IL-15 suppresses chemotaxis of mouse PBMCs to CX3CL1. PBMCs pooled from 5 C57Bl/6 mice were incubated for 12 hours in 50 ng/mL IL-15 or basic medium alone, washed, and then analyzed for their ability to chemotax in response to various concentrations of mouse recombinant CX3CL1 (chemokine domain) and mouse CXCL12. Data are presented as mean ± SEM and are pooled from 3 independent experiments.