Regulatory architecture underlying immune dysregulation reconstructed by single-cell multi-omics in lupus nephritis

ObjectivesLupus nephritis (LN) is a severe complication of systemic lupus erythematosus with heterogeneous clinical outcomes and limited therapeutic options. Although immune dysregulation is central to LN pathogenesis, the underlying cell-type-specific regulatory mechanisms and their genetic determinants remain poorly characterized. MethodsWe generated a single-cell multi-omics atlas of peripheral blood mononuclear cells (PBMCs) from newly diagnosed, minimally treated LN patients by integrating single-cell RNA-seq (scRNA-seq) and single-nucleus ATAC-seq (snATAC-seq) profiles. To elucidate genetically driven regulatory programs in a broaden LN population, we generated a blood expression quantitative trait loci (eQTL) atlas from 99 Chinese LN patients and performed Bayesian colocalization analysis to systematically prioritize putative causal genes for LN. Finally, we investigated how fine-mapped SNPs associated with LN phenotypic manifestations exert regulatory effects within distinct single-cell chromation contexts by leveraging peak-to-gene linkages at single-cell resolution. ResultsOur single-cell multi-omic dataset and orthogonal analytical approaches revealed extensive immune remodeling in LN, characterized by amplified innate immune activation and impaired adaptive immune responses, and identified transcription factors (TFs) orchestrating immune regulatory circuits. Bayesian colocalization analysis nominated 14 high-fidelity causal genes for kidney function and 23 for SLE. Integration with fine-mapped GWAS variants highlighted critical cell type convergence across autoimmune disorders and immune-mediated nephropathies, particularly within B cell subsets, where TF-driven programs delineated stage-specific differentiation networks. ConclusionsTogether, these analyses reconstruct the regulatory architecture underlying immune dysregulation in LN and connect genetic variation to cell-type-specific regulation, guiding genetically informed therapeutic development.