers the SLE-specific cutaneous changes: malar rash, discoid rash, photosensitivity, and oral mucosal lesions as well as SLE nonspecific skin manifestations, their pathophysiology, and management. A deeper thorough understanding of the cutaneous manifestations of SLE is essential for diagnosis, prognosis, and efficient management. Thus, dermatologists should cooperate with other specialties to provide optimal care of SLE patient.

Urban legends series: lichen planus

Oral Diseases (2012) Lichen planus (LP) is a common disorder affecting the oral cavity (OLP) and skin. Despite intensive research, LP/OLP etiology and treatment remain controversial. We investigated four controversial topics: (i) Is hepatitis C virus (HCV) infection associated with LP and involved in its pathogenesis? (ii) Should all patients with LP be screened for HCV? (iii) Should patients with OLP have all their amalgam restorations removed? (iv) Are there any new treatments for OLP? Results from extensive literature searches suggested that: (i) Robust evidence from three meta-analyses indicate that HCV is associated with LP and might be involved in OLP pathogenesis (ii) It would be prudent to screen patients with LP/OLP at significant risk with an ELISA for HCV antibodies using country-specific screening strategies (iii) There is no evidence that either OLP or oral lichenoid lesions patients would routinely benefit from having all their amalgam restorations replaced. Weak evidence from potentially very biased, small, non-randomized, unblinded studies suggests that a small fraction of patients may benefit from targeted amalgam replacement. (iv) There is weak evidence that, among new OLP treatments, topical pimecrolimus, aloe vera, and oral curcuminoids may be useful. The development of specific formulations for oral delivery of topical medications is a promising field.

Genome-wide analysis reveals the active roles of keratinocytes in oral mucosal adaptive immune response

To elucidate the roles of oral keratinocytes in the adaptive immune response of oral mucosa, global gene expression analysis was performed by microarray technique and integrating computational methods, including hierarchical clustering, biological process Gene Ontology analysis, Kyoto Encyclopedia of Genes and Genomes pathway analysis, self-organizing maps (SOMs) and biological association network analysis (BAN). Raw data from microarray experiments were uploaded to the Gene Expression Omnibus Database, http://www.ncbi.nlm.nih.gov/geo/ (GEO accession GSE28035). We identified 666 differentially expressed genes in the early stage (48 h) and 993 in the late stage (96 h) of the oral mucosal adaptive immune response. The analysis revealed that oral keratinocytes exerted diverse biological functions in different stages of immune response. Specifically, in 48 h the differentially expressed genes encompassed an array of biological ontology associated with immune response, such as antigen processing and presentation, and positive regulation of T-cell-mediated cytotoxicity. Several pathways which have been reported to be critical in inflammation, including mitogen-activated protein kinase pathway, were activated. Furthermore, after BAN construction, some putative hub genes and networks such as interleukin-1α and its subnetwork were recognized. Taken together, these results give substantial evidence to support the active roles of keratinocytes in the oral mucosal adaptive immune response.

Association between oral lichenoid reactions and amalgam restorations

BACKGROUND

The aim of this study was to perform a clinical assessment of the association between oral lichenoid reactions (OLR) and amalgam restorations and to determine the salivary concentrations of interleukin-6 (IL-6) and IL-8 before and after replacement of the amalgam restorations.

METHODS

The study included 20 patients with OLR and 20 healthy volunteers, who were examined between 2001 and 2005 at the Oral Medicine Unit of the Medical Faculty University of Rijeka. All patients were skin patch tested by an experienced physician. Saliva samples were collected, prepared and analysed for IL-6 and IL-8 concentrations using enzyme-linked immunosorbent assay.

RESULTS

Sixteen out of 20 patch-tested patients showed a sensitization to inorganic mercury or amalgam. Total replacement of all amalgam fillings was carried out on 20 patients with fillings based on composite resin, gold, porcelain or a combination of these. Sixteen out of 20 patients showed complete healing of OLR; three patients had marked improvement, whereas one patient showed no improvement. Levels of IL-6 detected before replacement were significantly higher than IL-6 levels following the replacement (P = 0.003). The IL-8 levels measured before replacement procedure were significantly higher than the IL-8 levels after replacement of the fillings (P < 0.001).

CONCLUSIONS

On the basis of clinical observations, restorative therapy resulted in tissue healing. Following the replacement of amalgam fillings with fillings based on other restorative materials, levels of both IL-6 and IL-8 shifted towards normal, as measured in healthy subjects.

CD40 in human oral epithelia

CD40 is a transmembrane glycoprotein belonging to the tumour necrosis factor receptor superfamily, which has a role in a number of biological functions, including the regulation of cell growth and division, and cell mediated immunity. Although originally described on leucocytes, principally B lymphocytes, there is now abundant evidence for the cellular diversity of CD40. The aim of this article is to review the available data on CD40 in oral epithelium, principally that lining the oral mucosa, but also that of the salivary glands.

Th1/Th2 cytokine ratio in tissue transudates from patients with oral lichen planus

OBJECTIVE

The characteristics of oral lichen planus (OLP) provoke investigators to explore possible biomarkers by which to monitor disease activity and therapeutic efficacy. Oral fluids may provide an accessible medium for analysis of such biomarkers. Previous studies have shown that activation of nuclear factor-kappa B (NF-kappa B) plays an important role in the pathogenesis of oral lichen planus (OLP), which is a chronic inflammatory disorder mediated by T cells. Prior to the present investigation, reports of the levels of NF-kappa B and its dependent cytokines in oral fluids have not been forthcoming. The purpose of this study was to detect the level of NF-kappa B dependent cytokines, TNF-alpha, IL-1-alpha, IL-6, and IL-8 in tissue transudates directly from lesions of OLP, and explore the feasibility of the data for clinical application.

STUDY DESIGN

Thirteen definitively diagnosed OLP subjects were enrolled in the study as were 13 age-sex matched controls. In each subject, lesion tissue transudates (TTs) were collected by a novel collection technique with a filter paper. The level of cytokines, TNF-alpha, IL-1-alpha, IL-6, and IL-8 in three types of oral fluids were determined by ELISA.

RESULTS

In the tissue transudate(TT), there were significantly higher level of cytokines TNF-alpha, IL-1-alpha, IL-6, and IL-8 detected in OLP patients than in controls: (TT: 40.0 +/- 9.8 versus 4.5 +/- 0.7, 710 +/- 114 versus 305 +/- 78, 150 +/- 25 versus 1.7 +/- 0.5, 2800 +/- 260 versus 1450 +/- 130, P < .0001; unit: pg/mL).

CONCLUSIONS

These results indicate that NF-kappa B dependent inflammatory cytokines may be detected at increased levels in oral lesion tissue transudates which may have diagnostic and prognostic potentials for monitoring disease activity and making therapeutic decisions in patients with OLP.

Expression profile of chemokines and chemokine receptors in epithelial cell layers of oral lichen planus

BACKGROUND

To understand the immunopathological features of oral lichen planus (OLP), we analyzed the expression of chemokines in the epithelial cell layers.

METHODS

Epithelia from OLP or healthy gingiva were collected by laser microdissection. The chemokine and chemokine receptor expressions in the epithelia were analyzed by DNA microarray.

RESULTS

High levels of MIP-3alpha/LARC/CCL20 and its receptor CCR6 were expressed in the lesional epithelia. Furthermore, DC-CK1/CCL18, ELC/CCL19, SDF-1/CXCL12 and CXCR4 expressions were also increased. Immunohistologial analysis showed that high numbers of Langerhans cells (LCs) were present in the epithelia of OLP. Lesional epithelia also expressed high levels of the ligands specific for CXCR3 (e.g. MIG/CXCL9, IP-10/CXCL10 and I-TAC/CXCL11) and CCR5 (e.g. RANTES/CCL5).

CONCLUSIONS

Infiltration of LCs is orchestrated by CCR6. Further, LCs residing in the lesional epithelia may be a mature phenotype. Moreover, infiltration of T cells in OLP could be mediated by signaling pathways through CXCR3 and CCR5.

Transfection of CD40 in a human oral squamous cell carcinoma keratinocyte line upregulates immune potency and costimulatory molecules

BACKGROUND

There is upregulation of class II molecules of the major histocompatibility complex (MHC) by keratinocytes in oral squamous cell carcinoma (OSCC) and inflammatory diseases such as lichen planus. The significance of this expression, or whether it is accompanied by upregulation of membrane-bound costimulatory molecules, is unknown.

OBJECTIVES

To compare the expression of CD40, CD80, CD86, MHC class II and intercellular adhesion molecule-1 (ICAM-1), and the ability to induce allogeneic T-lymphocyte proliferation in vitro, of a CD40- OSCC cell line, its CD40+ transfected derivative and null transfectants.

METHODS

OSCC cell lines and purified T lymphocytes were cocultured and T cell proliferation recorded. Phenotypes were analysed by flow cytometry.

RESULTS

After T lymphocyte proliferation, which all OSCC cell lines were able to induce, there was upregulation of MHC class II and ICAM-1. However, the CD40+ transfectants were the most immunologically potent and were the only cells to show increased expression of CD86 (as well as further upregulation of CD40 and a statistically insignificant rise in CD80). The effects of blocking antibodies on T-cell proliferation were only statistically significant with the CD40+ transfectants.

CONCLUSIONS

While not essential, expression of CD40 by OSCC cells is necessary for optimal induction of allogeneic T lymphocytes, possibly because of concurrent upregulation of other membrane-bound costimulatory molecules.

Enhancing the buccal mucosal uptake and retention of triamcinolone acetonide

In this study, the buccal mucosal uptake and retention of triamcinolone acetonide (TAC) were assessed in the presence of the skin penetration enhancer, Azone (AZ). Porcine buccal mucosa was excised, mounted in modified Ussing chambers, and pretreated with ethanolic solutions of AZ. After 2 h, the rate of TAC disappearance from the donor chamber and TAC appearance in the receptor chamber was monitored, and the mucosal retention of TAC was determined at the completion of the experiment. The permeability and mucosal uptake of TAC was also determined using the TAC-containing proprietary product, Kenalog in Orabase (KO), in the presence and absence of AZ. Pretreatment of the buccal mucosa with AZ increased the TAC disappearance permeability coefficient from 4.78+/-0.31x10(-5) cm/s to 7.12+/-0.53x10(-5) cm/s. While the TAC appearance permeability coefficient was also enhanced 3.8-fold, a 4.4-fold increase in the tissue concentration of TAC was observed. Incorporation of AZ into KO did not result in an enhanced tissue concentration of TAC, however, when the tissue was pretreated with AZ, significantly higher amounts of TAC accumulated in the tissue. Pretreatment of the buccal mucosa with AZ results in increased tissue concentrations of TAC, which may be of clinical benefit in the treatment of oral mucosal inflammatory conditions.

A comparison of the pro-inflammatory, NF-kappaB-dependent cytokines: TNF-alpha, IL-1-alpha, IL-6, and IL-8 in different oral fluids from oral lichen planus patients

To explore the feasibility of detection of the level of NF-kappaB-dependent cytokines in oral fluids from patient with oral lichen planus (OLP) for clinical application, 13 OLP subjects were enrolled in the study as were 13 age-sex-matched controls. In each subject, the whole unstimulated saliva (WUS), mixture of saliva and isotonic saline oral rinse (Saliva-NaCl), and lesion tissue transudates (TT) were collected by standard techniques. The level of cytokines, TNF-alpha, IL-1-alpha, IL-6, and IL-8 in three types of oral fluids was determined by ELISA. In the three types of oral fluids, a significantly higher level of these cytokines was detected in OLP patients than in normal controls. These results indicate that NF-kappaB-dependent inflammatory cytokines may be detected at increased levels in certain oral fluids which may have diagnostic and prognostic potential for monitoring disease activity and making therapeutic decisions in patients with OLP.

Lichen planus, lichenoid drug reactions, and lichenoid mucositis

Lichen planus is a common mucocutaneous disease affecting a significant portion of the general population. This article reviews the most current concepts on the epidemiology, etiology, pathogenesis, clinical presentations, and treatment of oral lichen planus, lichenoid drug reactions, and lichenoid mucositis.

Oral lichen planus: an overview

Lichen planus (LP) is a chronic inflammatory muco-cutaneous disease. Since disorders of NK-cell functional activity could be observed in patients with LP, it is considered to be an autoimmune disease. The pathogenesis of LP is complex and not completely understood. The involvement of mucous membranes is frequently seen, usually asymptomatic, but occasionally complicated by extensive painful erosions, causing a considerable loss of quality of life. Patients with symptomatic oral lichen planus (OLP) often require intensive therapy to reduce the signs and symptoms of this painful and disabling inflammatory disease. OLP is considered to be a precancerous lesion for the development of squamous cell carcinomas. OLP is highly resistant to topical treatment and tends to pursue a chronic course with little tendency to spontaneous resolution. Until now meta-analysis provided little evidence for the superiority of the assessed interventions over placebo for palliation of symptomatic OLP.