CCL21 abundance in the CNS is increased after immunization in CCX-CKR^−/− mice. Female SJL/J mice were immunized for EAE. At days 0, 2, 4, 9, 12, and 21 mice were killed and spinal cords were collected with the protein fraction extracted. CCL19 and CCL21 protein levels were determined in the spinal cord using a 2-site ELISA assay. All data points represent the mean amount of chemokine recovered from the whole spinal cord ± SEM (n = 3 mice per time point). (B) Spinal cords from either naive wild-type or day 15 EAE mice were harvested, RNA extracted and cDNA reverse-transcribed. Real time PCR for CCX-CKR and acidic ribosomal phosphoprotein P0 (RPLP0) was then performed (n = 3 mice per group). (C) Spinal cord protein lysates were prepared from female wild-type and CCX-CKR^−/− mice on days 0 and 12 postimmunization for MOG_35-55 EAE and CCL21 protein levels assessed by ELISA. Data points show the mean amount of CCL21 per mg of spinal cord homogenized ± SEM (n = 9 mice per group per time point; **P < .01).