Single-cell-based sequencing reveals that CD8+ T cells regulate SGK1 expression in psoriasis

Abstract Background Psoriasis is an autoimmune disease mediated by T cells. Downregulation of SGK1 is known to exacerbate psoriasis. However, the specific significance of SGK1 expression in psoriasis and the associated regulation of SGK1 remain unknown. Methods Here, we performed a comprehensive analysis of the significance and impact of SGK1 expression.We obtained transcriptome expression profiles of skin lesions in 13 psoriasis patients from the original psoriasis-related dataset (GSE151177).Subpopulations of T cells and keratinocytes (KC) were first analyzed. The expression of SGK1 was utilized to identify the different functions of keratin-forming cells.Finally, the association between CD8 + T cells and cells expressing SGK1 was revealed by cellular interactions and validated by FISH. Results Single-cell transcriptome analysis was performed using psoriasis lesion tissues from 13 cases in the database. Subpopulation analysis of T cells and keratinocytes (KC) was performed.We found that CD8 + T cells have characteristics of tissue-resident memory T cells and are involved in the proliferative differentiation of KC.Different SGK1 expression levels were found to have different physiological functions in KC analysis.Analysis of intercellular reciprocal communication indicated that CD8 + T cells may intervene in keratinocyte and monocyte-macrophage SGK1 expression through CCL/TIGIT signaling.FISH showed that SGK1 was widely distributed in the infiltration sites of CD8 + T cells, suggesting a potential relationship between CD8 + T cells and SGK1 expression. Conclusion The above results show that CD8 + T cells upregulate SGK1 expression in keratinocytes and monocyte macrophages mainly through TIGIT signaling, a process that is inhibited in psoriasis.