Interleukin-3 coordinates glial-peripheral immune crosstalk to incite multiple sclerosis

ABSTRACT: Multiple sclerosis (MS) is a neuroinflammatory disease of the central nervous system (CNS). While CNS-resident glial cells and infiltrating immune cells contribute to MS pathogenesis, the networks that govern peripheral-central immune crosstalk and coordinate functionality among these ontologically distinct populations remain unclear. Here we show, in mice and humans, that astrocyte- and CD44hiCD4+ T cell-sourced interleukin-3 (IL-3) programs microglia and infiltrating myeloid cells to exacerbate neuroinflammation by inciting a cellular recruitment program that drives the accrual of immune cells in the CNS thereby worsening MS and its preclinical model experimental autoimmune encephalomyelitis (EAE). We find that CNS-resident astrocytes and peripherally-derived CD44hiCD4+ T cells generate IL-3 while resident microglia and infiltrating monocytes, macrophages, and dendritic cells respond to the cytokine by expressing IL-3Rɑ, IL-3's specific receptor. Astrocytic and T cell IL-3 elicit an immune migratory, recruitment, and chemotactic program by IL-3Rɑ+ myeloid cells that enhances immune cell infiltration into the CNS leading to exacerbated neuroinflammation, demyelination, and clinical disease. Multiregional single-nuclei RNA sequencing (snRNAseq) of human CNS tissue from unaffected controls and MS patients reveals the appearance of a subset of IL3RA-expressing myeloid cells in MS plaques with unique recruitment, migratory, and chemotactic programing and function. In humans with MS, IL3RA expression by plaque myeloid cells and IL-3 levels in the cerebrospinal fluid (CSF) predict myeloid and T cell abundance and recruitment into the CNS. Together, our findings establish IL-3:IL-3RA signaling as a bidirectional glial-peripheral immune crosstalk network that promotes neuroinflammation, prompts immune cell recruitment to the CNS, and worsens MS.

ORGANISM(S): Homo sapiens

PROVIDER: GSE227781 | GEO | 2023/05/16

REPOSITORIES: GEO