Chemotactic activity for various concentrations of LL-37.

Polymorphonuclear (PMN) leukocytes and PBMC (A) and CD4⁺and CD8⁺ lymphocytes (B) were assessed for chemotactic response by using a 48-well microchemotaxis chamber. PMN cells and PBMC both showed concentration-dependent migration to LL-37, over a range of 0.1 μmol/L to 1 μmol/L (PMN cells) or 1 μmol/L to 10 μmol/L (PBMC). Typing of PBMC subtypes revealed a chemotactic response of CD4 lymphocytes to LL-37, whereas the peptide was ineffective in activating CD8 cells for migration. The results shown are the mean ± SD values of triplicates in 4 to 5 assays performed with leukocytes from different donors. * indicates significant difference from leukocytes not exposed to peptide (P = .01).