Assistant Professor University of Michigan, United States
Disclosure(s):
Shilpa Kodati, MD: No financial relationships to disclose
Introduction/Rationale: Although TNF inhibitors (TNFi) are widely used in the treatment of non-infectious uveitis, the mechanisms underlying treatment response remain unclear. The purpose of this study was to characterize immune cell alterations and molecular responses to TNFi therapy in non-infectious uveitis.
Methods: Paired peripheral blood samples from 16 uveitis patients were collected before and after TNF inhibitor (TNFi) treatment was started. Single-cell RNA sequencing, surface-protein (CITE-seq), and T-cell receptor (TCR-seq) sequencing were performed on PBMCs using the 10x Genomics platform. Data processing, QC, batch correction, and clustering were performed using Seurat v5.3. Differential gene expression, surface protein analysis, and TCR clonotype assessment were analyzed between paired samples (obtained pre-treatment and while on treatment), as well as between clinical responders and non-responders.
Results: The most upregulated genes in pre-treatment samples compared to samples obtained on treatment were involved in antigen presentation and interferon signaling (HLA-DRB1, HLA-DRB5, CD74, AIF1, GNA15, ISG15, MX1). Treatment samples showed elevated expression of the S100A8, S100A12, FCN1, GZMB, PRF1, and GNLY genes, suggestive of enhanced innate immune regulation. The baseline samples from patients who were deemed responders showed reduced proportions of activated CD4+ and CD8+ T-cells, and increased levels of B cells, MAIT cells, and NK cells, in comparison to those who were non-responders. Additionally, at baseline, responders demonstrated higher regulatory and cytotoxic gene expression (GZMB, PRF1, GNLY, IL7R, KLRB1). Non-responders at baseline showed elevated expression of inflammatory genes (HLA-DRB1, CD74, ISG15, IFI44L). Overall, TCR analysis revealed decreased clonal expansion post-treatment.
Conclusion: Single-cell sequencing demonstrates that TNFi therapy reduces activated T-cell populations and downregulates genes associated with antigen presentation and interferon pathways.
