TCR repertoire analysis reveals predominant local clonal expansion of T cells with minimal circulation in oral lichenoid contact lesions

Abstract

Objective

Oral lichenoid contact lesions (OLCLs) are inflammatory oral mucosal disorders triggered by hypersensitivity to dental metals and resemble oral lichen planus (OLP) clinically and histologically. The T-cell receptor (TCR) repertoire in lesions reflects the type and frequency of the antigen; however, the details of the TCR repertoires of OLCLs have never been reported. The aim of this study was to evaluate the presence of clonally expanded T cells within the lesion tissue and peripheral blood of OLCL, and to determine whether differences exist between these compartments.

Methods

We analyzed TCR repertoires in lesion tissues from nine OLCL patients and peripheral blood from five of these patients using high-throughput next-generation sequencing. V–J gene usage, and complementarity-determining region 3 clonotypes were examined to detect antigen-driven clonal expansions.

Results

All OLCL lesions exhibited clonally expanded T-cell populations, with dominant clones exceeding 1 % frequency. These large expanded clones were predominantly localized within lesion tissues and were either absent or found at very low frequencies in peripheral blood. In one patient, an identical expanded clone was detected in two separate OLCL lesions contacting metal prostheses but was undetectable in blood.

Conclusion

Our study demonstrates that OLCL lesions harbor clonally expanded T cells that remain primarily localized within the tissue and are largely absent from peripheral blood. This distribution pattern supports the hypothesis that resident memory T cells responding to metal-related antigens may contribute to disease pathogenesis.