Transcriptome Response to Autoantibodies in Human Primary Epidermis Keratinocyte Model for Pemphgus Vulgaris

Pemphigus vulgaris (PV) is an autoimmune disease caused by autoantibodies (AAbs) targeting Desmoglein 1 (DSG1) or Desmoglein 3 (DSG3) on keratinocytes, leading to disrupted cell-cell adhesion and epidermal blistering. To investigate the early signaling events triggered by AAb binding, we examined transcriptomic responses in a human primary epidermis keratinocyte (HPEK) model for PV. After incubating the single-chain variable fragment (scFv) PX43, which targets DSG1 and DSG3, and human IgG as control for 5h, 10h and 24h, differentially expressed genes (DEGs) and regulated pathways was analyzed using DESeq2 and pathway enrichment analysis. Few significantly differentially expressed DEGs (under 10) were identified of PX43 compared to hIgG at all three time points (5h, 10h and 24h) with adjusted pvalue below 0.05 and |log2FC| >1. Upregulated inflammatory related pathways including TNFα signaling were identified only at 24h. Correlation analysis of the log2 transformed transcripts per million (TPM) shows the very high positive correlation of PX43 and hIgG at all time points (spearman correlation above 0.9) These findings indicate that AAbs targeting DSG1 and DSG3 do not drive broad transcriptomic or proteomic changes at the HPEK model. Human skin normal human epidermal keratinocytes from three healthy human donors were grown in 2D until 85% confluenent. Calcium concentration was increased to establish cell-cell adhesion and differentiation. Cells were then incubated with DSG-targeting PX43 (DSG1 and DSG3) antibodies and human IgG as controls, with transcriptome data collected by RNA-seq at 5, 10, and 24, 48 hours post-stimulation.