Fig. 1: Myelopoiesis and blood monocytosis precede and predict clinical disability and neuroinflammation in relapsing-remitting EAE.

a Schematic design of experiment. Relapsing-remitting EAE was induced in female SJL/L mice, 8 weeks old, by administering proteolipid protein (PLP_139-151) mixed with complete Freund’s adjuvant (CFA) by sub cutaneous injection on day 0. Naïve SJL/L mice were used as controls. Mean clinical disease scores over the course of 35 days shows multiphasic episodes of disability with an initial peak, followed by remission, and subsequent relapse. Tissue was collected during peak disease and remission for analysis. (n = 7) (b) Quantification of CD45⁺ leukocyte populations in the spinal cord (n = 6 naïve, n = 8 peak, n = 9 remission). c Quantification of Ly6C^hi monocytes and neutrophils in the blood (n = 6 naïve, n = 7 peak, n = 8 remission). d Flow cytometry analysis of bone marrow hematopoietic progenitors. Quantification of CD45⁺ cells, LSKs, and MPP3 leukocyte progenitors in the femur bone marrow (n = 3 naïve, n = 5 peak, n = 5 remission, except MPP3s and LSKs where n = 6 naive) (e) Measurement of growth factors in femur bone marrow fluid by ELISA (n  = 6 naïve, n = 9 peak, n = 10 remission) (f) Quantification of LSKs and MPP3 leukocyte progenitors in vertebral bone marrow (n = 5/time point). g Measurement of splenic weight (n = 6 naïve, n = 9 peak, n = 10 remission) and enumeration of LSKs and MPP3 leukocyte progenitors in the spleen (n = 3 naïve, n = 5 peak, n = 5 remission). h Mean clinical disease scores of RR-EAE mice over the course of 35 days with corresponding blood Ly6C^hi monocytes and neutrophils quantification at days 0, 8, 14, 21, and 35 dpi (n = 7). i Correlation of the number of circulating Ly6C^hi monocytes and neutrophils at pre-onset (day 8) with the subsequent peak clinical score (n = 7). Data presented as mean ± SEM, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001. a–h are a combination of 2, 3 individual experiments, i is from a representative experiment. b–g one-way ANOVA, I Pearson’s correlation. Created in BioRender. McAlpine, C. (2025) https://BioRender.com/kvggmpp. EAE experimental autoimmune encephalomyelitis, PLP proteolipid protein, CFA complete Freud’s adjuvant, LSK Lin^-Sca1⁺cKit^+, MPP3 myeloid-biased multipotent progenitor 3, GM-CSF granulocyte-macrophage colony-stimulating factor, IL-3 interleukin-3, M-CSF macrophage colony stimulating factor, dpi days post immunization.