Figure 3.

LL-37 uses FPRL1 as its receptor. (A) Selective induction of FPRL1/293 cell chemotaxis by LL-37. The migration of parental HEK293 (open bars), FPRL1/293 (dotted bars), or ETFR (closed bars) cells was assessed by chemotaxis assay with the use of collagen-coated 10-μm membranes. Cells were used at a concentration of 10⁶ cells/ml. The average C.I. (mean ± SD) of triplicate wells is shown. Spontaneous cell migration (without LL-37) was ∼10–20 cells per HPF. *P < 0.05 when compared with chemotaxis medium alone. (B) LL-37–induced Ca²⁺ flux in FPRL1/293 cells. Arrow indicates the time point at which LL-37 was applied to the cells. (C) Cross-desensitization of LL-37–induced Ca²⁺ flux in monocytes by FPRL1-specific agonistic ligand. Arrows indicate the time points at which LL-37 and Su peptides were applied to the cells.