Cell-type- and state-resolved transcriptomics uncovers distinct T cell and monocyte dysregulation in multiple sclerosis.

Multiple sclerosis (MS) is a complex immune-mediated disorder with polygenic and multicellular underpinnings, necessitating cell-type-specific molecular studies to delineate dysregulated pathways. Here, we profile 1,075 transcriptomes from 167 patients with MS and 42 healthy participants across six peripheral immune cell-type-states. MS-associated transcriptional differences are more pronounced in primary (unstimulated) immune cells than in in vitro-stimulated counterparts. We identify shared and cell-type-specific transcriptional alterations at the level of genes, pathways, and co-expressed gene modules, prioritizing regulators, such as ZBTB16, across T cells and monocytes, and replicating six MS-associated modules in independent datasets. The top T cell module is enriched for MS susceptibility genes and affects proliferation. The top monocyte module implicates dysregulated TNF-α/NF-κB signaling, for which an in silico drug screen and in vitro validation nominate alvespimycin as a candidate modulator. Together, these findings define stable peripheral immune dysregulation signatures in MS that may serve as diagnostic or prognostic biomarkers in at-risk individuals.