Enhancement of formylmethionyl-leucyl-phenylalanine-induced directional locomotion of human neutrophils by serum low-density lipoproteins.

Human low-density lipoproteins (LDL) significantly increased neutrophil locomotion in a gradient of the chemotactic peptide formyl-methionyl-leucyl-phenylalanine (FMLP), while LDL alone had no effect on either directional or random locomotion. The enhancing effect on directional locomotion was constantly observed at FMLP concentrations of 10(-8) M and 5 X 10(-8) M after addition of 50 microgram LDL/ml.