ABSTRACT
Objective:To construct single-cell transcription landscape of T cell in peripheral blood mononuclear cells(PBMCs) and thyroid tissue of patients with Hashimoto ′s thyroiditis(HT), and to analyze the changes in the proportion and functionality of T cell clusters in HT disease state.Methods:Single cell RNA sequencing was performed on PBMCs and thyroid tissue from 5 HT patients. Single cell RNA sequencing data of PBMCs from 5 healthy individuals were retrieved from public databases. After preliminary clustering, the clusters expressing CD3E were extracted and clustering again, and the names of each cluster were determined according to the known cell markers. The proportion of each cell subtype was compared, and the differentially expressed genes in different samples were analyzed.Results:After quality control, the 71 533 T cells were classified into 19 cell clusters. Among them, the proportion and function of C1_CD4 + Naive T cell clusters, C3_CD4 + Treg cell clusters, C7_CD8 + Naive T cell clusters, C8_GNLY -CD8 + T cell clusters, C10_RORC + CD8 + T cell clusters, C11_ GZMK + CD8 + T cell clusters, C12_CCL4 + CD8 + T cell clusters, and C18_PTGDS + NK cell clusters in thyroid tissue of HT patients were significantly different from those in PBMCs of healthy controls and HT patients. Conclusion:The proportion of multiple T cells in thyroid tissue of HT patients were significantly different from those in PBMCs. Among them, the proportion of three of CD8 + T cell subsets with high expression of cell killing-related genes in thyroid tissue T cells of HT patients is higher than that in PBMCs T cells, and it is statistically significant. In addition, the functionality of various T cells in the thyroid tissue of HT patients are also significantly different from those in PBMCs. A cluster of GZMK + CD8 + T cells showes significantly lower expression of genes related to PD1 pathway in thyroid tissues of HT patients compared with cells in PBMCs of HT patients, also a cluster of CCL4 + CD8 + T cells showes significantly lower expression of genes related to IL-12 pathway.