Comparison of chemotactic activity of SDF-1 and CKβ-11/MIP-3β/ELC for splenic T cells with that for thymic T cells. Murine CD4⁺ (A) and CD8⁺ (B) SP T cells from thymus and spleen were assayed for their chemotactic responsiveness to SDF-1 and CKβ-11/MIP-3β/ELC. Input and migrated cells were stained with fluorescent antibodies to human or mouse CD4 and CD8, acquired for 30 seconds, and analyzed by FACscan. Cell migration to lower chambers is expressed as the mean percentage (±differences of duplicated experiments) of input subset cell number added in the upper chamber at the start time of chemotaxis. Background migration was subtracted from the mean migration to show net migration. Significant differences were observed between the following 2 peak points: A and B, A and C, A and D, B and C, B and D, and C and D (for [A]); and A and D and B and D (for [B]).