CD8+ tissue-resident memory T (CD8+ Trm) cells play key roles in many immune-inflammation-related diseases. However, their characteristics in the pathological process of oral lichen planus (OLP) are unclear. Therefore, we investigated the function of CD8+ Trm cells in the process of OLP. Single-cell RNA sequencing profiling and spatial transcriptomics revealed that compared with non-erosive OLP, CD8+ Trm cells, which were mainly distributed in the lamina propria close to the basement membrane, were increased and functionally more active by secreting multiple cytokines in patients with erosive oral lichen planus (EOLP), including IFN-γ, TNF-α, and IL17. And our clinical cohort of 1-year follow-up was also supported the above results in RNA level and protein level. In summary, this study provided a novel molecular mechanism for triggering OLP erosion by CD8+ Trm cells to secrete multiple cytokines, and new insight into the pathological development of OLP.

The authors have declared no competing interest.

National Natural Science Foundation of China (No. 81730030 and No. 82001059)

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The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

this study was supported by the Ethics Committee of West China Hospital of Stomatology Sichuan University [WCHSIRB-2019-167].

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The data of this study, including scRNA-seq data, ST data, and bulk RNA-seq data are available in the Gene Expression Omnibus (GEO) database and the accession number is waiting to obtain.