Abstract
Background: Co-trimoxazole (Co-T), an antibiotic used globally for bacterial infections and opportunistic infection prophylaxis is one of the most common causes of Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN); a life-threatening CD8+ T cell-dependent HLA-class I-restricted blistering drug eruption. We aimed to elucidate the differential single-cell immunopathology of Co-T SJS/TEN in persons living with HIV (PLWH) and without HIV (PLWoH).
Method: We obtained blister fluid cells (BC) from three populations: 1) Co-T SJS/TEN PLWH, all of whom were co-infected with tuberculosis (TB) (n = 5); PLWoH (n = 6), or 3) burns patients as control (n = 6). BC were analysed by 5’ scRNA-TCR-CITE-seq with bioinformatic normalization (CellRanger v9.0), transcriptome-based clustering (Seurat v5), and TCRαβ (ClusTCR), differential (VGAS), and proportional analyses (scCODA). Affected skin from two PLWoH with paired BC were analysed by 10x Visium-HD spatial transcriptomics.
Results: Private oligoclonal TCRαβ in blister fluid across Co-T SJS/TEN patients with shared HLA-class I peptide binding specificities were expressed by the same two populations of cytotoxic (GNLY, GZMB, PRF1) and proliferative (STMN1, TUBA1B, H2AFZ) CD8+ T-cells enriched in SJS/TEN and in contact with spatially resolved keratinocytes at the epidermal junction. At late timepoints pathogenic CD8+ T-cells were reduced while M1-like (STAT1, HLA) phagocytes transitioned to M2-like (RNASE1, LIPA) signatures indicative of wound repair. In Co-T SJS/TEN PLWH compared to PLWoH, CD8+ T-cells expressed markers of inactivation (EEF1A1, BTG1, ZFP36L2) and reduced expression of cytotoxic mediators (GNLY, GZMB). PLWH were further discerned by CD1C dendritic cells differentially enriched for markers of activation (CD83, CALR, AIF1), monocytes and macrophages for markers of immune regulation (THBS1, TFGBI, VCAN, STAB1), and CD4+ T-cells for markers of cytotoxicity (GNLY, GZMA), phosphodiesterase-signalling (PDE3B, PDE7B), and immune dysregulation (TFGB1, CRIP1).
Conclusion: We identify putative pathogenic TCR to model shared drug- and HLA-restriction and cell signatures that discern early (cytotoxic) from late (repair) disease processes and a unique cellular sub phenotype of SJS/TEN in PLWH associated with immune dysregulation. These data provide avenues toward personalised treatment approaches for patients with earlier- or later-stage disease and sub phenotypes of SJS/TEN associated with infectious co-morbidities.