CX3CL1 upregulation within the brain during EAE is associated with A2A adenosine receptor signaling. (A) CX3CL1 gene expression (relative to DMSO vehicle) in the brains of wild type mice following 4 hour A2A adenosine receptor agonist CGS21680 treatment as determined by quantitative real-time PCR. Error bars represent the s.e.m.; n ≥ 3 mice / treatment. Significant differences (P < 0.05, *; P < 0.001, ***) are indicated as determined by the Student’s t-test. (B) EAE disease profile in wild type mice given either the A2A adenosine receptor antagonist SCH58261 (1 mg/kg, open diamonds, n = 8; 5 mg/kg, open triangles, n = 7) or a vehicle control (n = 8). Error bars represent the s.e.m. EAE data is combined from 2 separate experiments. (C) CD45 and CD4 stained frozen brain sections (hippocampal area) from day 10 post-EAE induction SCH58261 and vehicle treated wild type mice. Positively stained cells (red) are shown against a hematoxylin counterstain (blue). Black scale bars represent 50 μm. (D) Brain CX3CL1 expression over time in wild type mice induced to develop EAE and given either SCH58261 or a vehicle control as determined by quantitative real-time PCR. Error bars represent the s.e.m. Significant differences (P < 0.001, ***) are indicated as determined by the Student’s t-test.