Inflammation-related cytokines in oral lichen planus: an overview

Recent progress in cancer vaccines and nanovaccines

Vaccine science, nanotechnology, and immunotherapy are at the forefront of cancer treatment strategies, each offering significant potential for enhancing tumor-specific immunity and establishing long-lasting immune memory to prevent tumor recurrence. Despite the promise of these personalized and precision-based anti-cancer approaches, challenges such as immunosuppression, suboptimal immune activation, and T-cell exhaustion continue to hinder their effectiveness. The limited clinical success of cancer vaccines often stems from difficulties in identifying effective antigens, efficiently targeting immune cells, lymphoid organs, and the tumor microenvironment, overcoming immune evasion, enhancing immunogenicity, and avoiding lysosomal degradation. However, numerous studies have demonstrated that integrating nanotechnology with immunotherapeutic strategies in vaccine development can overcome these challenges, leading to potent antitumor immune responses and significant progress in the field. This review highlights the critical components of cancer vaccine and nanovaccine strategies for immunomodulatory antitumor therapy. It covers general vaccine strategies, types of vaccines, antigen forms, nanovaccine platforms, challenges faced, potential solutions, and key findings from preclinical and clinical studies, along with future perspectives. To fully unlock the potential of cancer vaccines and nanovaccines, precise immunological monitoring during early-phase trials is essential. This approach will help identify and address obstacles, ultimately expanding the available options for patients who are resistant to conventional cancer immunotherapies.

Lower Serum IL-10 Linked to Oral Manifestations in Diabetes Patients

Background

Diabetes mellitus (DM) is a chronic disease that remains a global health problem with increasing prevalence, particularly in Indonesia. The presence of oral manifestations in patients with DM is influenced by changes in immune system function. Interleukin-10 (IL-10) is an inflammatory marker implicated in DM. However, no studies have investigated the differences in IL-10 levels between non-DM and DM patients with and without oral manifestations.

Objective

This study aimed to compare the serum levels of IL-10 between non-DM and DM patients with and without oral manifestations at Dr. Hasan Sadikin Hospital Bandung.

Methodology

This observational study used a cross-sectional design. A total of 88 serum samples that met the inclusion criteria were selected, consisting of 37 (42%) samples from non-DM patients, 35 (39.8%) samples from DM patients with oral manifestations, and 16 (18.2%) samples from DM patients without oral manifestations. Serum levels of IL-10 were measured using an enzyme-linked immunosorbent assay (ELISA) kit.

Results

Among the 35 DM patients with oral manifestations, xerostomia was the most common (80%). The mean serum IL-10 level was 0.93 pg/mL in non-DM patients, 0.80 pg/mL in DM patients with oral manifestations, and 1.08 pg/mL in DM patients without oral manifestations. Statistical analysis using the Kruskal-Wallis test showed a p-value of 0.008 (p ≤ 0.05), indicating a significant difference in serum levels of IL-10 between non-DM and DM patients with and without oral manifestations.

Conclusion

DM patients with oral manifestations had lower IL-10 serum levels compared to non-DM patients and DM patients without oral manifestations. These findings suggest that monitoring IL-10 levels could help identify diabetic patients at higher risk for oral complications.

Is There a Correlation Between Quality of Life and Salivary Interleukin-6 in Patients With Oral Lichen Planus or Burning Mouth Syndrome?

OBJECTIVES

The aim of our study was to compare the salivary interleukin-6 (IL-6) concentration and the quality of life (QoL) in patients with oral lichen planus (OLP) or burning mouth syndrome (BMS).

MATERIALS AND METHODS

A total of 160 subjects participated in the cross-sectional study. The unstimulated whole saliva (UWS) was used as a reference for the determination of salivary IL-6 concentration by enzyme-linked immunosorbent assays (ELISAs). QoL was assessed using the Croatian version of the Oral Health Impact Profile Questionnaire (OHIP-CRO14).

RESULTS

The salivary IL-6 concentration showed no statistically significant difference between patients with OLP, patients with BMS or control subjects (p = 0.244). There was a strong/good positive correlation between symptom intensity (pain/burning) and the OHIP-CRO14 dimension "physical pain" (r = 0.720, p < 0.001) and "physical impossibility" (r = 0.372, p = 0.003) in patients with OLP. There was a good positive correlation between symptom intensity (pain/burning) and the OHIP-CRO14 dimension "handicap" (r = 0.353, p = 0.005) in patients with BMS.

CONCLUSIONS

Symptom intensity (pain/burning) showed no correlation with salivary IL-6 concentration in patients with OLP or BMS. A slight increase or decrease in salivary IL-6 concentration in OLP or BMS indicates an inflammatory etiopathogenesis of OLP and a loss of neuroprotection in BMS.

The Mechanism of Immune Intervention by Iguratimod in Oral Lichen Planus Patients: An In Vitro Experimental Study

BACKGROUND

Oral lichen planus (OLP) is a T cell-mediated immune disease. Iguratimod (IGU) is a novel immunomodulatory agent for rheumatoid arthritis. No studies have been reported on the mechanism of IGU in the treatment of OLP, which deserves investigation.

METHODS

Samples were collected from two batches of non-erosive OLP, erosive OLP (EOLP) patients and healthy control subjects. In the first batch, the effects of IGU or the same volume of dimethyl sulfoxide (DMSO) on proliferation, apoptosis and migration of peripheral blood T lymphocytes (PBL T) were examined by CCK-8, flow cytometry and transwell assay respectively. The levels of IL-6, IL-17, TNF-α, TGF-β and IL-10 were measured by enzyme-linked immunosorbent assay. In the second batch, the percentages of Th17 and Treg cells were determined by flow cytometry in peripheral blood mononuclear cells after IGU or DMSO stimulation.

RESULTS

Compared with the control, IGU promoted apoptosis and inhibited migration, but had no significant effect on the proliferation of PBL T in OLP. IL-6, IL-17 and TNF-α were decreased in OLP. TGF-β and IL-10 showed an upward trend in the IGU-treated EOLP. IGU decreased Th17 in OLP and reduced Th17/Treg ratio in EOLP. The percentage of Treg cells showed an upregulated trend but the difference was not statistically significant.

CONCLUSION

IGU may intervene in the immune response of OLP by affecting functions of PBL T, improving the balance of Th17/Treg and regulating related cytokines.

Secukinumab in adult patients with lichen planus: efficacy and safety results from the randomized placebo-controlled proof-of-concept PRELUDE study

BACKGROUND

Patients with lichen planus (LP) refractory to available therapies often experience a high disease burden, representing a population with a clear unmet need for new treatments.

OBJECTIVES

To evaluate the efficacy and safety of secukinumab 300 mg over 32 weeks in adult patients with biopsy-proven cutaneous LP (CLP), mucosal LP (MLP) or lichen planopilaris (LPP) that is inadequately controlled by topical corticosteroids.

METHODS

PRELUDE was a randomized double-blind placebo-controlled phase II proof-of-concept study that enrolled patients with CLP, MLP or LPP. Eligible patients were randomized to either secukinumab 300 mg every 4 weeks for 32 weeks (SECQ4W) or placebo for 16 weeks followed by secukinumab 300 mg every 2 weeks (SECQ2W) for 16 weeks. The primary endpoint was achievement of the newly designed Investigator's Global Assessment (IGA) score ≤ 2 at week 16.

RESULTS

Overall, 111 patients were randomized (n = 37 each) to CLP, MLP and LPP cohorts. As the proof-of-concept criteria were not met for any of the three cohorts, the primary objective was not met. A numerically higher proportion of patients achieved IGA ≤ 2 response at week 16 with SECQ4W vs. placebo in the MLP {37.5% [95% credibility interval (Crl) 20.3-57.2] vs. 23.1% (95% Crl 6.5-49.2)} and LPP cohorts [37.5% (95% Crl 20.2-57.3) vs. 30.8% (95% Crl 10.8-57.6)]. In the LPP cohort, a sustained response for IGA ≤ 2 from week 16 to week 32 was achieved with SECQ4W (week 16, 37.5%; week 32, 45.8%), and a substantial improvement was observed in IGA ≤ 2 response in patients from this cohort who switched from placebo (week 16, 30.8%) to SECQ2W after week 16 (week 32, 63.6%). The safety profile was consistent with the known profile of secukinumab and showed no new or unexpected signals.

CONCLUSIONS

PRELUDE is the first randomized controlled basket trial evaluating interleukin (IL)-17A inhibition with secukinumab across three subtypes of LP. Secukinumab was well tolerated and safe, showing different response rates across the three subtypes, with numerical IGA improvements in MLP and LPP, and no response in CLP. The study raises the question of a differential role of IL-17A across LP subtypes. The novel IGA score showed significant correlation with both patient- and physician-reported outcome measurements.

Expression of neutrophil extracellular trap-related proteins and its correlation with IL-17 and TNF-α in patients with oral lichen planus

Background

Neutrophil extracellular traps (NETs) are produced by polymorphonuclear neutrophils (PMNs) stimulated by interleukin-17 (IL-17) and tumor necrosis factor α (TNF-α). However, the level and role of NETs in oral lichen planus (OLP) remain poorly understood.

Objective

This study aimed to investigate the expression of NETs in OLP and explore the correlation between NETs and the levels of IL-17 and TNF-α.

Methods

The expression and distribution of NET-related proteins in tissue samples from each group were assessed using hematoxylin-eosin (HE) staining and immunofluorescence (IF). Additionally, the expression of NET-related proteins in peripheral blood samples from each group was evaluated using cell IF technique and fluorescence spectrophotometry. The relative formation level of NETs in each group was determined by fluorescence spectrophotometry via plasma co-culture. Furthermore, the levels of inflammatory cytokines IL-17 and TNF-α in plasma and culture supernatant were measured using enzyme-linked immunosorbent assay (ELISA).

Results

NET-related proteins were located in the subepithelial and lamina propria layers of OLP lesions. OLP had significantly higher expression of NET-related proteins in lesion tissues and peripheral blood compared to the healthy control (HC) group (p < 0.05). The rate of NETs formation in the erosive-stage OLP (EOLP) group was significantly higher than that in the HC group (p < 0.05), in contrast, no significant increase was observed in the non-erosive OLP (NEOLP) group (p > 0.05). Furthermore, the levels of IL-17 and TNF-α in the EOLP group were significantly elevated compared to those in the NEOLP group and HC group (p < 0.05), while the levels in the NEOLP group did not significantly differ from those in the HC group (p > 0.05). The rate of NETs formation showed a positive correlation with the levels of IL-17 and TNF-α in plasma.

Conclusion

The expression of NET-related proteins was upregulated in OLP lesion tissues and peripheral blood. Elevated levels of IL-17 and TNF-α in peripheral blood plasma positively correlated with the rate of NETs formation, suggesting that IL-17 and TNF-α mediate the formation of NETs in OLP patients, and may thereby contribute to the development of OLP.

Histological Improvement and Cytokine Levels Reduction in Patients with Oral Lichen Planus after Photobiomodulation Therapy

Background: Oral lichen planus (OLP) is a mucocutaneous disease associated with the formation of symptomatic lesions in the mouth that are often refractory to treatment. An as-yet-unknown antigen triggers an inflammatory reaction in which various immune and non-immune cells release multiple cytokines that contribute to disease progression. The ability of photobiomodulation (PBM) to reduce the symptoms and signs of the disease has been shown, but little is known about its molecular and cellular effects. The aim of this study was to evaluate changes in pro-inflammatory cytokine levels and in histological findings in OLP patients treated with photobiomodulation therapy. Methods: Twenty OLP patients underwent PBM with diode laser (810 nm), (0.50 W, 30 s, 1.2 J/cm2), 3 times weekly for a month. Pain level and clinical scores of lesions were recorded before and after therapy. Salivary levels of IL-1β, IL-6, and TNF-α in OLP patients were measured before and after PBM and compared with those of 10 healthy controls. Biopsies were taken at the beginning and end of treatment to assess pathomorphological changes. Results: PBM significantly reduced the level of pain and clinical scores of the lesions. Salivary levels of IL-1β, IL-6, and TNF-α in OLP patients were significantly higher compared to those in healthy controls and decreased after therapy. 60% of the post-treatment OLP biopsies demonstrated histological improvement, characterized by inflammatory infiltrate reduction (50%), epithelial hyperplasia reduction (30%), epithelial thickening (15%), or epidermal-dermal attachment repair (5%). Conclusion: The effectiveness of PBM therapy in OLP patients was confirmed at the clinical, molecular, and histomorphological levels.

B Cells Infiltration Potentially Responded Better to Systemic Corticoids in Oral Lichen Planus and Oral Lichenoid Lesions

Oral lichen planus (OLP) and oral lichenoid lesion (OLL) are chronic inflammatory diseases involving the oral mucosa. B cells infiltration in OLP and OLL, however, little is known about these cells in OLP and OLL. To analyze the function and infiltrating features of B lymphocytes in OLP and OLL, and to preliminarily evaluate their correlation with clinical outcomes. Tissue samples were collected from OLP, OLL, and healthy mucosa. The phenotypes and amounts of B cells in tissues were analyzed by single-cell sequencing. Their proportion and infiltrating features in tissues were examined by immunohistochemistry and immunofluorescence. With the systemic medication of corticoids, the correlation between B cells infiltrating characteristics and the clinical outcomes were evaluated. A quantified proportion increase of B cells was shown in both OLP and OLL. B cells in OLP demonstrated heightened activation and enhanced regulation in immune response. A cohort of 100 patients with OLP/OLL and 13 healthy controls were examined to investigate the B cells infiltration pattern. B cells were distributed in the superficial layer of lamina propria in 92.9% and 41.9% of OLP and OLL, respectively(P < 0.01); focally distributed in 25.0% and 62.9% of OLP and OLL, respectively(P < 0.01). With the systemic medication of corticoids, the cases with B cell infiltration (B+) in OLP and OLL groups showed a statistically significant reduction in REU scores before and after treatment (P < 0.01). B cells are widely present in OLP and OLL, and B cell infiltration in OLP and OLL are related to the better therapeutic effect of oral corticoids.

Assessment of interleukin-18 gene polymorphism and serum levels in cutaneous lichen planus

BACKGROUND

Lichen planus (LP) is a chronic inflammatory disease with uncertain etiology. Interleukin-18 (IL-18) is an interferon gamma (INFγ) inducing agent. It is a pro-inflammatory cytokine that was found to play a role in the pathogenesis of some autoimmune disorders.

MATERIAL AND METHODS

This study included 50 patients with classic cutaneous lichen planus (CLP) and 50 healthy volunteers serving as controls. Venous blood samples were withdrawn from the study subjects under complete aseptic precautions. Blood samples were examined for single nucleotide polymorphisms (SNPs) of IL-18 gene at promoter -137(G/C) and -656 (G/T) using polymerase chain reaction (PCR) and IL-18 level was assessed using enzyme linked immunosorbent assay (ELISA).

RESULTS

The mean level of IL-18 was significantly higher in CLP patients (31.63 ± 4.90) compared to control subjects (13.95 ± 6.82). Significantly high levels of IL-18 were found among patients with diabetes, hypertension (p < 0.01 in both). HCV positive patients and patients with both OLP and CLP also expressed higher levels of IL-18. Genotypic and allelic distribution at position -137(G/C) showed that the genotype GG was present at significantly higher frequency in cases (58%) compared to controls (28.0%). On the other hand the CC genotype at position -137 was significantly higher in the controls (28%) as compared to CLP cases (6%). Polymorphism of IL-18 at position -656(G/T) showed no significant difference between cases and controls. No significant difference could be detected in IL-18 level between different genotypic variants at position -137(G/C) and -656(G/T).

CONCLUSION

IL-18 may play important role in pathogenesis of LP. Elevated IL-18 levels could be part of the pro-inflammatory autoimmune process in LP. The presence of OLP, HCV, diabetes and hypertension is associated with higher production of IL-18. IL-18 promotor region -137(G/C) polymorphism might be a factor that increase the risk of development of lichen planus in Egyptian patients.

Salivary Histamine Levels in Patients with Oral Lichen Planus Lesions

Background and Objectives: An oral lichen planus (OLP) chronic lesion refers to a group of oral potentially malignant disorders (OPMDs) that still lack a proper understanding from the point of view of relevant biomarkers for diagnostics and prognosis. The aim of the study was to assess the salivary histamine levels in patients with oral lichen planus lesions. Materials and Methods: The study included a group of 76 patients with oral lichen planus. General diseases and medication taken, smoking habits, severity of pain assessed using a visual analogue scale (VAS), oral hygiene status, and duration of OLP were evaluated. ELISA diagnostics for histamines in saliva levels were assessed. Results: The histamine levels in the OLP group were higher (0.468) in comparison with the control group (0.056), without a statistically significant value p = 0.090 (Mann-Whitney U Test). The median age of 76 OLP patients was 63 years (min 22.0-max. 81), with the biological sex being 80.3% females and 15 19.7% males. The average duration of OLP lesion presence was 29.4 months (SD 37.1) and the median value was 14.5 months. The median of the VAS was 3.0. OLP assessment in accordance with the Malhotra methodology showed the highest frequency-30.3% for only two of the point areas involved and 17.1% for three points. Clinical assessment of the different OLP grades, severity, and oral site involvement and the VAS in correlation with histamine salivary levels showed a lack of statistical significance in the investigated population. Conclusions: Undertaking further research could provide further possibilities for searching for general factors in OLP development.

MALT1 Protease Regulates T-Cell Immunity via the mTOR Pathway in Oral Lichen Planus

Oral lichen planus (OLP) is a T cell-mediated immune mucosal disease of unknown pathogenesis. Whether mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1), an intracellular signaling protein, is involved in the T-cell immune dysfunction of OLP remains elusive. MALT1 expression in local and peripheral T cells of OLP and controls was analyzed using immunohistochemistry, multiplex immunohistochemistry, and flow cytometry. The expression of MALT1 in activated Jurkat T cells incubated with either OLP plasma or interleukin (IL)-7/IL-15 was determined by flow cytometry. The effects of MALT1 and mechanistic target of rapamycin (mTOR) on T-cell immunity were investigated through western blot, CCK8 assay, and flow cytometry. The expression of MALT1 protein was elevated in local OLP T cells and mucosal-associated invariant T (MAIT) cells, while reduced in peripheral OLP T cells, MAIT cells, and follicular helper-like MAIT (MAITfh) cells. Stimulation with OLP plasma and IL-7/ IL-15 had no effect on MALT1 expression in activated Jurkat T cells. MALT1 protease-specific inhibitor (MI-2) induced mTOR phosphorylation, increased B-cell lymphoma 10 (BCL10) expression, inhibited T-cell proliferation, and promoted T-cell apoptosis. The combination of MI-2 and rapamycin increased MALT1 expression, further suppressed T-cell proliferation, and facilitated T-cell apoptosis. MALT1 expression is aberrant in both local lesions and peripheral blood of OLP. Inhibition of the mTOR pathway further enhances the suppression of T-cell proliferation and the promotion of apoptosis induced by the MALT1 inhibitor MI-2.

Implications of innate lymphoid cells in oral diseases

Innate lymphoid cells (ILCs), as newly discovered antigen-independent innate immune cells, respond promptly to stimuli by secreting effector cytokines to exert effector functions similar to those of T cells. ILCs predominantly reside at mucosal sites and play critical roles in defending against infections, maintaining mucosal homeostasis, regulating inflammatory and immune responses, and participating in tumorigenesis. Recently, there has been a growing interest in the role of ILCs in oral diseases. This review outlines the classifications and the major characteristics of ILCs, and then comprehensively expatiates the research on ILCs in oral cancer, primary Sjogren's syndrome, periodontal diseases, oral lichen planus, oral candidiasis, Behcet's disease, and pemphigus vulgaris, aiming at summarising the implications of ILCs in oral diseases and providing new ideas for further research.

Assessment of TNF-α (-857 C/T) gene polymorphism in oral lichen planus disease: A case-control study

Background and aims

Oral lichen planus (OLP) is an inflammatory mucocutaneous disorder with an immune-mediated pathogenesis. The tumor necrosis factor-α (TNF-α) level in the serum of OLP patients is significantly higher than in the control group. TNF-α-857 C/T polymorphism can be related to the increased TNF-α level in blood circulation. This study investigated the relationship between TNF-α (-857 C/T) polymorphism and OLP patients in an Iranian population.

Methods

Saliva samples were taken from 200 people, including 100 patients with OLP and 100 healthy people who did not have significant differences in age and sex. Then, DNA was extracted from them and the TNF-α (-857 C/T) genotype was identified using the polymerase chain reaction with confronting two-pair primers method. Statistical Package for the Social Sciences version 16 software analyzed the results.

Results

The frequency of C/C, C/T, and T/T genotypes of the TNF-α-857 C/T polymorphism in the patient group were 78%, 18%, and 4%, respectively, and in the control group were 72%, 23%, and 5%, respectively. The differences between the two groups regarding allele (χ 2  =  0.97, p  = 0.32) and genotype (χ 2  =  0.96, p  = 0.62) frequency among the studied population were insignificant.

Conclusion

This study showed that the difference in the frequency of single nucleotide polymorphism TNF-α-857 C/T polymorphism in the patient and control group had no significant relationship with the increased OLP incidence. Also, no significant association was observed between allele and genotype frequency of TNF-α (-857 C/T) with OLP subtypes.

Inflammatory cytokines and oral lichen planus: a Mendelian randomization study

Background

Inflammatory cytokines have long been considered closely related to the development of oral lichen planus (OLP), and we further explored the causal relationship between the two by Mendelian randomization (MR) method.

Methods

We performed bidirectional MR analyses by large genome-wide association studies (GWAS). The data included a large-scale OLP dataset, as well as datasets of 41 inflammatory cytokines. All data were obtained from the University of Bristol database, which includes 41 inflammatory cytokines, and the GWAS Catalog database, which includes 91 inflammatory cytokines. OLP data were obtained from the Finngen database, which includes 6411 cases and 405770 healthy controls. We used the inverse variance weighted (IVW) method, MR-Egger method, weighted median method, simple mode method and weighted mode method to analyze the causal relationship between inflammatory cytokines and OLP, and we also combined with sensitivity analysis to further verify the robustness of the results. We performed a meta-analysis of positive or potentially positive results for the same genes to confirm the reliability of the final results.

Results

We primarily used the IVW analysis method, corrected using the Benjamin Hochberg (BH) method. When p<0.00038 (0.05/132), the results are significantly causal; when 0.00038

Conclusion

There is a causal association between OLP and some inflammatory cytokines, which may play an important role in the pathogenesis of OLP and require further attention.

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Key Words

• Mendelian randomization
• immunity
• inflammation
• inflammatory cytokines
• oral lichen planus

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MESH Headings

• Humans
• Cytokines/genetics
• Genome-Wide Association Study
• Lichen Planus, Oral/genetics
• Mendelian Randomization Analysis
• Reproducibility of Results

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Affiliation(s)

Xin Chen Department of Oral and Maxillofacial Surgery, Jiangyin People's Hospital Affiliated to Nantong University, Wuxi, Jiangsu, China
Simin Zhang Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi’an Jiaotong University, Xi’an, Shaanxi, China Department of General Dentistry, College of Stomatology, Xi’an Jiaotong University, Xi’an, Shaanxi, China
Xiao Wu Endodontic Department, School of Stomatology, Nanjing Medical University, Nanjing, Jiangsu, China
Yuxi Lei Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi’an Jiaotong University, Xi’an, Shaanxi, China Department of Emergency Room, College of Stomatology, Xi’an Jiaotong University, Xi’an, Shaanxi, China
Bing Lei Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi’an Jiaotong University, Xi’an, Shaanxi, China Department of General Dentistry, College of Stomatology, Xi’an Jiaotong University, Xi’an, Shaanxi, China
Zhibai Zhao Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi’an Jiaotong University, Xi’an, Shaanxi, China Department of General Dentistry, College of Stomatology, Xi’an Jiaotong University, Xi’an, Shaanxi, China

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Evaluation of the association between TNF-α-1031 T/C polymorphism with oral lichen planus disease

BACKGROUND

Oral lichen planus (OLP) is a T-cell-mediated autoimmune disease that affects the epithelial cells of the oral cavity. This study was performed to investigate any possible relationship between - 1031(T/C) polymorphism (rs1799964) of the tumor necrosis factor α (TNF-α) gene with the risk and severity of oral lichen planus (OLP) disease among an Iranian population.

METHOD

Saliva samples were collected from 100 patients with OLP and a similar number of healthy controls (age and sex-matched). Then, DNA was extracted from the collected samples for genotyping TNF-α-1031 T/C polymorphism using the PCR-CTPP method. The results were assessed using SPSS software.

RESULTS

The findings revealed a significantly higher prevalence of the C allele in OLP patients (53%) compared to healthy controls (36%), suggesting an association between TNF-alpha gene polymorphism and OLP. A multivariate logistic regression analysis supported this finding, as the presence of the C allele was significantly associated with an increased risk of OLP [χ2 = 4.17, p = 0.04, 95% CI = 1.01-2.65, OR = 1.64]. However, our data indicated no significant association between TNF-alpha-1031 T/C gene polymorphism and OLP severity.

CONCLUSIONS

These findings provide the first evidence supporting a possible role of TNF-α-1031 T/C gene polymorphism in OLP susceptibility in the Iranian population. The findings of this study demonstrate a positive association between TNF-α-1031 C/T allele distribution and the risk of OLP disease in the Iranian population. Therefore, carrying the C allele may increase the susceptibility to OLP disease.

Salivary metabolomics in patients with oral lichen planus: a preliminary study based on NMR spectroscopy

OBJECTIVES

The present preliminary study aimed to investigate the salivary metabolic profile in patients with asymptomatic oral lichen planus (OLP) using nuclear magnetic resonance (NMR) spectroscopy.

MATERIAL AND METHODS

Stimulated whole mouth saliva (SWMS) samples were collected from 15 reticular OLP female patients and 15 from age- and sex-matched controls (HCs). A total of 23 metabolites were identified and quantified. Mann-Whitney's U test was used to compare the determined concentration salivary metabolite concentrations between OLP patients and the healthy controls.

RESULTS

The concentration of acetate, methylamine, and pyruvate was elevated, whereas the concentration of tyrosine was decreased in the saliva of OLP patients compared with HCs. To identify a combination of metabolites, multivariate discrimination function analysis (DFA) was conducted. DFA analysis have shown that the most powerful discrimination between the groups was achieved when methylamine and tyrosine were considered as combined biomarkers.

CONCLUSIONS

Salivary tyrosine was of particular interest and a promising finding for the screening of OLP and its progression. Further longitudinal studies are required to establish it as a reliable salivary biomarker in OLP.

CLINICAL RELEVANCE

The salivary metabolic profiling can describe the pathologic characteristics of OLP on non-invasive saliva samples and NMR analysis. Salivary metabolites provide details to considered early detectors and to impact oral health of OLP patients.

Inter-relationships of galectin-3 and NLR family pyrin domain containing 3 inflammasomes with oral lichen planus: a preliminary cross-sectional in vitro study

BACKGROUND

The nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family pyrin domain-containing 3 (NLRP3) inflammasome has been reported to be highly expressed in oral lesions with the potential for malignant development such as oral lichen planus (OLP). And the NLRP3 inflammasome can be activated by galectin-3 (Gal-3) in immune-mediated chronic inflammatory diseases. This study aimed to explore the inter-relationships among Gal-3, NLRP3 inflammasome, and OLP.

METHODS

A cross-sectional analysis of oral biopsy specimens from 30 patients with Erosive OLP and 30 healthy controls was performed. Immunohistochemical staining was used to evaluate the expression of Gal-3 and NLRP3 inflammasome. Two-sample t-test and Pearson correlation test were applied to analyze the data.

RESULTS

Erosive OLP patients had significantly higher Gal-3 levels compared with controls (p < 0.0001). A similar pattern emerged for NLRP3 inflammasome. In the overall sample, a positive correlation was observed between Gal-3 and NLRP3 (r = 0.92, p < 0.01).

CONCLUSIONS

Patients with Erosive OLP lesions showed increased protein expression levels of Gal-3. A positive correlation was observed between Gal-3 and NLRP3 inflammasome.

Nanovaccines: An effective therapeutic approach for cancer therapy

Cancer vaccines hold considerable promise for the immunotherapy of solid tumors. Nanomedicine offers several strategies for enhancing vaccine effectiveness. In particular, molecular or (sub) cellular vaccines can be delivered to the target lymphoid tissues and cells by nanocarriers and nanoplatforms to increase the potency and durability of antitumor immunity and minimize negative side effects. Nanovaccines use nanoparticles (NPs) as carriers and/or adjuvants, offering the advantages of optimal nanoscale size, high stability, ample antigen loading, high immunogenicity, tunable antigen presentation, increased retention in lymph nodes, and immunity promotion. To induce antitumor immunity, cancer vaccines rely on tumor antigens, which are administered in the form of entire cells, peptides, nucleic acids, extracellular vesicles (EVs), or cell membrane-encapsulated NPs. Ideal cancer vaccines stimulate both humoral and cellular immunity while overcoming tumor-induced immune suppression. Herein, we review the key properties of nanovaccines for cancer immunotherapy and highlight the recent advances in their development based on the structure and composition of various (including synthetic and semi (biogenic) nanocarriers. Moreover, we discuss tumor cell-derived vaccines (including those based on whole-tumor-cell components, EVs, cell membrane-encapsulated NPs, and hybrid membrane-coated NPs), nanovaccine action mechanisms, and the challenges of immunocancer therapy and their translation to clinical applications.

Risk factors for the development of oral precancerous lesions in a cohort of 293 oral lichen planus patients with or without chronic periodontitis in southern Taiwan

Background/purpose

Oral lichen planus (OLP) may contribute to the risk of chronic periodontitis, and no reports have shown whether OLP patients with periodontitis have a greater risk of oral precancerous lesions, Candida infection or other clinicopathological diseases. This study aimed to assess the risk factors for the development of oral precancerous lesions in a cohort of 293 OLP patients with or without chronic periodontitis in southern Taiwan.

Materials and methods

The current study recruited 293 OLP patients without preexisting periodontitis at a tertiary institution from 1995 to 2018. The patients were divided into two groups based on the presence or absence of periodontitis. The study compared various clinical and pathological characteristics between the two groups, and also estimated the odds ratio (OR) and the 10-year cumulative risk of chronic periodontitis in OLP patients using logistic regression models and Kaplan‒Meier analysis methods, respectively.

Results

After adjusting for age and gender, the significant contributors to oral precancerous lesions in OLP patients (P < 0.05) were periodontal disease (OR = 2.24) and the male gender (OR = 7.52). Betel nut consumption (OR = 2.61), smoking (OR = 2.46), and candidiasis infection (OR = 3.02) also showed significant associations. Older OLP patients had a lower lesion risk, while a longer OLP duration heightened the periodontal disease likelihood.

Conclusion

The present study demonstrated that coexisting periodontal disease increases the likelihood of developing precancerous lesions in patients with OLP. Periodontal management with oral hygiene care and quitting betel nut consumption and smoking can reduce the risk.

Group 1 and 3 innate lymphoid cells are increased in oral lichen planus and oral lichenoid lesions

OBJECTIVES

Innate lymphoid cells (ILCs) are vital innate immune cells cooperating with T cells. While their phenotypes and functions in oral mucosa kept unclear yet. In the present study, the relative proportions and distribution of different ILC subsets in oral mucosa of oral lichen planus (OLP), oral lichenoid lesions (OLL), and controls were compared.

SUBJECTS AND METHODS

Oral mucosal samples were collected from control (n = 29), OLP (n = 20), and OLL (n = 22) donors. ILCs subsets were characterized in single-cell suspensions by flow cytometry. Immunohistochemistry was performed to locate the CD127+ cells in situ.

RESULTS

ILCs were present in healthy and increased infiltration in OLP/OLL (p = 0.0092, p = 0.0216). Infiltration of ILC1 increased in OLP/OLL mucosa (p = 0.0225, p = 0.0399), as did the infiltration of ILC3 increase in OLL mucosa (p = 0.0128). The ILC2/ILCs ratio was significantly reduced in OLP and OLL (p = 0.0124, p = 0.0346). CD127+ cells were mainly located closely at the basement membrane.

CONCLUSIONS

The results of increased ILC1, decreased ILC2, and increased ILC3 suggested that changes of ILC distributions in oral mucosa may be relevant to persistent inflammation in local tissues, by promoting immune factors and weakening repair capacity.

Upregulation of IL-37 in epithelial cells: A potential new mechanism of T cell inhibition induced by tacrolimus

Oral lichen planus (OLP) is a chronic T cell-mediated mucocutaneous disease characterized by T cell infiltration at the connective tissue-epithelium interface. Traditionally, topical corticosteroids are used as the first-line drugs to treat OLP. However, long-term use of corticosteroids may lead to drug tolerance, secondary candidiasis, and autoimmune adrenal insufficiency. Although topical tacrolimus has often been recommended for short-term use in corticosteroid-refractory OLP, the precise role of tacrolimus in epithelial cells remains elusive. This study showed that tacrolimus could directly upregulate the expression of IL-37 in human gingival epithelial cells by promoting the TGF-βRI/Smad3 pathway independently of calcineurin inhibition and MAPKs. In contrast, dexamethasone, one of the corticosteroids, did not have the same effect. Moreover, IL-37 could inhibit the proliferation of activated T cells and the secretion of effector cytokines and alleviate epithelial cell apoptosis and death caused by activated T cells ina co-culturesystem. Furthermore, compared with healthy controls, IL-37 and p-Smad3 levels significantly increased in the oral mucosa affected by OLP, especially in the epithelium. IL-37 might have mediated a negative feedback mechanism to curb excessive inflammation in OLP. However, the expression of IL-37 was not associated with the infiltration of CD8+ T cells and Tregs in OLP, implying that IL-37 might mostly affect T cell activation rather than T cell differentiation and migration. Overall, this study discovered a potential novel mechanism by which tacrolimus might indirectly inhibit T cell-mediated immune damage by upregulating IL-37 in human gingival epithelial cells.

Cancer Stem Cells' Biomarker ALDH1&2 Increased Expression in Erosive Oral Lichen Planus Compared to Oral Leukoplakia

INTRODUCTION

ALDH1&2 has been considered an oral cancer stem cell (CSC) marker. Oral carcinogenesis is a process that usually passes through oral potentially malignant disorders (OPMD). Oral lichen planus (OLP) consists of immune-related chronic disorders that have been included in the OPMDs due to their possible transformation into oral cancer. The aim of this study was to investigate the early presence of ALDH1&2 in OLP compared to early oral leukoplakias (OL), especially mildly and non-dysplastic OL.

MATERIALS AND METHODS

The study type is experimental, and the study design is characterized as semiquantitative research which belongs to the branch of experimental research. The study sample consisted of paraffin-embedded OLP biopsy samples from the archives of the Department of Oral Medicine/Pathology, School of Dentistry, Aristotle University of Thessaloniki, Greece, during the period 2009-2019. The study sample contained 24 cases of OLP (14 erosive and 10 reticular) and 30 cases of OL (16 cases of moderately and severely dysplastic OL and 14 cases of mildly and non-dysplastic OL). The CSC-related biomarker ALDH1&2 was examined using semiquantitative immunohistochemistry (monoclonal antibody sc-166362, Santa Cruz Biotechnology, Dallas, Texas, USA, 1:100). ALDH1&2 expression was evaluated through a scale of 1 to 3 depending on the percentage of positive epithelial cells and was compared to normal epithelium as well as cases of OL (the most prominent OPMD). The statistical analysis was performed with the Pearson chi-square test and the significance level was set at p≤0.05.

RESULTS

The cytoplasmic staining of ALDH1&2 was observed mostly in the epithelial cells of the basal layer of the epithelium of OLP. Overall, this expression was significantly increased compared to normal epithelium. In addition, statistically significantly higher expression of ALDH1&2 was observed in the erosive form of OLP. Interestingly, this OLP positivity was higher compared to mild and non-dysplastic leukoplakias (p<0.001).

CONCLUSIONS

ALDH1&2 is a confirmed CSC marker that was found to be clearly increased in OLP and characteristically in erosive OLP epithelium for the first time. Noteworthy, it was more prominent in erosive OLP rather than in mildly and non-dysplastic OL. Whether this pattern of expression raises the red flag of an early epithelial "CSC" phenotype in OLP or that ALDH1&2 expression indicates a response to the OLP inflammatory process requires further investigation.

COVID-19 and Oral Lichen Planus: Between an "Intriguing Plot" and the "Fata Morgana Effect"

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has led to significant morbidity and mortality worldwide since its declaration as a global pandemic in March 2020. Alongside the typical respiratory symptoms, unusual clinical manifestations such as oral lichen planus (OLP) have been observed. OLP is a chronic inflammatory mucocutaneous dermatosis that results from a cell-mediated reaction, and its pathogenesis involves the loss of immunological tolerance. OLP has been associated with several triggering factors, such as certain drugs, stress, smoking, and even some viruses. Exposure to the spike protein antigen of SARS-CoV-2 during an infection can trigger autoimmune reactions and lead to the onset or flare of OLP. The E3 protein ligase TRIM21, which is identified in the lamina propria of OLP lesions, is overexpressed in COVID-19 patients and plays a critical role in autoimmune pathologies. Furthermore, the psychological stress of the lockdown and quarantine can be a trigger for the onset or exacerbation of OLP. However, the diagnosis of OLP is complex and requires a biopsy in order to confirm a clinical diagnosis, rule out other pathologies, and establish the most appropriate therapeutic procedure. Further research is needed to understand the potential link between Co-19 and OLP.

Skin-infiltrating T cells display distinct inflammatory signatures in lichen planus, bullous pemphigoid and pemphigus vulgaris

Introduction

We here thought to dissect the inflammatory signature in lesions of three skin disorders, which show a common adaptive immune response against autoantigens of the skin but are characterized by diverging clinical phenotypes. Pemphigus vulgaris (PV) and bullous pemphigoid (BP) are type-2-dependent, IgG autoantibody-driven blistering disorders of mucous membranes and skin, which target desmoglein (Dsg)3 and bullous pemphigoid (BP)180, respectively. In contrast, lichen planus (LP) is a common chronic inflammatory disease of the skin and mucous membranes with a pronounced dermal T cell infiltrate. We previously identified peripheral type 1 and 17 T cell responses against Dsg3 and BP180 in a cohort of LP patients strongly suggesting that the underlying inflammatory T cell signature may drive the evolving phenotype.

Methods

Paraffin-embedded skin biopsies from well-characterized patients with LP (n=31), BP (n=19), PV (n=9), and pemphigus foliaceus (PF) (n=2) were analysed. Areas with the most prominent inflammatory infiltrate were excised with punch biopsies and tissue microarrays (TMA) containing multiple biopsies were created. Using multicolor immunofluorescence, the inflammatory infiltrate was stained with antibodies against multiple cellular markers, i. e. CD3ϵ, CD4, CD15, TCR-δ, the cytokine IL-17A, and the transcription factors, T-bet and GATA-3.

Results

In LP, there was a higher number of CD4+ T cells expressing T-bet compared to GATA-3. In contrast, CD4+ T cells in PV and BP skin lesions more frequently expressed GATA-3 than T-bet. IL-17A+ cells and IL-17A+ T cells were found to a similar extent in all the three disorders. IL-17A+ granulocytes were more predominant in BP than in LP or PV. Of note, the majority of IL-17A+ cells in LP were neither T cells nor granulocytes.

Discussion

Our findings in inflammatory skin infiltrates clearly show a predominant type 1 signature in LP in contrast to a preponderance of type 2 T cells in PV and BP. In contrast to LP, granulocytes and to a much lesser extent CD3+ T cells were a cellular source of IL-17A in BP and PV. These data strongly suggest that different inflammatory cell signatures drive evolving clinically diverse phenotypes of LP, PV and BP despite common target antigens of the skin.

Association of interleukin-8 polymorphism (+ 781 C/T) with the risk of oral Lichen Planus disease

BACKGROUND

Oral Lichen Planus (OLP) is a chronic inflammatory mucosal disease. The pathogenesis of OLP is unknown. The Single Nucleotide Polymorphism (SNP) that occurs in the regulatory position + 781 could affect the expression of interleukin-8. This polymorphism is probably associated with increased serum levels of IL-8. The current study aimed to investigate the genotype and allele frequencies of IL-8( + 781 C/T) in OLP patients and whether it is associated with the severity of OLP disease in an Iranian population.

METHODS

Three milliliters of saliva were taken from 100 patients with OLP and 100 healthy individuals who were matched in age and gender. After DNA extraction from saliva samples of patients and healthy individuals, the genotype of IL-8 at position + 781 is detected using the PCR-RFLP method. The results were analyzed using SPSS software.

RESULTS

Frequency of C/C, T/C, and T/T genotypes at position IL-8 + 781 gene in the patient group were 47%, 41%, and 12%, respectively, and in the control group, were 37%, 42%, and 21%. The difference between the two groups regarding allele frequency distribution was statistically significant (χ² = 3.86, p = 0.049, 95% CI = 0.44-1, OR = 0.66). Our results indicated the significantly higher frequency of the TT genotype in the erosive OLP compared to the nonerosive group (p = 0.03, OR = 0.89, 95% CI = 0.49-1.6).

CONCLUSION

This study depicted the difference in the frequency of SNP IL-8 + 781 C/T allele in the patient and control groups had a significant association with the risk of OLP. In addition, our data revealed that IL-8 + 781 C/T polymorphisms might be associated with the severity of OLP in the Iranian population.

Immunological Aspects of EBV and Oral Mucosa Interactions in Oral Lichen Planus

Oral lichen planus (OLP) is considered a T cell-mediated chronic inflammatory process activated by an unknown antigen, making basal keratinocytes vulnerable to a cytotoxic cell mediated immune response. The aim of this review is to summarize information on the role and pathways of Epstein–Barr virus (EBV) and immune cells in inducing OLP as an autoimmune lesion. The pathogenesis of OLP is analyzed from immunological aspects of interactions between EBV and oral mucosa. The results of the available studies allow us to assume that EBV can act both as an exogenous and an endogenous antigen in the pathogenesis of OLP. We emphasized the role of antigen-presenting cells (APC), such as dendritic cells (Langerhans cells, LC), in detecting and capturing antigens and modulating the adaptive immune response. Although EBV shows tropism for B cells and epithelial cells, under certain conditions it can infect monocytes, LCs, NK, and T lymphocytes. It means that under some circumstances of the chronic inflammatory process, EBV particles can react as endogenous agents. During the development of the autoimmune process, a decisive role is played by the loss of immune tolerance. Factors like the activity of cytokines, chemokines, and autoantibodies secreted by EBV-positive plasma cells, autoantigens formed due to virus protein mimicry of human proteins, new self-peptides released from damaged tissues, self-reactive B and T cells, dysregulation of LC function, the anti-apoptotic effect of EBV early lytic antigens, and an imbalance between inflammatory and anti-inflammatory immune cells facilitate the development of an autoimmune process.

Serum and salivary cytokines in patients with oral lichen planus treated with Photobiomodulation

OBJECTIVES

To evaluate the serum and salivary levels of IL-1β, IL-6, IL-17A, TNF-α, IL-4, and IL-10 in patients with oral lichen planus (OLP) treated with Photobiomodulation (PBM) and clobetasol propionate 0.05%.

MATERIAL AND METHODS

Thirty-four OLP patients were randomized into two groups: Control (clobetasol propionate 0.05%) and PBM (660 nm, 100 mW, 177 J/cm2 , 5 s, 0.5 J per point). Serum and saliva were collected at baseline and at the end of treatment (after 30 days) and evaluated using ELISA. The cytokine results were correlated with pain, clinical subtypes, and clinical scores of OLP.

RESULTS

IL-1β, IL-6, IL-17A, TNF-α, and IL-4 levels were higher in saliva in relation to serum. IL-1β was the most concentrated cytokine in saliva, and a positive correlation with the severity of OLP was noticed. After treatment with corticosteroid, IL-1β in saliva decreased significantly. No modulation of all cytokines was observed after PBM.

CONCLUSION

IL-1β appears to be an important cytokine involved in OLP pathogenesis. In addition, the mechanisms of action of PBM do not seem to be linked to the modulation of pro or anti-inflammatory cytokines at the end of treatment. It is possible that this events occurred early during treatment.

Altered Expression of Vascular Cell Adhesion Molecule-1 in Oral Lichen Planus

Oral lichen planus (OLP) is a T cell-mediated chronic inflammatory mucocutaneous disease affected by the interaction between keratinocytes and T cells. Recent evidence indicates that vascular cell adhesion molecule-1 (VCAM1) plays a vital role in mediating immune and inflammatory responses. In this study, the expression of VCAM1 in OLP was detected by immunohistochemical staining and its correlations with clinical features were analyzed. The disease severity of OLP was assessed by the reticular, atrophic, and erosive scoring system. We found that VCAM1 was generally localized in the cytoplasm of epithelial cells, and in nucleus, cytoplasm, and extracellular matrix of subepithelial infiltrated cells in superficial layer of lamina propria. Moreover, VCAM1 levels in epithelium and lamina propria of OLP were significantly higher than that in controls, respectively. In addition, VCAM1 level in epithelium was increased compared with that of lamina propria. There were no significant differences for VCAM1 expression between nonerosive and erosive forms of OLP. The expression of VCAM1 in OLP was not associated with the severity of disease, gender, and age. Thus, we speculated that spatial expression differences of VCAM1 in local lesions of OLP may involve the pathogenesis of OLP.

Comprehensive Insight into Lichen Planus Immunopathogenesis

Lichen planus is a chronic disease affecting the skin, appendages, and mucous membranes. A cutaneous lichen planus is a rare disease occurring in less than 1% of the general population, while oral illness is up to five times more prevalent; still, both forms equally impair the patient's quality of life. The etiology of lichen planus is not entirely understood. Yet, immune-mediated mechanisms have been recognized since environmental factors such as hepatitis virus infection, mechanical trauma, psychological stress, or microbiome changes can trigger the disease in genetically susceptible individuals. According to current understanding, lichen planus immunopathogenesis is caused by cell-mediated cytotoxicity, particularly cytotoxic T lymphocytes, whose activity is further influenced by Th1 and IL-23/Th-17 axis. However, other immunocytes and inflammatory pathways complement these mechanisms. This paper presents a comprehensive insight into the actual knowledge about lichen planus, with the causal genetic and environmental factors being discussed, the immunopathogenesis described, and the principal effectors of its inflammatory circuits identified.

Autophagy-related 9 homolog B regulates T-cell-mediated immune responses in oral lichen planus

OBJECTIVES

This study aimed to explore the impacts of autophagy-related 9 homolog B (ATG9B)-mediated autophagy on T-cell immune responses in oral lichen planus.

DESIGN

ATG9B expression was detected in lesions and local T cells by immunohistochemical analysis and immunofluorescence assay. The effects of ATG9B-mediated autophagy on T-cell immune responses were explored after ATG9B-overexpression or ATG9B-knockdown lentivirus transfection. A coculture system of activated T cells and lipopolysaccharide-induced keratinocytes was used to simulate the main cell crosstalk in oral lichen planus.

RESULTS

The expression of ATG9B upregulated in lesions and local T cells of oral lichen planus, especially in non-erosive oral lichen planus, suggesting that ATG9B may be a diagnostic factor for oral lichen planus. Notably, ATG9B-knockdown T cells of oral lichen planus demonstrated autophagy suppression, enhanced proliferation, and attenuated apoptosis, whereas overexpression of ATG9B showed opposite effects on T cells. In the coculture system of T cells and keratinocytes, ATG9B-knockdown T cells of oral lichen planus, but not ATG9B-overexpression T cells, promoted the proliferation and apoptosis of their cocultured keratinocytes. Additionally, exogenous insulin-like growth factor 1 (IGF1) significantly reversed the apoptosis rates of keratinocytes cocultured with T cells expressing abnormal ATG9B. Furthermore, ATG9B-overexpression T cells showed decreased secretion of interferon-γ and tumor necrosis factor-α in the coculture system.

CONCLUSIONS

This study revealed the regulatory roles of ATG9B-mediated T-cell autophagy on T-cell immune responses and crosstalk between T cells and keratinocytes in of oral lichen planus.

Saliva - a new opportunity for fluid biopsy

Saliva is a complex biological fluid with a variety of biomolecules, such as DNA, RNA, proteins, metabolites and microbiota, which can be used for the screening and diagnosis of many diseases. In addition, saliva has the characteristics of simple collection, non-invasive and convenient storage, which gives it the potential to replace blood as a new main body of fluid biopsy, and it is an excellent biological diagnostic fluid. This review integrates recent studies and summarizes the research contents of salivaomics and the research progress of saliva in early diagnosis of oral and systemic diseases. This review aims to explore the value and prospect of saliva diagnosis in clinical application.

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.

Paeoniflorin drives the immunomodulatory effects of mesenchymal stem cells by regulating Th1/Th2 cytokines in oral lichen planus

Lichen planus (LP) is a chronic inflammatory disease. Oral lichen planus (OLP) mainly appears as oral mucosal reticular or ulcerative lesions with an unknown etiology. We aimed to explore the immunomodulatory effect of paeoniflorin (PF) in mesenchymal stem cells (MSCs) and the potential involvement of Th1/Th2 cytokines in OLP. The effects of paeoniflorin on the proliferation and migration of MSCs were detected by Cell Counting Kit-8 (CCK8) and Transwell assays. MSCs were subjected to osteogenic, adipogenic and neurogenic induction followed by Alizarin red, oil red O, real-time PCR and immunofluorescence assays. We found that paeoniflorin promoted the proliferation, migration and multilineage differentiation of MSCs from OLP lesions (OLP-MSCs) in vitro. Paeoniflorin pretreatment increased the inhibitory effect of OLP-MSCs on peripheral blood mononuclear cells. Furthermore, paeoniflorin-pretreated OLP-MSCs simultaneously decreased Th1 cytokine levels and increased Th2 cytokine levels in T lymphocyte cocultures. Finally, paeoniflorin-pretreated OLP-MSCs also promoted the Th1/Th2 balance both in vitro and in the serum of mice that received skin allografts. In conclusion, paeoniflorin enhanced MSC immunomodulation and changed the inflammatory microenvironment via T lymphocytes, suggesting that the improvement of OLP-MSCs is a promising therapeutic approach for OLP.

Regulatory T cell therapy suppresses inflammation of oral mucosa

Oral inflammatory diseases, including oral lichen planus (OLP) and recurrent aphthous ulcer (RAU), seriously affect the patient’s quality of life. Due to the lack of ideal disease models, it is difficult to determine whether novel immunotherapy strategies are effective in treating oral inflammatory diseases. Here, we show that the deficiency of Foxp3 or IL-2 caused oral mucosa inflammation in mice, proving that Treg cells are important in maintaining the immune homeostasis in the oral mucosa. Then we determined that adoptive transfer of CD4⁺CD25^-CD45Rb^high T cells could induce oral inflammation in Rag1^-/- mice, and co-transfer of Treg cells together with CD4⁺CD25^-CD45Rb^high T cells could suppress the development of oral inflammation in this mouse model. Our study showed that adoptive transfer of CD4⁺CD25^-CD45Rb^high T cells into Rag1^-/- mice could be a novel disease model of oral inflammation. Our data provides direct evidence that Treg cell therapy is effective in suppressing oral mucosa inflammation in mice. Therefore, Treg cell therapy may be a promising novel strategy to treat oral inflammatory diseases.

Extracts of Rheum palmatum and Aloe vera Show Beneficial Properties for the Synergistic Improvement of Oral Wound Healing

Various local and systemic factors compromise oral wound healing and may lead to wound dehiscence, inflammation, or ulcers. Currently, there is a lack of topical therapeutical options. Thus, this study aimed to investigate the effect of Aloe vera (AV) and Rheum palmatum root (RPR) on oral wound healing capacity in vitro. The effect of AV and RPR on human primary fibroblast viability and migration was studied by measuring metabolic activity and gap closure in a scratch assay. Furthermore, cell cycle distribution and cytoskeletal features were analyzed. Antimicrobial activity against the oral pathogen Porphyromonas gingivalis was evaluated by broth microdilution assay. AV and RPR increased fibroblast migration after single agent treatment. Synergistic effects of the plant extract combination were observed regarding cellular migration which were confirmed by calculation of the phenomenological combination index (pCI), whereas the cell cycle distribution was not influenced. Furthermore, the combination of AV and RPR showed synergistic antibacterial effects as determined by the fractional inhibitory concentration index. This study demonstrated that the combination of AV and RPR can promote the migration of human primary fibroblasts in vitro and exert antimicrobial efficacy against P. gingivalis, suggesting these compounds for the topical treatment of wound healing disorders.

Association of polymorphisms in Th1/Th2-related cytokines (IFN-γ, TGFβ1, IL-1β, IL-2, IL-4, IL-18) with oral lichen planus: A pooled analysis of case–control studies

Background/purpose

Increasing evidence suggests that single-nucleotide polymorphisms (SNPs) in Th1/Th2-related cytokine genes correlated with oral lichen planus (OLP) susceptibility. However, these results were inconsistent and inconclusive. Hence, the aim of this study is to draw a more precise estimation of the genetic associations between SNPs in 6 cytokines (IFN-γ, IL-18, TGFβ1, IL-1β, IL-2, IL-4) and OLP.

Materials and methods

A systematic literature search was conducted to identify all eligible case-control studies on the association between SNPs in 6 cytokines and OLP susceptibility. Odds ratios (ORs) and 95% confidence intervals (CIs) from each study were pooled to estimate the strength of the association.

Results

A significant association of IFN-γ (874A/T) polymorphism with OLP was found (OR, 1.49; 95%CI, 1.22-1.81; P < 0.001) based on 6 eligible studies. A significant association of IL-18 (137G/C) polymorphism with OLP was found (OR, 1.64; 95%CI, 1.24-2.18; P < 0.001) based on 3 studies. A marginally significant association of TGFβ1 (509C/T) polymorphism in allele model with OLP was found (OR, 1.31; 95%CI, 1.01-1.71; P = 0.05) based on 4 studies. Nevertheless, lack of significant association of IL-1β (3954C/T), IL-2 (330T/G), IL-4 (590C/T), and IL-18 (607C/A) polymorphisms with OLP was found (P > 0.05) based on 3 studies, respectively.

Conclusion

This is the first meta-analysis to investigate the associations of 6 cytokines polymorphisms with OLP, suggesting that SNPs in IFN-γ, IL-18, and TGFβ1 may act as genetic factors for OLP risk. Further well-designed studies with larger sample size and multiple ethnicities are needed to validate these associations.

Network Pharmacology and Molecular Docking Analysis Explores the Mechanisms of Cordyceps sinensis in the Treatment of Oral Lichen Planus

Objective

Oral lichen planus (OLP) is the most common potentially malignant disorder of the oral cavity. This study aimed to investigate the mechanism of action of Cordyceps sinensis in the treatment of OLP and provides a theoretical support for improving current treatment regimens for OLP.

Methods

The active components and therapeutic targets of Cordyceps sinensis were predicted and screened using the TCMSP, SymMap, PubMed, HIT 2.0, and PharmMapper databases, while the relevant OLP targets were predicted and screened using the DisGeNET and GeneCards databases. Protein-protein interactions (PPI) were examined using the String database, and Cytoscape was used to combine and illustrate the findings. GO and KEGG pathway enrichment analyses were carried out using RStudio, and AutoDock Vina and Pymol were used for molecular docking and visualization, respectively.

Results

A total of 404 potential target genes were discovered after evaluating 21 active compounds from Cordyceps sinensis. Potential therapeutic targets included 67 targets that matched and overlapped with OLP, including TNF, IL-6, CD4, EGFR, and IL1B. Key targets were predominantly engaged in the PI3K-Akt signaling pathway and the MAPK signaling pathway, according to the GO and KEGG analyses. These targets have a connection to biological processes including apoptosis signaling pathway regulation, T cell activation, and oxidative stress response. The molecular docking results showed that TNF, IL-6, CD4, EGFR, and IL1B could bind to their corresponding active components.

Conclusions

Cordyceps sinensis contains multiple components and acts on multiple targets and multiple pathways. Particularly, Cordyceps sinensis targets TNF, IL-6, CD4, EGFR, and IL1B, regulates PI3K-Akt and MAPK signaling pathways, as well as takes part in biological processes including apoptosis, T cell activation, and oxidative stress. Cordyceps sinensis could be a crucial choice in the therapy of OLP.

Electrospun patch delivery of anti-TNFα F(ab) for the treatment of inflammatory oral mucosal disease

Chronic ulcerative oral mucosal inflammatory diseases, including oral lichen planus and recurrent aphthous stomatitis, are painful and highly prevalent, yet lack effective clinical management. In recent years, systemic biologic therapies, including monoclonal antibodies that block the activity of cytokines, have been increasingly used to treat a range of immune-mediated inflammatory conditions such as rheumatoid arthritis and psoriasis. The ability to deliver similar therapeutic agents locally to the oral epithelium could radically alter treatment options for oral mucosal inflammatory diseases, where pro-inflammatory cytokines, in particular tumour-necrosis factor-α (TNFα), are major drivers of pathogenesis. To address this, an electrospun dual-layer mucoadhesive patch comprising medical-grade polymers was investigated for the delivery of F(ab) biologics to the oral mucosa. A fluorescent-labelled F(ab) was incorporated into mucoadhesive membranes using electrospinning with 97% v/v ethanol as a solvent. The F(ab) was detected within the fibres in aggregates when visualised by confocal microscopy. Biotinylated F(ab) was rapidly eluted from the patch (97 ± 5% released within 3 h) without loss of antigen-binding activity. Patches applied to oral epithelium models successfully delivered the F(ab), with fluorescent F(ab) observed within the tissue and 5.1 ± 1.5% cumulative transepithelial permeation reached after 9 h. Neutralising anti-TNFα F(ab) fragments were generated from whole IgG by papain cleavage, as confirmed by SDS-PAGE, then incorporated into patches. F(ab)-containing patches had TNFα neutralising activity, as shown by the suppression of TNFα-mediated CXCL8 release from oral keratinocytes cultured as monolayers. Patches were applied to lipopolysaccharide-stimulated immune-competent oral mucosal ulcer equivalents that contained primary macrophages. Anti-TNFα patch treatment led to reduced levels of active TNFα along with a reduction in the levels of disease-implicated T-cell chemokines (CCL3, CCL5, and CXCL10) to baseline concentrations. This is the first report of an effective device for the delivery of antibody-based biologics to the oral mucosa, enabling the future development of new therapeutic strategies to treat painful conditions.

Differential genotypes of TNF-α and IL-10 for immunological diagnosis in discoid lupus erythematosus and oral lichen planus: A narrative review

Discoid lupus erythematosus and oral lichen planus are chronic systemic immune system-mediated diseases with unclear etiology and pathogenesis. The oral mucosa is the common primary site of pathogenesis in both, whereby innate and adaptive immunity and inflammation play crucial roles. The clinical manifestations of discoid lupus erythematosus on the oral mucosa are very similar to those of oral lichen planus; therefore, its oral lesion is classified under oral lichenoid lesions. In practice, the differential diagnosis of discoid lupus erythematosus and oral lichen planus has always relied on the clinical manifestations, with histopathological examination as an auxiliary diagnostic tool. However, the close resemblance of the clinical manifestations and histopathology proves challenging for accurate differential diagnosis and further treatment. In most cases, dentists and pathologists fail to distinguish between the conditions during the early stages of the lesions. It should be noted that both are considered to be precancerous conditions, highlighting the significance of early diagnosis and treatment. In the context of unknown etiology and pathogenesis, we suggest a serological and genetic diagnostic method based on TNF-α and IL-10. These are the two most common cytokines produced by the innate and adaptive immune systems and they play a fundamental role in maintaining immune homeostasis and modulating inflammation. The prominent variability in their expression levels and gene polymorphism typing in different lesions compensates for the low specificity of current conventional diagnostic protocols. This new diagnostic scheme, starting from the immunity and inflammation of the oral mucosa, enables simultaneous comparison of discoid lupus erythematosus and oral lichen planus. With relevant supportive evidence, this information can enhance physicians’ understanding of the two diseases, contribute to precision medicine, and aid in prevention of precancerous conditions.

The New Era of Salivaomics in Dentistry: Frontiers and Facts in the Early Diagnosis and Prevention of Oral Diseases and Cancer

Nowadays, with the development of new and highly sensitive, blood is not the only medium of choice for the diagnosis of several diseases and pathological conditions. Saliva is now considered a safe and non-invasive sample to study oral and systemic diseases, showing great diagnostic potential. According to several recent studies, saliva has emerged as an emerging biofluid for the early diagnosis of several diseases, indicated as a mirror of oral and systemic health and a valuable source of clinically relevant information. Indeed, several studies have observed that saliva is useful for detecting and diagnosing malignant tumours, human immunodeficiency virus, heart disease, and autoimmune diseases. The growing realisation that saliva is an inexhaustible source of information has led to the coining of the term ‘Salivaomics’, which includes five “omics” in connection with the main constituents of saliva: genome and epigenome, transcriptomics, metabolomics, lipidomics, proteomics and microbiota. All those may be changed by disease state, so they offer significant advantages in the early diagnosis and prognosis of oral diseases. The aim of the present review isto update and highlight the new frontiers of salivaomics in diagnosing and managing oral disorders, such as periodontitis, premalignant disorders, and oral squamous cell carcinoma (OSCC).

MiR-155-5p modulates inflammatory phenotype of activated oral lichen-planus-associated-fibroblasts by targeting SOCS1

BACKGROUND

Oral lichen planus (OLP) is a chronic inflammatory oral mucosal disease. Cytokines are closely associated with OLP development. In addition to immune cells, fibroblasts have been reported to induce regional inflammation. MicroRNA(miR)-155-5p is reportedly increased significantly in OLP and is known to regulate inflammation. This study aimed to investigate the role of miR-155-5p in fibroblasts of OLP lesions.

METHODS AND RESULTS

Normal mucosal fibroblasts (NFs) and OLP associated-fibroblasts (OLP AFs) were isolated from the oral mucosa of 15 healthy controls and 30 OLP patients. We detected the expression of miR-155-5p and fibroblast activation protein alpha (FAP-α) using quantitative RT-PCR and analyzed their correlation. Interleukin (IL)-6 and IL-8 levels were determined using ELISA. Expression of suppressor of cytokine signaling (SOCS) 1 was analyzed by western blotting. A dual-luciferase reporter assay was performed to investigate the interaction between miR-155-5p and SOCS1. MiR-155-5p and FAP-α were significantly increased and positively correlated in OLP AFs. Overexpression of miR-155-5p in OLP AFs augmented IL-6 and IL-8 release and decreased SOCS1 expression, whereas knockdown of miR-155-5p in OLP AFs decreased IL-6 and IL-8 release. The expression of SOCS1 was downregulated in OLP AFs, and SOCS1 silencing augmented IL-6 and IL-8 production in OLP AFs. Furthermore, miR-155-5p inhibited SOCS1 expression by directly targeting its 3'-UTR in OLP AFs.

CONCLUSIONS

MiR-155-5p regulates the secretion of IL-6 and IL-8 by downregulating the expression of SOCS1 in activated OLP AFs. Our results provide novel insights into the pathogenesis of OLP and identify a potential new target for OLP therapy.

Salivary expression of lncRNA DQ786243 and IL-17 in oral lichen planus: case-control study

Background

A growing number of studies has investigated IL-17 in OLP. However, its exact role and interactions are not fully determined. In addition, the literature investigating its salivary expression is limited. The scarcity in the literature studying lncRNAs was noticed, particularly with regards to correlating them with cytokines in OLP. In the current study, the salivary expression of lncRNA DQ786243 and IL-17 was assessed among different forms of OLP.

Methods

The study included 52 participants in four equal groups: reticular OLP, erythematous OLP, ulcerative OLP, and control group. All eligible OLP patients underwent conventional oral examination, along with basic charting of their demographic data, pain intensity using a visual analogue scale, and clinical evaluation using the Thongprasom et al. scale. The salivary expression of lncRNA DQ786243 and IL-17 was evaluated for all participants using qRT-PCR. Unstimulated whole saliva samples were used. Data were analyzed for statistical significance.

Results

No statistically significant difference was observed when comparing the mean age and gender distribution of the studied groups. A statistically significant difference was detected when comparing pain and clinical scores in the three OLP forms. The highest expression of both salivary biomarkers was noticed in ulcerative OLP, followed by erythematous OLP and reticular OLP, then the controls, with a significant difference between the studied groups. Upon comparing the salivary expression of DQ786243 in ulcerative and erythematous OLP, no significant difference was detected. No significant difference was detected when comparing salivary expression of IL-17 in erythematous OLP to the other OLP forms.

Conclusions

The salivary expression of lncRNA DQ786243 and IL-17 was upregulated in OLP compared to healthy individuals. Besides, their expression increased when the severity of OLP was at its highest level in ulcerative OLP. There was a positive correlation between DQ786243 and IL-17.

Trial registration The protocol was registered at ClinicalTrials.gov (NCT04503824). The date of registration is 07/08/2020.

Mechanisms of reactive oxygen species in oral lichen planus: A literature review

Oral lichen planus is a chronic non-infectious mucosal inflammatory disease caused by an imbalance between reactive oxygen species homeostasis and antioxidant defense systems. Notably, excessive oxidative stress products result in related autoimmune reactions. Further, it activates signaling pathways related to the development of oral lichen planus, as evidenced by the detection of damage to deoxyribonucleic acid, protein, and lipid. Thus, the mechanisms of reactive oxygen species-mediated oxidative stress in the pathogenesis of oral lichen planus are numerous and complex. In this review, we first introduce oxidative stress and oxidative products. Then, we summarize the role and possible mechanisms of reactive oxygen species-mediated oxidative stress in the pathogenesis of oral lichen planus and present a clinical correlation between oxidative stress and oral lichen planus. Finally, we discuss the current challenges and future perspectives.

Oral Microbiome Research on Oral Lichen Planus: Current Findings and Perspectives

Simple Summary

Oral lichen planus is a disease of the oral mucosa, which frequently affects women aged 40 years or older. Though the T cell-mediated immune response is involved in the development of oral lichen planus, attempts to identify a microorganism that causes the disease have been unsuccessful. Recent studies on the development of oral lichen planus are focusing on the role of the oral microbiome, which includes oral microbiota and their products, and the host environment. The role of the human microbiome in various diseases has been identified and regulating the microbiome is becoming important in personalized medicine. In this review, we summarized current findings on the role of the oral microbiome in the development of oral lichen planus. The homeostasis of the oral microbiome is disrupted in patients, and functional analysis of oral microbiota and oral mucosa implies that pathways involved in defense against bacterial infection and in the inflammatory response are activated in the oral lichen planus-associated oral microbiome. Though the lack of studies to date makes it difficult to conclude, further studies on the oral microbiome associated with the disease will enable a holistic understanding of the role of the oral microbiome in the development of oral lichen planus and developing a personalized therapy for the disease.

Abstract

Oral lichen planus (OLP) is a chronic inflammatory disease of the oral mucosa with an unknown etiology. The role of oral microbes in the development of OLP has gained researchers’ interest. In this review, we summarized the findings of studies focused on the relationship between OLP and oral microbiome, which includes the composition of oral microbiota, molecules produced by oral microbiota or the host, and the oral environment of the host. According to the studies, the oral microbial community in OLP patients undergoes dysbiosis, and the microbial dysbiosis in OLP patients is more prominent in the buccal mucosa than in the saliva. However, no same microorganisms have been suggested to be associated with OLP in multiple investigations, implying that the functional aspects of the oral microbiota are more important in OLP development than the composition of the oral microbiota. According to studies on host factors that make up the oral environment, signal pathways involved in cellular processes, such as keratinization, inflammation, and T cell responses are triggered in OLP. Studies on the functional aspects of the oral microbiota, as well as interactions between the host and the oral microbiota, are still lacking, and more research is required.

Cell-Free DNA Promotes Inflammation in Patients With Oral Lichen Planus via the STING Pathway

Background

Damaged and dead cells release cell-free DNA (cfDNA) that activates cyclic GMP–AMP (cGAMP) synthase (cGAS), which leads to the activation of stimulator of interferon genes (STING) via the second messenger cGAMP. STING promotes the production of inflammatory cytokines and type I interferons to induce an inflammatory response. Oral lichen planus (OLP), a chronic autoimmune disease involving oral mucosa characterized by the apoptosis of keratinocytes mediated by T-lymphocytes, is related to the activation of multiple inflammatory signaling pathways. Currently, the relationship between cfDNA and OLP has not been confirmed. We hypothesized that cfDNA may be a potential therapeutic target for OLP.

Methods

cfDNA was extracted from the saliva and plasma of OLP patients; its concentration was measured using the Quanti-iT-PicoGree kit and its relationship with OLP inflammation was assessed. cfDNA of OLP patients (cfDNA-OLP) was transfected into THP-1 macrophages and the expression of inflammatory factors was investigated by performing quantitative real time PCR (qRT-PCR), western blotting, and enzyme-linked immunosorbent assay (ELISA). STING expression was analyzed in the tissues of OLP patients and healthy controls using immunohistochemical staining and western blotting. siRNA was used to knockdown STING expression in THP-1 macrophages, and the inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) secreted by cells following cfDNA-OLP transfection were detected using ELISA. Finally, the effect of the cationic polymer PAMAM-G3 was evaluated on the treatment of inflammation induced by cfDNA-OLP.

Results

The concentration of cfDNA in the saliva and plasma of OLP patients was considerably higher than that of healthy controls, and it positively correlated with the levels of inflammatory cytokines and clinical characteristics. cfDNA-OLP induced an inflammatory response in THP-1 macrophages. STING expression was significantly higher in OLP tissues than in the gingival tissues of healthy controls. STING knockdown suppressed cfDNA-OLP-induced inflammation in THP-1 macrophages. PAMAM-G3 inhibited the inflammatory response caused by cfDNA-OLP.

Conclusion

The cfDNA level is increased in OLP patients, and the STING pathway activated by cfDNA-OLP might play a critical role in OLP pathogenesis. Treatment with PAMAM-G3 reduced the inflammation induced by cfDNA-OLP, and therefore, may be a potential treatment strategy for OLP.

Probiotics as Potential Biological Immunomodulators in the Management of Oral Lichen Planus: What's New?

Oral lichen planus (OLP) is a T cell-mediated chronic inflammatory disorder with multifactorial aetiology and malignant transformation potential. Despite the treatments so far identified, new tailored and safe specific measures are needed. Recently, human microbiota imbalance has been linked to several immune-mediated diseases, opening new therapeutic perspectives for probiotics; besides their ability to directly interact with the host microbiota, they also display a strain-specific immune-modulatory effect. Thus, this non-systematic review aims to elucidate the molecular pathways underlying probiotic activity, mainly those of Lactobacilli and Bifidobacteria and their metabolites in OLP pathogenesis and malignant transformation, focusing on the most recent in vitro and in vivo research evidence. Findings related to their activity in other immune-mediated diseases are here included, suggesting a probiotic translational use in OLP. Probiotics show immune-modulatory and microbiota-balancing activities; they protect the host from pathogens, hamper an excessive effector T cell response, reduce nuclear factor-kappa B (NF-kB) signalling and basal keratinocytes abnormal apoptosis, shifting the mucosal response towards the production of anti-inflammatory cytokines, thus preventing uncontrolled damage. Therefore, probiotics could be a highly encouraging prevention and immunotherapeutic approach for a safer and more sustainable OLP management.