Distinct Immunological Features Compared to Lichen Planus and Oral Lichen Planus

Area of Science:

• Immunology
• Transcriptomics
• Oral Medicine

Background:

• Lichen planus (LP) and oral lichen planus (OLP) share similarities but have distinct immunopathogenic mechanisms.
• Accurate diagnosis and management require understanding these differences.
• This study investigates the systemic immune profile of OLP and compares OLP and LP inflammatory microenvironments.

Purpose of the Study:

• To investigate the systemic immune profile of oral lichen planus (OLP) using single-cell transcriptomics.
• To identify distinct immune cell subsets and signaling pathways in OLP.
• To compare the inflammatory lesion microenvironments of OLP and LP.

Main Methods:

• Single-cell transcriptomic analysis of peripheral blood mononuclear cells (PBMCs) from OLP patients and healthy controls.
• Analysis of PBMCs and lesion tissues from OLP and LP patients.
• Validation of key findings using independent datasets and ELISA.

Main Results:

• Prostaglandin D2 synthase (PTGDS) was elevated in NK cells from OLP patients, serving as a potential diagnostic marker.
• A novel CXCR4high-TSC22D3high CD4 cytotoxic T cell subset with enhanced cytotoxicity was identified in OLP.
• OLP showed upregulated TNF and TLR signaling in NK cells, and intensified TNF-driven inflammation with disrupted HIF1A-VEGF interactions in tissues compared to LP.

Conclusions:

• Distinct immunopathogenic mechanisms differentiate OLP from LP.
• Upregulation of PTGDS in NK cells and specific CD4 T cells suggests systemic immune dysregulation in OLP.
• Tissue-level differences indicate impaired vascular remodeling and chronic inflammation in OLP, highlighting potential therapeutic targets.