The potential roles of Th17 cells in the pathogenesis of oral lichen planus

Increased pathogenicity and pro-inflammatory capabilities of mucosal-associated invariant T cells involved in Oral Lichen Planus

BACKGROUND

Mucosal-associated invariant T (MAIT) cells assume pivotal roles in numerous autoimmune inflammatory maladies. However, scant knowledge exists regarding their involvement in the pathological progression of oral lichen planus (OLP). The focus of our study was to explore whether MAIT cells were altered across distinct clinical types of OLP.

METHODS

The frequency, phenotype, and partial functions of MAIT cells were performed by flow cytometry, using peripheral blood from 18 adults with non-erosive OLP and 22 adults with erosive OLP compared with 15 healthy adults. We also studied the changes in MAIT cells in 15 OLP patients receiving and 10 not receiving corticosteroids. Surface proteins including CD4, CD8, CD69, CD103, CD38, HLA-DR, Tim-3, Programmed Death Molecule-1 (PD-1), and related factors released by MAIT cells such as Granzyme B (GzB), interferon (IFN)-γ, tumour necrosis factor (TNF)-α, interleukin (IL)-17A, and IL-22 were detected.

RESULTS

Within non-erosive OLP patients, MAIT cells manifested an activated phenotype, evident in an elevated frequency of CD69+ CD38+ MAIT cells (p < 0.01). Conversely, erosive OLP patients displayed an activation and depletion phenotype in MAIT cells, typified by elevated CD69 (p < 0.01), CD103 (p < 0.05), and PD-1 expression (p < 0.01). Additionally, MAIT cells exhibited heightened cytokine production, encompassing GzB, IFN-γ, and IL-17A in erosive OLP patients. Notably, the proportion of CD103+ MAIT cells (p < 0.05) and GzB secretion (p < 0.01) by MAIT cells diminished, while the proportion of CD8+ MAIT cells (p < 0.05) rose in OLP patients with corticosteroid therapy.

CONCLUSIONS

MAIT cells exhibit increased pathogenicity and pro-inflammatory capabilities in OLP. Corticosteroid therapy influences the expression of certain phenotypes and functions of MAIT cells in the peripheral blood 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.