GEOapplication/xmlftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE324nnn/GSE324824/primaryOK200TranscriptomicsHomo sapiensExpression profiling by high throughput sequencinghttps://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE324824GEOGSEfalseAnti-CD19 CAR T cell therapy induces CNS-specific immune alterations in multiple sclerosisMultiple sclerosis (MS) is a chronic inflammatory central nervous system (CNS) disease. Although current immunotherapies control relapses, they have limited impact on progression, likely due to poor CNS penetration and failure to target meningeal B cell follicles and activated myeloid cells. Chimeric antigen receptor (CAR) T cells can infiltrate tissues, but their ability to access and eliminate CNS-resident immune cells has remained unclear. We treated five individuals with progressive or relapsing-remitting MS with anti-CD19 CAR T cells to assess safety, CNS bioavailability, and compartment-specific effects. Treatment was well tolerated and induced profound remodeling of the CNS B cell pool, with sustained reduction of cerebrospinal fluid humoral biomarkers. CNS-infiltrating CAR T cells selectively upregulated PDE7B, suggesting a CNS-specific biomarker and trafficking mediator. Peripheral B cell reconstitution showed altered cytokine and homing profiles. These findings indicate compartment-specific immunomodulation beyond peripheral B cell depletion and support controlled trials to test durability and efficacy.2026/09/15GSE324824GSM9586849GSM9586859GSM9586869GSM9586858GSM9586864GSM9586853GSM9586863GSM9586852GSM9586851GSM9586862GSM9586861GSM9586850GSM9586857GSM9586868GSM9586867GSM9586856GSM9586866GSM9586855GSM9586854GSM9586865GSM958686024676324824Homo sapiens