Transcriptomic profiling of iris tissue highlights LCK signaling and T cell-mediated immunity in Behcet's uveitis

Uveitis is the most common form of ocular lesions in Behcet's disease, severely affecting visual function. Molecular pathological changes of ocular lesions in patients with Behcet's uveitis (BU) are largely unknown. In this study, we performed the first comprehensive transcriptomic profiling of iris specimens from BU patients and healthy donors to provide an insight into intraocular immunopathogenesis. The mRNA sequencing identified 1633 differentially expressed genes (DEGs) between the BU group and healthy controls. GO functional enrichment analysis on DEGs showed that T cell activation was the most significantly enriched biological process. KEGG analysis of DEGs also revealed several prominently enriched T cell-related pathways, including the T cell receptor signaling pathway, Th17 cell differentiation, and Th1 and Th2 cell differentiation. The lymphocyte-specific protein tyrosine kinase (LCK) was identified as the key hub gene in the protein interaction network of DEGs. Western blot analysis further showed increased expression of active LCK in the BU group, suggesting activation of LCK signaling. Using publicly accessible single-cell RNA-sequencing data of the healthy iris, LCK was found to be expressed in clusters of activated T cells but not in other iris cell clusters, suggesting an overt association between LCK upregulation and T cell-mediated immune dysregulation. Additionally, 16 drugs were predicted to be potential inhibitors of LCK. Overall, these findings not only highlighted the central role of T cell-mediated immunity and previously unreported LCK signaling in intraocular immunopathogenesis but also revealed the potential value of LCK as a new therapeutic target for BU patients.