Metabolic reprogramming in lacrimal gland GVHD: Stage-specific shifts in acinar cells as drivers of disease progression.

PURPOSEOcular graft-versus-host disease (oGVHD) progresses through inflammatory and fibrotic phases, yet the temporal dynamics of the lacrimal gland (LG) cellular ecosystem remain unclear. This study aims to delineate the phase-specific alterations driving oGVHD pathogenesis.

METHODSWe performed integrated single-cell RNA sequencing on murine LGs at acute (7-day) and chronic (28-day) GVHD stages. Transcriptional profiling was combined with pseudotime trajectory analysis, computationally inferred cell-cell communication networks, and immunofluorescence validation.

RESULTSTemporal analysis revealed extensive phase-specific cellular reprogramming. Acute GVHD was characterized by expansion of globulin-specific acinar cells with altered glycan metabolism, alongside inflammatory fibroblasts predicted to license cytotoxic T-cell responses via H2-k1-Cd8 interactions. Chronic GVHD featured metabolic diversification of acinar subtypes, including upregulated N-glycan biosynthesis in lipid-associated cells and activated α-linolenic acid metabolism in water/electrolyte-secreting cells, along with emergent myeloid-epithelial crosstalk. Computational analyses identified novel ligand-receptor pairs, suggesting plasmacytoid dendritic cells engage water/electrolyte-secreting acinar cells via Gm-Sort1, and mast cells target lipid-associated subtypes via Ptprc-Cd22. Infiltration of pDCs and mast cells was validated by immunofluorescence. Trajectory analysis indicated acinar plasticity reflects environment-instructed adaptation rather than hierarchical differentiation.

CONCLUSIONSThese results define a phase-shift mechanism in oGVHD: acute damage involves a fibroblast-T cell-epithelium triad, while chronic dysfunction is driven by acinar metabolic reprogramming and myeloid-mediated epithelial dysregulation. Our temporal single-cell atlas integrates computational predictions with morphological validation to reveal stage-specific therapeutic targets for intervening in disease progression.