Chemoattraction of thymocytes from thymuses (organ chemotaxis) by SDF-1 and CKβ-11/MIP-3β/ELC. Thymocytes in thymus before chemotaxis (A) and thymocytes migrating to control medium (B), CKβ-11/MIP-3β/ELC (C), and SDF-1 (D) are shown. Total cell numbers per count for 30 seconds by FACscan and the percentage of each subset in total thymocytes, representative of 4 experiments, are shown. Thymus organ chemotaxis assays were performed as described in the Materials and Methods. Migrated thymocytes were stained with anti–CD4-TriColor and anti–CD8-FITC, acquired for 30 seconds, and analyzed by FACscan. The mean composition (±SD) of the 4 thymocyte subsets from the 4 experiments is 12.1 ± 0.6 (CD4⁺ SP), 83.8 ± 2.8 (DP), 2.8 ± 0.6 (DN), and 2.6 ± 0.7 (CD8⁺SP) for control thymocyte suspension; 11.2 ± 1.9 (CD4⁺SP), 80.2 ± 2.8 (DP), 5.6 ± 2.3 (DN), and 3.0 ± 0.7 (CD8⁺ SP) for those attracted to SDF-1; and 50.1 ± 9.8 (CD4⁺ SP), 30.7± 8.8 (DP), 2.4 ± 0.8 (DN), and 16.9 ± 3.2 (CD8⁺ SP) for those attracted to CKβ-11/MIP-3β/ELC. *Significant differences (P < .05) from control thymocyte subset composition.