1549 Single cell transcriptome reveals complex keratinocyte and immune responses in cutaneous chronic graft-versus-host disease

Cutaneous manifestations are the most common presenting sign of chronic graft-versus-host disease (cGVHD) and extent cutaneous involvement is also highly correlated with prognosis. Very little understood about underlying pathogenesis underpinning injury at this location, especially contribution keratinocytes other structural skin cells. We performed single-cell RNA-sequencing to compare transcriptome epidermal dermal cGVHD healthy control samples. Our findings reveal unique non-immunologic immunologic changes in immune Specifically, we observed upregulation alarmins inflammatory cytokines downregulation anti-redox AP-1 pathway genes keratinocyte compartments. In cell subsets, showed increased CD8+ T, CD4+ CD4+Foxp3+regulatory T natural killer cells cGVHD, accompanied by signals leukocyte functions, responses, cytolysis, macrophage M1 polarization. Lastly, delineated donor vs. recipient cellular origin non-immune populations sex-mismatched cGVHD. Taken together, these data complex responses GVHD, supporting future studies contributions potential local treatment strategies.