CCL19 and CCL21 induce the in vitro migration of human neutrophils. (A) Purified human neutrophils were first incubated or not with 20 ng/mL of GM-CSF and 500 ng/mL of LPS. Neutrophil chemotaxis in response to 300 ng/mL of CCL19 and 250 ng/mL of CCL21 or to 50 ng/mL of IL-8 was evaluated at 30 minutes, 60 minutes, and 3 hours in a Transwell assay. Results are expressed as the number of migrated cells (mean ± SEM, n = 5). *P < .05. (B) Human neutrophils were treated or not with 20 ng/mL of IL-17, 50 ng/mL of TNFα, 20 ng/mL of GM-CSF, 1 μg/mL of PGE2, 500 ng/mL of LPS, 20 μL of CFA, or 5 μg/mL of TAg. Chemotaxis was assessed using Transwell in response to a 3-hour stimulation with 300 ng/mL of CCL19 and 250 ng/mL of CCL21. Results are expressed as the number of migrated neutrophils (mean ± SEM, n = 5). *P < .05.