Figure 1

Astrocytes produce IL-6 during chronic EAE. IL-6 co-localizes with GFAP⁺ astrocytes (A) in both WT and GFAPγR1Δ mice during the acute EAE, but not with Iba-1⁺ macrophage/microglia (B). Bars = 25 μm in the main panel, 5 μm in the insets. (C) During resolving (WT mice) and progressive (GFAPγR1Δ mice) EAE at day 35 post immunization, IL-6-secreting cells were restricted to white matter areas within the spinal cord of both WT and GFAPγR1Δ mice. Bar = 200 μm in the main figure, bar = 50 μm in the inset. (D) During progressive EAE, activated astrocytes are found in both gray matter (marked with a dashed line) and white matter lesion areas. No astrocytes producing IL-6 were detected in the gray matter (yellow frame). Only astrocytes in or around white matter lesions produced IL-6 (cyan frame). Images were obtained from the lumbar segments of both WT and GFAPγR1Δ mice and are representative of three mice per group. Bar = 50 μm.