Fig. 1.
An endogenous population of alternatively activated immature neutrophils emerges in the CNS during EAE. Spinal cord immune cells and peripheral blood mononuclear cells were harvested on day 7 post-transfer (p.t.) of encephalitogenic CD4 + T cells. A-C Cells pooled from 3 mice were analyzed by multiparameter flow cytometry. A t-distributed stochastic neighbor embedding (tSNE) of pooled neutrophils, identified as viable Ly6G+ CD11b+ CD45+ cells. Spinal cord clusters were manually delineated based on their spatial segregation within the t-SNE map. B Representative histograms showing mean fluorescent intensity (MFI) of the indicated markers across the three identified neutrophil clusters. Gray histograms indicate fluorescence minus one (FMO) controls used to define gating thresholds. C Linear regression analysis depicting the correlation between the total number of Arg1+ neutrophils per spinal cord at peak EAE against the area under the clinical disease score curve (AUC) for individual mice. D-G Spinal cord immune cells and peripheral blood mononuclear cells were isolated from EAE mice at four stages (preclinical, onset, peak, and late) and analyzed by single-cell RNA sequencing (RNAseq). D UMAP visualization of blood-derived (left) and spinal cord-derived (right) neutrophils pooled across all time points. E Heatmap of selected differentially express genes (scaled log2) across the three neutrophil clusters, highlighting markers of neutrophil maturation and alternative activation. F Gene Ontology Biological Process (GO BP) enrichment analysis of Cluster 3 marker genes. G Pie charts showing the relative proportions of circulating (left) and spinal cord-infiltrating (right) neutrophils within each cluster across different stages. H Heatmap of differentially expressed genes comparing blood- and spinal cord- derived neutrophils within cluster 3. I Violin plots comparing Arg1 expression blood- versus spinal cord- derived neutrophils within cluster 3. Data are from 1 experiment representative of two independent experiments with n = 3–5 mice per time point per experiment
